United States
Environmental Protection
Agency
Office of Water
(4305)
EPA 823-R-98-002
February 1998
vvEPA
National Sediment
Bioaccumulation
Conference
Proceedings
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• National Sediment Bioaccumulation Conference \
Proceedings
National Sediment Bioaccumulation
Conference
September 11-13,1996
Bethesda, Maryland
Printed on Recycled Paper
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National Sediment Bioaccumulation Conference
Abstract
During September 11-13, 1996, the U.S.-Environmental Protection Agency (EPA)
sponsored the National Sediment Bioaccumulation Conference in Bethesda, Mary-
land. The assessment of bioaccumulative sediment contaminants has become an
important issue for EPA and other agencies. Data compiled to date for EPA's National
Sediment Quality Survey and the National Listing of Fish and Wildlife Consumption
Advisories indicate that the presence of bioaccumulative substances in sediments is a
potentially serious national problem. EPA uses bioaccumulation data to make regulatory
decisions in a number of its programs. The Superfund Program uses bioaccumulation data
to assess contaminated sites for cleanup. Results of bioaccumulation tests are used in the
assessment of new and existing industrial chemicals under the Toxic Substances Control Act
(TSCA) and in the review process for National Pollutant Discharge Elimination System
(NPDES) permits and dredged material discharge permits. Bioaccumulation studies are also
required to support registration of pesticides under the. Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA). Advances in the science of bioaccumulation testing and
assessment and interpretation of test results will benefit all of these programs.
The purpose of this conference was to present the current state of our knowledge of
assessment of bioaccumulative sediment contaminants and to discuss how bioaccumulation
data are integrated into EPA's decision-making processes. The conference was organized
into the following seven sessions:
Session One Field and Laboratory Methods for Measuring Bioaccumulation
Session Two Interpretation and Applications of Bioaccumulation Results
Session Three Modeling Bioavailability of Sediment Contaminants
Session Four Food Chain Models and Bioenergetics
Session Five , Human Health-Based Risk Assessment
Session Six Ecological-Based Risk Assessment
Session Seven Integrating Bioaccumulation Results into EPA's Decision-
Making Process
Each session consisted of individual presentations and a discussion period with
questions and comments from the audience and responses by the speakers. The Proceedings
document contains a paper and graphics summarizing each speaker's presentation and a
summary of audience questions and panel responses during the discussion period. It also
contains the conference agenda and additional information developed for the conference.
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National Sediment Bioaccumulation Conference •
Contents
Acknowledgments ,..:...... ix
Day One: Wednesday, September 11 ,
Welcome and Introduction .....1-1
Dr. Elizabeth Souther/and and Dr. Thomas Armitage
BIOACCUMULATION OVERVIEW AND APPROACHES
Bioaccumulation Overview and Approaches .1-3
Contaminated Sediments:
State of the Science and Future Research Directions 1-5
Dr. Oilman D. Veith
Field and Laboratory Methods for Measuring Bioaccumulation .1-9
Dr. Peter Chapman, Moderator
Methods for Assessing Sediment Bioaccumulation
in Marine/Estuarine Benthic Organisms Irll
Dr. Henry Lee II
Methods for Assessing Bioaccumulation of
Sediment-Associated Contaminants with Freshwater Invertebrates 1-25
Dr. Christopher-G. Ingersoll ,
Kinetic Models for Assessing Bioaccumulation ..; 1-47
Dr. Peter Landrum ,
Session One: Questions and Answers 1-51
Interpretation and Applications of Bioaccumulation Results 2-1
Dr. Richard Pnfell, Moderator
Reference Sediment Approach for Determining Sediment Contamination 2-3
: Mr. Norman I. Rubinstein
Development of Tissue Residue Threshold Values 2-9
Dr. David R.Mount
Use of Tissue Residue Data in Exposure and
Effects Assessments for Aquatic Organisms... ,2-21
Mr. L Jay Field .'•'•'
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Comments on the Significance and Use of
Tissue Residues in Sediment Toxicology and Risk Assessment 2-25
Dr. Lynn S. McCarty
Quantification of Ecological Risks to
Aquatic Biota from Bioaccumulated Chemicals 2-31
Mr. Burt K. Shephard
Session Two: Questions and Answers 2-53
Modeling Bioavailability of Sediment Contaminants 3-1
Mr. Nelson Thomas, Moderator
Equilibrium Partitioning and Organic Carbon Normalization 3-3
Dr. Dominic M. Di Toro
Estimating Bioaccumulation Potential in Dredged Sediment Regulation 3-7
Dr. Victor A. McFarland
Development of Bioaccumulation Factors for
Protection of Fish and Wildlife in the Great Lakes 3-19
Dr. Philip M. Cook
From Modeling to Criteria: Integrated Approach to Criteria Development 3-29
Ms. Mary C. Reiley
Session Three: Questions and Answers 3-33
Day Two: Thursday, September 12
Food Chain Models and Bioenergetics .....4-1
Dr. Lawerence Burkhard, Moderator
Food Chain Models for Predicting Bioaccumulation 4-3
Dr. Frank Cobas
Use of Food Web Models to Evaluate Bioaccumulation Data 4-5
Dr. John P. Connolly
Bioaccumulation Modeling of PCBs
in the Hudson Estuary: A Review and Update 4-19
Dr. Robert V. Thomann
Session Four: Questions and Answers 4-23
BIOACCUMULATION AND RISK ASSESSMENT
Risk Assessment Overview 5-1
Dr. Dorothy Patton
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Human Health-Based Risk Assessment.... .................5-3
Dr. Marc Tuchman, Moderator .
Methodology for Assessing Human Health-Based Risks 5-5
Dr. Judy L. Crane
Bioaccumulation Models and Applications:
Setting Sediment Cleanup Goals in the Great Lakes 5-9
Ms. Amy Pelka
Use of Human Health-and Ecological-Based
Goals in Developing a Whole River
Sediment Strategy: Fox River, Wisconsin :... 5-31
Mr. Robert L. Paulson .
Development of Health-Based Sediment Criteria for Puget Sound >.... 5-35
Ms. Laura B. Weiss
Development of Bioaccumulation Guidance for
Dredged Material Evaluations in EPA Region 2 .;.... 5-47
Mr. Alex Lechich
Session Five: Questions and Answers •. 5-61
Ecological-Based Risk Assessment 6-1
Dr. James Andreasen, Moderator
Use of Bioaccumulation Data in Aquatic Life Risk Assessment 6-3
Dr. Wayne R. Munns, Jr.
Wildlife Risk Assessment 6-9
Dr. David Charters
Session Six: Questions and Answers — 6-15
Day 3: Friday, September 13
BIOACCUMULATION RESULTS AND DECISION-MAKING
Integrating Bioaccumulation Results into EPA's
Decision-Making Process . 7-1
Dr. Elizabeth Southerland, Moderator
Opening Remarks 7-3
Dr. Elizabeth Southerland
Bioaccumulation Testing and Interpretation for the Purpose of
Sediment Qualify Assessment: Status and Needs.... ,.. 7-5
Mr. Michael Kravitz
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Panel Presentations 7-15
Bioaccumulation Results and Decision-Making:
The Superfund Program 7-17
Dr. Lawrence Zaragoza
Sediment Bioaccumulation—A National Pollutant Discharge
Elimination System (NPDES) Program Perspective 7-23
Mr. James Pendergast
Integrating Bioaccumulative Results into EPA's Decision-Making Process 7-31
Mr. Thomas Murray
U.S. EPA/OPPT and Sediments: Screening New and Existing Chemicals for
Potential Environmental Effects „ 7-35
Dr. Maurice Zeeman
Dredged,Material Management Program 7-49
Mr. Craig Vogt
Dredged Material Management: A Regional Perspective 7-51
Mr. Mario Del Vicario
Session Seven: Questions and Answers 7-53
$
Speakers'Biographies 8-1
ATTACHMENTS
Agenda
List of Attendees
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National Sediment Bioaccumulation Conference
Acknowledgments
The National Sediment Bioaccumulation Conference was funded jointly by two
offices in the U.S. Environmental Protection Agency, the Office of Science and
Technology (in the Office of Water) and the Office of Research and Development
(ORD). The Standards and Applied Science.Division in the Office of Science and
Technology (OST) organized the conference. Tetra Tech, Inc. provided logistical support
for the conference and production support for the proceedings under EPA contract number
68-C3-0374. . '
, A planning workgroup consisting of representatives from OST, ORD, Great Lakes
National Program Office (GLNPO), and EPA Region 5 participated in developing the
agenda and identifying speakers for the conference. The workgroup members were: Tom
Armitage, EPA^OST; Ed Earth, EPA ORD; Mike Kravitz, EPA OST; Amy Pelka, EPA
Region 5; Rich Pruell, EPA ORD; Lara Pullen, EPA Region 5; Dave Redford, EPA
OWOW; Leanne Stahl, EPA OST; Marc Tuchman, GLNPO; Howard Zar, EPA Region 5;
and Chris Zarba, EPA ORD. The contributions of these individuals in planning the
conference are ..greatly appreciated.
Finally, the contributions of the invited speakers and moderators are gratefully
acknowledged. Then- efforts were critical to the success of the conference and.production
of the proceedings.
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National Sediment Bioaccumulation Conference
Welcome and Introduction
Dr. Elizabeth Southerland
Acting Director, Standards and Applied Science Division
Office of Science and Technology
U.S. Environmental Protection Agency
Dr. Thomas Armitage
Acting Chief, Risk Assessment and Management Branch
Office of Science and Technology
U.S. Environmental Protection Agency
Dr. Southerland
D
i. Southerland welcomed the participants and
turned the podium over to Dr. Thomas Armitage
to outline the agenda for the conference.
Dr. Armitage
I would like to take this opportunity to welcome
you to the National Sediment Bioaccumulation Confer-
ence sponsored jointly by the Office of Water and the
Office of Research and Development. I would also like
to acknowledge the assistance we received in planning
the conference from the Great Lakes National Program
Office and EPA Region 5.
We are very pleased to finally be holding this
conference. Planning for this conference began over a
year ago. We persevered through the federal budget
crisis and government shutdowns, and are delighted to
finally have all of you here to participate. The response
to our announcement of this bioaccumulation conference
was overwhelming. When we started planning this
conference, we had no idea that so many people would be
interested in attending. Over 400 people are here today,
which clearly indicates that assessment of
bioaccumulative sediment contaminants. is an issue of
major interest and importance in the scientific'and regu-
latory community.
For the next two and one-half days, we will be
hearing from a number of distinguished experts in the
. field of assessment of bioaccumulative sediment con-
taminants. We have organized the conference into
several sessions. Each session will be chaired by a
moderator who will lead a discussion "and question and
answer session following the presentations. We encour-
age audience participation during the discussion period
and have provided microphones in the aisles for your
comments and questions. During the first two days of the
conference, there will be sessions covering field and
laboratory methods for measuring bioaccumulation, in-
terpreting and applying bioaccumulation results, model-
ing bioavailability of sediment contaminants, and assess-
ing human health and ecological risks associated with
bioaccumulative contaminants. On the final day of the
conference, an EPA program panel will address how
results of bioaccumulation assessments are being inte-
grated into EPA's decision-making process. '
The assessment of bioaccumulative contaminants
in sediment has become an important issue for EPA and
other Federal agencies. From our work to date on the
National Sediment Quality Survey and the Listing of Fish
and Wildlife Advisories, it is becoming increasingly
apparent that the presence of bioaccumulative substances
in sediments is a potentially serious widespread national
problem. EPA evaluated more than 21,000 sampling
stations nationwide to develop the National Sediment
Quality Survey. Of the sampling stations evaluated, 26
percent were classified as Tier I and 49 percent were
classified as Tier 2. Tier I is a category indicating that
associated adverse effects are probable, and Tier II is a
category indicating that associated adverse effects are
possible, but expected infrequently. The classes of
bioaccumulative contaminants most frequently associ-
ated with contaminated sediment sites include metals,
polychlorinated biphehyls (PCBs), organochlorine pesti-
cides; and polynuclear aromatic hydrocarbons (PAHs).
The 1996 update of the Listing of Fish and Wildlife
Advisories includes all available information describing
state-, tribal-, and federally-issued fish consumption
advisories for the 50 states, the District of Columbia, four
U.S. territories, and several Native American tribes. It
has been expanded to also include fish advisories issued
for the 12 Canadian provinces and territories. The total
number of advisories in the United.States increased by 26
percent from 1995 to 1996. Advisories increased for four
major contaminants, including mercury, PCBs, chlor-
dane, and DDT. More monitoring accounts for part of the
increase in the number of advisories, but it also indicates
a greater awareness of the problem and underscores the
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National Sediment Bioaccumulation Conference
need for increased monitoring and reliable techniques for
assessing the risks of exposure to these chemicals.
EPA uses information and data on bioaccumulation
to support program responsibilities in a number of its
regulatory programs. The Office of Pesticide Programs
requires bioaccumulation studies for the registration of
pesticides under the Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA). The Office of Pollution
Prevention and Toxics uses bioaccumulation data to
assess new and existing industrial chemicals under the
Toxic Substances Control Act (TSCA). The Superfund
Program in the Office of Solid Waste and Emergency
Response uses bioaccumulation data to assess contami-
nated sites for cleanup. The Office ofWater incorporates
results of bioaccumulation tests in the review process for
dredged material disposal permits and National Pollution
Discharge Elimination System (NPDES) permits. Ad-
vancing the state of our knowledge in bioaccumulation
testing and assessment will benefit all of these programs.
A number of important unresolved issues remain
for bioaccumulation assessment, including uncertainties
in test procedures and limited understanding of the
relationships between contaminant body burdens and
adverse ecological effects. I would like to again
acknowledge the Office of Research and Development
(ORD) cosponsorship of this conference and stress that
we are looking to ORD to maintain leadership in answer-
ing some of these questions.
We organized this conference to provide a forum
,.to discuss the current state of our knowledge of assess-
ment of bioaccumulative sediment contaminants and to
examine how bioaccumulation data are integrated into
EPA's decision-making processes. We will be publish-
ing a conference proceedings and are currently working
on a report summarizing the status of bioaccumulation
testing and interpretation for- the purpose of sediment
quality assessment. This conference and our status
report will help us to better understand the state of the
science, to identify the data and knowledge gaps, to
focus research efforts on providing answers to the
most important questions, and to eventually develop
consistent cross program guidance on interpretation
of bioaccumulation data for use in EPA's regulatory
programs.
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National Sediment Bioaccumulation Conference
Bioaccumulation Overview
and Approaches
Gilman D. Veith
U.S. EPA, Office of Research and Development,
Research Triangle Park, North Carolina
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National Sediment Bioaccumulation Conference
lied Sediments: State of
the Science and Future Research
Directions
Gilman D. Veith
U.S. Environmental Protection Agency, Office of Research and Development, National Health and
Environmental Effects Research Laboratory, Research Triangle Park, North Carolina
It is a real pleasure to be here today and speak at the first
National Sediment Bioaccumulation Conference. As
many of you know, when Bob Huggett came into the
Office of Research and Development (ORD) as the Assis-
tant Administrator, he brought with him a strong belief
that sediment contamination is one of the compelling
research issues that we face as a nation. He still holds that
belief. Bob is at an international meeting for the Agency,
so I am presenting for him today on behalf of ORD.
However, my comments reflect my own perspective.
This conference is exciting because it represents the
culmination of many years of work related to sediments.
It also demonstrates, better than many other examples in
environmental research, how science can be applied in a
partnership of researchers, risk managers, regulators, pri-
vate interest groups, and agencies at all levels of govern-
ment to accomplish risk reduction.
Abouttenyearsago,JimFalco,Director of Environ-
mental Processes Research in EPA, asked that I meet with
himandseveralmembersoftheOfficeofWater.Hewanted
to discuss building the scientific framework necessary to
- establish the concept of sediment quality criteria. The
existing methods then were highly empirical and often
unreproducible, and they did not allow us to predict
effects. We needed criteria to make sense of the field
measurements we were making. He asked if the ORD
laboratories could provide support for development of
sediment quality criteria, and we agreed to get the labora-
tories involved.
Soon after we organized scientists familiar with
sediment issues and began research, a Senator involved hi
revising the Clean Water Act visited our laboratory and
wanted to know about sediment contamination and why it
needed attention. After giving a technical presentation
that included an explanation of bioaccumulation factors
under steady-state conditions, he surprised us by asking
"what is a sediment?" There is a communication chal-
lenge, in addition to the challenge of developing a work-
able regulatory strategy for contaminated sediments. In
the last ten years, research has taught us how to begin
making sense out of the data on sediment effects.
In addition to developing sediment toxicity tests,
we have established methods to measure the
bioaccumulation potential of sediment contaminants.
When we published our first work on bioaccumulation,
we chose the term "bioaccumulation potential" rather
than "bioconcentration factor" because kinetics and ther-
modynamics really intersect in bioaccumulation testing.
It is very difficult to predict the kinetics of uptake because
it is largely experimentally controlled and most of the
bioaccumulation methods are operationally defined.
"Bioaccumulation potential" is primarily a thermody-
namic term that separates chemicals that bioaccumulate
from those that do not. If organic chemicals are unlikely
to bioaccumulate, they would probably not even be in the
sediments. The "bioaccumulation potential" represents
the probability that a chemical is going to penetrate an
ecosystem by dispersing from a source and moving up
food chains to cause effects at levels we might not have
anticipated.
Sediments were recognized as the final repository
for contaminants as early as the 1970s. During that decade
we were still struggling to define toxicity and to establish
permitting and control programs. Today, the issue of
reducing risks from sediments that have already been
contaminated is an important problem that merits atten-
tion. Right now we are making good progress on work in
dredged material management, food chain modeling, and
development of tissue-based residue methodologies to
address this problem. The academic community and
agencies at all levels of government have efforts under-
way to describe the dynamics of food chains and to define
how to use this information in a risk assessment. The
Office of Water is spearheading' one such effort by devel-
oping the bioaccumulationpaperentifledBzoaccwmwtozon
Testing and Interpretation for the Purpose of Sediment
' Quality Assessment: Status and Needs. About 40 people
from several EPA offices are collaborating to draft that
report, which will include information on chemicals of
concern and methods for assessing bioaccumulation, an
Agency summary on bioaccumulation data collection and
interpretation, and recommendations for further research.
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National Sediment Bioaccumulation Conference
Another sediment-related effort being conducted at an
ORD laboratory is the development of toxicity identifica-
tion evaluation (TIE) procedures to analyze complex
chemical mixtures.
Iwanttosummarizebrieflyhowweformulatepriori-
ties for budgeting in ORD and how conferences like this
can help. Surprisingly enough, when we went through the
budget planning process, some participants expressed the
belief that contaminated sediments are not a serious
national problem, that sediments do not present a signifi-
cant risk to the envkonment, and that sediments do not
merit further research based on their negligible risks. At
first I laughed because I did not think they were serious,
but then I realized that they were serious. They made their
case using some of the same data we were using to try to
show that sediment contamination is a significant prob-
lem. Data from a spatially subsampled survey conducted
under the Environmental Monitoring and Assessment
Program (EMAP) hi ORD covered estuaries in the Virgin-
ian, Louisianan, and Carolinian provinces. Looking at the
benthic condition with some of the EMAP indicators, one
could see that about 29 percent of the estuaries had
degraded benthic condition.
That information alone, however, does not con-
vince skeptics that sediment contamination is a significant
problem. The skeptics viewed 29 percent of our estuaries
as impacted to mean 71 percent were not.
I realized that we have not clearly answered the "So
what?" questions with respect to ecological consequences.
How much impact is too much? When are fisheries and
the productivity of coastal waters affected? How much
degradation could exist in the benthic systems to streams
and lakes before there are ecological consequences and
loss of integrity? We can say that there are 17,000 square
kilometers in our estuaries where you can measure an
effect in the benthos, compared to reference conditions.
That is a large area. So what? Similarly in the Great
Lakes, many have overlooked the fact that reproduction in
major species of the food chain has been shut off sincethe
1940s due to chemical residues. EMAP combines measures
of effect with stressors and has associated the degraded
communities with sediment contaminants. For example,
when you link some of the areas of degraded benthic
condition with measures of observed toxicity, you will
find that these are the sites where survival of benthic
organisms in bioassays was below 80 percent This evidence
establishes an association strong enough to say that parts
of the benthic community degradation are due to contami-
nated sediments. The question that remains is how we can
establish a cause-effect relationship between the loss of
integrity and the sediment residues over large areas.
The importance of these field studies in strengthen-
ing the risk assessment process for sediment certainly
plays into the risk-based priority setting in ORD. The new
strategic plan for ORD is based on the risk paradigm. We
now evaluate a problem based on whether or not we think
the science can reduce the uncertainty associated with
estimating effects, exposure, the assessment capability,
and risk management There are some issues where ORD
has concluded that we do not need to do more effects
research, because further effects research would not
contribute significantly to our understanding of the prob-
lem. Contaminated sediments is one issue where major
uncertainties still exist in effects and exposure assess-
ment. In the process of planning the budget according to
risk-based priorities, we have consolidated the intramural
research hi ORD to focus on contaminated sediments by
designating this area as a budget subcomponent. ORD has
created a work force of about 45 full-tune equivalents
(FTEs), which represents an increase in the level of effort
for sediment issues in the laboratories. We are revising the
research strategy for contaminated sediments, and
research recommendations that come out of this confer-
ence will be considered hi developing the plan, particu-
larly for projects directed at the Office of Water's needs.
I would also like to direct your attention to the
extramural research program, known as the Science to
Achieve Results (STAR) Program, that ORD initiated in
1995. STAR is a competitive research grants program
being run by ORD's National Center for Environmental
Research and Quality Assurance in Washington, D.C.
This year the grants program included only about
$2 million specifically for issues involving contaminated
sediments. There were more than 40 proposals and 8 of
these proposals received high rankings by the peer review
panel. The small STAR budget for the sediment program
could only fully fund four or five grants this year, but it is
a start. We anticipate a modest increase in funding for
contaminated sediment research grants in FY 1997.
We may have temporarily won the battle to con-
vince planners that contaminated sediments are impacting
a significant part of our resources. Through the ORD
planning process, ORD has agreed to focus more re-
sources on research related to contaminated sediments. In
FY 1998 there may even be an increase of about $3 million
of extramural money to support the laboratories in the
ORD intramural research program. We need .to maintain
this focus and increase our effectiveness through partner-
ships with other interested EPA offices and federal agen-
cies, including Office of Water, the Superfund Program,
the Great Lakes National Program Office, the Chesapeake
Bay Program, the National Oceanic and Atmospheric
Administration (NOAA), the U.S. Army Corps of Engi-
neers, and the U.S. Geological Survey. We also need to be
refining approaches that are implementable at the state
level and work with the states to achieve risk reduction.
Today is a good time to rededicate ourselves to working
as partners and to make the contaminated sediment issue
the best example of how we can work together to solve the
environmental problems.
The ORD research program will continue support
for pollution prevention efforts. We will be addressing
the issues remaining for sediment quality criteria, includ-
ing data to support the guidelines and response to public
comment on the technical basis for the criteria. Another
area ORD will support is applying what we know about
the sediment effects of chemicals to a cleanup strategy for
a particular Superfund site. There are some excellent
presentations coming up in this conference on how to
apply the concept of criteria to restoration.
The management of risks associated with the dis-
posal of dredged material will require a strong EPA
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Proceedings
collaboration with the U.S. Army Corps of Engineers arid
the States in order to develop a workable process. ORE)
will support that effort. We have identified research needs
such as tissue-based effects models to understand the
bioavailability and pharmacokinetics that explain why
residues bring about long-term damage to ecosystems.
Food chain models are becoming ever more sophisticated,
but they need further development. There is a critical need
to develop population level assessment methods to link up
the "So what?" questions of the declining biological
diversity and loss of certain species. Assessment of the
impact of complex chemical mixtures will be necessary to
unravel the causative agents in the chemical mixtures that
are often found in sediments.
Finally, I would like to emphasize the importance of
the development and application of remediation methods.
There has been much progress on remediation of contami-
nated sediments, with mitigation success at Superfund
sites. However, the mitigation options are still too limited
for larger areas. In terms of communication challenges,
we need a breakthrough to instill hope in our political
leaders that we can actually remediate contaminated
sediments. We have to overcome what seems to be an
overwhelming pessimism that we will ever reduce the
risks posed by sediments except by waiting decades. The
work that our Region 2 Office is doing on treating harbor
sediments in the New York area is resulting in some of the
most exciting new developments in the last five years.
They appear to be setting the stage for the future in
sediment remediation.
As we participate in this conference and prepare for
thenextdecadeofworktoreducethe impacts of sediments
in the environment, I encourage you to avoid letting our
energies become fragmented by using data to support a
personal or organizational interest. The danger I see in the
sediment literature is the number of papers designed to
support hypotheses rather than test hypotheses. There is
a need for debate in risk management, certainty among
uncertainties in our scientific understanding of sediment
interactions which merit debate, but the objective applica-
tion of the scientific method in gathering data to support
these debates is crucial. ' •
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National Sediment Bioaccumulatton Conference
Session One:
Field and Laboratory Methods for
Measuring Bioaccumulation
Peter Chapman, Panel Moderator
EVS Environment Consultants, Ltd.,
North Vancouver, British Columbia
Henry Lee II
U.S. EPA, Office of Research and Development,
Newport, Oregon
Methods for Assessing Sediment Bioaccumulation
in Marine/Estuarine Benthic Organisms
Christopher G. Ingersoll
U.S. Geological Survey,
Columbia, Missouri
Methods for Assessing Bioaccumulation of
Sediment-Associated Contaminants with
Freshwater Invertebrates
>
Peter Landrum
NOAA, Great Lakes Environmental
Research Laboratory,
Ann Arbor, Michigan
Kinetic Models for Assessing Bioaccumulatipn
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National Sediment Bioaccumulation Conference
Methods for Assessing Sediment
Bioaccumulation in Marine/Estuarine
*
Benthic Organisms
Henry. Lee II
U.S. Environmental Protection Agency, Office of Research and Development, Coastal Ecology
Branch, Western Ecology Division, Newport, Oregon
Introduction
Organic pollutants can be divided into two
general classes (see-page 1-15). The first •
consists of compounds with high water solubil-
ity and low Kow values, such as acetone, that do not tend
to adsorb to particulates. Their major reservoir is the
water column, where they are accumulated through
bioconcentration. The second suite of organic pollutants
are the low water solubility, high Kow compounds, such as
DDT, dieldrin, and polychlorinated biphenyls (PCBs),
that readily partition to particulates. They accumulate in
the sediment where they can be bioaccumulated by
benthic organisms. From the benthos, these high Kow
compounds can be introduced into higher trophic levels
through trophic transfer. Other presentations at this confer-
ence are addressing, the trophic transport and the effects of
these pollutants. This presentation will focus on methods
to, measure/predict the bioavailability of sediment-asso-
ciated contaminants to marine/estuarine benthos, and the
use of sediment bioaccumulation tests hi particular.
When designing any test method, it is critical to
assess how are "the data are going to be used. Tissue
residue data can be used in risk assessments in a number
of ways, which are summarized in the figure on page
1-16. "The column labeled "Steady-State?" refers to
whether, estimates of steady-state tissue residues are
required to adequately address the particular component
of a risk assessment. For the sediment bioaccumulation
tests, the need for steady-state data defines how long the
test needs to be conducted to assure that steady-state
tissue residues have been approached. The column la-
beled "Max Residue?" refers to whether an upper limit
estimate of the tissue residue is required to address the
particular risk assessment component. That is, is it nec^
essary to use a duration, species, or test method that tends
to maximize uptake?
As suggested in the figure on page 1-16, residues
• approaching steady-state are required for quantitative
ecological or human health risk assessments other than
hazard identification and identifying specific uptake
routes. Tissue residues substantially less than steady-state
residues will underestimate both exposure and effects,
and this error will propagate through the risk assessment
(e.g., estimate of trophic transport). The need for the
more stringent requirement of an upper-limit estimate of
tissue residue depends upon the specific question. For
example, amphipods metabolize PAHs to a greater ex-
tent than most bivalves. If the goal is to assess PAH
exposure to amphipods, an amphipod would be a suitable
test species. However, if the goal is to extrapolate PAH
bioavailability to other species, an upper limit estimate
would be more appropriate, and a bivalve species should
, be used.
Bioaccumulation Methods
There are a suite of methods available to assess or
to predict bioaccumulation that will be discussed in
various presentations during the conference (see listing
on page 1-16). Two approaches provide direct measures
of existing conditions: the field approach and the bioac-
cumulation test. Both approaches involve measuring
tissue residues in either field-collected or laboratory-
exposed organisms. These direct approaches have high
ecological relevance but can be costly, and they have
limited ability to predict tissue residues resulting from
changes in sediment contamination (e.g., after a clean-up).
Sediment bioaccumulation models can serve as
cost-effective "screens" to determine when direct mea-
surements are required and as a method to predict tissue
residues when direct measurements are not practical. The
two general types of sediment bioaccumulation models
are equilibrium-based and kinetic approaches (see
Landrum et al., 1992). The equilibrium-based approaches
assume steady-state, conditions between the organism
and the environment, whereas, the kinetic approaches
describe bioaccumulation as the net effect of rate processes.
The two equilibrium models are bioaccumulation factors
(BAF = tissue residue/sediment concentration) and the
equilibrium partitioning model. The two basic types of
1-11
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National Sediment Bioaccumulation Conference
kinetic approaches are kinetic process models and
bioenergetically based toxicokinetic models. Kinetic mod-
els can be more accurate than the steady-state models, but
they require extensive data. A decision tree has been
developed to guide the risk assessor in choosing which
tests or models should be used to assess or predict
bioaccumulation given the project goals (Boese and Lee,
1992) (see figure on page 1-17).
Equilibrium Partitioning
Bioaccumulation Model
The equilibrium partitioning model is based on the
theory that neutral organic pollutants partition between
the lipid phase in the organism, sediment carbon, and
interstitial water until equilibrium is obtained (see
page 1-18). Assuming that organic carbon is the only sink
for neutral organics in the sediment and that lipids are the
only sink in the organism, the model becomes:
' Ctss/L = (Cs/TOC) * BSAF
where:
Ctss = tissue concentration at steady-state (|ig/g)
L = lipid content (g/g)
Cs = sediment concentration ((ig/g)
TOC = total organic carbon in sediment (g/g)
BSAF = biota-sediment accumulation factor
(g carbon/g lipid)
The biota-sediment accumulation factor (BSAF)
has also been referred to as the "accumulation factor"
(AF). BSAFs can be determined empirically for each
pollutant from laboratory exposures or field surveys. If
partitioning is not a function of lipid or carbon type, the
value of the BSAF for a compound should not vary
among sediments or species. However, data from
bioaccumulation tests indicate that differences in the
sediment can affect the BSAF values. Tests were run
with spiked sediments using the deposit-feeding clam
Macoma nasuta, one of the bioassay animals for marine
and estuarine systems. Two sediment types were spiked
with 13 PCB congeners and hexachlorobenzene (HCB)
at concentrations of about 50 parts per billion for each
congener or compound. Test results show differences in
the BSAFs for the two sediment types (see page 1-18),
so the equilibrium model did not completely account
for sediment differences. The results also show dra-
matic differences in BSAF values among congeners. A
possible kinetic explanation for these results are that
PCB congeners with lower Kow values undergo rapid
degradation whereas PCB congeners with higher Kow
values have limitations moving across membrane sur-
faces which can result in low uptake. Nor does the
equilibrium partitioning bioaccumulation model to-
tally account for species differences. In a study of a
DDT-contaminated site, we found that field-collected
Macoma nasuta had tissue residues of total-DDT and
dieldrin 7 to 9 times higher than filter-feeding bivalves
(Lee et al., 1994, see Figure 15, page 1-22). It seems,
then, that there is about a 2- to 10-fold uncertainty in
BSAF values. Even with these uncertainties, BSAFs
have utility as a screening tool and in extrapolating
among species or sediments. Additionally, this uncer-
tainty can be reduced by extrapolating among similar
feeding and sediment types.
Sediment Bioaccumulation test
A laboratory test is often the preferred method to
evaluate a specific sediment and to generate BSAFs
under controlled conditions. Although these tests had
been conducted for over a decade, there was no stan-
dardized methodology. Scientists at the U.S. Environ-
mental Protection Agency (EPA) in Newport, Oregon
developed a sediment bioaccumulation test for marine
and estuarine systems, published it in a guidance manual
in 1989, and revised it in 1993 (Lee et al., 1993, see
page 1-19). Since then, the EPA scientists have worked
with Peter Landrum of NOAA to develop a guide for
sediment bioaccumulation tests for marine and fresh-
water benthic invertebrates (ASTM, 1995). The
bioaccumulation test includes six key procedures (see
page 1-19): (1) 28-day exposure duration, (2) use of
sediment-ingesting organisms, (3) no supplemental food
added, (4) independent exposure of species, (5) recom-
mended accuracy of 80 percent of steady-state tissue
residues, and (6) use of long-term tests or toxicokinetic
approaches for greater than 80 percent accuracy or for
slowly accumulated compounds. Information used to
support the recommended procedures is discussed below.
The recommendation for testing 28 days was
based on a literature review of percentage of steady-
state residue levels achieved in 10 days (the period then
used for testing dredged materials) and 28 days. Results
were available for a variety of compounds such as
PCBs, dioxins, furans, PAHs (orPNAs), and metals (see
page 1-20). These compounds generally achieved 80
percent of steady-state tissue residues within 28 days.
We evaluated the adequacy of the 28-day duration in the
experiment exposing Macoma nasuta to the sediments
spiked with 13 PCBs and HCB (see discussion under
Equilibrium Partitioning Bioaccumulation Model). The
experiment was run for 120 days. The figure on page
1-20 shows the results for PCB congeners 153 and 209.
Though bioaccumulated to different amounts, both PCB
congeners approached or exceeded 80 percent of steady-
state residue after 28 days, as did the other congeners.
Data from other studies indicate that a period of 28 days
can be insufficient for bioaccumulation testing. The
United Heckathorn Superfund site in San Francisco Bay is
highly contaminated with DDT and dieldrin. A
bioaccumulation test was conducted with Macoma nasuta
for 90 days using sediment from the most contaminated
site. Test results for total DDT (DDT, DDE, and ODD)
are displayed on page 1-21. At 28 days, the tissue residues
only reached about one-third of the steady-state residues.
The graphs of the tissue residues for the three most abundant
compounds show even worse results (see page 1-21).
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Proceedings
1-13
These results raise the question of whether DDT and its
metabolites are different than PCBs or whether the
difference is due to field versus spiked sediments. It also
raises the question about the adequacy of the 28rday test.
There are practical limitations to consider in setting the
length of any laboratory test. A proposal to resolve this
problem is to maintain 28 days as the standard duration,
but to multiply the 28-day residues .by an "adjustment
factor" which is the ratio of the steady-state residue to the
28-day residue. Adjustment factors would be developed
through long-term lab studies. For the DDT compounds
and dieldrin, these adjustment factors ranged from 1.7 to
10.8, with a value of 2.9 for total DDT. For compounds
which accumulate rapidly, such as the low molecular
weight polycyclic aromatic hydrocarbons (PAHs), the
adjustment factor should approach 1.
Several criteria for organism selection for use in
marine/estuarine bioaccumulation tests are listed on
page 1-22. Of these, the requirement for using sediment-
ingesting organisms to maximize uptake of sediment-
associated contaminants is critical. The figure on page
1-15 (modified from Landrum, 1989) helps illustrate
why. An organism can accumulate sediment-associated
contaminants from the interstitial water or from ingested
particles. Compounds with higher .Kow values will be
associated mainly with the particulate phase, so particle '
ingestion will be the primary uptake route for these
chemicals; A series of experiments conducted with
hexachlorobenzene, a low solubility compound, showed
that at least 70 percent of the uptake in Macoma nasuta
was from ingested particles. Although it can be argued
that if all the phases are in equilibrium the uptake phase
does not matter, the 7- to 9-fold higher residues in the
sediment-ingesting Macoma, nasuta compared to filter-
feeding bivalves at the United Heckathorn site (see page
1-22) clearly demonstrates the importance of sediment
ingestion on bioaccumulation. Based on similar reason-
ing, supplemental feeding is not recommended as the
addition of uncontaminated food could "short-circuit"
the'solid-phase uptake route and result in an erroneously
low evaluation of bioavailability. The marine/estuarine
environment contains a number of deposit-feeding ani-
mals (various bivalves and polychaetes) that meet the
criteria, particularly with respect to providing sufficient
.biomass for chemical analysis at the end of the test. The
1993 guidance manual and the ASTM guide .identify
animals suitable for bioaccumulation testing, in marine
and estuarine systems.
With any laboratory test there is the question of
whether it accurately predicts tissue residues in field organ-
isms. At the United Heckathorn Superfund study site,
we were able to compare tissue residues in laboratory-
exposed Macoma nasuta and Macoma collected at sev-
eral of the field sites. As mentioned above, the 28-day
exposure underestimated steady-state of DDT and dield-
rin, so it was necessary to use the adjustment factors from
the 90-day test at station 1 to correct the 28-day residues
from the other five sites. After adjustment, ratios of
laboratory to field tissue residues for total DDT and
dieldrin at each station (see graph on page 1-23) ranged
from about 0.5 to 3. At least for this suite of high Kow
neutral organics, the standard test appears to predict field
residues within 2- to 3-fold.
Research Needs
Areas requiring further study to advance the
science related to sediment bioaccumulation assessment
are summarized on page 1-23. They include:
(1) interlaboratory round-robin testing; (2) field valida-
tion of the bioaccumulation test, particularly for PAHs
and metals; (3) identification of local test species, espe-
cially for subtropical, subarctic, and oligohaline habitats;
(4) "standardization" of lipid methods for derivation of
BSAFs; (5) evaluation of effects of sediment storage and
spiking on bioavailability; (6) refinement of the experi-
mental design, including criteria for controls and refer-
ences; and (7) evaluation of kinetic and physiological-
based alternatives to the 28-day bioaccumulation test. Of
these, perhaps the most troubling question is whether
there is slower uptake or a lower bioavailability with
field-contaminated sediments compared to spiked sedi-
ments, as suggested by the slow uptake rates for DDT
compared to the rates from the spiked PCBs. Enhanced
bioavailability of spiked sediment could potentially result
in erroneously high BSAFs and toxicity.
The above research needs address how to conduct
tests and their accuracy and precision. The overriding
question, however, is: "What is the ecological signifi-
cance of tissue residues?" This needs to be addressed at
several .scales. At the scale of individual benthos, the
question is, "What are the effects of the accumulated
toxicants on growth, fecundity, and survival?" Use of
critical body residues, as are being developed for neutral
narcotics, is a promising approach. However, in nearly
all cases, the goal of marine/estuarine ecological risk
management is to protect a resource or higher levels of
biological organization (e.g., "ecological integrity"). To
achieve this goal, we will need to develop the insights and
methods to translate toxic effects on individuals into
effects on populations and communities. Addressing
these higher levels of biological organization will require
assessments at larger spatial scales than the classical
"end-of-the-pipe" evaluations, and will often require
evaluation of contaminated sediment effects in the con-
text of multiple stressors. This will be a critical challenge
for the future.
References
ASTM. 1995. Standard Guide for Determination of
the Bioaccumulation of Sediment-Associated
.Contaminants by Benthic Invertebrates.
E 1688-95.
Boese, B. and H. Lee II. 1992. Synthesis of Methods to
Predict Bioaccumulation of Sediment Pollutants.
ERLN N232. U.S. Environmental Protection
Agency, Newport, OR. 87 pp. .
Landrum, P. 1989. Bioavailability and toxicokinetics
pf polycyclic aromatic hydrocarbons sorbed to
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National Sediment Bioaccumulation Conference
sediments for the amphipod Pontoporeia hoyi.
Environ. Sci. Technol. 23:588-595.
Landrum, P., H. Lee II, and M. Lydy. 1992.
Toxicokinetics in aquatic systems: Model
comparisons and use in hazard assessment.
Environ. Toxicol. Chem. (Annual Review).
11:1709-1725.
Lee II, H. et al. 1993. Guidance Manual: Bedded Sedi-
ment Bioaccumulation Tests. EPA/600/R-93/183.
U.S. Environmental Protection Agency, Office of
Research and Development, Washington, D.C.
Lee II, H., et al. 1994. Ecological Risk Assessment
of the Marine Sediments at the United
Heckathorn Superfund Site. ERLN N269. U.S.
Environmental Protection Agency, Newport,
OR. 298 pp. + appendices.
-------
BIOAVAILABILITY OF SEDIMENT-ASSOCIATED POLLUTANTS
AQUEOUS AND PARTICULATE POOLS
Ingestible Particles
(HighTOC)
Non-ingestible Particles
(lowTOC)
rapidly
desorbed
pool
slowly
desorbed
pool
rapidly
desorbed
pool
freely
dissolved
pool
DOM bound
pool
Organism
slowly
desorbed
pool
Idealized Pollutant Pathways in Marine Ecosystems
Bioconcentration
Water
Dissolved
Sorption
Runoff
Discharge
Deposition
Particulate
Particles
SEDIMENT
"interstitial' Water"
- = High water solubility, low Kow, rapidly metabolized
- = Low water solubility, high Kow, slowly metabolized
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National Sediment Bioaccumulation Conference
USE OF TISSUE RESIDUE DATA IN
RISK ASSESSMENTS
I. HAZARD IDENTIFICATION
• Identify bioavailable compounds
• Quantitative measure of bioavailability
II. EXPOSURE ASSESSMENT
• Quantify exposure to assessment endpoint
species.(e.g., edible clam)
• Test species is an indicator (measurement
endpoint) for exposure to other species
• Test species is prey for higher trophic levels
DI. ECOLOGICAL EFFECTS ASSESSMENT
• Tissue residue effects on benthos
• Derive "Tissue Residue Criteria"
IV. HUMAN HEALTH EFFECTS ASSESSMENT
V. RESEARCH
• Evaluate Sediment Quality Criteria and
bioaccumulation models
• Determine importance of uptake routes
Steady-
State?
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
"Max"
Residue?
. No
No
No
Yes
Yes
Yes/No
Yes
No
Yes
Yes/No .
PREDICTING BIOACCUMULATION OF
SEDIMENT POLLUTANTS BY BENTHIC ORGANISMS
• FIELD APPROACH
• BIOACCUMULATION TEST
• STEADY-STATE MODELS
- BIOACCUMULATION FACTORS (BAFs)
- EQUILIBRIUM PARTITIONING (BSAFs)
• KINETIC MODELS
- COMPARTMENT-BASED MODELS (1ST-ORDER KINETIC MODEL)
- PHYSIOLOGICAL- & ENERGETIC-BASED MODELS
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Proceedings
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SUMMARY OF QUESTIONNAIRE CHOICES. NUMBERS ABOVE
DECISION BOXES REFER TO QUESTIONNAIRE CHOICES.
Use EqPB Model
Section 4
Use BAF Model
Section 3
Yes
Are site-specific
BAFs available?
Predict or model
tissue residues.
No
Yes
Use a standard model
to predict residues.
3
Yes
No
Yes
Model used as quick
screening tool for
bioaccumulation?
No'
Model more than one uptake
route (as opposed to
modeling uptake only from
bedded sediment)?
Yes
Predict time to specific
tissue residue value
(time to steady-state
or elimination time)?
Yes
No
Will organism grow
substantially during
test or modeling?
Yes
Yes
Is measured AF
available for
compound and sedi-
ment of concern?
Yes
Use EqPB Model
Section 4
I Go to Next Page j
\ for Field or Lab j
j questions (15). j
Collect field samples
to derive regression
Section 11
Use bioenergetics-
based toxicokinetic
model. Section 5
Yes
Changes in test organism
behavior are likely due
to changes in sediment
characteristics.
No
Yes
No
Accurate estimate not possible.
Either make screening prediction
(Box 4) or make site-specific ,
measurement (Box 15).
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National Sediment Bioaccumulation Conference
EQUILIBRIUM PARTITIONING BIOACCUMULATION MODEL
Sediment \
Ctss/L = (Cs/TOC) *AF
AF = (Ctss / L) / (CS / TOC)
Where:
. Ctss = Tissue cone, at steady-state (ug/g)
L = Lipid content (gig)
TOC = Total organic carbon in sediment (gig)
Cs = Sediment cone, (ug/g)
AF = Accumulation Factor (g carbon/g lipid)
1) Tissue residues cannot exceed the concentration set by partitioning (AF < = 2)
2) AFs do not vary among species, sediments, or compounds
PCB Congener AFs in
Fine and Bulk Sediments
11-,
i£t
10-
6-
4~
2-
t
— j *
pi
if
1
pr-
M
ft
i
*
j-
*:
iS««
1
S^
g
fi
5
?
1
C3
n
^1
1
1
I
1
1
is>
r
t
fes
I
"j
** q
e,
r
*.
,T
s-
A
4,
*
i
j
rr«j
j
|
r
•!
«
f
!*
8?
.
!
s
«'
h-
J
^
«
^
-
•C
»
v:
,
i
;
>
T*,
1 ^
, V,
X
*'•
•• \ Bulk
!iw] Fine
p':
fc"! AF(max) = 1.7
S fii
:-' 1 •'' i ta
i
Log Kow
8
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Proceedings
1-19
United States
Environmental Protection .
Agency
Office of Research and
Development
Washington, DC'20460
EPA/600/R-93/183
September.! 993
5ER& Guidance Manual
Bedded Sediment
Bioaccumulation Tests
SEDIMENT BIOACCUMULATION TEST
KEY PROCEDURES
1. 28-DAY EXPOSURE DURATION.
1. SEDIMENT-INGESTING ORGANISM REQUIRED.
3. NO SUPPLEMENTAL FOOD USED.
4. SPECIES EXPOSED INDEPENDENTLY.
5. 80% OF STEADY-STATE TISSUE RESIDUES RECOMMENDED ACCURACY.
6. LONG-TERM TESTS OR TOXICOKINETIC APPROACHES USED FOR >80% ACCURACY
OR SLOWLY ACCUMULATED COMPOUNDS. .
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National Sediment Bioaccumulation Conference
Percent of Steady-State
100
% of Steady-State
80-
60-
40-
20-
0
'lit 5
PCBs (N=26) PCDD/PCDFs (N=4) METALS (N=9)
Pollutant Type
I | 10 Day 28 Day
PNAs (N=14)
UPTAKE OF PCB CONGENERS 153 VS 209 BY MACOMA NASUTA
1200
1000
OQ
800
1 600
o>
400
200
0
I PCB 153
I PCB 209
0 20 40 60 80 100 120 140
Exposure Length (Days)
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Proceedings
1-21
PPB
100000
80000
60000
40000
20000
0
SUM DDT UPTAKE
20 40 60
EXPOSURE TIME (DAYS)
80
100
TISSUE UPTAKE
4,4 DDE
2,4 ODD
20 40 60 80
EXPOSURE TIME (DAYS)
100
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National Sediment Bioaccumulation Conference
CRITERIA FOR ORGANISM SELECTION
1. Sediment ingester
2. Infaunal (preferably non-tubicolous)
3. Hardy
4. Easily collected or cultured
5. Sufficient biomass for chemical analysis
6. High bioaccumulation potential
7. Feeding behavior understood
8. Suitable for mechanistic/kinetic studies
BSAFs IN FIELD-COLLECTED MACOMA NASUTA VERSUS
FILTER-FEEDING BIVALVES IN RICHMOND HARBOR
ZDDT
DIELDRM
Macoma
0.75
1.13
Filter-Feeding
Bivalves
0.10
0.13
Difference
7.5X
8.7X
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i-23
LAB/FIELD TISSUE RESIDUE RATIOS
LAB/FIELD RATIO
3
2.5
2
1.5
1
0,5
0
DDT
Dieldrin
3.4
STATION
8
SEDIMENT BIOACCUMULATION ' %
RESEARCH NEEDS
INTERLABORATORY ROUND-ROBIN
FIELD VALIDATION (PAHs, METALS) ,
LOCAL TEST SPECIES, ESP. FOR SUBTROPICAL, SUBARCTIC, AND
OLIGOHALINE HABITATS
"STANDARDIZATION" OF LIPID METHODS FOR BSAFs
EFFECTS OF SEDIMENT STORAGE AND SPIKING ON BIOAVAILABILTY ,
REFINEMENT OF EXPERIMENT DESIGN, INCLUDING CRITERIA FOR
CONTROLS AND REFERENCES
EVALUATION OF KINETIC & PHYSIOLOGICAL-BASED ALTERNATIVES TO
28-DAY TEST
WHAT IS ECOLOGICAL SIGNIFICANCE?
PREDICT TISSUE RESIDUE EFFECTS
INTEGRATE TISSUE RESIDUE EFFECTS INTO ECOLOGICAL RISK
ASSESSMENTS
- ECOLOGICALLY RELEVANT SPATIAL SCALES
- MULTIPLE STRESSORS - MULTIPLE ENDPOINTS ,
- COMPARATIVE RISK TO OTHER TRADITIONAL & NON-TRADITIONAL
STRESSORS ,
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National Sediment BioaocumufatJon Conference
Methods for Assessing
Bioaccumulation of Sediment-
Associated Contaminants with
t : - ' '
Freshwater Invertebrates
Christopher G. Ingersoll, Eric L. Brunson, and F. James Dwyer
U.S. Geological Survey, Columbia, Missouri
Over the past 10 years, a variety of methods have
been described for evaluating the toxicity of
sediment-associated contaminants with freshwa-
ter invertebrates (i.e., USEPA, 1994; ASTM, 1997a).
Howevex, only a limited number of standard methods are
currently available for assessing bioaccumulation of con-
taminants from field-collected or laboratory-spiked sedi-
ments (see page 1-31). Standard guides have recently
been published for conducting 28-day bioaccumulation
tests with the oligochaete Lumbriculus variegatus includ-
ing determination of bioaccumulation kinetics for differ-.
ent compound classes (USEPA, 1994; ASTM, 1997b),
These methods have been applied to a variety of sediments
to address issues ranging from site assessments to
bioavailability of organic and inorganic contaminants
using field-collected and laboratory-spiked samples
(Schuytemaet al., 1988; Nebeker et al., 1989;.Ankley et
al., 1991; Call etaL, 1991; Carlson et al., 1991; Ankleyet
al., 1993; Kukkonen and Landrum, 1994; Brunson et al.,.
1998; see ASTM, 1997b for a listing of these citations).
Results of laboratory bioaccumulation studies with
L. variegatus have been confirmed with comparisons to
residues (polychlorinated biphenyls,-PCBs; polycyclic
aromatic hydrocarbons, PAHs) present from field popula-
tions of oligochaetes collected from the same sites as
sediments used in the laboratory exposures (Ankley et al.,
1992; Brunson etal., 1998). Additional method develop-
ment is under way to evaluate bioaccumulation kinetics
and to provide additional data confirming responses ob-
served in laboratory sediment tests with benthic commu-
nities in the field.
Selection of test Organisms
The choice of a test organism has a major influence
on the relevance, success, and interpretation of a test.
Various organisms have been suggested for use in studies
of chemical bioaccumulation from freshwater sediments
(Table 1). The following criteria outlined in Table 1 were
used to select L: variegatus for bioaccumulation method
development by USEPA (1994) and ASTM (1997b):
(1) ease of culture and handling, (2) known chemical
exposure history, (3) adequate tissue mass for chemical
analyses, (4)tolerancetoawiderangeofsedimentphysico-
chemical characteristics, (5) low sensitivity to contami-
nants associated with sediment, (6) amenability to long-
term exposures without,feeding, (7) ability to accurately
reflect concentrations of contaminants in field-exposed-
organisms (i.e., exposure is realistic), and (8) data con-
firming the response of laboratory test organisms with
natural 'benthic populations. Thus far, extensive
interlaboratory testing has not been conducted with
L. variegatus. Other organisms did not meet many of the
selection criteria outlined in Table 1, including mollusks
(valve closure), midges (short life cycle), mayflies (diffi-
cult to culture), amphipods (i.e., Hyalella azteca: small
tissue mass, too sensitive), cladocerans and fish (not in
contact with sediment).
Testing Procedures for Lumbriculus
variegatus
The 28-day bioaccumulation test with L. variegatus
described in USEPA (1994) and ASTM (1997b).is conducted
with adult oligochaetes at 23°C with a 16L:8D photoperiod
at an illuminance of about 500 to 1000 lux. Test chamber
size ranges from 4 to 6 L, and the chamber contains 1 to
2 L of sediment and 1 to 4 L of overlying water with five
replicates recommended for routine testing. To minimize
depletion of sediment contaminants, a ratio of 50:1 total
organic carbon in sediment to dry weight of organisms is
recommended. A minimum of 1 g(wetweight)/replicate,
with up to 5 g/replicate should be tested. Organisms are
not fed during a bioaccumulation test (see page 1-36).
1-25
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National Sediment Bioaccumulation Conference
Table 1. Selection criteria for sediment bioaccumulation test organisms (EPA, 1994; ASTM, 1997b;
Ingersoll et al., 1995). A "+" or "-" rating indicates a positive or negative attribute; "NA" is not applicable;
and "?" is unknown.
Criterion
Laboratory culture
Known chemical exposure
Adequate tissue mass
Low sensitivity to
contaminants
Feeding not required
during testing
Realistic exposure
Sediment physico-
chemical tolerance
Response confirmed with
benthic populations
Lumbriculus Mollusks Midges Mayflies
variegatus . •
Amphipods Cladocerans Fish
NA NA
If sediments could be toxic to L. variegatus, a 4-day
toxicity screening test should be conducted before starting
a bioaccumulation test (ASTM, 1997b). Endpoints
monitored in the toxicity test are survival and behavior.
Test organisms should burrow into test sediment because
avoidance of test sediment by L. variegatus may reduce
bioaccumulation. Survival of L. variegatus in the toxicity
screening test should not be significantly reduced in the
test sediment relative to a control sediment. Additional
requirements for test acceptability are outlined in USEPA
(1994) and ASTM (1997b).
At the end of the bioaccumulation test, live oli-
gochaetes are transferred to a 1-L beaker containing
overlying water without sediment for 24 hours to elimi-
nate gut contents (oligochaetes clear more than 90 percent
of the gut contents in 24 hours). A correction for the extent
of elimination from the body burden may need to be made
for compounds with log Kow less than 5. Oligochaetes are
not placed in clean sediment to eliminate gut contents
because clean sediment can contribute 15 to 20 percent to
the dry weight of the oligochaetes, resulting in a dilution
of contaminant concentrations on a dry weight basis.
Minimum tissue mass required for various analyses at
selected lower limits of detection are listed in USEPA
(1994) and ASTM (1997b). Depending on study objec-
tives, total lipids can be measured on a subsample of the
total tissue mass of each replicate sample. Dry weight of
oligochaetes can be determined on a separate subsample
from each replicate.
Because bioaccumulation tests are often used in
ecological or human health risk assessments, the proce-
dures are designed to generate estimates of steady-state
tissue residues. Eighty percent of steady state is used as
the general goal for a test (ASTM, 1997b). An option
when conducting a bioaccumulation test is to perform a
kinetic study to estimate steady-state concentrations in-
stead of conducting a 28-day bioaccumulation test (e.g.,
sample on Days 1,3,7,14,28). A kinetic test can be used
when 80 percent of steady state will not be obtained
within 28 days or when more precise estimates of steady-
state tissue residues are required (see page 1-37).
Case Studies
Methods for conducting bioaccumulation tests with
L. variegatus have varied slightly over the years; how-
ever, test conditions (e.g., test length, exposure systems)
have been consistent enough for evaluation of the robust-
ness of the guidance outlined in USEPA (1994) and
ASTM (1997b). In a study with sediments from the lower
Fox River in Green Bay, Wisconsin, Ankley et al. (1992)
compared the bioaccumulation of PCBs by
L. variegatus exposed in the laboratory to PCB residues
in collections of oligochaetes from the field. Good
agreement was observed between PCB concentrations in
the laboratory and field organisms, particularly for those
congeners with Kow values <7 (see Figure 1). This
indicates that for super-hydrophobic chemicals, labora-
tory exposures longer than 28 days may be required to
reach equilibrium.
Good agreement was also observed in
bioaccumulation between L. variegatus exposed in the
laboratory for 28 days and field-collected oligochaetes
from sediments collected from the upper Mississippi
River (Brunson et al., 1998). About 90 percent of the
corresponding concentrations of PAHs were within a
factor of 3 between the laboratory-exposed and field-
collected oligochaetes (see Figure 1). Concentrations
that differed by more than a factor of 3 included
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Proceedings
1-27
u>
o
DC
m
o
UJ
(0
Brunson et al. (1998)
Ankley et al. (1992)
O
•O
00
o
o
o
I
I
I
3 4 5 6
FIELD-COLLECTED OLIGOCHAETES
8
Figure 1. Biota-sediment accumulation factors (BSAFs) for labbratory-exposed
Lumbriculus variegatus and field-collected pligochaetes for PAHs (Brunson et al.,
1998) and PCB homologs (Ankley et al., 1992).
naphthalene, l-methylnaphthalene, 2-methylnaphthalene,
2,6-dimethylnaphthalene, 1,6,7-trimethylnaphthalene,
phenanthrene, 1-methylphenanthrene, and benz(a)an-
thracene. Tissue concentrations of naphthalenes were gen-'
erally higher in field-collected oligochaetes relative to
laboratory-exposed oligochaetes (naphthalenes are low
molecular weight (LMW) PAHs with log Kow values less
than 4.5). Compounds with similar concentrations in.
both the laboratory-exposed and field-collected oligo-
chaetes included a similar number of high molecular
weight (HMW) and LMW PAHs. These compounds
included biphenyl, fluorene, 1-methylphenanthrene,
pyrene, fluoranthene, chrysene, andbenzo(e)pyrene. Most
of these compounds are intermediate in molecular weight
and log Kow (except for benzo(e)pyrene, which has the
highest molecular weight and log Kow compared to these
other compounds). Compounds with concentrations
typically higher in the laboratory-exposed oligochaetes
compared to field-collected oligochaetes were primarily
HMW PAHs. These compounds included phenanthrene,
benz(a)anthracene, benzo(b,k)fluoranthene, andperylene
(with log Kow greater than 4.5).
Differences between tissue concentrations in the
laboratory-exposed and field-collected oligochaetes may
be the result of differential exposure, including the fol-.
lowing factors: (1) LMW PAHs imay be lost during the
sampling of sediments from the field; (2) spatial hetero-
geneity of contaminants in the field may have resulted in
differential accumulation; (3) the route of exposure for
oligochaetes in the field is through sediment, food, and
overlying water, while the primary route of exposure to
oligochaetes in the laboratory is sediment; and
(4) species^specific
differences in expo-
sure exist between L.
variegatus and the
native oligochaetes.
Concentra-
tions of DDT
reached 90 percent
of steady state by
Day 14 of a 56-day
test with L. varie-
•gatus exposed to
field-collected sedi-
ments (unpublished
data). However,
LMW PAHs (i.e.,
acenaphthylene,
fluorene, phenan-
threne) generally
peaked by Day 3 and
tended' to decline
to Day 56. Concen-
trations of HMW
PAHs (i.e., benzo
(b)fluoranthene,
benzo(e)pyrene,
indeno ( 1,2,3-
c,d)pyren'e) typi-
cally either peaked
by Day 28 or continued to increase during the 56-day
exposure. Bioaccumulation of contaminants by indig- •
enous oligochaetes that were recovered on Day 28 from
the same chamber with introduced L. variegatus were
also evaluated. Peak concentrations of select PAHs and
DDT were similar in the indigenous oligochaetes and in
L. variegatus exposed in the same chamber (unpublished
data). Bioaccumulation of metals from sediments has
also been evaluated using L. variegatus. Ankley et al.
(1991) reported elevated concentrations of Cd and Ni in
worms after 10-day exposures to field-collected sedi-
ments where the metal (Cd + Ni):acid-volatile sulfide
ratio exceeded 1, but not in samples where the ratio was
<1. Ankley et al. (1994) also found that worms did not
bioaccumulate metals from three sediments containing
elevated concentrations of Cd, Ni, Zn, Cu and Pb, when
there was sufficient acid-volatile sulfide to complex
metals.
Biota-Sediment Accumulation Factors
Biota-sediment accumulation factors (BSAFs) were
calculated for L. variegatus by dividing the lipid-normal-
ized tissue concentrations by the organic carbon-normal-
ized sediment concentrations (Table 2; Brunson et al.,
1998). Forlaboratory-exposedoligochaetes,meanBSAFs
ranged from 1.1 for benz(a)anthracene to 5.3 for naphtha-
lene. Forfield-collected oligochaetes, meanBSAFs ranged
from 0.5 for benz(a)anthracene to'8.8 for naphthalene.
For individual samples, BSAFs for .naphthalene ranged
from 1.6 to 10.1 in laboratory-exposed oligochaetes and
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1-28
National Sediment Bioaccumulation Conference
Table 2. Mean biota-sediment accumulation factors (range in parentheses) reported by Lee
(1992) and by Brunson et al. (1998). NR is not reported.
Compound
Naphthalene
2-methyl naphthalene
Pyrene
Fluoranthene
Chrysene
Benz(a)anthracene
Benzo(b,k)fluoranthene
Perylene
Lee (1992)
NR
NR
, 0.4(0.18-0.5)
NR
NR
0.4 (0.2-0.6)
0.4 (0.2-1.0)
NR
Brunson et al. (1998)
Lab-exposed oligochaetes
. 5.3 (1.6-10.1)
2.6 (0.9-5.1)
2.3 (0.8-3.9)
1.8(0.9-3.9)
1.5 (0.7-2.4)
1.1 (0.4-2.5)
NR
2.24 (0.5-4.7)
'Brunson el al.. (1998)
Field-collected oligochaetes
8.8 (2.5-26.6)
6.7 (2.2-12.2)
2.2 (0.7-5.6)
1.6 (0.6-4.9)
1.1 (0.3-2.0)
0.5 (0.4-0.7)
NR
1.02 (0.3-1.9)
2.5 to 26.6 in field-collected oligochaetes. The BSAFs for
pyrene, benz(a)anthracene, and benzo(b,k)fluoranthene
were typically greater that BSAFs reported for marine
organisms in Lee (1992) for these compounds (Table 2).
BSAFs were also calculated using PCB homolog data
reported in Ankley et al. (1992) for laboratory-exposed
L. variegatus and field-collected oligochaetes (Figure 1).
BSAFs were similar between laboratory-exposed and
field-collected oligochaetes in both Ankley et al. (1992)
and Brunson et al. (1998); however, BSAFs reported in
Brunson et al. (1998) were typically greater (0.5 to 8.8)
than BSAFs from Ankley et al. (1992; 0.17 to 2.26;
Figure 1).
A theoretical value of 1.7 for BSAFs has been
estimated based on partitioning of nonionic organic com-
pounds between sediment carbon and tissue lipids (ASTM;
1997b). A BSAF of less than 1.7 indicates less partition-
ing into lipids than predicted, and a value greater than
1.7 indicates more uptake than can be explained by
partitioning theory alone (Lee, 1992). The majority of the
BSAFs in Figure 1 and Table 2 were within a. range of
about 0.5 to 2.6, suggesting the theoretical BSAF value of
1.7 could be used to predict these mean BSAFs with a fair
amount of certainty. However, meanBSAFs for naphtha-
lene (8.8) and 2-methyl naphthalene (6.7) in the field-
collected oligochaetes were elevated relative to a theoreti-
cal BSAF of 1.7 (Table 2), with BSAFs for individual
samples as high as 10.1 for laboratory-exposed oligo-
chaetes and 26.6 for field-collected oligochaetes. The
higher BSAFs in the field-collected oligochaetes may be
the result of (1) exposure to contaminants in the overlying
water; (2) spatial differences in sediment contamination
(i.e., sediments were not sampled from a depth represen-
tative of the habitat of the oligochaetes); or (3) taxon-
specific differences in exposure. BSAFs substantially
different from the theoretical value of 1.7 may also result
from the system not being at equilibrium (i.e., depletion or
release of contaminants in pore water).
In summary, procedures, for evaluating the
bioaccumulation of contaminants associated with fresh-
water sediment using the oligochaete L. variegatus have
been well described. Results of laboratory studies using
these procedures are generally similar to the
bioaccumulation of contaminants exhibited by oligo-
chaetes in the field. Ongoing research includes further
evaluations of bioaccumulation kinetics and field valida-
tion of laboratory bioaccumulation methods, use of
formulated sediments and sediment spiking, and stan-
dardization of micro-lipid analytical methods.
References
Ankley G.T., G.L. Phipps, E.N. Leonard, D.A. Benoit,
V.R. Mattson, P.A. Kosian, A.M. Cotter, J.R.
Dierkes, D.J. Hansen, and J.D. Mahony. 1991.
Acid-volatile sulfide as a factor mediating
cadmium and nickel bioavailability in contami-
nated sediment. Environ. Toxicol. Chem. 10:1299-.
1307.
Ankley, G.T., P.M. Cook, A.R. Carlson, D.J. Call, J.A.
Swenson, H.F. Corcoran, and R.A. Hoke. 1992.
Bioaccumulation of PCBs from sediments by
oligochaetes and fishes: Comparison of laboratory
and field studies. Can. J. Fish. Aquat. Sci. 49:2080-
2085.
Ankley, G.T., E.N. Leonard, and V.R. Mattson. 1994.
Prediction of bioaccumulation of metals from con-
taminated sediments by the oligochaeteLwmfcn'cK/KS
variegatus. Water Res. 28:1071-1076.
ASTM. 1997a. Standard test methods for measuring the
toxicity of sediment-associated contaminants with
freshwater invertebrates. E1706-95b. In ASTM
annual book of standards, Vol. 11.05, American
Society for Testing and Materials, Philadelphia,
PA, pp. 1138-1220.
ASTM. 1997b. Standard guide for determination of bio-
accumulation of sediment-associated contaminants
by benthic invertebrates. E1688-97a. In ASTM an-
nual book of standards, Vol. 11.05, American
Society for Testing and Materials, Philadelphia,
PA, pp. 1072-1121.
Brunson, E.L., TJ. Canfield, F.J. Dwyer, N.E. Kemble,.
and C.G. Ingersoll. 1998. An evaluation of bioac-
cumulation with sediments from the upper Missis-
sippi River using field-collected oligochaetes and
-------
1-29
laboratory-exposed Lumbriculusvariegatus. Arch.
Environ. Contam. Toxicol. In press.
Ingersoll, C.G., G.T. Ankley, D.A. Benoit, G.A. Burton,
F.J. Dwyer, I.E. Greer, T.J. Norberg-King, and
P.V. Winger. 1995. Toxicity and bioaccumulation
of sediment-associated contaminants with fresh-
• water invertebrates: A review of. methods and
applications. Environ. Toxicol. Cheiri. 14:
1885-1894.
Lee, H. EL 1992. Models, muddles and mud. In
Sediment toxicity assessment, ed. G.A. Burton,
Lewis Publishers, pp. 267-293. Chelsea,
Michigan.
USEPA. 1994. Methods for measuring the toxicity and
bioaccumulationofsediment-associated contami-
nants with freshwater invertebrates. EPA 600/R-
94/024. U.S. Environmental Protection Agency,
Duluth, MN.
USEPA/USDOI. 1997. An assessment of sediments from
the upper Mississippi River. Final report. EPA
823-R-97-005. U.S. Environmental Protection
Agency, Office of Water, Washington, DC.
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1-30
National Sediment Bioaccumulation Conference
Methods for Assessing
Bioaccumulation of
Sediment-Associated Contaminants
with Freshwater Invertebrates
USEPA National Sediment
Bioaccumulation Conference
Wednesday September 11,1996
Hyatt Regency, Bethesda, MD
Chris Ingersoll, Eric Brunson, Jim Dwyer
U.S. Geological Survey
Columbia, MO
Objectives:
• Standard methods
•Approaches
• Laboratory exposures
-Methods
- Lab to Field comparisons
-Kinetic studies
• Differences among standard methods
• Future directions
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1-31
Standard sediment methods
^^^1- ' • " •-.. v
^M F^liwSer
^^^^| Estuarine & Marine
^^H Toxicity: Soil
^^^^| Bioaccumulation
H^^H Collection
^^H Manipulation
^^^| Guidance
^H A^Sce
ASTM
E1706
E1367,
E1611
El 676
E1688
E1391
E1391
E1525
E1525*
EPA
1994a
1994b
1986
1989,19943
1995,1996?
1995,1996?
1994a,b
1995
EC ^^^H
1996a,b JJ
1999972aa? ^H
1994a, 1999? ^^^1
— s~^^B
1995 l^^l
1996b. 1997b ^^^H
isolooo ^H
' -
- ' , . ' - - '
Approaches:
• Laboratory-exposed organisms
• Field-collected organisms
• Bioaccumulation factors (BAF)
• Equilibrium partitioning models (BSAF)
• Kinetic models
• Bioenergetic models
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1-32
National Sediment Bioaccumulation Conference
Approaches (cont.)::
• Bioaccumulation factor:
BAF = [tissue]/[sediment]
• Equilibrium partitioning models:
Biota-sediment accumulation factor
BSAF = [tissue/lipid]/[sediment/TOC]
~ 1.7 (4.0 USEPA-USCOE; 1991)
Approaches (cont.):
•Assumptions associated with BSAFs:
-sediment only source
-equilibrium & not kinetically limited
- no metabolic degradation
= lipid, TOC = TOC
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Proceedings
1-33
Selection criteria: Toxicity testing organisms
HA DS CT CR LV TT HS MQ GL
Sensitivity
Round robin
Contact sed.
Taxonomy
Ecological
Geographical
Physico-chem.
Field validation
Peer review
Endpoints
SGM SBA SGE BS BR SR | SG
Selection Criteria: Freshwater
bioaccurnulation testing organisms
Mol Mdg May Amp Cla Fish
Tissue mass
Sensitivity
Feeding
Realistic exposure
Physico-chem.
Field validation
LV: Lumbriculus variegatus, Mol: Mollusks, Mdg: Midges,
May: Mayflies, Amp: Amphipods, Cla: Cladocerans
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National Sediment Bioaccumulation Conference
Selection Criteria: Recommended freshwater
bioaccumulation testing organisms
Species
Chironomus
tentans
Chironomus
riparius
Diporeia spp.
Hexagenia spp.
Hyalella azteca
Lumbriculus
variegatus*
Earthworms
Feeding I Biomass I Sensitive I Culture I Data
rr/ - T- - - TT I -t--t-
SDF
FF/
SDF
SSDF
SSDF
SSDF
FF = fitter feeder; SDF = surface deposit feeder
SSDF = subsurface deposit feeder; Adapted from ASTM E1688
Relative sensitivity: water 10-d LCSOs (ug/L
I'hemical
Copper
Zinc
Nickel
Cadmium
Lead
>,p'-DDT
>,p'-DDD
),p'-DDE
Dieldrin
lorpyrifos
Hyalella Chironomus
azteca tentans
35 54
73 1125
2.8 NT
780 NT
<16 NT
0.07 1.23
0.17 0.18
1.39 3.0
7.6 1.1
0.086 0.07
; ASTM E1 706)
Lumbriculus ^^H
••^•H
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Proceedings
1-35
Lumbriculus variegatus (oligochaeta):
• Location: North America and Europe
• Habitat: tunnels aerobic sediments
lakes, rivers, ponds
• Behavior:
-buries anterior portion in sediment and
undulates posterior end in overlying
water for respiration
-processes >12 x weight/day
Lumbriculus variegatus (cont.):
•Adults:
-40 to 90 mm length
-1.0 to 1.5 mm diameter
-5 to 12 mg wet weight
-about 1% lipid
• Reproduction: asexual (i.e., architomy)
• Culture:
-adults of various size
-population doubles in about 8 to 12
days at 23C
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1-36
National Sediment Btoaccumulation Conference
Laboratory exposures:
• Single sampling time:
-steady state (i.e., Day 28?)
- ANOVA and BSAFs
• Kinetic study:
-time course (i.e., Day 1, 3, 7,14, 28, 56)
-regression models (i.e., Ks and Ka)
• Depuration:
-experimental (i.e., 24-h gut purge)
-regression models (i.e., Ks and Ka)
BIOACCUMULATION
Lumbriculus:
EPA & ASTM
Macoma:
EPA & ASTM
Polychaetes:
EPA & ASTM
Temperature (C)
Luminance (lux)
Photoperiod
Chamber (L)
Sediment (L)
Water (L)
Water renewal
Age
Loading
Feeding
Replicates
Duration (days)
Endpoints
Acceptability
16:8 to 12:12
10-25
16:8 to 12:12
adult
>1 g/rep.
; adult
1 g/50 g sed.
juvenile
1 g/200 g sed.
No
28/kinetics
T,A,B,R
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Proceedings
1-37
Percent of steady state (ASTM E1688)
Compound
Day Day
10 28
Phenanthrene
Benzo(a)pyrene !
Benzo(a)pyrene '
Benzo(a)pyrene :
Chrysene '
Hexachlorobenzene
Hexachlorobiphenyl 88 100
Aroclor1242 1!
Total PCBs
Cadmium ',. , .
Organism
amphipod
'mayfly
clam
amphipod
clam
clam
mayfly
polychaete
clam
shrjmp
Percent loss during gut purging (ASTM E1688)
Compound 24 h 72 h
PCB :
Hexachlorobenzene <
Benzo(a)pyrene
Phenanthrene .. |
Benzo(a)pyrene 14-26 43-99
Phenanthrene
HCBP
77-100
14-26 43-99
Organism
shrimp
clam
amphipod
amphipod
mayfly
mayfly
mayfly
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1-38
National Sediment Bioaccumulation Conference
Errors associated with gut purging:
• Gut sediment error greatest:
-selective ingest high TOC
-large gut
-early in exposure (low uptake)
-cmpds. not bioaccumulated
« Purging error greatest:
-rapidly depurated/metabolized cmpds.
-dilution by uncontammated sediment
Performance-based criteria:
• Survival (should; 4-d screening test for LV)
•Avoidance (should)
• Food (should; measure chemicals of concern)
•Water quality (should)
• Culture conditions (should)
• Reference toxicants (must: monthly/start of test)
• Physico-chemical characteristics (should)
•Temperature (must; i.e., consistent life stage)
•Storage sediment (2-8 weeks; no consensus)
•Spiked sediment (1 month holding before testing)
-------
Proceedings -••--
1-39
Mean BSAFs for PCBs (Lee 1992)
ORGANISM
Yoldia limatula
Nereis virens
Macoma nasuta
Yoldia limatula
Nereis virens
M acorn a nasuta
Nereis virens
Nereis virens
Macoma nasuta
Nereis virens
Macoma nasuta
Oligochaetes*
BSAF
10.6
10.0
0.8/0.9
Mean BSAFs for other compounds
COMPOUND
Chlordane
Hexaehlorobenzene
ODD
DDE
2,3,7>TCDD
Pyrene
Ben zo (b, k)f iu pranthe he
Chrysene ;
Benz(a)anthracene
Benzo(a)pyrene : ;
BSAF1 RANGE BSAF2 RANGE
4.7 4.0-5.9 '
3.1 | 2.1-4.1 I ,
2.1 0.4-4.8 '
1.3 0.7-2.8 '
0.7 0.5-0.8 '
0;4 0.2-0.5 1.1-2.3 0.7-5.6
0,4/0.2-1.0 0.6-0.8 0.3-1.5
0.4 0:2-0.6 i.0-1.4 0.3-2.4
0,4 0.2-0.6 0.5-1.0 0.4-2.5
0.2 0.05-0.9'
BSAF1 (Lee 1992) and BSAF2 (Bruhson et al. 1998)
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1-40
National Sediment Bioaccumulation Conference
Mean BSAFs for oligochaetes
COMPOUND
2-rnethyInaphthalene
Benz(a)anthracene
Benzo(b,k)fluoranthene
Chirysene
Fluoranthene
Naphthalene
Perylene
Pyrene
LAB RANGE FIELD I RANGE
0.9-5.1
0.4-2.5
2.2-12.2
0.4-0.7
0.6-1.5
0.7-2.4
0.85-3.9
1.6-10.1
0.5-4.7
0.3-1.5
0.3-2.0
0.6-4.9
2.5-26.6
0.3-1.9
0.8-3.9
0.7-5.6
Brunson etal. 1998
Frequency of Detected Concentrations:
Tissue vs sediment (Brunson et aL, 1998)
Lab-exposed Lumbriculus Field-collected Oligochaetes
H Detect in tissue, no detect in sediment
• No detect in tissue, detect in sediment
D Detect or no detect in tissue and sediment
-------
Proceedings
1-41
BSAFs for PCBs: Oligochaetes and fish
2.5
W
(0
o
Q
UJ
CO
1.5
2 1
0.5
Lumbriculus
•
Fatheads
o
Line of Unity
Line of unity ±40%-
Ankleyetal.(1992)
0.5 1 1.5 2 2.5
FIELD-COLLECTED OLIGOCHAETES
BSAFs for oligochaetes
.
1
o
DC
m
!4
Q
III
f3
I*
<
DC
O -•
<
_1
0
Brunson etal. (199,8) for PAHs Ankleyetal. (1992) for PCBs 0
, • o
i -
' • ' • ' *
- • • , - -
•
*
Q*
^ . , '
r "o o
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1-42
National Sediment Bioaccumulation Conference
Mean PAH concentrations (ug/g lipid; Brunson et ai. 1998)
0.1 0.2 0.5 1 2 5 10 20 50 100
FIELD-COLLECTED OLIGOCHAETES
10
9
8
Q 7
f-
A
2 4
3
2
1
2
3
A 5
3 6
111
10
i
i
i
i
i
i
i
1 1
1
<
<
i
i
i
i 1
i
i
i
i
i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
AAABABACCBBBCCCB
COMPOUND #
-------
Proceedings
1-43
Tissue Concentrations (ug/g of lipid)
10
8
Pyrene
2 4 6 8 . 10
FIELD COLLECTED
— Line of Unity
1-Methyl Phenanthrene
2.5
Q
111
| 1.5
•^ 0.5
0
(5.7)
0 0.5 1 1.5 2 2.5
HELD COLLECTED
Line of unity ± 40%
Other compounds displaying a similar pattern (i.e. field ~ lab):
Fluoranthene, Fluorene, Benzo(e)pyrene
Tissue Concentrations (ug/g of lipid)
Chrysene
Perylene
200
150
100
1C
O
CD
3 50
12 3 4 5 6
FIELD COLLECTED
50 100 150 200
HELD COLLECTED
Line of Unity ----- Line of unity ± 40%
Other compounds displaying a similar pattern (i.e. lab>fie!d):
Benzo(a)anthracene, Benzo(b,k)fluoranthene
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1-44
National Sediment Bioaccumulation Conference
Tissue Concentrations (ug/g of lipid)
2-methyl Naphthalene
30
Naphthalene
25
8
§20
§15
S
oc
-§1°
3
5
24 6 8 10 12
FIELD COLLECTED
5 10 15 20 25 30
FIELD COLLECTED
Line of Unity Line of unity ± 40%
Other compounds displaying a similar pattern (i.e. field>lab):
other Naphthalenes
Differences among standard
sediment methods:
• Static vs. flow-through (fresh vs. marine)
• Type & quantity of food (toxicity vs. bioaccum.)
•Age (Hyalella and Chironomus: EC vs. EPA)
• Duration & endpoints (Hyalella: EC vs EPA)
• Sieving sediment (EC vs. EPA and ASTM)
• Sediment storage (2 to >8 weeks; consensus?)
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Proceedings
t-45
Future directions:
• Spiking & formulated sediments
• Quality assurance:
- Lab certification (EC)
-Reference toxicants
• Standardization of micro-lip id methods
• Kinetics and bioenergetics models
• Field validation
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National Sediment Bioaccumulation Conference
Kinetic Models for Assessing
Bioaccumulation
Peter Landrum -
National Oceanic and Atmospheric Administration^ Ann Arbor, Michigan
WW'inetic models for exposure of aquatic organisms
•fc- were developed for water-only exposures to
M^Ldeyelop a method for shorter-term studies to
estimate steady state (Branson et al., 1975; Neely, 1979).
The toxicokinetics were assumed to be driven primarily
by the thermodynamic differences in the chemical
activities in the storage compartment (organism) and the
source compartment (water). The driving force for the
ultimate storage may be limited through a number of
kinetically limiting steps representing a number of
potential mechanisms. Some of these limits are external
to the organism, some are external but driven by the
interaction of the organism with its environment, and
some represent internal physiological processes of
, the organism.
What are some of these physiological and environ-
mental limitations? The rate of presentation of the
contaminant to the uptake membrane may be limited by
diffusion within the source compartment. The extreme
example of a diffusion-restricted environment is
sediment, where the diffusion path can be very tortuous.
Such diffusion limitations can be reduced by organism
behavior including increases in respiration, resulting in
the active pumping of water across the gills and increased
ingestion rates, which exposes the organism to a larger
volume or mass of the source compartment and thus the
contaminant. Environmental factors such as temperature
may alter physiological processes and result in changes in
physiological features such as respiration and metabo-
lism. These in turn may alter the volume of the source
compartment encountered and the resultant exposure.
The balance may result in greater or lower concentrations
over time. Limitations at the physiological level also
include limitations of compound transport from the site of
accumulation to the ultimate storage site within the organ-
ism. Such processes can limit or enhance the transport
from the site of uptake. If the transport from the site of
uptake is limited, then the apparent difference in chemical
activity forcing the transport into the organism may be
reduced and the rate process slowed. Likewise, if the
internal distribution is rapid, a large chemical activity ,
gradient can be maintained and the rate will be rapid.
, Changes in the metabolic rate within the organism can
also alter the rate of biotransformation, and thus
the ultimate rate and potential for the accumulation of the
parent compound. However, in these cases the flux into
the organism remains high, and if the metabolite is
the toxic form, its flux and accumulation will be
enhanced.
Using the simplest model of accumulation and loss,
some of these various factors can be demonstrated, e.g.,
the effect of respiration rate'on the uptake process. As-
suming no biotransformation:
= Flux.m - Fluxmt
At
In this form, it is difficult to quantitate the changes
in concentration in the organism or predict them, but by
making additional restrictions, quantitation and predic-
tion become possible. The formalisms available for this
simple model can be represented in compartment, clearance
volume, or fugacity forms. In this simple model, the
various formalisms can be interconverted (Landrumetal.,
1992a). However, each of the approaches has slightly
different assumptions to yield mathematically equivalent
results.
: In addition to compartment-based kinetic models,
both physiologically andbioenergetics-basedmodels have
been employed to describe the accumulation and distribu-
tion of contaminants in aquatic organisms (Landrum et al.,
1992a). For instance, a bioenergetics model for the clam,
Macoma nasuta, was studied with the contaminant
hexachlorobiphenyl(Boeseetal., 1990). In this case, the
routes and rates of accumulation and loss could be well
defined. The difficulty with these approaches is the need
for a large amount of data to parameterize the model.
These models are particularly useful for relating the
exposure of organisms to fundamental processes such as
respiration and feeding rates. ,
In the compartment-based formalism and the ab-
sence of biotransformation:.
JFluxIn |
ED
JFluxOut|
, 1-47
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1-48
National Sediment Bioaccumulation Conference
dCa
dt
Where:
ku = uptake clearance (ml g'1 br1)
Cs = concentration in the source (ng ml'1)
ke = elimination constant (bf1)
Ca = concentration in the organism (mg g'1)
In this form, some restrictions that are not usually
recognized come into play. First, the concentration in the
source is the bioavailable concentration. If the total
concentration is included as the source concentration, it
will affect the estimate of k^. This is useful for assessing
differences in bioavailability assuming that the conditions
of the experiment do not vary significantly. In water with
little complexing capacity, it is generally the concentra-
tion in the water that is the source concentration.
However, there are examples where water concentrations
are modified by the presence of dissolved organic carbon
(DOC) (Landrum et al., 1992a). In sediment, the fraction
that is bioavailable is less clear and often the total sedi-
ment concentration or a concentration on some
normalized basis, i.e., carbon, is employed. It is generally
understood that C5 is not limiting and that the system is
homogeneous. If this is not true, then the flux into the
organism will vary considerably over time. Such
variation would preclude exact integration of the
differential equation and make it necessary to perform
numerical integration, for which substantially more
information is required.
In the compartment formalism, ku is the clearance of
the source compartment by the organism, usually ex-
pressed on a weight-specific basis for the organism and a
volume- or mass-specific basis for the source compart-
ment. It is assumed to remain constant over the course of
a study or prediction. Whether it actually remains con-.
slant over longer predictions or measurements is ques-
tionable. This term includes the interaction between the
source compartment and the organism and distribution
rates for both the internal and external distribution of the
compound. Ku is also conditional based on factors that
affect the physiology of the organism, the chemistry of the
source compartment, and the interaction between these
two. Thus if k is to be used for comparison of differences
in bioavailabihty, as it often is in many sediment contami-
nant evaluations, the conditions of the experiment need to
be constant across a range of conditions, such as across a
range of sediments, so that the comparisons will be valid.
In addition, ke is also assumed to remain constant and is
subject to many of the physiological changes that occur in
the organisms.
With aqueous exposures, there is an exact conver-
sion between the compartment model and both the clear-
ance volume model and a fugacity model. There are,
however, some subtle differences in assumptions and-
definitions in these models. For the fugacity model, the
system tracks the differences in chemical activity within
the system. The concentrations are given in terms of
moles per volume, and the relative capacities of the
systems for the compound are expressed in terms of both
partition coefficients and fugacity capacities. The model
could work as well in sediment exposures as in aqueous
exposures for it is really a compartment model in which
the terms are redefined. In the case of the clearance
volume model, there are some assumptions that are usu-
ally notreadily recognized. In the aqueous case, the fluxes
into and out of the organism are assumed to primarily
occur across the same membrane or at least the membrane
resistance is assumed to be equal. This leads to the
description of the steady-state condition as the relative
capacity of the organism compared to the source compart-
ment. For sediments, it would be necessary to add
additional routes of exposure to be accurate with this
model. The volume of distribution would reflect the
relative capacity of the aqueous phase of the system.
Thus, it is not as easy to directly apply the clearance
volume model to the sediment environment without modi-
fication of the mathematical formalism.
The simple compartment model approach to
toxicokinetics in sediments has been employed to demon-
strate differences in bioavailability among classes of
contaminants, sediments, the effects of concentration, and
the impact of normalization procedures. The toxicokinetics
approach has shown that two major classes of contami-
nants, polychlorinated biphenyls (PCBs) and polycyclic
aromatic hydrocarbons (PAHs) seem to have differential
bioavailability when the log KOW values are essentially the
same (Landrum and Faust, 1991). This also seems to be
the case for the relative bioavailability of other chlori-
nated hydrocarbons and PAHs as well (Harkey et al.,
1994). This approach was also useful in attempting to
evaluate the relative importance of exposure to interstitial
water versus the exposure to whole sediment, suggesting
that multiple routes can be important (Harkey et al., 1994).
In this case, the relative ku normalized for the organic
carbon content in the media was much greater for expo-
sure to whole sediment than for exposures to interstitial
water, suggesting that the exposure in sediment employed
additional sources (routes) of exposures compared to
simple exposure to interstitial water. Exposures to vary-
ing concentrations of sediment-associated contaminants
can cause accumulation of sufficient doses that the uptake
is affected. When Diporeia spp. were exposed to pyrene,
ku increased to a maximum and then tended to decline at
doses that produced mortality (Landrum et al., 1994).
Finally, the relative bioavailability among sediments of
individual contaminants has been estimated through ex-
posures under essentially identical conditions but with
differing amounts of DOC in water and among sediments.
In one study, the variation in the bioavailability as mea-
sured using uptake clearance demonstrated that for sedi-
ments collected in Lake Michigan normalization to or-
ganic carbon removed essentially all the variability
(Landrum and Faust, 1994). However, in the comparison
to materials from another source, in this case a soil from
Florissant, Missouri, the carbon normalization was not
adequate to describe the difference in bioavailability
and the differences increased with log Kow. Additional
work has shown that the range of variability among
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Proceedings
1-49
sediments after carbon normalization is somewhat
greater than a factor of 10 for selected organic
contaminants.
. The compartment approach has dembnstrated some
limitations to our ability to understand and measure the
accumulation of contaminants from sediments. The first
appearance of complications with this approach was
demonstrated in the accumulation of a series of PAHs
from a single sediment. The shapes of the kinetics curves
varied, with log Kow of the compound. It was originally
thought that this was an equilibrium problem between the
sediment particles and the interstitial water (Landrum,
1989) similar to the observed chemical equilibrium and
extraction problem with chemical analyses (Karickhoff,
1980). Experimental designs seemed to indicate that this
disequilibrium was avalidissue (Landrum, 1989; Landrum
et al., 1992b). However, exposures of organisms to field-
collected sediments also seemed to show some of the same
kinetic complications where organisms would in some
cases rapidly accumulate a compound only to lose con-
centration over time. Since the sediments were field-
collected, it was thought that they were less out of equilib-
rium than those dosed in the laboratory. Experimentally,
it appears that the concentration of biologically available
material is changing over time. If the desorption of a
compound is inadequate to maintain the interstitial water
concentration from the surface easily desorbed concentra-
tion, then the bioavailable component of the total con-
taminant load in the sediment will decline because diffu-
sion within the sediment is limited. When the interstitial
water is a greater source than sediment ingestion, as is
probably the case early in the exposures, then the potential
for depletion of the bioavailable fraction would seem
more likely. This issue seems to be more problematic for
compounds with log Kow values less thap about 5. When
pyrene was studied with a laboratory-dosed sediment, the
shape of the kinetic curve appeared to be a classic first-
order curve with steady state. However, when the elimi-
nation estimated from such a curve was compared to'
directly measured elimination values, it appeared to be
inordinately fast. This suggests that the depletion process
is important from these sediments (Landrum, 1989;
Landrum etal., 1992b). The issue becomes more pro-
nounced with phenanthrene, a compound with a smaller
log Kow value. Compounds with larger log Kow values do
not generally show such depletion. However, in some
work with oligpchaetes, which have a faster initial uptake
rate than Diporeia, an initial uptake with a subsequent
plateau or decline was evident. Overall, it would appear
that the rate of accumulation from the aqueous phase
dictates some of this process and likely itis the relative rate
of uptake versus the rate of desorption that is important
since diffusion in sediment should be slow. In most of the
work that has been performed to date, it is not possible to
separate out the mechanisms that may. be contributing to
such observed variation in the kinetics. Some of the data
that would be necessary to evaluate this include good
estimates of the desorption rate constants from sediment
and estimates'of the feeding rate on sediment particles and
the associated assimilation efficiencies.
Another feature of the kinetics with Lumbriculus
•• variegatus that produced an apparent increase with a
subsequent decline in contaminant concentration was
found to result from loss of weight by the organisms.
Lumbriculus from the culture are healthy and fat. When
exposed in sediments, they sometimes lose weight and
lipids with subsequent losses of contaminant, while in one
study, the kinetics on a lipid basis formed a standard first-
. order uptake that approached steady state (Kukkonen and'
Landrum, 1994). In addition to the impact on the weight,
when Lumbriculus were exposed in different ratios rela-
tive to the organic carbon content of the sediment, but at
the same organic carbon-normalized concentrations, the
kinetics changed, suggesting an interaction (Kukkonen
and Landrum, 1994). At least by performing a kinetic
study, the relationship to steady state for these organisms
can be observed instead of assumed and variations in the
- conditions that impact the steady state determined.
Because of the limitations—in particular, the poten-
tial absence of homogeneity of sediment systems— mov-
ing from a concentration-based to a mass balance-based
model that incorporates more of the physical-chemical
processes can help demonstrate which processes are im-
portant in the accumulation process. A mass balance'
model was established to examine the accumulation of
sediment-associated contaminants. The model attempted ••
to parameterize the partitioning phenomena as well as the
accumulation by several routes for Diporeia (Landrum
and Robbins, 1990). This first pass at a mass balance
model did demonstrate the importance of the role of
desorption of contaminants from sediment, perhaps
coupled with diffusion limits:, on the accumulation pro-
cess. Further, the desorption rate from particles seemed to
be very slow compared to the uptake processes and may
well dictate $ie bioavailability of sediment-associated
contaminants along with the ingestion rate and .assimila-
tion efficiency. In the model as originally formulated,
there was a general absence of data on desorption rates,
assimilation efficiencies, and feeding rates.
Today, the ability to estimate the assimilation effi-
ciency for ingested sediment remains extremely difficult.
The difficulties are essentially twofold. Fkst, it is nearly
impossible to determine the concentration of contaminant
in the ingested fraction of sediment for many inverte-
brates. For oligochaete worms that are general feeders,
e.g., they do not strongly select particles, estimating the
ingested contaminant concentration is easier. The second
issue is to estimate the fraction of material that is retained
by the organism. This is generally performed using anon-
assimiiated tracer. Polydimethylsiloxane and 51Cr have
been used, but in both cases the tracers do not sorb to the
same particles or in the same proportion as the contami-
nants (Lydy andLandrum, 1993; Kukkonen andLandrum,
1995). Another approach has been to estimate the relative
loss of carbon and subsequently estimate contaminant
loss (Lee et al., 1990; Lydy and Landrum, 1993). How- , .
ever, there are not even good assimilation values for the
carbon from sediments, so this approach is limited. Over- .
all, development of good assimilation efficiencies is re-
quired to improve the estimation of contaminant
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1-50
National Sediment Bioaccumulation Conference
accumulation from sediments through kinetic models
except with compounds with large log Kow values, where
desorption and uptake from interstitial water is of lesser
importance.
Summary
Kinetic studies can demonstrate factors that affect
the accumulation process and the relationship between
the length of exposure and steady state.
Kinetic studies do not seem to be able to determine
steady-state potential hi all cases due to complications
with changes in bioavailability or the length of time
required to achieve steady state, which is coupled to
changes hi physiology.
Mass balance models or models incorporating
more of the processes suggest that the desorption rate
from sediment particles is an important kinetically limit-
ing process.
Ingestion as the primary route of exposure com-
pared with interstitial water is a less dominant route for
chlorinated hydrocarbons compared to PAHs and a less
dominant route for more hydrophilic compounds.
To improve kinetic models, data on ingestion rates,
assimilation efficiency, desorption rates, feeding selec-
tivity, and measure of contaminant concentrations on
ingested particles need improved description and un-
proved chemical measurement techniques. It will be
important to move from bulk sediment measures to mea-
sures that reflect the exposure environment.
References
Boese, B.L., H. Lee, D.T. Specht, R.C. Randall, and M.
Windsor. 1990. Comparison of aqueous and solid
phase uptake for hexachlorobenzene in the tellinid
clam, Macoma nasuta (Conrad): A mass balance
approach. Environ. Toxicol. Chem. 9:221-231.
Branson, D.R., G.E. Blau, H.C. Alexander, and W.B.
Neely. 1975. Bioconcentration of 2,2',4,4'-
tetrachlorobiphenyl hi rainbow trout as measured
by an accelerated test. Trans. Am. Fish. Soc. 4:785-
792.
Harkey, G.A., P.F. Landrum, and S.J. Klanie. 1994.
Comparison of whole sediment, elutriate, and
porewater for use in assessing sediment-associated
organic contaminants hi bioaccumulation assays.
Environ. Toxicol. Chem. 13:1315-1329.
Karickhoff, S.W. 1980. Sorption kinetics of hydrophobic
pollutants in natural sediments. In R.A. Baker, ed.,
Contaminants and sediments, Vol. 2, Ann Arbor
Science Publishers, Ann Arbor, MI, pp. 193-206.
Kukkonen, J., and P.F. Landrum. 1994. Toxicokinetics
and toxicity of sediment-associated pyrene to
Lumbriculus variegatus (Oligochaeta). Environ.
Toxicol. Chem. 13:1457-1468.
Kukkonen, J., and P.P. Landrum. 1995. Effects of sedi-
ment-bound polydimethylsiloxane on the
bioavailability and distribution of benzo(a)pyrene
in lake sediment to Lumbriculus variegatus. Environ.
Toxicol. Chem. 14:523-531.
Landrum, P.F. 1989. Bioavailability andtoxicokinetics of
polycyclic aromatic hydrocarbons sorbed to sedi-
ments for the amphipod Pontoporeia hoyi. Environ.
Sci. Technol. 23:588-595.
Landrum, P.P., and J.A. Robbins. 1990. Bioavailability of
sediment-associated contaminants to bentbic inver-
tebrates. In R. Baudo, J.P. Giesy, and H. Muntau,
eds., Sediments: Chemistry and toxicity ofin-place
pollutants, Lewis Publishers, Boca Raton, FL, Chap-
ter 8, pp. 237-263.
Landrum, P.P., and W.R. Faust. 1991. Effect of variation
in sediment composition on the uptake rate coeffi-
cient for selected PCB and PAH congeners by the
amphipod, Diporeia spp. In M. A. Mayes and M.G.
Barren, eds., Aquatic toxicology and risk assess-
ment: Fourteenth volume, ASTM STP1124, Ameri-
can Society for Testing and Materials, Philadelphia,
PA, pp. 263-279.
Landrum, P.P., and W.R. Faust. 1994. The role of
sediment composition on the bioavailability of labo-
ratory-dosed sediment-associated organic contami-
nants to the amphipod, Diporeia (spp.) with sedi-
ment aging. Chem. Speat. Bioavail. 6:85-92.
Landrum, P.F., H. Lee II, and M.J. Lydy. 1992a.
Toxicokinetics hi aquatic systems: Model compari-
sons and use in hazard assessment. Environ. Toxicol.
Chem. 11:1709-1725.
Landrum, P.P., W.R. Faust, and B.J. Eadie.. 1992b. Varia-
tion in the bioavailability of polycyclic aromatic
hydrocarbons to the amphipod Diporeia (spp.) with
sediment aging. Environ. Toxicol. Chem. 11:1197-
1208.
Landrum, P.P., W.S. Dupuis, and J. Kukkonen. 1994.
Toxicokinetics and toxicity of sediment-associated
pyrene and phenanthrene hi Diporeia (spp.): Ex-
amination of equilibrium-partitioning theory and
residue-based effects for assessing hazard. Environ.
Toxicol. Chem. 13(11):1769-1780.
Lee, H. II, B.L. Boese, R.C. Randall, and J. Pelletier. 1990.
A method for determining gut uptake efficiencies of
hydrophobic pollutants in a deposit-feeding clam.
Environ. Toxicol. Chem. 9:215-219.
Lydy, M.J., and P.F. Landrum. 1993. Assimilation effi-
ciency for sediment-sorbed benzo(a)pyrene by
Diporeia spp. Aquat. Toxicol. 26:209-224.
Neely, W.B. 1979. Estimating rate constants for uptake
and clearance of chemicals by fish. Environ. Sci.
Technol. 13:1506-1510.
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National Sediment Bfoaocumufatfon Conference
Day One: September 11, 1996
Session One:
Questions and Answers
A
fter each session, there was an opportunity for
questions and answers and group discussions per-
.taining to the speakers' presentations.
Q(MauriceZeemon, U.S.EPA, Office of Pollution Preven-
, tion and Toxics): I heard Gil Veith talk this morning and
I would like to comment briefly on a point he-made. At a
gut level, I believe issues related to bioaccumulation and
sediment assessment are important issues. I would like to
seek reactions from this panel or others to the following
comments. Most of us are scientists. We deal with a
Cartesian system where we have divided things up into
' little discrete parts, because they are too complex to try to
handle as a group. The risk assessment paradigm is a
perfect example. The key issue is how and when to start
putting the parts back together to make some sense out of
it. Throughout the conference, I would like to ask that you
focus again and again on what Gil Veith said in his
presentation where he got that "So what?" reaction from
a fairly knowledgeable group of people to the statement
that 29 percent of the sediments in major estuaries were
being impacted. As we go through our methods and our
models for bioaccumulation and sediment assessment, try
to think about what additional research will provide
essential data to help the public, lawmakers, and regulatory
agencies make sound decisions and take sensible actions.
Betsy Southerland:
We are looking for ecological significance. What
we are going to try to do, as we go through the next couple
days of this conference, is look at the tissue residues from
bioaccumulative pollutants and see what impact they have
on aquatic life, what impact they have on wildlife consum-
ers of that aquatic life, and their potential for human health
impacts. We already have some field studies conducted
by Rick Swartz that show a significant impact on popula-
tions of other benthos if there is acute toxicity in the
amphipod test species. That certainly gives us an indica-
tion that at least the acute toxicity tests have ecological
significance. What I want to. hear today, which was one of
the prime drivers for organizing this conference, is what
information is available on bioaccumulation tests and
tissue residue measurements to make equally important
interpretations of ecological significance. Interpretation
is the key. We can all do laboratory tests, but then we have'
to determine what the tests mean. Would anyone else care
to comment?
Peter Landrum:
I will add a few comments. It has been my observa-
tion that whenever a particular group studies some aspect
of the lower end of the food web, there is generally less
interest in the work than if it involves fish or fish-
consuming wildlife and birds. There seems to be a general
lack of recognition of the supporting ecosystem required
to maintain the reproduction and the productivity of the
higher levels of the food chain. I do not know if it is within
the purview of this group to be able to drive -that point
home. This point applies to studying phytoplankton pro-
ductivity or contaminants at the lower end of the food
web. The issue remains that the connections between the
lower food web and the upper food web get lost, particularly
when you move into the regulatory realm of lawmakers
responsible for environmental legislation.
Q (Peter ^Chapman, EVS Environment Consultants): I
would like to address a question to any of the panel
members. We have talked about bioaccumulation in
terms of relating it to toxicity effects we already see
occurring. One of the attractions bioaccumulation has to
me is the possibility of anticipating things before they
occur. At this point, do we have any examples where
bioaccumulation datd'have really enabled us to predict
impacts, and, if not, how much further do you think we
have to go before we can do that?
Henry Lee:
. One example would be the work Rick Swartz did on
the sum PAH model. Since these are neutral narcotics, we
discussed bypassing sediment concentration and just going
directly to thetissue residues. Thatwouldelrminate the issue
ofbioavailability. I think that is possible, if we can get good
relationships between tissue residues and some
1-51
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1-52
National Sediment Bioaccumulation Conference
ecologically Significant effects. I would also like to add
to some of Peter Landrum's earlier comments. Peter, I
think the onus is on us to show that these changes in the
benthos are important enough that they have affected
fisheries populations or wildlife. The public is not
primarily interested in amphipods, oligochaetes, or clams,
but in fisheries and wildlife. If we cannot protect these
populations, then we have failed.
Q (Norm Rubinstein, U.S. EPA, Office of Research and
Development): The session this morning really focused on
the issues of measuring bioaccumulation and predicting
bioavailability. I imagine as the meeting progresses, we
will get into the other side of the issue, which is the
corresponding effects. But I am curious to see how you
gentlemen feel about our current ability to predict
bioavailability and bioaccumulation, either thermody-
namically or kinetically. Do you have a sense of confidence
in our ability to identify bioavailable fractions and go on
from there to identify the corresponding ecological effects?
Peter Landrum:
My feeling about that, Norm, is that if we are talking
about neutral organic compounds from sediments, we can
probably predict bioaccumulation within a factor of ten to
twenty, if that is adequate. I think trying to get any better
predictions than that right now is not possible because, as
I pointed out earlier, we do not have a complete under-
standing of how contaminants partition among sediment
size fractions and the degree of feeding selectivity by the
organisms. Without this information, we really do not
know how much contaminant an organism is exposed to.
Chris Ingersoll:
We have been focusing quite a bit this morning on
the nonpolar organics, but what you have not seen today
is some of the work that has been done relative to metals
and acid volatile sulfides (AVS). Some of the metals are
able to be predictive of bioaccumulation that we are
seeing. A series of papers on AVS andmetalbioavailability
will be published hi the December 1996 Society of Envi-
ronmental Toxicology and Chemistry (SETAC) journal.
That issue will also include a good review article by Gary
Ankley and others for a variety of studies to address the
question of whether or not we can predict bioaccumulation
relative to AVS andSEM (simultaneously extractedmetal).
He found that the SEM/AVS approach offers a more
reliable and predictable tool than what is currently
available.
Q (Steve Bay, Southern California Coastal Water Re-
search Project): Peter Chapman listed coupling tissue
residues with toxicity responses as one of the key issues for
this session. But I was wondering about how the recom-
mendations to often use insensitive or hardy test animals
will impact this issue. Are we going to end up with a really
nice data set, but no ability to couple residue levels with
toxicity responses because we do not understand how to
predict the responses from uptake residues in insensitive
organisms? Are we in danger of that, or will we be able
to figure that out once we get a good data set together?
Peter Landrum:
I think we could be somewhat in danger because
these insensitive organisms are going to tell us that they
can accumulate more than some of the sensitive organ-
isms will. The sensitive animals will pass the toxicity
threshold and produce a response. Insensitive organisms
should give you some idea of what the maximum amount
that could accumulate in an organism would be. This
would allow you to at least define the level that you would
have to drive down to protect against responses in other
organisms.
Chris Ingersoll:
We, as lexicologists, need to develop adequate
designs for studies involving water or sediment to
measure toxic effects and bioaccumulation in the same
exposures. I am really looking forward to hearing from
some of the panelists later this afternoon about their
databases. Some data are available, but you really have to
search the literature to find those kinds of data sets.
Peter Chapman:
I have found it useful in toxicity tests, where the
chemicals and organisms are appropriate, to measure
bioaccumulation and toxic effects. Among other things,
it can help me sort out what may be causing any effects I
see. We are trying to move in that direction, but it is a very
valid concern.
Q (Joe Greenblott, U.S. EPA, Office of Research and
Development): I would like to ask a question about how
models fit into the experimental work within the decision-
making and risk assessment framework. What level of
attention is being given to developing and researching
these models and developing laboratory data to the
conservative level required for decision-making, in light
of the variability in laboratory data and the large
uncertainty associated with the predictive models?
Henry Lee:
I will give you a different perspective. We are
working now to determine ecosystem responses and cu-
mulative effects, The variability is even greater for this
work than for the data you saw here. • I think you have to
go to a risk aversion philosophy or a more environmentally
protective approach. We cannot accurately predict a dose
response, a stressor response, but we know it is bad to lose
prey in a system or to lose a wetland. The direction we are
going to have to go is to a risk aversion strategy. That is
where comparative risk factors in, so we can determine how
important one risk is versus another. Even if we cannot be
quantitative, we can at least rank the risks.
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Proceedings
1-53
Q (Eric Rifkin, Rifkin & Associates): A number of the
panelists today referenced BSAFs, biota-sediment
accumulation factors, and how they varied based on
whether or not you were using lipid-normalized organ-
. isms and carbon-normalized sediment. Could the panel-
ists comment on whether BSAFs can be used in a generic
context or whether they need to be used in a site-specific
context? I would also be interested in hearing how they
can be used in developing sediment quality criteria
in general. -
Henry Lee:
It comes down to how well you need to know
the answer. I agree with Peter that we can predict
bioaccumulation within an order of magnitude. If that is
good enough for the neutral organics, then you are home
free. If you need a better answer, then you have
a problem. The better the answer you need, the more
expensive and more site-specific it gets. But I
am' comfortable working within the order of
magnitude range.
Q (Lynn McCarty, L.S. McCarty Scientific Research and
Consulting): I would like ta raise a question related to an
earlier question. The question is about sensitivity. I am
always concerned that we do not really define what
sensitivity is. Are we referring to sensitivity defined
according to exposure-based tests or, since we have been
discussing tissues residues, are we referring to sensitivity
on a residue basis or received dose effect? In fact, as I will
show this afternoon, you can consider these things for the
same set of data and come to quite different conclusions.
Most of the differences in sensitivity that I have seen in the
literature can be readily'* expected and predicted from
differences in modifying factors such as the size of the
organism, the metabolic activity, and temperature. Until
we clearly define what sensitivity means, we should not be
making comparisons about which animals are more sen-
sitive than others. In sediment testing, as we have seen
from some of the discussions this morning, the variability
that results from the differences in media and conditions
•of those media dramatically affects the accumulation
rates and amounts of accumulation. Therefore, sensitivity
is a confusing factor that needs to be clearly identified
' before we make some final pronouncements about it.
Peter Landrum:
I think if you go back and look at the toxicological
literature, sensitivity had to do with differences between
species. Sensitivities were usually determined, at least in
the mammalian literature, with a defined dose approach.
A known dose of something was given to two different
species by the same route. There is no doubt that the route
of exposure is going to alter the response that you expect,
particularly for sediment where there are a lot of con-
founding factors that can influence the dose received.
You can take one animal and move it from sediment to
sediment with the same compound and get a change in
response, because factors change that influence the
bioavailability and, therefore, the received dose. If we are
going to talk about sensitivity between organisms,
we need to talk about the sensitivity based on the
received dose.
Henry Lee:
I would like to add a comment on sensitivity. When
Chris arid I talk about sensitivity, we are referring to a
value that is empirically derived. That was the basis for
the sensitivity Chris snowed in his diagram during his
talk. In determining the sensitivity of potential test
animals, we need to find animals that will survive for 28
days or however long it takes to reach steady state.
Q (Tom O'Connor, NOAA, National Ocean Service):
Two of you have agreed with each other that the predic-
tions based on equilibriumpartitioning are good to within
one order of magnitude. How would you assess the
imprecision of extending the equilibrium partitioning
methodology to body burdens in fishes?
Henry Lee:
In general, the imprecision is greater. We derived
BSAFs for two fish that have limited home ranges in our
DDT Superfund study. These BSAFs turned out to be
relatively close to the values we derived for Macoma and
other benthic organisms. However, these values are more
variable for fish like flatfish that have extensive home
ranges. But I think we can at least determine a maximum
value for demersal fishes.
Q (Tom O'Connor): So the imprecision is in the range of
the fish, not in the equilibrium between a given sediment
and a fish? .
Peter Landrum:
•-' I think you have to consider the routes of exposure
as well. If you have a pelagic fish and it is not feedi'ng on
things that are well connected with the sediment, then it is
inappropriate to try to make a connection between the
sediment and that fish. Whereas if you have an organism
like a flatfish that is feeding on benthic organisms, it might
be easier to make the connection. But you still have
additional routes of exposure that you need
to consider. •
Q (Tom O'Connor): Yes, but equilibrium does not matter
for this. .
Peter Landrum:
But that is assuming the process is passive. All the
models I talked about imply a passive process. When we
look at fish in particular, we may no longer be considering
a passive process as the sole driving force. So, the
thermodynamics that you are trying to consider in terms of
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National Sediment Bioaccumulation Conference
sediment to the fish are no longer applicable. If feeding
is taking place and the benthic organism is in equilibrium
with the sediment, we could make the assumption that
there is a connection between fish and sediment. But if
feeding and digestion are taking place, they are active
processes that may change the thermodynamics that apply
to a particular fish.
Q (Tom O'Connor): So, the answer to my original question
is that you cannot apply equilibrium at all to extrapolate
the fish.
Peter Landrum:
Not unless they are eating the sediment.
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National Sediment Bioaccumulation Conference
Session Twos
Interpretation and Applications of
Bioaccumulation Results
Richard Pruell, Panel Moderator
U.S. EPA, Office of Research and Development,
Narragansett, Rhode Island
Norman I. Rubinstein
U.S. EPA, Office of Research and Development,
Narragansett, Rhode Island
Reference Sediment Approach for Determining
Sediment Contamination "
David R. Mount
U.S. EPA, Mid-Continent Ecology Division, .
Duluth, Minnesota
Development of Tissue Residue Threshold Values
L. Jay Field
NOAA, National Ocean Service,
Seattle, Washington
Use of Tissue Residue Data in Exposure and Effects
Assessments for Aquatic Organisms
Lynn S. McCarry
L.S. McCarty Scientific Research and Consulting,
Oakville, Ontario, Canada
Comments on the Significance and Use of Tissue
Residues in Sediment Toxicology and Risk Assessment
Burt K. Shephard
URSGreiner, Inc.,
Seattle, Washington
Quantification of Ecological Risks to Aquatic Biota
from Bioaccumulated Chemicals . .
2-1
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National Sediment Bioaccumulation Conference
Reference Sediment Approach for
Determining Sediment Contamination
Norman I. Rubinstein
U.S. Environmental Protection Agency, Office of Research and Development
Atlantic Ecology Division, Narragansett, Rhode Island
One of the more contentious and highly publicized
regulatory programs.capturing headlines today
is the dredging and dredged material disposal
program, which is jointly administered by the US. Army
Corps of Engineers (USACE), the U.S. Environmental
Protection Agency (EPA) and, in inland waters, therespec-
,tive state and local authorities. Within this regulatory
program, one of the more controversial issues is the iden-
tification and use of reference sediments to facilitate the
permitting process for dredged material disposal.
The application of a reference sediment approach to
identify sediment contamination in dredged materials was
developed more than twenty years ago for the ocean
dumping program. In this discussion, which reflects my
personal views and should not be construed as Agency
policy, I will review the statutory basis for the dredged
material program, the rationale used to develop this refer-
ence-based regulatory approach, and the operational defi-
nition of reference sediment as described in the current
testing manual. I will also identify how the reference
approach is applied today, how it can be improved, and
what future research is needed to support the program.
Program Statutes
Section 103 of the Marine Protection, Research, and
Sanctuaries Act (MPRSA) stipulates that all operations
involving the transportation and dumping of dredged
material into ocean waters must be evaluated to determine
the potential environmental impacts of these activities. Simi-
lar legislation in Section ,404 of the Glean Water Act
(CWA) addresses dredging and disposal operations in
inland waters. There is a pending rule change that will
make program operations and use of reference sediments
consistent for both ocean and inland waters. This discus-
sion, however, will focus on the existing requirements in
the ocean dumping regulations.
The Green Book
The testing manual for Section 103 of the MPRSA
is commonly referred to as the Green Book(USEPA/
USAGE, 1991). It was first developed in 1977 and later
revised in 1991 by a joint USEPA/USACE technical
committee. The Green Book provides specific guidance
for conducting the evaluative protocols used to assess the
suitability of dredged materials for open water disposal. It
also defines testmaterials, reference sediments, and control
treatments, and specifies details on test methodologies
and provides guidance for the interpretation of data gen-
erated by these tests. Much of the remaining discussion
will be based on material from Ibis manual.
Reference Sediment Approach
In 1976 the ocean disposal regulatory program
adopted the reference sediment comparison approach
because at that time it was considered the most direct and
pragmatic way to satisfy the requirements of the MPRSA.
The statutory language of the MPRSA prohibits dumping
of dredged materials containing certain constituents as
other than trace contaminants unless they are "rapidly
rendered harmless." This regulatory language comes
directly from the London Convention which represents
international agreements on ocean disposal activities.
The reference comparison approach provides a mecha-
nism that allows regulators to make decisions, that take
into account existing background or baseline conditions
in tile vicinity of the disposal site as defined by the specific
test endpoints selected. The rationale as originally ap-
plied viewed dredging and disposal activities not as
remediation activities aimed specifically at improving
existing condition, but as activities that at a minimum
must be conducted in a manner that would not further
degrade environmental conditions at the disposal site.
Evaluation of benthic impacts for the dredged ma-
terial program employs sediment toxicity tests and
bioaccumulation tests (Green Book). The benthic sediment
toxicity tests consist of 10-day whole sediment exposures
conducted with appropriately sensitive species and fo-
cuses on mortality as the test endpoint. The standard
bioaccumulation test involves a 28-day exposure with
tissue residue contaminant levels in selected biota as the
test endpoint.
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National Sediment Bioaccumulation Conference
The reference sediment is the key to making regu-
latory decisions concerning dredged material disposal
(Figure 1). Results from benthic toxicity and
bioaccumulation tests using representative biota and ref-
erence sediments are compared to results from tests using
dredged sediments (test material). These comparisons
serve as the basis for determining the potential for adverse
ecological impacts resulting from dredged material dis-
posal at the environs of the disposal site.
Initiating the Dredging Process
The dredging process begins with identifying the
need for dredging a navigation channel. The decision on
whether or not to dredge is based primarily on economic
and societal issues. Navigation channels must be main-
tained to support marine transportation, which is the
primary mode for global tirade, currently estimated at
about three trillion dollars annually. The management of
dredged material, however, is an environmental issue that
is further defined by applying the federal standard which
stipulates that disposal occur according to the least cost
option that is en vironmentally appropriate. Once the need
to dredge is determined, a disposal site is identified
(USEPA, 1990).
The next step in the process is to identify and collect
appropriate reference sediment. There are two approaches
for identifying the reference material. One approach is to
physically locate a reference site, define its location and
boundaries, and collect sediments from the site. The other
approach, referred to as the reference area approach,
involves collecting sediment samples using a grid overlay
which provides a composite of sediments representative
of the disposal site. The reference material represents the
existing benthic environmental conditions in the vicinity
of the disposal site. The reference material must satisfy
the definition in the Green Book, particularly with respect
to three critical requirements (Figure 2). Reference sedi-
ment should be: (1) substantially free of contaminants;
(2) as similar as possible to the grain size of the sediment
in the dredged materials and at the disposal site; and
(3) reflective of conditions that would exist at the disposal
site if no dredged material disposal had taken place and
that represent all other influences on sediments in the area.
The test material (dredged material) is then collected in
a manner representative of the sediments from the reach
and depth of the project area to be dredged. Finally a
control sediment is identified which is free of contami-
nants and known to satisfy the physical requirements (i.e.
grain size) of the test organism. This material serves as the
laboratory control treatment.
Program Testing
As stated above, testing consists of conducting
benthic toxicity and bioaccumulation tests on the refer-
ence material and the test dredged material with appropri-
ate laboratory controls and comparing the results of each
test. Interpretation of the benthic toxicity test data is fairly
straightforward. Dredged material is predicted to be
acutely toxic to benthic organisms when mean test organ-
ism mortality is statistically greater than the reference
sediment and exceeds mortality in the reference sediment
by at least 10 percent. Statistical differences between test
and reference treatments can be greater than 10 percent
depending on the inherent variability measured in specific
test species (e.g., a 20 percent value for mortality can be
used for amphipods).
Interpretation of the benthic bioaccumulation test
results is more complicated. Comparisons between the
test material and the reference treatments do not provide
pass/fail criteria, but rather serve as a screen for a more
comprehensive analysis. Results are compared initially to
determine whether there are statistically significant dif-
ferences in contaminant residue levels between the test
treatments and the reference treatment. This comparison
indicates that contaminants are present in greater than
trace quantities with the potential for bioaccumulation
and possible trophic transfer. A more comprehensive
analysis involves comparisons of tissue residue levels to
FDA action levels and consideration of the lexicological
properties of the contaminants of concern. If tissue
concentrations of one or more contaminants of concern
are statistically greater than the FDA action levels, then
the test dredged material is predicted to result in benthic
bioaccumulation of contaminants. If tissue concentra-
tions are either statistically less than FDA action levels or
there are no FDA action levels for the contaminants of
concern, the information is considered insufficient .to
reach a conclusion about the potentialfor bioaccumulation.
In these cases further evaluation, including assessment of
additional factors such as the magnitude of
bioaccumulation relative to biota indigenous to the ,dis-
posal site, may be necessary to address the potential for
biomagnificationandtrophictransferandassociatedhealth
risks.
The test endpoints (percent mortality and level of'
contaminant bioaccumulation), as measured in laboratory
tests with reference sediment, serve as de facto standards
in making regulatory decisions regarding the disposal of
dredged material. Obviously, the selection of appropriate
reference sediment is of paramount importance if the
goals of environmental protection are to be realized.
Reference Site Selection
Current practice in selecting a reference site inevi-
tably requires some degree of compromise to meet the
somewhat ambiguous requirements of a reference mate-
rial (i.e., "substantially free" of contaminants, yet "as
similar as possible" to the dredged material and disposal
site sediments,-and reflective of conditions "had no dis-
posal occurred"). In some areas of the country, groups
responsible for dredging and dredged material manage-
ment are exploring ways to insure consistency and suit-
ability of reference materials selected for dredged material
evaluation. This is a function, in part, of the open process
employed by the USAGE and USEPA to solicit and
promote involvement of the states, the local communities,
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Proceedings
2-5
and stakeholders in establishing what they believe
represents environmentally appropriate and acceptable
reference material for their localities.
A review of data generated by benthic toxicity and
bioaccumulation tests in reference sediments from major
dredging projects in New York, Boston, San Francisco,
and Puget Sound (personal communication with regional
ocean disposal coordinators) indicate that the reference
sediments employed in these areas reasonably reflect
baseline conditions characteristic of minimally impacted
environments Amphipod survival in the 10-day acute
toxicity tests averaged around 90 percent in the first three
areas (Figure 3). Survival was slightly lower in Puget
Sound where a more regionally integrated approach is
applied. Tissue residue data from bioaccumulation tests
conducted on reference material in all four areas using the
polychaete Nereis yirens and the clamMacoma nasuta for
polychlorinated biphenyls (PCBs), cadmium, and mer-
cury are shown in Figure-4. PCB tissue concentrations
measured 20 to 30 ppb, and mercury and cadmium tissue
concentrations measured less than 0.05 ppm on a wet
weight basis. These concentrations also approximate
current background levels typically measured in mini-
mally impacted aquatic systems (USEPA, 1997). These
data support the contention that selection of reference
sediments in these major U.S. ports are serving their
intended purpose of providing appropriate levels of envi-
ronmental protection for the dredged material disposal
program. However, given the subjectivity inherent in the
reference sediment selection process, I believe establish-
ment of national criteria for identification of appropriate
reference material would further promote greater consis-
tency in regulatory decision making, and perhaps en-
hance the margin of environmental protection provided
by. the current regulatory protocol.
Future Needs , •
, ' ?
Criteria which defrne the minimum requirements for
reference material selection that will maintain environ-
mental integrity and sustainability at the environs of the
disposal site should be developed as additional guidance
for the dredged material evaluation process. An example
of where this is already happening is Puget Sound where
regulators have developed an extensive database that
accurately represents background conditions. This data-
base provides the basis for selecting reference materials
andestablisbing statistically basedcriteriausedfor dredged
material evaluation. Although development of such data-
bases is expensive and time consuming, this approach
could serve as a model for insuring appropriate reference
'standards are employed for dredged material evaluation.
Additional research needs include improving our
ability to predict community, population and ecosystem
level impacts from existing effects test endpoints (i.e.,
acute toxicity), and development of tissue residue-effects
linkages for contaminants of concern (Figure 5). What
does a whole-body residue concentration mean in terms
of the health of the organism, its ability to reproduce, and
the propensity for a contaminant to biomagnify? Suffi-
cient data to answer these questions currently do not
exist. Predictive models that elucidate residue effects
linkages along with the data to validate these modeling
efforts should be developed. Efforts to develop tissue
residue databases must also continue to ensure effective
interpretation of bioaccumulation data.
References
USEPA. 1990. Site designation, monitoring, and
management guidance for ocean disposal of
dredged material (working draft). U.S. Environ-
mental Protection Agency, Office of Water Regula-
tions and Standards, Washington, DG.
USEPA. 1997. The incidence and severity of sediment
contamination in surface waters of the United
States, Volume 1: National sediment quality sur-
vey. EPA 823-R-97-006. U.S. Environmental Pro-
tection Agency, Office of Science and Technology,
Washington, DC.
USEPA/USACE. 1991. Evaluation of dredged material
proposed for ocean disposal—Testing manual.
EPA-503/8-91/001. U.S. Environmental Protection
Agency, Office of Marine and Estuarine Protection,
Washington, DC.
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National Sediment Bioaccumulation Conference
Figure 1.
How is the reference sediment
approach used to make decisions?
Potential adverse impacts are determined
on the basis of comparison of test endpoints
(benthic toxicity and bioaccumulation)
between test and reference treatments
Figure 2.
Reference Sediment: Definition
^ Substantially free of contaminants
• As similar as possible to the grain size of the
dredged material and sediment at the disposal
site
> Reflects conditions at the disposal site that
would exist had no dredged material disposal
taken place; reflects all other influence on
sediments in the area
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Proceedings
2-7
Figure 3*
Amphipod Survival in Reference
Sediments from Major U.S. Ports
Figure 4.
Bioaccumulation in Reference Sediment
; (mg/kg wet wt.)
0.05
PS
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National Sediment Bioaccumulation Conference
Figure 5.
Reference Approach
Suggested Improvements
Establish minimum criteria for reference site
selection that insures environmental integrity
and sustainability are preserved (i.e., background
database approach used in Puget Sound)
Develop extrapolation models for single
species toxicity endpoints that provide
meaningful ecological interpretation at the
community and population levels
Elucidate residue-effects relationships to
provide meaningful interpretation of
bioaccumulation data.
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National Sediment Bioaccumulation Conference
Development of Tissue Residue
Threshold Values
Alfred W. Jarvinen, David R. Mount, and Gerald T. Ankley,
U.S. Environmental Protection Agency, Mid-Continent Ecology Division, Duluth, Minnesota
Background
chemical residue-based, approach for evaluating
dose, also called critical body residue (CBR) or
Llethal body burden (LBB), has been advocated as
an improvement for prediction of toxicity to organisms in
the environment (Friant and Henry, 1985; McCarty, 1986;
Cook et al., 1987; Van Hoogen and Opperhuizen, 1988;
Cook et al., 1991; McCarty, 1991; McCarty et al., 1991;
Tas et al., 1991; Landrum etal., 1992; andMcCarty and
MacKay, 1993). The correlation of body residues to toxic
effects (residue-based dose) has a number of advantages
over using an exposure-based 'approach (i.e., water or
food concentrations that cause toxic effects). As outlined
by McCarty and MacKay (1993), these advantages include
the following: (1) bioavailability is explicitly considered;
(2) accumulation kinetics are considered, which reduces the
confounding effect of exposure duration when interpreting
results; (3) uptake from food (as distinct from water) is
explicitly considered; (4) toxic potencies are expressed in
a less ambiguous manner, facilitating identification and
investigation of different modes of toxic action; (5) effects
of metabolism on accumulation are considered; (6) mix-
ture toxicity can be more readily assessed; and (7) experi-
mental verification can be more readily determined be-
tween laboratory and field.
Bioaccumulation testing is being used increasingly
in various environmental monitoring and regulatory pro-
grams involving sediments, m these tests, sediment
organisms are exposed to sediment samples for a pre-
scribed time period (e.g., 28 days). Following this uptake
period, exposed organisms are analyzed for chemicals of
interest. While these tests are one mechanism for assess-
ing the bioavailability and accumulation of sediment
contaminants, they do not intrinsically predict the toxico-
logical effects of bioaccumulative toxicants. For this
prediction, some association between tissue residues and
lexicological effects must be developed. Thus, bioaccu-
mulation tests are a natural application for residue-based
effects assessment. • .
To help evaluate the basis for, and applicability of,
residue-based effects assessment, we have undertaken the
development of a comprehensive database containing
literature data on tissue concentrations of toxicants and
associated biological effects for aquatic animals. The
purpose of this presentation is to describe the database and
provide some examples of analyses that can be conducted
from these data.
Database Content and Development
Pertinent literature was identified through several
search mechanisms, including electronic databases (e.g.,
POLTOX I®; Cambridge Scientific Abstracts),' in-house
literature files, Current Contents®, and other assorted
sources. For all literature, hard copies of the primary
literature were obtained and are maintained in the project
files. ' ..••'•
From this literature, residue/effect information was
manually extracted. General inclusion criteria were:
• Organism was a marine or freshwater fish, inver-
tebrate, or aquatic lifestage of amphibian (terres-
trial, animals, birds, and plants were not included);
• There was a measured chemical concentration in
the whole body or in a specific tissue; and
• There was some observation of biological effect in
the form of survival, growth, or reproduction
(physiological and biochemical endpoints were
. not considered).
In general, only data from exposures using a single
chemical were used; information from mixture studies
was not used unless the mixture contained only related
chemicals (same, mode of action). Control treatments
were required as a basis for comparison of biological
effect, except in studies where survival was >90 percent
(thus-survival was not reduced). All chemical types (e.g.,
organic and inorganic, ionic and nonionic) were
included.
For references meeting these criteria, specific
information was extracted for inclusion in the database.
Database fields are as follows: ". \
• Study Type:, acute or chronic ^
• Chemical Name: exact chemical form (e.g.,
metal salt) is included parenthetically
• CAS Number
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National Sediment Bioaccumulation Conference
* 1*8 K*.
• Molecular Weight
• Species
• Life Stage: life stage exposed, or range if multiple
life stages were exposed
• Lab/Field: whether exposures were conducted in
the laboratory or in the field
• Test Conditions: static, static-renewal, flow-
through, microcosm, mesocosm, etc.
• Exposure Route: water, sediment, diet, injection,
maternal
• Exposure Concentration: measured if given,
otherwise nominal
• Test Duration: in days
• Tissue Analyzed: whole body, soft parts, blood,
carcass, organ(s)
• Tissue Residue: in ug/g wwt and umol/wwt
• Biological Response: survival, growth, or repro-
duction; no effect observations included
• Reference: literature source
• Comments: flags on unusual conditions (e.g.,
control performance problems, discrepancies in
the data, etc.)
As of September 1996, the database contained resi-
due data from more than 480 literature sources, spanning
237 chemicals, and resulting in approximately 3,000 indi-
vidual residue/effect pairs. Chemicals with the greatest
number of residue/effect pairs at this time are:
• More than 400 residue/effect pairs
cadmium
• 100 to 250 residue/effect pairs
DDT, TCDD, hexachlorobenzene, mercury,
PCB(s), selenium
• 40 to 100 residue/effect pairs
aminocarb, arsenic, copper, 2,4 dinitrophenol, en-
dosulfan, endrin, fenvalerate, kepone, lead, Un-
done, nickel, 4-nitrophenol, pentachlorophenol,
terbufos, toxaphene, tributyltin, zinc
these chemicals were for whole-body analyses, the expo-
sure regimes varied widely with regard to species, lab
versus field, and route of exposure, among other vari-
ables. Regardless of these differences, these values do
suggest a range of chemical residues associated with
biological effects, with the threshold for reported effects
in the vicinity of 1 ug/g wwt for both chemicals.
Once data entry, accuracy checking, and initial
analysis are complete, it is our intention to make this
database available to the scientific community for further
analysis.
References
Buckler, D.R., A. Witt, F.L. Mayer, and IN. Huckins.
1981. Acute and chronic effects of Kepone and
Mirex on the fathead minnow. Trans. Am. Fish.
Soc. 110:270-280.
Cook, P.M., A.R. Carlson, and H. Lee. 1987. Tissue
residue approach. Sediment classification methods
compendium, Chapter 7. EPA 823-R-92-006.
Cook, P.M., M.K. Walker, D. W. Kuehl, and R.E. Peterson.
1991. Bioaccumulation and toxicity of 2,3,7,8-
tetrachlorodibenzo-p-dioxhiandrelated compounds
in aquatic ecosystems. In Banbury report 35:
Biological basis for risk assessment ofdioxins and
related compounds. Cold Spring Harbor Labora-
tory Press, Plainview, NY, pp. 143-167.
Fisher, D.R., M.E. Bender, and M.H. Roberts. 1983.
• Effects of ingestipn of Kepone-contaminated food
by juvenile blue crabs. Aquat. Toxicol.
4:219-234.
Fisher, D.R., J.R. Clark, M.H. Roberts, J.P. Connolly, and
L.H. Mueller. 1986. Bioaccumulation of Kepone by
spot: Importance of dietary accumulation and in-
gestionrate. Aquat. Toxicol. 9:161-178.
Example Data Sets
Compilation and analysis of the
data are ongoing at this time. However,
as an example of data analyses than can
be performed using the database, we ex-
tracted data for chlorpyrifos (Jarvinen et
al., 1983; Macek et al., 1972; Serrano et
al., 1995; Hansen et al., 1986; Montanes
et al., 1995) and kepone (Buckler et al.,
1981;Hansenetal., 1977a, 1977b; Fisher
and Clark, 1990; Sanders et al., 1981;
Stehlik and Merriner, 1983; Fisher et al.,
1983; Fisher etal., 1986; Goodman etal.,
1982).
Figures 1 and 2 display the resi-
due/effect pairs for chlorpyrifos and
kepone, segregated by biological end-
point (survival, growth, or reproduc-
tion). Although all residues reported for
Chlorpyi
10,000
1,000
In
§» 100
to
| 10
1
1 1
o
0.1
0.01
-ifos Residues Versus Biological Responses
*
S3
* '
»
if ' •'
# m
m m • •
m , *
H
NO Effect/Effect No Effect/Effect No Effect/Effect
Survival Growth Reproduction
Figure 1. No effect (squares) and effect (diamonds) concentrations
for chlorpyrifos in tissues.
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Proceedings
Kepo
50
20
^ 10
ro 5
• 3^
S 2
o
a ,.
0.5
0.2
ne Residues Versus Biological Responses
" * ' ' '•'•".
" - « * '• •" *
• ' . ! *
* * H
s m ^
1 , » .
* "
No Effect/Effect No Effect/Effect No Effect/Effect
Survival Growth Reproduction
Figure 2. No effect (squares) and effect (diamonds) concentrations
for kepone in tissues.
Fisher, D.R., and J.R. Clark. 1990. Bioaccumulation of
Kepone by grass shrimp: Importance of dietary
accumulation and food ration. Aquat. Toxicol.
17:167-186.
Friant, S.L., and L. Henry. 1985. Relationship between
toxicity of certain organic compounds and their
concentrations in tissues of aquatic organisms: A
perspective. Chemosphere 14:1897-1907.
Goodman, L.R., D.J. Hansen, C.S. Manning, and L.F.
Faas. 1982. Effects of Kepone on the sheepshead
minnow in an entire life-cycle toxicity test. Arch.
Environ. Contain. Toxicol. 11:335-342.
Hansen, D.J., L.R. Goodman, and AJ. Wilson. 1977a.
Kepone: chronic effects on embryo, fry, juvenile,
and adult sheepshead minnows. Chesapeake Sci,
18:227-232.
.Hansen, D.J., D.R. Nimmo, S.C. Schimmel, G.E. Walsh,
and A.J. Wilson. 1977b: Effects of Kepone on
estuarine organisms, pp. 20-29. In R.A. Tubb, ed.
Recent advances in fish toxicology. EPA/600/3-77/
085. U.S. Environmental Protection Agency,
Corvallis, OR.
Hansen, D.J., Goodman, L.R., G.M. Gripe, and S.F.
' McCauley. 1986. Early life-stage toxicity test
methods for gulf toadfish and results using
chlorpyrifos. Ecotoxicol. Environ. Saf. 11:15-22.
Jarvinen, A.W., B.R. Nordling, and M.E. Henry. 1983.
Chronic toxicity of Dursban to the fathead minnow
and the resultant acetylcholinesterase inhibition.
Ecotoxicol. Environ. Saf. 7:423-434.
Landrum, P.F., H. Lee, and M.J. Lydy.
1992. Toxicokinetics in aquatic
systems: Model comparisons and
use in hazard assessment.
Environ. Toxicol. Chem.
11:1709-1725.
Macek, K.J., D.R. Walsh, J.W. Hogan,
and D.D. Holz. 1972. Toxicity
of the insecticide Dursban to fish
and aquatic invertebrates in
ponds. Trans. Am. Fish. Soc.
101:420-427.
McCarty, L.S. 1986. The relationship
between aquatic toxicity
QSARs and bioconcentration
for some organic chemicals.
Environ. Toxicol. Chem.
, 5:1071-1080.
McCarty, L.S. 1991. Toxicant body
residues: Implications for aquatic
bioassays with some organic
chemicals. Aquat. Toxicol.
14:183-192.
McCarty, L.S., D. Mackay, A.D. Smith, G.W. Ozburn,
andD.G. Dixon. 1991. Interpreting aquatic toxic-
ity QSARs: the significance of toxicant body resi-
dues at the pharmacologic endpoint. Sci. Total
Environ. 109/110:515-525.
McCarty, L.S., and D. Mackay. 1993. Enhancing
ecotoxicological modeling and assessment.
Environ. Sci. Tech. 27:1719-1728. .
Montanes, J.F.C., B. Van Hattum, and J. Deneer. 1995.
Bioconcentration of chlorpyrifos by the freshwater
isopod Asellus dquaticus .in outdoor experimental
ditches. Environ. Pollut. 88:137-146.
Sanders, H.O., J. Huckins, B.T. Johnson, and D. Skaar.
1981. Biological effects of Kepone and Mirex in
freshwater invertebrates. Arch. Environ. Contam.
Toxicol. 10:531-539.
Serrano, R., F. Hernandez, J.B. Pena, V. Dosda, and J.
Canales. 1995. Toxicity and bioconcentration of
selected organophosphorus pesticides in Mytilus
galloprovincialisand Venus gallina. Arch. Environ.
Contam. Toxicol. 29:284-290.
Stehlik, L.L., and J.V. Merriner. 1983. Effects of accu-
mulated dietary Kepone on spot. Aquatic Toxicol.
15:53-62.
Tas,J.W.,W.Seinen,andA.Opperhuizen. 1991. Lethal
body burden of triphenyltin chloride hi fish: Pre-
liminaryresults. Comp. Biochem. Physiol. 100C:59-
60.
VanHoogen, G. and A. Opperhuizen. 1988. Toxicokinetics
ofchlorobenzenesinfish. Environ. Toxicol. Chem.
7:213-219. ;
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2-12
National Sediment Bioaccumulation Conference
Development of Tissue
Residue Threshold
Values
Alfred W. Jarvinen, David R. Mount, and
Gerald T. Ankley
USEPA
Office of Research and Development
Midcontinent Ecology Division
Duluth, MN
Impetus for Research
Need for interpretive guidance for
bioaccumulation testing
Desire for decision criteria that are based on
biological effects
-------
Proceedings
Z-13
Impetus for Research
Proposal that risk assessment be based on
tissue residues rather than concentrations in
environmental matrices
Assemble data necessary to evaluate a
tissue residue approach
Evaluate tissue residue approach relative to
mode of action or other characteristics
Tissue Residue/Toxicity Database
• Exhaustive search of literature for residue
data linked to biological effect observations
• Selection criteria designed to maximize
quality, comparability, and interpretability of
resulting data
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2-14
National Sediment Bioaccumulation Conference
Scope of Data Collection
marine and freshwater, fish and invertebrates
- does not include amphibians, terrestrial
vertebrates or birds
endpoints focused on survival, growth, and
reproduction
- histological/biochemical/physiological
endpoints not included
virtually all chemicals included, regardless of
mode of action
Database Fields
Acute/chronic
Chemical name
CAS number
Log Kow
Molecular weight
Species
Life stage
Lab/field
Test conditions
Exposure route
Exposure concentration
Test duration
Tissue analyzed
Residue
Effect
Reference
Comments
-------
Proceedings
2-15
Criteria for Data Inclusion
Measured tissue residue (whole body or
specific tissue)
Effect data or statement concerning the
health of the test organisms
Mixture papers used only if no effect was
observed
Control not necessary if no mortality was
observed
Database Content
Currently, the database contains
approximately:
-485 references
- 200 chemicals
- 2,552 residue/effect pairs
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2-16
National Sediment Bioaccumulation Conference
Largest Datasets
More than 400
- cadmium
100-250
- DDT
- TCDD
- hexachlorobenzene
- mercury
- PCB(s)
- selenium
• 40 to 100
- aminocarb
- arsenic
- copper
- 2,4 dinitrophenol
- endosulfan
- endrin
- fenvalerate
- kepone
- lead
- lindane
- nickel
- 4-nitrophenol
- pentachlorophenol
- terbofbs
-toxaphene
- tributyltin
- zinc
Kepone Data
32 residue/effect pairs
- 8 references
- 6 species (3 fish, 3 invertebrate)
- lab exposures only
- water, diet, parental exposures
- exposures 4 to 141 days
-------
:edings
2-17
Chldrpyrifos Data
Species (n)
Fathead minnow (6)
Bluegill (2)
Largemouth Bass (2)
Mussel (Mytilus) (2)
Mussel (Venus) (1)
Gulftoadfish(4)
Isopod (Asellus) (3)
Age
Larva
Juvenile
Juvenile
Adult
Adult
ELS
Adult
Days
Lab 200
Field 63
Field 63
Lab 4
Lab 4
Lab 49
Field 23
S/G/R
S,G,R
S
S
S
S
S,G
S,G
Source
Jarvinen etal. 1983
Macek etal. 1972
Macek etal. 1972
Serrano etal. 1995
Serrano etal. 1995
Hansenetal. 1986
Montanes & Hattum
1995
Chlorpyr
10,000
1,000
"§> 100
(0
1 10
I 1
0.1
0.01
ifos Residues Versus Biological Responses
V ; ' • '
m • ' [
S ' ' -
A ' • ' • ' ' .
f w
- ' • -
No Effect/Effect No Effect/Effect No Effect/Effect
Survival Growth Reproduction
;
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2-18
National Sediment Bioaccumulation Confe
Kepc
50
20
-. 10
D) 5
3^
¥ 2
o
0.5
0.2
0.1
me Residues Versus Biological Responses
*
m *
i !
m
~ m
1
m
m
No Effect/Effect
Survival
« I m
m ^
m .
m
m
No Effect/Effect No Effect/Effect
Growth Reproduction
u.
<
m
BAF versus Exposure Duration
Kepone (water exposures)
50,000
20,000
10,000
5,000
2,000
1,000
500
I
0 20 40 60 80 100 120 140 .160
Exposure Duration (days)
-------
Proceedings
1-19
BAF versus Exposure Duration
Chlorpyrifos (water exposures)
10,000
5,000 :
2,000
it 1,000
m 500
200
100
50
0
I
50 , 100 150 200
Exposure Duration (days)
250
Paired Effect/No Effect Data
Chlorpyrifos
Survival
Gulf toadfish
Mussel (Mytilus)
Fathead minnow
Isopod (Asellus)
Bluegill
Largemouth Bass
Growth
Fathead minnow
'Gulf toadfish
Reproduction
Fathead minnow
Effe,ct
770
53
5.11
1 ;79
3.82
2.55
3.03
0,95
0.95
No Effect
175
4
3.03
0.97
0.42
0.4Z
0.95
0.14
0.47
Geo. Mean
367
14.6
3.93
1.32
1.27
1.09
1.70
0.36
0.67
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2-20
National Sediment Bioaccumulation Conference
Paired Effect/No Effect Data
Kepone
Survival
Sheepshead minnow
Fathead minnow
Sheepshead minnow
Sheepshead minnow
Spot
Fathead minnow
Growth
Fathead minnow
Sheepshead minnow
Sheepshead minnow
Effect
11
3.8
2.3
2.5
2.7
1.7
3.8
2.2
0.41
No Effect
4.7
2.6
1.3
0.9
0.7
0.26
2.6
1.2
0.30
Geo. Mean
7.19
3.14
1.73
1.50
1.37
0.66
3.14
1.62
0.35
Interpretation Issues
Quantity and type of data varies greatly
between chemicals
Target tissue data not available consistently
Relatively few data for individual PAH
PCB mixtures vs. single congeners
-------
National Sediment Bioaccurnulation Conference
Use of Tissue Residue Data in
Exposure and Effects Assessments
for Aquatic Organisms
L Jay Field
National Oceanic and Atmospheric Administration, Hazardous Materials Response arid.
Assessment Division, Coastal Resources Coordination Branch, Seattle, Washington
Under the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA, or
Superfund),meNationalOceanicandAtmospheric
Administration (NOAA) is responsible for protecting and
restoring natural resources that may be injured by releases
fromSuperfund sites in coastal areas. As part of NOAA's,
role of providing EPA with technical support in the
evaluation of natural resource concerns at hazardous
waste sites, NOAA's Coastal Resources Coordination
Branch often recommends collecting tissue residue data.
Tissue residue data can play an important role at
different stages in the process of evaluating hazardous
waste sites, including ecological risk assessment, model-
ing conducted to evaluate different remedial alternatives,
and the monitoring necessary to determine the effective-
ness of remediation. An ecological risk assessment is a
major component of hazardous waste site evaluations..
For an ecological risk assessment to provide useful infor-
mation for remedy selection, exposure should be related
both to the source of contamination and to an important
toxicity endpoint. This means that it is necessary to link
any estimated or observed adverse effects to site-related
contamination, which enjphasizes the importance of iden-
tifying and quantifying major exposure pathways. Be-
cause bioaccumulation is often more of a concern for
higher-trophic level organisms, which may receive much
of their contaminant exposure via the food web, any effort
to develop bioaccumulation-based criteria should iden-
tify and address significant, sensitive toxicity endpoints in
fish and other higher-trophic level organisms. For ex-
ample, reproductive or early life stage toxicity in fish is
both a .sensitive toxicity endpoint and an endpoint with
potentially significant implications for the health of a fish
population.
The appropriate application of tissue residue data
depends upon the type of contaminant under consider-
ation. For some contaminants, tissue residue concentrations
may be directly linked to toxicity endpoints. Also, the
concentrations of contaminants in the tissues of aquatic
organisms often provide a direct measure of bioavailability
that integrates exposure overtime and integrates exposure
from water, sediment, and food web pathways. In this
presentation, I will be focusing primarily on the use of
field-collected tissue residue data in exposure and effects
assessments for aquatic ecological risk assessment. Be-
cause of the importance of bioaccumulation for higher-
trophic level organisms, I will focus my discussion on the
use of tissue residue data in assessing toxicity and expo-
sure in fish. Addressing these issues is particularly impor-
tant since currently available criteria for sediment explic-
itly exclude any consideration of contaminant exposure
through the food web. "These [sediment] criteria do not
address, the question of possible contamination of upper
trophic level organisms..." (USEPA, 1993a). And, "...a
site-specific investigation appears to be the only available
method for performing an evaluation of the effect'of
contaminated sediments on the body burdens of upper-
trophic level organisms" (USEPA, 1993b).
Aquatic risk assessment requires information on the.
bioavailable fraction of the contaminants, in the system.
Accurate and meaningful assessments of exposure from
water and sediment are difficult due to a potentially high
degree of temporal and/or spatial variability. Because of
high biocqncentration factors, particularly for hydropho-
bic organic contaminants, very low analytical detection
limits are required to ensure that concentrations below
analytical detection limit values could not contribute to
significant exposure concentrations. Determining the
bioavailable contaminant fraction is also complicated by
partitioning suspended particulates and dissolved organic
carbon. Modeling food web exposure in fish requires
making many assumptions for which there is frequently
little site-specific or reliable information available. Col-
lection of site-specific tissue residue concentrations can
be used to reduce some of this uncertainty in the applica-
tion of the exposure models used in the assessment. In
2-21
-------
2-22
National Sediment Bloaccumulation Conference
many cases, tissue residue data can be used to provide
time-integrated and location-specific information on bio-
available contaminant concentrations.
Metals
The bioaccumulation of metals in benthic
macroinvertebrates can provide a useful measure of the
extent and magnitude of contamination that temporally
integrates exposure via the water column and sediment.
Because benthic invertebrates represent an important
source of food for fish, the accumulation of metals in
invertebrates, which may have some tolerance to chronic
exposure to metals, may also serve as a significant source
of exposure to fish. Exposure via the food web may be
particularly important for fish early life stages, which are
also very sensitive to waterborne exposure to metals.
Thecombined effects ofreducedsurvival and growth
in fish early life history stages, which may have important
implications for adverse effects on the health of alocal fish
population, is one of the most sensitive toxicity endpoints
for waterborne exposure to a variety of metals (such as
cadmium, copper, lead, mercury, and zinc). Laboratory
studies on the effects of metals contamination on young of
the year fish La the Clark Fork River in Montana demon-
strated that feeding metals-contaminated invertebrates (at
concentrations comparable to those found in the river)
resulted in reduced growth and survival hi rainbow trout
(Woodward et al., 1994) and reduced growth and physi-
ological abnormalities hi rainbow trout and brown trout
(Woodwardetal., 1995).'These studies also Indicated that
the exposure via dietary intake could be at least as impor-
tant as aqueous exposure in age-0 fish. Another study,
however, found no effects on survival or growth in age-0
rainbow trout that were fed metals-contaminated brine
shrimp at similar concentrations (Mount et al., 1994).
Additional studies are needed to more clearly resolve the
relative importance of additional dietary exposure and to
develop a method for determining the total effective dose
that includes all exposure pathways.
In conducting arisk assessment for metals-contami-
nated sites, tissue residue concentrations in invertebrate
prey organisms may reduce the uncertainty in estimating
exposure via the water column and sediment (by integrat-
ing exposure over time at specific locations) as well as also
providing information on exposure via the food web. This
may be particularly important in assessments involving
vulnerable receptor populations (for example, the early
life history stages of threatened and endangered salmonid
populations).
Polycyclic Aromatic Hydrocarbons
(PAHs)
Because fish rapidly metabolize and excrete PAHs,
fish tissue residue concentrations of parent PAH
compounds do not provide a useful measure of exposure
to fish (Varanasi et al., 1989). However, exposure to
PAHs has been linked to reproductive impairment,
immune dysfunction, increased incidence of liver lesions,
and other histopathological endpoints hi fish (Malms et
al., 1987; Johnson et al., 1988; Varanasi et al., 1992).
High concentrations of PAHs in stomach contents offish
from a PAH-contaminated harbor indicate that the con-
sumption of contaminated benthic invertebrates can be an
important exposure pathway (Malms et al., 1985).
Measuring tissue concentrations hi invertebrates
that have minimal capacity for metabolism of PAHs, such
as bivalve shellfish, can provide location-specific and
temporally integrated information on bioavailable PAH
concentrations," which can be used hi food web models of
exposure to fish and other higher trophic level organisms.
Using tissue residue concentrations from caged bivalves
allows for more control of specific location and other
variables such as organism size or age. Other methods for
determining the relative differences hi PAH exposure
include measuring concentrations of PAH metabolites in
fish bile (Krahn et al., 1984, 1986), which can provide
useful information on recent exposure to PAHs, and semi-
permeable membrane devices (SPMDs), which provide
temporally integrated measurements of dissolved and
presumably bioavailable PAHs in the water column at
specific locations (Lebpetal., 1992;HuckhisetaL, 1996).
The patterns of PAH concentrations in field-collected or
caged bivalves and SPMDs can also play an importantrole
in linking exposure to the source of PAHs using various
fingerprinting methods.
Poly chlorinated Biphenyls (PCBs)
Fish tissue residue PCB concentrations, unlike
PAHs, can provide useful information on both exposure
and toxicity. Reproductive and early life stage effects
(e.g., reduced larval growth or survival), where the pri-
mary exposure to the developing larvae results from the
maternal transfer of accumulated PCBs to the eggs, is one
of the most sensitive toxicity endpoints for PCB effects in
fish. Consequently, PCB concentrations hi the ovaries of
mature female fish immediately prior to spawning may be
the most useful measurement for estimating potential
reproductive effects in species of concern. Higher-trophic
level species, which tend to accumulate the highest con-
centrations of PCBs, may be at the greatest risk.
Field-collected tissue residue PCB concentrations
hi fish can play an integral role hi exposure assessments,
since they provide a measure of exposure via all exposure
pathways. This is particularly important since fish gener-
ally receive much of their PCB exposure via the food web.
The composition of the PCBs found in environmental
samples often differs substantially from the original PCB
source (e.g., commercial Aroclor mixtures). This differ-
ence results from physicochemical and biological pro-
cesses that differentially affect individual PCB congeners
(Safe et al., 1987). For example, the solubility and
volatility of individual PCB congeners range over several
orders of magnitude and greatly affect partitioning be-
tween sediment-water and water-air interfaces. Thus, less
chlorinated congeners tend to be more soluble in water
and are more quickly removed from sediment into water.
-------
Proceedings
2-23
Biological processes also alter the pattern of congener
distributions in tissue residue samples. Differences in
uptake, depuration, metabolism, and efficiency of assimi-
lation among individual congeners may result in large
differences between the PCB mixtures in samples and in .
commercialAroclormixtures.andthesedifferenceswould •
be expected to increase with increasing trophic level.
Because of the major differences between the PCB
congener distributions in environmental samples and in
commercial mixtures, analysis methods based on Aroclor
standards can provide only a semi-quantitative estimate of
total PCBs (Safe etal., 1987). Modeling PCB behavior in
the environment, monitoring trends in .PCB concentra-
tions, and relating fish tissue PCB residues to their sources
can be considerably enhanced by congener-specific analy-
sis. 'Samples of several species of fish collected from
multiple locations over 170 miles of the Hudson River
were analyzed for PCB congeners as part of the ecological
risk assessment for a Superfund Remedial Investigation.
Samples of the same species at a given location had very
similar congener compositions, although their total PCB
concentrations sometimes varied by a factor of 2 or more
on either a wet weight or lipid-normalized basis, The PCB
congener compositions and concentrations in fish tissue
are being used in the ecological risk assessment to help
clarify the relationship between the PCB sources in the
river and the fish body burdens.
Two general screening approaches are available to
evaluate the potential toxicity of PCBs to fish based on
PCB body burdens:' comparison to total PCB concentra-
tions associated with adverse effects, or estimation of
dioxin toxic equivalent concentrations and comparison to
No Observable Adverse Effect Levels (NOAELs) for
2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD). A variety
of field and laboratory studies provide evidence of repro-
ductive and other adverse effects hi different fish species
at low total PCB tissue residue concentrations. The total
PCB concentrations in fish tissue residue samples associ-
ated with adverse effects range over several orders of
magnitude, which may reflect the differences in toxicity
among different PCB mixtures and/or a high degree of
inter-species difference in sensitivity to the effects of
PCBs. The combination of these factors results in consid-
erable uncertainty in estimating the risk of reproductive
toxicity to selected fish species based on total PCB tissue
residue concentrations.
The coplanar PCBs—a group of PCB congeners
that is similar in structure and biological "activity to the
highly toxic polychlorinated dioxins and dibenzofurans—
are considered to be the most toxic PCBs (Safe, 1984).
Although most of these coplanar PCBs are found at
relatively low concentrations hi the commercial PCB
mixtures, several have been identified as important com-
ponents of PCB tissue residues in aquatic biota and may
be preferentially accumulated, particularly by highef-
\ trophic level organisms (Safe, 1984; Hansen, 1987; Smith
etal., 1990; Schwartz etal., 1993). Recentstudies suggest
that only the non-or tho substituted PCB congeners exhibit
dioxin-lifce activity in fish (Walker and Peterson, 1991;
Newsted et al.,, 1995; Zabel et al.~, 1995). The early life
stage toxicity of these individual PCB congeners has been
investigated in .trout and compared to the toxicity of
dioxin to develop fish-specific toxic equivalent factors, or
TEFs (Walker and Peterson, 1991; Zabel et al., 1995).
The TEFs for the non-ortho congeners calculated for trout
are 1 to 2 orders of magnitude less than the TEFs deter-
mined for mammalian systems. Thus, using mammalian-
based TEFs for PCBs may overestimate the potential for
dioxin-like reproductive toxicity in fish.
Conclusions
Tissue residue data can play an important role in
aquatic ecological risk assessments at hazardous waste
sites, in part by linking exposure to the source of contami-
nation and to important toxicity endpoints.
The development of bioaccumulation-based criteria
should identify, .and address toxicity endpoints hi fish that are
both sensitive and ecologically significant This is particu-
larly important for higher-trophic level species, which may
receive much of their contaminant exposure via the food web.
For some contaminants, such as PAHs and possibly
metals, dose-response models that include all exposure
pathways need to be developed. Tissue residue concentra-
tions in macroinvertebrates may provide key input into
exposure models for these types of contaminants.
Tissue residue PCB concentrations in fish have
important applications to both exposure and toxicity as-
sessments. Because the PCB .congener distributions in
environmental samples often differ considerably from the
original commercial PCB mixtures, congener-specific
PCB analysis of fish tissue samples provides more useful
information on exposure than a standard Aroclor analysis.
PCB concentrations in the ovaries of .mature female fish
immediately prior to spawning may be the most useful
measurement for estimating potential reproductive toxic-
ity in fish species of concern.
References
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composition and toxicity of polychlorinated biphenyl
(PCB) residues. Rev. Environ. Toxicol. 3: 149-212.
Huckins, J.N., J.D. Petty, J.A. Lebo, C.E. Orazio, H.F.
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2-24
National Sediment Bioaccumulation Conference
Krahn, MM., L.D. Rhodes, M.S. Myers, L.K. Moore,
W.D. MacLeod, Jr., and D.C.Malins. 1986. Asso-
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USEPA. 1993a. Sediment quality criteria for the protec-
tion of benthic organisms: Fluoranthene. EPA-
822-R-93-012. U.S. Environmental Protection
Agency, Office of Water, Washington, DC.
USEPA. 1993b. Technical basis for deriving sediment
quality criteria for nonionic organic contaminants
for the protection of benthic organisms by using
equilibriumpartitioning.EPA.-&22-R-93-On. U.S.
Environmental Protection Agency, Office of Wa-
ter, Washington, DC.
Varanasi, U., I.E. Stein, and M. Nishimoto. 1989.
Biotransformation and disposition of polycyclic
aromatic hydrocarbons (PAHs) in fish. In U.
Varanasi, ed., Metabolism of polycyclic aromatic
hydrocarbons in the aquatic environment, CRC
Press, Boca Raton, FL, pp. 94-149.
Varanasi, U., I.E. Stein, L.L. Johnson, T.K. Collier, E.
Casillas, and M.S. Myers. 1992. Evaluation of
bioindicators of contaminant exposure and effects
in coastal ecosystems. In D.H. McKenzie, D.E.
Hyatt, and V.J. McDonald, eds., Ecological indicators,
Vol.1. Proceedings of an international symposium,
Fort Lauderdale, Florida, October 16-19, 1990.
Walker, M.K., and R.E. Peterson. 1991. Potencies of
polychlorinated dibenzo-p-dioxin, dibenzofuran,
and biphenyl congeners, relative to 2,3,7,8-
tetrachlorodibenzo-p-dioxinforproducing early life
stage mortality in rainbow trout (Oncorhynchus
mykiss). Aquatic Toxicol. 21: 219-238.
Woodward, D. F., W.G. Brumbaugh, A.J. DeLonay, E.E.
Little, and C.E. Smith. 1994. Effects on rainbow
trout fry of a metals-contaminated diet of benthic
invertebrates from the Clark Fork River, Montana.
Trans. Amer. Fish. Soc. 123: 51-62.
Woodward, D. F., A. M. Farag, H.L. Bergman, AJ.
DeLonay, E.E. Little, C.E. Smith, and F.T. Bar-
rows. 1995. Metals-contaminated benthic inverte-
brates in the Clark Fork River, Montana: Effects on
age-0 brown trout and rainbow trout. Can. J. Fish.
Aquat. Sci. 52: 1994-2004.
Zabel, E.W., P.M. Cook, andR.E. Peterson. 1995. Toxic
equivalency factors of polychlorinated dibenzo-p-
dioxin, dibenzonfuran, and biphenyl cogeners based
on early life stage mortality in rainbow trout
(Oncorhynchus mykiss). Aquatic Toxicology
31: 315-328.
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National Sediment Bioaccumulation Conference
Comments on the Significance and
Use of Tissue Residues in Sediment
Toxicology and Risk Assessment
Lynn S. McCarty
L.S. McCarty Scientific Research 8^ Consulting, Oakville, Ontario, Canada
Introduction
^^Whe explicit use of body residues in ecotoxicology
• and risk assessment is relatively new and is
Jft. cuirently' hampered by the limited availability of
residueTeffect data. However, the body-residue-based
approach is theoretically sound and ultimately lies at the
heart of existing enyironmental-media-based method-
ologies. It is expected that residue-effect methodologies
will soon supplant toxicity-only and bioaccumulation-
only based procedures. In. the interim, methods to Com-
bine and exploit existing tbxicity and bioaccumulation
knowledge are being developed and refined. However,
there is still an opportunity to examine and direct how
residue-based approaches may be best employed. Five
topics are reviewed and recommendations offered.
What are the assumptions,
applications, and limitations for each
bloaccumulation or risk assessment
methodology being described?
All bioaccumulation-related approaches make.the
assumption that bottom-up extrapolation is valid and,has
been validated. That is to say that results and information
obtained in laboratory or controlled testing can be readily
generalized and .extrapolated to population/community/
ecosystem levels of organization. This is essentially a
matter of faith or at best a policy decision. Such ap-
proaches may be useful and/or effective in protecting the
environment, but they are not firmly based in science
. since most such ecological organization theories have not
been validated. . -
For example, the conventional levels of a biologi-
cal organization model are presented by Odum (1971).
However, the practical ability to exploit this model for
environmental protection and environmental risk assess-
ment is not universally accepted. Consider Fry's Para-
digm, which addresses it: "You take the properties of a
level of organization and use those observations to ana-
lyze the next level of organization below it. If you take
, the properties too many steps down, you're being stupid;
and you cannot go the other directio'n." (Kerr, 1976)
Fry's Paradigm clearly indicates that the very
essence of much of the current risk assessment process—
extrapolation from laboratory testing at the level of the
individual organism (and below) to effects in the field at
the population, • community, and ecosystem levels of
organization—is unwise if not impossible. Furthermore,
it should be pointed out that the model presented by
Odum is not the only model for looking at how ecology
is organized. In fact, there is no single, generally ac-
. cepted ecosystem paradigm (Botkin, 1990 as cited by
•Suter, 1993). Less than half of about two dozen ecosys-
tem concepts proposed by ecologists have been em-
ployed by risk managers/assessors and only about one-
. third are used with any regularity (Vigerstad, manuscript).
Munkittrick and McCarty (1995) examined the
uneasy relationship between ecology and toxicology
known as ecotoxicology. They point out that such con-
ceptual models of environmental impacts, although
considering direct and indirect factors, do not usually
consider wh.at they term nondirect factors, or induced
factors as they are called in other disciplines. Nondirect
factors are those which dp not originate with a response
to a chemical stressor and cannot be expressed in terms of
a lexicological dose. For example, what is the dose
metric of loss of half of the habitat of a species and how •
is it quantitatively combined with the direct and indirect
effects of toxicant stress?
Basing a comprehensive and extensive regulatory
framework on using a risk assessment process that
depends heavily on the discipline of ecology, which
itself is in turmoil and undecided on a generally ac-
cepted paradigm, and toxicology, which is struggling to
expand beyond the boundaries of the laboratory, is
clearly policy rather than science. The biblical warning
about building an edifice on a foundation of sand ap-
pears appropriate. It niay be good policy, but scientists
2-25
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National Sediment Bioaccumulation Conference
and risk assessors should be wary of confusing science-
policy with science.
How can bioaccumulation assessment
be effectively applied to human
health and ecological risk
assessments?
Bioaccumulation in and of itself is not an adverse
environmental effect. Only accumulation that is associ-
ated with an adverse effect in organisms which have
accumulated the material, either directly or via the food
chain, is of importance. Furthermore, many materials
produce adverse effects without any significant accumu-
lation. For environmental protection and associated
regulations bioaccumulation is not the issue, adverse
effects are!
More work has been done on examining dose-
response relationships for changes and adverse effects in
the lab, effects that are possible, than for changes and
adverse effects in the field, effects that are probable. As
too little is known about ecosystems and effects at higher
levels of organization (Calow, 1994), it is not surprising
that relationships between lab effects at the individual/
population levels and field effects at the community/
ecosystem levels are poorly understood.
Furthermore, science policy must provide techni-
cal definitions of significant adverse effects in the field
that are quantifiable by ecologists and risk assessors and
consistent with current ecological theories. It is safe to
say, with the multiplicity of changes andputative adverse
effects being studied and reported in the literature, that
currently there is no general agreement on what consti-
tutes significant adverse environmental effects. Risk
assessment is useful only in a comprehensive risk man-
agement framework where risk management goals are
specified in the technical terms that scientists practicing
risk assessment can quantitatively address (McCarty and
Power, in press).
What are the requirements for
selecting species for bioaccumulation
testing? Are indigenous species
necessary?
Using residue information and appropriate bioas-
say interpretation, real differences in species sensitivity
can be separated from differences associated with bio-
availability and toxicokinetics: Indigenous species may
be useful and may provide important information but
only when thenature of "sensitivity" differences are clear
and sensitivity itself is clearly defined. For example, the
influence of bioavailability, exposure medium, and vari-
ous modifying factors (e.g., body size) is often not
considered in toxicity test interpretation. There is an
almost mythical belief that a most sensitive species can be
determined and that this determination will be useful.
However, most sensitivity examinations use exposure-
medium-based LCSOs or similar estimates and do not
fully interpret toxicity test results to remove the effects of
modifying factors. Such efforts are largely futile (Power
and McCarty, manuscript).
Some headway can be made with a residue-based
approach. Lanno and McCarty (in press) discuss a case
comparing pentachlorophenol toxicity to a freshwater
fish, a freshwater benthic invertebrate, and the common
earthworm. Based on exposure-based LC50 bioassay
results, it appears that the fish is more sensitive (threshold
LC50 of 0.00039 mmol/L) than the benthic invertebrate
(threshold LC50 of 0.0019 mmol/L). The threshold
LC50 of 0.14 mmol/kg dry soil for the earthworm is not
comparable due to the differences in exposure media.
However,, when the lethal body residues (LR) are exam-
ined, a sensitivity comparison is possible between the
three organisms. The LR50 range is 0.08-0.17, 0.33-
0.79, and 0.3-101 mmol/kg wet weight for the fish,
earthworm, and benthic invertebrate, respectively. The
fish appears to be slightly more sensitive, but the effect of
differing body lipid contents has yet to be determined and
may alter the relationship.
How can tissue-specific residue levels
be coupled with chronic toxicity
response data to develop dose-
response relationships for
bioaccumulative contaminants?
This issue is examined in detail in McCarty and
Mackay (1993) and in Rand et al. (1995). The basic
approaches are estimation using existing toxicity data
and bioaccumulation relationships (i.e., exposure-based
toxicity estimate* bioconcentration factor = whole-body
residue-based toxicity estimate) and generation of resi-
due-effect data from new experimental testing.
Work by Mayer (Mayer et al., 1986, 1992) on the
relationship between acute and chronic toxicity end-
points is particularly valuable in both approaches. He
has established that, in many cases, the lower tail (specifi-
cally, LC0.01) of the distribution of acutely lethal toxic-
ity is equivalent to the maximum acceptable toxicant
concentration (MATC)/lowest observed effect concen-
tration (LOEC) obtained in chronic toxicity testing for
growth/survival but not reproduction endpoints. Figure
1 (modified from Figure 5, McCarty and Mackay, 1993)
illustrates the point. When the toxicity data from a test
are transformed to a linear relationship using the log-
probit transformation, any proportional response can be
interpolated or extrapolated. When measured exposure-
based (LCx) or residue-based (LRx) toxicity data are
available, values can be directly estimated. Similarly,
LRx data can be estimated from LCx data where
bioconcentration factor information is available.
This approach provides many additional insights
due to a more complete exploitation of toxicity test
information. It was the basis for the suggestion that the
current separate acute toxicity, chronic toxicity, and
bioconcentration tests be combined into a single aquatic
toxicity test protocol (McCarty, 1991). Such a combined
approach would require an alteration in direction from
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Proceedings'
2-27
99.9
LCx and LRx Approach to Chronic Toxicity
% Mortality at Incipient Tox-icity Probit
.84 H
50
16 H
CBR = TOX ' BCF
LRx = LCx * BCF
interpolation
LC50 = 5.5 umol/L
LR50 - 5.5 mmol/kg
LC0.01 = 1 umol/L.
LR0.01 = 1 mmol/kg
0.01
LC10
LR10
extrapolation
-.3.2 umol/L
••3.2 mmol/kg
8
-7
-6
-5
-4
-3
-2
1
Exposure Concentration (umol/L)
BODY RESIDUE {mmol/kg)
10
Figure 1. LCx and LRx approach to chronic toxicity.
the current minimalistic trend in testing protocols.
Despite the additional observations and sampling that
would be required, it is still likely to be less costly than the
current trio of tests. As well, when conducted as scien-
tific research experiments, such an approach will ulti-
mately be more informative than abbreviated "regula-
tory" testing.
Although there is an increasing demand for more
chronic toxicity data, both exposure-based and residue-
based chronic information have a number of limitations.
These include the following: chronic data are more ex-
pensive to collect, chronic results usually have greater
uncertainty, some chronic endpoints are not readily inter-
pretable, relationships between whole body levels versus
those found in selected tissues have not been worked out,
and differences in body lipid content confound precise
residue-based interpretation.
It should be possible to, develop protocols and
procedures to address these limitations. The current
limited availability of chronic residue-effect data can be
overcome by estimation and new experimentation. How-
ever, the desirability of shifting the bulk of ecotoxicq-
logical testing to chronic effects is based on the largely
. my thical belief that chronic data are somehow "better" as
the basis of environmental regulations. This appears to
be largely based on the assumption that chronic effects in
the laboratory are equivalent to and readily comparable
to chronic effects in actual field situations. .This issue is
addressed in the next section.
How can bioaccumulation assessment
methods, including testing and
models, be used to address
population-level effects?
At the present time only acutely toxic effects and
major growth or reproductive effects can be effectively
modeled by population modelers. The major difficulty is
density-dependent responses, which are poorly known.
The objective of environmental protection is protection
of communities and local ecosystems. However, density-
dependent and other interspecies interactions, which are
largely unknown, represent a poorly quantified level of
complexity that effectively renders extrapolation from
bioassay to field largely an exercise in professional
judgment, not quantitative analysis and modeling (Power .
and McCarty, manuscript).
Laboratory toxicity testing is focused primarily on
addressing bioavailability,. kinetics, and the resistance/
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National Sediment Bioaccumulation Conference
tolerance of organisms exposed under highly controlled
conditions. The density-dependent factors that influence
toxic effects in the field are rarely studied in the lab. An
exception is work by Arthur and Dixon (1994). Juvenile
fathead minnows were placed in 1-L screen cages at a
density of 1, 5, and 10 individuals per cage and then
placed in a flow-through system exposure apparatus. The
chronic growth effects of pentachlorophenol and 2,4,5-
trichlorophenol were examined for 28 days. Up to about
twofold differences in chronic toxicity were found, e.g.,
low-density LOEC = 71 ug/L PCP; high-density LOEC
= 121ug/LPCP.
There is a significant effect of density on the
outcome of a toxicity test in ,tightly controlled experi-
mentation in the lab with a single species over a relatively
short time period. It is clear that, with the myriad of
opportunities for confounding influences in field situa-
tions of multiple populations under varying conditions,
density-dependent factors remain a serious obstacle to
extrapolating laboratory testing data to the field. The
severity of the problem increases as consideration moves
from short-term acute effects to long-term chronic effects
as there is more opportunity for density-dependent fac-
tors to operate the longer organisms are stressed but still
living. Thus, more chronic residue-based toxicity infor-
mation alone will not improve the success of extrapolat-
ing such information to the field. A much better under-
standing of the influence of density-dependent factors is
also required before any substantial improvement can be
expected.
Conclusions
1. Basic ecological theories need further development
and clear separation from science policy.
2. Bioaccumulation is not intrinsically an adverse effect
endpoint.
3. Body residues can help identify true differences in
species sensitivity by improving the understanding of
modifying factors.
4. Chronic body residue data can assist in interpretation
of toxicity testing results if improved methods and
analyses are adopted.
5. Improvementinlab-to-fieldextrapolationrequiresboth
greater residue-based toxicity knowledge and a better
understanding of the density-dependent modifying
factors acting within and between species in the field.
Recommendations
Policy. Separate science from science-based policy
by use of a clear risk management frame-
work.
Toxicity 1. Develop a single generic bioassay protocol
that integrates acute and chronic toxicity as
well as bioconcentration.
Toxicity 2. Do not use a local species unless at least
one standard species, selected from a very
restricted list, is also tested. Clarify that an
Ecology.
indigenous species is actually more sensi-
tive than the standard species using tissue
residue-effect relationships to determine the
influence of modifying factors such as body
size, temperature, behavior, and nutritional
characteristics.
Furtherdevelopabasicecological paradigm
and enhance population/community knowl-
edge, especially for density-dependent
interactions.
Acknowledgments
The content of this paper draws on past and ongoing
work with R. Lanno, K. Munkittrick, M. Power, and
T. Vigerstad.
References
Arthur, A.D., and D.G. Dixon. 1994. Effects of rearing
density on the growth response of juvenile fathead
minnow (Pimephales promelas) under toxicant-
induced stress. Can. J. Fish. Aquat. Sci. 51:365-371.
Botkin, D.B. 1990. Discordant harmonies. Oxford
University Press, New York, NY. Cited in Suter,
1993.
Calow, P. 1994. Ecotoxicology: What are we trying to
protect? Environ. Toxicol. Chem. 13:1549.
Kerr, S.R. 1976. Ecological analysis and the Fry para-
digm. /. Fish. Res. Bd. Can. 33:329-339.
Lanno, R.P., and L.S. McCarty. In press. Earthworm
bioassays: Adopting techniques from aquatic tox-
icity testing. Soil Biol. Biochem.
Mayer, Jr., F.L., K.S. Mayer, and M.R. Ellersieck. 1986.
Relation of survival to other endpoints in chronic
toxicity tests with fish. Environ. Toxicol. Chem.
5:737-748.'
Mayer, F.L., G.F. Krause, M.R. Ellersieck, and G. Lee.
1992. Statistical approach to predicting chronic
toxicity of chemicals to fishes from acute toxicity
test data. EPA/600/R-92-091. U.S. Environmental
Protection Agency, Gulf Breeze, FL. 94 p.
McCarty, L.S. 1991. Toxicant body residues: implica-
• tions for aquatic bioassays with some organic chemi-
cals. In M. A. Mayes andM.G. Barron, eds., Aquatic
toxicology and risk assessment, Vol. 14, ASTM
' STP1124, American Society for Testing and Mate-
rials, Philadelphia, PA, pp. 183-192.
McCarty, L.S., and D. Mackay. 1993. Enhancing
ecotoxicological modeling and assessment: Body
residues and modes of toxic action. Environ. Sci.
Technol. 27:1719-1728.
McCarty, L.S., and M. Power. In press. Environmental
risk assessment within a decision-making frame-
work. Environ Toxicol Chem.
Munkittrick, K.R., and L.S. McCarty. 1995. An inte-
grated approach to ecosystem health management:
Top-down, bottom-up or middle-out? /. Aquat.
Ecosys. Health 4:77-90.
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Proceedings
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Odum, E.P. 1971. Fundamentals of ecology. 3rd ed.
W.B. Saunders Company, Philadelphia, PA.
574pp.
Power, M., andL.S. McCarty. Manuscript. Ecotoxicology in
Wonderland: Myths arid misconceptions. Presen-
tation at SETAC '95, Vancouver, BC, Nov., 1995.
Rand G.M, P.O. Wells, and L.S. McCarty. 1995.
Chapter 1: Introduction to aquatic toxicology. In
G.M. Rand, ed. Fundamentals of aquatic toxi-
cology II: Effects, environmental fate, and risk
assessment, Taylor and Francis, Bristol, PA, pp.
3-67.
. Suter, G.W. II. 1993. Ecological risk assessment.
Lewis Publishers, Boca Raton, FL. 538 pp.
Vigerstad, T.J. Manuscript. Ecosystem assessment:
Paradigms and applications.
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National Sediment Bioaccumulation Conference
Quantification of Ecological Risks to
Aquatic Biota from Bioaccumulated
Chemicals
Burt K. Shephard
URS Greiner, Inc., Seattle, Washington
Abstract
JA simple sounding yet difficult to answer question
Mi^L is "What concentration of a chemical in fhe tis-.-
JiTLsues of aquatic biota is harmful to the biota
itself?" This question is of particular importance in
ecological risk assessment, where measurements of chemi-
cal residues in aquatic biota are often available, but the
interpretation of their effect on biota is difficult. The
objective of this work was to define tissue residues for a
number of chemicals which, if not exceeded, pose little
threat of risk to aquatic biota. These tissue screening
concentrations (TSCs) were designed to be nonsite- or
species-specific indicators of low risk residue levels.
TSCs have been derived for 152 chemicals, both metals
and organics, using a one-compartment first-order ki-
netic model. These TSC values are currently being used
in ecological risk assessments to identify chemicals of
potential concern, thus narrowing the focus of the risk
assessment. To confirm the validity of the TSCs, a
literature review of whole body tissue residues associated
with adverse lexicological or ecological effects was per-
formed. The review currently contains over 1400 records
of tissue residues associated with adverse effects of 120
of the TSC chemicals. For chemicals where the TSC
values are applicable, 94 percent of the literature re-
viewed indicates that adverse effects occur only at tissue
residues higher than the TSC values. This is comparable
to the U.S. Environmental Protection Agency's (USEPA)
ambient water quality criteria, which are designed to be
protective of 95 percent of aquatic genera. Analysis of
this literature indicates that as groups (1) marine and
freshwater biota are equally sensitive to chemical
residues in their tissues, and (2) benthic and pelagic biota
are equally sensitive to chemical residues in their tissues.
Sufficient literature is available for a number of chemi-
cals to permit direct estimates of the likelihood residues
in aquatic biota from a site pose adverse risks. The
existence of a tissue residue literature database relating
adverse effects to residue levels eliminates one of the
primary shortcomings preventing the use of the tissue
residue approach in sediment quality criteria develop-
ment: lack of documentation of tissue residues related to
adverse toxicological effects. The database also provides
indirect confirmation of a primary assumption of the
equilibrium partitioning approach to sediment quality
criteria development: benthic biota have a similar range
of sensitivity to chemicals as do pelagic biota. .
Introduction
Historically, the primary use of aquatic biota tissue
residue data in ecological risk assessments has been to
provide an indication that the biota have been exposed to
chemicals at a site. Seldom have, efforts been made to
directly quantify ecological risks from bioaccumulated
chemicals. •
The most common approach to quantifying eco-
logical risks to aquatic biota is to divide the concentration
of a chemical hi water or sediment by a toxicity reference
value (TRV), a concentration which if exceeded is ex-
pected to result in adverse ecological effects. The result-
ing hazard quotient is used'as a measure of risk to biota,
with the likelihood of adverse effects increasing with
increasing magnitude of the hazard quotient. TRVs
available for use in ecological risk assessment include
ambient water quality criteria (AWQC) and sediment
quality values from several sources. Unfortunately, there
is not a comparable set of TRVs-for use in assessing
ecological risks from tissue residues in the biota themselves,
despite a sizable amount of research relating body bur-
dens to toxic effects and the availability of several litera-
ture reviews of this information (McGarty and Mackay,
1993; McKim and Schmieder, 1991; Dillon, 1984).
Chemical concentrations in water and sediment are
surrogates for the actual dose of chemical at the site of toxic
action in biota. The use of these surrogates for the actual
2-31
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National Sediment Bioaccumulatlon Conference
dose has many limitations and introduces uncertainties in
assessing adverse effects of chemicals on aquatic biota,
some of which are outlined below. ,
• The bioavailable fraction of the total chemical
concentration in exposure media may not be
known.
• Surrogates do not consider multiple uptake routes
of chemicals by biota.
• Intermittent, pulsed, or varied exposures cannot
be readily assessed.
• Short exposure times can result in nonsteady-
state tissue residues and variable toxicity.
• Metabolic transformations of toxicants which en-
hance or reduce toxicity are not considered.
• Animal behavior (i.e., seasonal migration or toxi-
cant avoidance) is not accounted for.
• Analytical chemistry limitations (e.g.,
nondetectable concentrations hi exposure media)
mean the dose is often unknown.
By quantifying risks based on tissue residues asso-
ciated with adverse toxicological or ecological effects,
the above complicating factors are largely eliminated and
a more accurate risk assessment can be performed. .
The objectives of this work were as follows:
1. To derive risk-based screening concentrations
(RBSCs) for assessing ecological risks from chemi-
cal residues in aquatic biota tissues to the aquatic
biota themselves.
2. To confirm the utility of the derived RBSCs in eco-
logical risk assessment.
Methodology
USEPA's ambient water quality criteria are de-
signed to be protective of 95 percent of all aquatic genera
(Stephan et al., 1985). By 'extension of this principle,
tissue residues bioconcentrated from criteria concentra-
tions should also, if not exceeded, be protective of
95 percent of all aquatic genera. This is the fundamental
assumption behind the approach used to derive toxicity
reference values for bioaccumulated chemicals in aquatic
biota.
Tissue residues hi aquatic biota which, if exceeded,
may describe residues associated with adverse toxico-
logical or ecological effects are termed tissue screening
concentrations (TSCs) in this paper. This is because the
primary use of the TSC values is as a screening tool to
select chemicals of potential concern (COPCs) in eco-
logical risk assessments. COPC identification shortens
the list of chemicals carried through the entire ecological
riskassessmentprocess. TSCs are intended to be nonsite-
or species-specific indicators of tissue residues which, if
not exceeded, pose little threat of adverse risk to aquatic
biota.
TSCs were derived from the "one-compartment
first-order kinetic (1CFOK) toxicological model given in
Equation 1.
where:
Cb = chemical concentration in biota (mg/kg)
t = time (hours)
ku = chemical uptake rate constant (L/kg/hr)
Cw= chemical concentration in water (mg/L)
ke = chemical elimination rate constant (hour1)
If the chemical concentration in water is assumed to
be constant, Equation 1 may be exactly integrated to yield
Equation 2.
= x
x _
If it is further as sumed that the animal starts with no
tissue residue of the chemical of interest and the tissue
residue is at steady state with respect to the water concen-
tration, Equation 2 reduces to Equation 3.
^ „ ku
C>=C»*Te <»
By redefining the terms in Equation ,3, Cb becomes
the tissue screening concentration, Cw becomes an ambi-
ent water quality criterion (AWQC), ku/ke is a bioconcen-
tration factor (BCF), and the redefined Equation 3 can be
used to derive tissue screening concentrations, as shown
hi Equation 4.
TSC=AWQC-X,BCF,
(4)
dC,
dt
* —i
(1)
Although the derivation of TSCs is based on sound
toxicological concepts, in practice they are derived sun-
ply by multiplying a water quality criterion by a biocon-
centration factor.
To provide a more conservative screening value,
water quality criteria used in the calculations are the
lower of USEPA's freshwater or chronic ambient water
quality criteria. Since some of USEPA's water criteria
documents are for classes of chemicals (e.g. PAHs, chlo-
rinated benzenes, chlorinated phenols), a single criterion
value may be used in the derivation of multiple TSC
values. For metals with hardness-dependent criteria, a
hardness of 50 mg/L CaCO3 was assumed. If only an
acute criterion was available for a given chemical, the
acute criterion was divided by 8 to estimate a chronic
criterion. The bioconcentration factors used were taken
from the human health portion of the USEPA water
quality criteria documents. For metals, the BCFs are
geometric means of measured BCF values, whereas for
organics, the criteria BCFs were calculated using a re-
gression equation relating octanol-water partition coeffi-
cient to BCF. Most of the BCF values used are found hi
the SuperfundPublic Health EvaluationManual (USEPA,
1986).
To confirm the validity of the TSC values, a litera-
ture review was performed of papers relating measured
whole body, wet weight tissue residues to adverse toxico-
logical or ecological effects. For papers where dry
weight tissue residues were reported, a conversion to wet
weight was made assuming 80 percent water content if
the actual water content was'not given in the paper.
Effects considered in the review were population and
community effects, mortality, reproduction, growth,
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Proceedings
2-33
behavioral, cellular, biochemical, or physiological
changes.
The literature database' currently contains the fol- _
lowing information for each citation: chemical name,
tissue screening concentration, tissue residue associated
with effect (or the,no effect residue), common, and scien-
tific names of the species studied, lexicological or eco-
logical effect, a safety factor (defined in Equation 5), a .-
footnote field that contains information on the exposure
Conditions of the study, and the full literature citation.
To describe the difference between TSC values and
the tissue residues associated with adverse effects, a
safety factor (Equation 5) was calculated.
™,-r f ^ r * • Tissue concentration associated with effect
ISC safety factor = - — - : — - - ^ — (5)
The safety factor provides qualitative evidence of
the level of protection T.SCs provide aquatic biota from
adverse effects. Computationally, the safety factor can
also be considered a hazard quotient for a measured tissue
residue associated with a specified effect as given in the
literature.
It must be noted that the TSC values are intended to
identify tissue residues which, if not exceeded, pose little
or no risk to aquatic biota. They are not intended to define
tissue residues that are protective of avian, mammalian,
or other wildlife species that prey upon aquatic biota.
Results
Table 1 provides a representative example of the
152 currently available tissue screening concentrations.
All tissue residues given in Table 1 have units of mg/kg
whole body, wet weight. As shown in Table 1 , the TSC
values span a wide range of .tissue residues predicted to
have little or no effect on aquatic biota.
The literature review currently contains nearly 500
citations and 1400 records associating tissue residues to
Table 1. Derivation of selected tissue screening concentration values.
Chemical
Aldrin
Benzo(a)pyrene
Cadmium
Copper
4,4'-DDT ,
Dieldrin
Dioxin (2,3,7,8-TCDD)
Hexachlorobenzene
Mercury
PCB
/
Tributyltin
1 ,2,4-Trichlorobenzene
Zinc . . •
AWQC
"g/L
1.3
300
0.66
2.9
0.00 1
0.0019
0.00001
3.68
0.012
0.014
0.01
50
59
AWQC Source
Marine acute
PAH marine acute
Freshwater chronic
Marine acute
Freshwater chronic
Freshwater chronic
Freshwater chronic
Freshwater chronic
Freshwater chronic
Freshwater chronic
Marine chronic
Freshwater chronic
Freshwater chronic
BCF
L/kg
4,670
11,100
64
200
53,600
4,760.
5,000
8,690
4,994
31,200
693
2,800
47
TSC
mg/kg
0.71
416
0.042
0.17 ,
0.054
0.0090
0.000050
32
0.060
0.44
0.0069
140
2.8
AWQC - USEPA Ambient Water Quality Criterion
BCF - Bioconcentration Factor
TSC - Tissue.Screening Concentration
adverse effects. Of these, approximately 10 percent of the
individual records describe no observed adverse effect
.tissue residues. A range of tissue residues have been
associated with adverse ecological or lexicological effects.
Figure 1 shows the distribution of tissue residues associated
with adverse cadmium effects. The distribution in Figure 1
is typical of that for most chemicals, where no or only a few
citations indicate that effects occur below the tissue
screening concentration, but most adverse effects occur at
tissue residues above the tissue screening concentration.
At least one literature citation is available for 120
of the 152 chemicals for which TSCs exist., Ten or more
residue-effect records are available for about 40 chemicals.
Cadmium has the most literature information available of
any chemical in the database, while PCBs have the most
information available for any organic chemical. Other
chemicals that have a substantial amount of literature
available include mercury, copper, zinc, dioxin, pen-
tachlorophenol, and several chlorinated insecticides.
Once the no observed adverse effect residues are
removed from the database, 83 percent of the tissue
residues associated with adverse-effects are concentra-
tions higher than the tissue, screening concentrations.
Over half of the tissue residues associated with adverse
effects at concentrations lower than the TSCs are for
chemicals that are rapidly (within a few hours or days)
metabolized to more toxic compounds. The rapidly
metabolized chemicals are mostly PAH compounds, al-
though the chlorinated insecticide aldrin is also rapidly
converted to a. more toxic metabolite, dieldrin. Figure 2
shows tissue residues of benzo(a)pyrene associated with
adverse effects. For benzo(a)pyrene, every citation avail-
able shows an adverse effect at a whole body concentra-
tion below its TSC value.
Once chemicals rapidly metabolized to more toxic
forms are removed from the literature database, the
predictive ability of the TSC values to identify residue
levels below which adverse effects are unlikely im-
proves. By performing the TSC to adverse effects litera-
ture comparison without
chemicals rapidly metabolized
to more toxic forms, 94 percent
of the tissue residues associ-
ated with adverse effects are
higher than the tissue screen-
ing concentrations.
The calculated safety
factors (Equation 5) provide
a qualitative indication of the
conservative nature of the
TSC values. For all residue
effect citations in the litera-
ture database, the geometric
mean safety factor is 15, while
the arithmetic mean safety
factor is 41. The safety fac-
tors for individual literature
citations are generally largest
for measures of mortality and
smallest for biochemical
endpbints.
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r
2-34
National Sediment Bioaccumulation Conference
s
'(I)
CO
tn
CD
1
tn
I
CO
CC
100
90
80
70
TSC = 0.042 ng/g
0.001 0.01 0.1 1 10 100
[Cadmium], ng/g
1000 10000
Figure 1. Tissue residues associated with adverse effects: Cadmium.
on
OU -
^. OK
.3* ~
•-B I
'c 90 "
1 2°:
tn
.* -IK "
o 10 ~
Q.
w
» 10 :
^
§ :
°- 5
^
i—
i —
-m
_--
TSC = 416ng/g
,v
jf
s
• ''
^J
^
I
j r
r
r
'
i
i
..
••
0.001 0.01 0.1 1 10 100
[Benzo(a)pyrene], ng/g
Tissue screening approach does not work for chemicals rapidly
metabolized to more (or less) toxic forms
1000
Figure 2. Tissue residues associated with adverse effects: Benzo(a)pyrene.
The safety factors have been used to make several
statistical comparisons among various subsets of the litera-
ture data. These comparisons have found that, as groups:
1. There are no significant differences in residue levels that
cause adverse effects in freshwater or marine biota.
2. There are no significant differences in residue levels
that cause adverse effects in benthic compared to
pelagic biota.
3. There are no significant differences in the sensitivity
of biota to chemicals under field or laboratory expo-
sure conditions.
Although the results given above appear broadly
applicable based on the literature review, there are exceptions
in some instances. For example, arsenic residues associated
with adverse effects in freshwater biota are much lower
than arsenic residues that adversely affect marine biota.
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Proceedings
2-35
Table 2. Human health exposure scenario used to derive toxicity reference values (TRVs) for comparison of TSC
values to TRVs for consumers of fish and shellfish.
Exposure Scenario Parameter
Exposure frequency
Exposure duration
Body weight
Value
350 days/year
30 years
70 kilograms
Exposure Scenario Parameter
Fish and shellfish ingestion rate
Target noncancer risk
Target cancer risk
. Value
6.5 grams/day
1
1 x 10-6 ,
. Tissue screening concentrations have also been
compared to human health toxicity reference values
(TRVs) for chemicals hi fish and shellfish consumed by
humans. The exposure scenario and risk assumptions
used to derive the human health TRVs are presented in
Table 2. For noncarcinogenic chemicals where compari-
sons could be made, the ecological TSC values were
lower than the human health TRVs in 61 of 67 compari-
sons (91 percent). For carcinogenic chemicals, the hu-
man health TRVs were lower than the ecological TSCs in
36 of 42 comparisons (86 percent).
Discussion
To date, TSCs have been used as a screening tool in
ecological risk assessments at several Superfund sites. In
all cases, they have identified chemicals of potential
concern (COPCs) that have also been identified as COPCs
in at least one other human health or ecological risk
assessment scenario at the same site. This type of agree-
ment with other risk assessment procedures provides
corroborative evidence that the TSCs are successfully
identifying chemicals worthy of detailed investigation in
ecological risk assessments.
The largest shortcoming of the procedure appears
to be its lack of applicability to chemicals that are rapidly
metabolized to more toxic forms. Many PAH com-
pounds elicit adverse effects at tissue residues several
orders of magnitude below the PAH tissue screening
concentrations (Figure 2). Although this may be due in
part to the use of an old water quality criterion (USEPA,
1980a) for PAHs, a mechanistic reason for this observa-
tion can also be given.
Many PAHs are known to be rapidly metabolized
to more toxic compounds (USEPA, 1980a). A tissue
screening concentration based on residues of a less toxic
parent compound will not represent a safe concentration
of a more toxic metabolite. For rapidly metabolized
chemicals, a TSC for the more toxic metabolite should be
used to assess risks, rather than the TSC for the parent
compound. An example of this approach is shown in
Figure 3. Aldrin is rapidly metabolized by many species
to dieldrin (USEPA, 1980b). The limited amount of
TSC = 0.009 jig/g '
25
••^ oh
.> 20 -
0)
w 15 -
.,8
'8
£• 10
•". '• 1
ro 5 -
o: °
0 -
-
i
j
/'
"i
•^
r"
.
• i
ji
^
I
•
1
i
-=
. -•
0.001 0.01 0.1 i 10 100 1000 10000
[Dieldrin], ng/g
The toxicity of a metabolic product of aldrin is correctly predicted by the TSC of
the metabolic product.
figure 3. Tissue residues associated with adverse effects: Dieldrin.
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2-36
National Sediment Bioaccumulation Conference
aldrin residue data associated with adverse effects brack-
ets the aldrin TSC value. A substantial amount of
literature is available for dieldrin residue toxicity (Figure
3). In all cases, dieldrin residues associated with adverse
effects are higher than the dieldrin TSC value. Unfortu-
nately, TSC values do not currently exist for PAH
metabolites, limiting the utility of the TSC approach to
chemically and metabolically stable toxicants.
They are also not applicable for chemicals whose
toxicity does not result from an internally absorbed dose.
Examples of chemicals in this second category may be
aluminum and iron, whose toxicity largely comes from
formation, under certain water quality conditions, of a
flocculent material that suffocates aquatic biota.
Several of the TSC values appear to be overly
conservative based on the literature review. In particular,
no adverse effects have been associated with copper
residues below 3 mg/kg or zinc residues below
20 mg/kg, considerably higher than the respective calcu-
lated TSC values of 0.17 and 2.8 mg/kg. In practice, we
are now using the 3 mg/kg copper and 20 mg/kg zinc
values as screening concentrations in ecological risk
assessments. Many aquatic species can regulate their
body burdens of copper and zinc. The 3 and 20 mg/kg
screening values for copper and zinc are much closer to
the known or estimated physiological requirements of
these two elements in aquatic biota (van Tilborg and van
Assche, 1996; White and Rainbow, 1985) than are the
TSC values in Table 1.
At least one TSC is not sufficiently conservative
for use as a screening tool in ecological risk assessment.
The hexachlorobenzene TSC of 32 mg/kg is higher than
9 of the 10 literature citations associating hexachloro-
benzene residues with adverse effects. If the hexachloro-
benzene TSC is recalculated using the bioconcentration
factor from Table 1 and the Canadian Water Quality
Guideline of 0.0065 jag/L instead of the draft USEPA
ambient water quality criterion of 3.68 |ig/L, the resulting
TSC is 0.056 mg/kg. This recalculated TSC is lower than
all 10 hexachlorobenzene adverse effect residue levels
reported in the literature. Use of the Canadian Water
Quality Guidelines is currently under investigation for
use in calculation of additional TSC values for chemicals
where USEPA currently has no ambient water quality
criteria.
The availability of a literature database of tissue
residues associated with adverse effects permits the use
or derivation of several other ecological risk estimation
methods. The hazard quotient approach has already been
discussed. For aquatic species where asubstantial amount
of literature is available, the best approach may be the
direct identification of tissue residues associated with
adverse effects. Rainbow trout (Oncorhynchus mykiss)
and blue mussels (Mytilus edulis) are the freshwater and
marine species with the most tissue residue information
available in the literature. By comparing the distribution
of tissue residues associated with adverse effects (Figures
1-3) to the residue distribution in animals from a site of
interest, probabilistic risk assessments could be per-
formed. Other endpoints analogous to sediment or water
quality criteria or guidelines, such as apparent effects
thresholds (AETs), lowest observed adverse effect lev-
els (LO AELs), or tissue residues above which effects on
a defined percentile of species occur could all be calcu-
lated from the literature database. The defined percen-
tile approach could be the tissue residue equivalents of
the Long and Morgan (1991) effects range-low (ER-L)
and effects range-median (ER-M) sediment quality
guidelines.
Although the primary focus of this paper has been
on the use of tissue residue information to define eco-
logical risks to aquatic biota, the tissue residue approach
also has applicability to the derivation of sediment
quality criteria. USEPA (1993) has identified the tissue
residue approach as a technically valid approach for the
derivation of sediment quality criteria. One of the major
identified shortcomings of the tissue residue approach
to sediment criteria development is the absence of a
database of residue levels associated with toxicity
(USEPA, 1993). The database developed to confirm the
utility of the TSC values could also serve to eliminate
this identified shortcoming of the tissue residue approach
to sediment criteria development. The database also
provides indirect evidence that benthic biota, as a group,
are equivalent in their response to toxicants to pelagic
biota, a fundamental assumption of the equilibrium
partitioning approach to deriving sediment quality criteria.
Summary and Conclusions
Although the literature database compiled during
this study allows a number of hypotheses to be tested
and conclusions to be drawn, the three primary conclu-
sions that have been drawn to date are:
1. Tissue residues of chemicals in aquatic biota can, for
many chemicals, be used to directly assess ecologi-
cal risks to aquatic biota.
2. Chemicals for which tissue residues cannot be used
to quantify risks can be identified from mechanistic
considerations.
3. The level of protection from adverse risk provided
by the tissue screening concentration approach is
comparable to that provided by USEPA's ambient
water quality criteria.
The TSC method appears to provide a conservative
initial screen capable of eliminating from an ecological
risk assessment chemicals that,do not pose significant
risks to aquatic biota. Exceedance of a tissue screening
concentration does not automatically imply that an ob-.
served tissue residue poses an adverse risk to biota. It does,
however, identify those chemicals which require more
detailed investigation in an ecological risk assessment.
The existence of an interpretive tool for assessing
risks or hazards to aquatic biota from bioaccumulated
chemicals has many potential applications in addition to
ecological risk assessment. Environmental assessments,
dredging bioassessments, and criterion and standard
development are three of the many possible uses. Inter-
pretation of tissue residues has the potential to provide
substantially more information than its current primary
use, which is as an indicator of exposure to chemicals.
-------
Proceedings ^_
References
Dillon, T.M. 1984. Biological consequences of bioaccu-
mulation in aquatic animals: An assessment of the
current literature. Technical Report D-84-8. U.S.
Army Corps of Engineers, Waterways Experiment
Station, Vicksburg, MS.
Long, E.R. and L.G. Morgan. 1991. The potential for
biological effects of sediment-sorbedcontaminants
tested in the National Status and Trends Program.
NOAA Technical Memorandum NOS OMA 52,
National Oceanic and Atmospheric Administra-
tion, Seattle, WA.
McCarty, L.S., and D. Mackay. 1993. Enhancing
ecotoxicological modeling and assessment.
Environ. Sci. Technol. 27:1719-1728.
McKim,J.M., andP.K. Schmieder. 1991. Bioaccumula-
tion: Does it reflect toxicity? In R. Nagel and
R. Loskill, eds., Bioaccumulation in aquatic sys-
tems. Contributions to the assessment, VCH Pub-
lishers,Weinheim, Germany, p. 161-188.
Stephan, C.E., D.I. Mount, D.J. Hansen, J.H. Gentile,
G.A. Chapman and W.A. Brungs. 1985. Guidelines
• for deriving numerical national water quality cri-
teria for the protection of aquatic organisms and
- 2-37
their uses. U.S. Environmental Protection Agency,'
- Office of Research and Development, Duluth, MN.
USEPA. 1980a. Ambient water quality criteria for poly-
nuclear aromatic hydrocarbons. EPA 440/5-80-
069. U.S. Environmental Protection Agency, Of-
fice of Science and Technology, Washington, DC.
USEPA. 1980b. Ambient water quality criteria for
aldrin/dieldrin. EPA 440/5-80-019. U.S. Envi-
ronmental Protection Agency, Office of Science
and Technology, Washington, DC.
USEPA. 1986. Superfund public health evaluation
manual. EPA/540/1-86/060. U.S. Environmental
Protection Agency, Office of Emergency and Re-
medial Response, Washington, DC.
USEPA. 1993. Sediment classification methods com-
pendium. EPA 823-R-92-006. U.S. Environmen-
tal Protection Agency, Sediment Oversight Tech-
nical Committee, Washington, DC.
van Tilborg, W.J.M., and F. van Assche. 1996. Risk
assessment of essential elements: Proposal for a
fundamentally new approach. SETACNews 16(5),
September 1996:
White, S.L., and P.S. Rainbow. 1985. On the metabolic
requirements for copper and zinc in molluscs and
crustaceans. Mar. Environ. Res. 16:215.
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2-38
National Sediment Bioaccumulation Conference
Question
Can contaminant tissue residues in
aquatic biota be used to define
ecological risks to aquatic biota?
Objectives
O To derive risk-based screening
concentrations (RBSCs) for assessing
ecological risks of chemical residues in
aquatic biota tissues
0 To confirm the utility of the RBSCs in
ecological risk assessment
-------
•' Proceedings
2-39
A Newer Objective
To directly quantify ecological risks from
chemical residues in aquatic
biota tissues
Available Toxicity Reference
Values in Aquatic Toxicology
• Ambient water quality criteria (AWQC)
• Sediment quality criteria
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2-40
National Sediment Bioaccumulation Conference
The Fundamental Principle of
Toxicology
The magnitude of the toxic response is
proportional to the toxicant concentration at
the site of toxic action
Tissue Screening
Concentrations (TSCs)
Whole body, wet weight tissue residues of
chemicals which, if not exceeded, pose little
chance of causing adverse toxicological or
ecological harm to aquatic biota. TSCs are
intended to be non-site or species specific.
-------
Proceedings
2-41
Uses of Tissue Screening
Concentrations
Primary use is as a screening tool to
select chemicals of potential concern in
ecological risk assessment
Can also be used as the denominator in
hazard quotient calculations
Toxicological Basis for Tissue
Screening Concentrations
1CFOK model
(integrating form assuming constant water concentration)
Where:
Cb= chemical cone, in biota (mg/kg)
t = time (hours)
Cw= chemical cone, in water (mg/L)
k™= chemical uptake rate constant (L/kg/hr)
k" = chemical elimination rate constant (hour1)
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2-42
National Sediment Bioaccumulation Conference
lexicological Basis for Tissue
Screening Concentrations
If it is further assumed that:
O The initial tissue residue is zero, and
© The animal is at steady state
The 1CFOK model reduces to...
Calculation of Tissue
Screening Concentrations
Where:
TSC =
WQC =
BCF =
TSC = WQC x BCF
tissue screening concentration
water quality criterion (mg/L)
3% lipid normalized
bioconcentratipn factor (Ukg)
-------
Proceedings
2-43
Example TSC Values
(All values mg/kg whole body, wet weight)
Chemical
Arsenic
Cadmium
4,4'-DDT
Dioxin (2,3,7,8-TCDD)
Mercury
PCB
Tributyltin
1,2,4-Trichlorobehzene
TSC
1.6
0.042
0.054
0.00005
0.12
0.44
0.006
140
TSCs currently available for over 150 chemicals
"The direct prediction of chronic toxic
effects from measured or predicted tissue
residues requires validation before it can be
widely endorsed."
p.7-7, USEPA Sediment Classification
Methods Compendium (1993)
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2-44
National Sediment Bloaccumulation Conference
Performed literature review of measured
tissue residues associated with
toxicological effects. It currently contains
about 1400 records, 490 literature citations,
and information on 118 of the 152 chemicals
for which TSCs exist
Database Structure
O Chemical name
© TSC value
© Residue concentration associated with
effect
O Species
© Toxicological or ecological effect
© Safety factor
O Footnote
© Literature citation
-------
2-45
Safety Factor
Effect tissue concentration
TSC
Provides qualitative evidence of the level of
protection TSCs provide aquatic biota from
a specific effect. Also could be considered a
hazard quotient for the specified effect at a
given tissue residue.
Criteria for inclusion in
Database
Had to report measured tissue residues
Only papers reporting whole body residues
No limitation on toxicological endpoint
No limitation on route of exposure
Included both laboratory and field studies
Minor limitations on aquatic species
included
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2-46
National Sediment Bioaccumulation Confe
Distribution of
Tissue Residue Literature
Range of citations
1-9
10-19
20-29
30 - 39
40-49
50-59
60+
No. of chemicals
82
20
8
3
1
2
2
Assumptions in Validating
Utility of TSCs
No difference in sensitivity of freshwater,
estuarine or marine biota
No differences in sensitivity of benthic,
epibenthic or pelagic biota
No differences in response of laboratory
and field exposed biota
Interested only in identifying risks to aquatic
biota—TSCs not designed to be protective
of piscivorous birds and wildlife
-------
2-47
IT WORKS!
(At least for most chemicals)
Results of Literature Review
About 10% of results describe no observed
effect at a given tissue residue
For the entire database, 83% of adverse
effects occur at concentrations above TSC
values
When chemicals which are rapidly
metabolized to more toxic compounds are
removed, 94% of reported effects occur at
concentrations above TSC values
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2-48
National Sediment Bioaccumulation Conference
Results of Literature Review
Geometric mean TSC safety factor for
entire database is 15
Arithmetic mean TSC safety factor for
entire database is 41
Possible Approach for Chemicals
Rapidly Metabolized to More Toxic
Compounds
Aldrin
TSC = 0.71 mg/kg
2 of 2 records show adverse effects below
TSC (4 no effect records)
Dieldrin
TSC = 0.009 mg/kg
0 of 19 records show adverse effects below
TSC (1 no effect record)
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Proceedings
2-49
Care Must be Taken When Using
TSCs in Risk Assessment
Hexachlorobenzene
• TSC = 32 mg/kg
• Derived from USEPA AWQC of 3.68 ug/L
• 9 of 10 records show adverse effects below TSC
(11 no effect records)
• Deriving a TSC from the Canadian Water Quality
Guideline of 0.0065 ug/L
• TSC = 0.056 mg/kg
• 0 of 10 records show adverse effects below TSC
Care Must be Taken When Using
TSCs in Risk Assessment
Copper and zinc are two examples where
TSCs may be overly conservative
Copper
TSC = 0.17 mg/kg, toxicity threshold at 3 mg/kg
Zinc
TSC = 2.8 mg/kg, toxicity threshold at 20 mg/kg
Many aquatic species can regulate their Cu and
Zn burdens
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2-50
National Sediment Bioaccumulation Conference
Methods for Quantifying
Ecological Risks of Tissue
Residues
O Hazard quotients
© Apparent Effects Threshold (AET)
© Effects on defined percentile
O Direct assessment
0 Probabilistic risk assessment
Results from Risk
Assessments
Performed to Date
Tissue residue approach and TSCs have
identified only chemicals of concern (COCs)
which have also been identified as COCs by
one or more other human health or
ecological risk scenarios
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"Proceedings
Z-Si
Results Derived from Literature
Review and Analysis of Safety Factors
No significant difference in residue levels
causing adverse effects in freshwater and
marine biota (arsenic an exception)
No significant difference in residue levels
causing adverse effects in benthic and
pelagic biota
No significant difference in response of
biota in field and laboratory exposures
Comparison of Human Health Toxicity
Reference Values to Ecological TSCs
Compared TSCs to TRVs for a defined human
health exposure scenario for seafood consumers
Exposure frequency
Exposure duration
Body weight
Target noncancer risk
Target cancer risk
Seafood ingestion rate
350 days/year
30 years
70kg
1
1x10*
6.5 grams/day
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2-52
National Sediment Bioaccumulation Conference
Results of Comparing Human
Health TRVs and Ecological TSCs
O Ecological TSCs were lower than human
health TRVs for 61 to 67 (91%) of
chemicals where a comparison could be
made
© Human health TRVs were lower than
ecological TSCs for 36 of 42 (86%) of
chemicals where a comparison could be
made
Conclusions
Tissue residues of chemicals in aquatic biota
can, for many chemicals, be used to directly
assess ecological risks to aquatic biota
Chemicals for which tissue residues cannot be
used to quantify risks can be identified from
mechanistic considerations
The level of protection from adverse risk
provided by the tissue residue approach is
comparable to that provided by USEPA's ambient
water quality criteria
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National Sediment Bioaccumu/ato'on Conference
Day One: September 11, 1996
Session Two:
Questions and Answers
A
fter each session, there was an opportunity for
questions and answers and group discussions per-
.taining to the speakers' presentations.
Q (Dave Michaud, Wisconsin Electric Power Company):
Dr. Rubinstein, on your last slide you referencedthe need
to perhaps establish a minimum criteria for reference site
selection. What are your thoughts in terms of groups of
chemicals, or on a chemical-specific basis?
Norm Rubinstein:
Without having the residue effects data, we are
limited in regard to interpreting chemicals and concentra-
tions. I am talking more in terms of determining what
represents a healthy ecosystem. What are the things we
are measuring that satisfy our need to insure we are
maintaining environmentally consistent conditions? This
involves developing much broader databases, much like
is done hi the Puget Sound Dredged Disposal Analysis
(PSDD A) Program. From information developed by this
program, we know that the benthic communities are
functioning and the animals that are supposed to be there
are there.
Q (Dave Michaud): So, the concept might be, for ex-
ample, going to an area where you have a healthy benthic
community, taking sediment samples, andanalyzing them
for a suite of possible contaminants.
Norm Rubinstein: >
Right, and then using that as your point of compari-
son. This is known as a reference comparison.
Q (John Zambrano, NYS Department of Environmental
Conservation): Dr. Rubinstein, in your definition of
reference sediment you have three components. The first
and the third could be in conflict. The first component is
one that is substantially free of contaminants, and the
third component reflects the site if no material had been
disposed of there. What do you do when they are in
conflict, and could you explain how those two compo-
nents relate to the purpose of using a reference sediment?
Norm Rubinstein:
I will be the first to admit that I think the definition
does need to be revisited. The intent, when we started
thinking about this issue, was to recognize the fact that
many of the areas that require maintenance dredging are
in highly industrialized and urbanized areas where the
benthic habitat has been degraded over long periods of
time. We have never looked at this program as a
remediation program. The intent was to insure that we do
not cause further degradation. So, as impractical as the
language sounds, it was hi fact a realistic way of getting
a handle on what was there. We do have to go back, look
at this definition, and establish what we are now consid-
ering to be environmentally acceptable material.
Q (Gayle Garman, NOAA): Dr. Rubinstein, I am familiar
with the PSDD A program. I think it is interesting that you
hold that up as an example for us, and yet the data you
showed indicated that there was a lower survival rate for
the amphipods at the control or reference sites in Puget
Sound than for the other harbors. So, the Puget Sound
approach did not seem to be the most protective ap-
proach for the data that you showed us. I would also like
you to address the fact that you are talking about a
healthy benthic community, and what we are focusing on
here is bioaccumulation.[ A healthy benthic community
does not necessarily indicate whether or not there is a
potential for bioaccumulation.
Norm Rubinstein:
Yes, amphipod mortality was a little higher in
Puget Sound and that is exactly the point of the utility of
a toxicity endpoint in a given species. Mortality at 20 or
23 percent in a test species may not be indicative of a
significant impact at a population level. When you look
.at the sediments in Puget Sound> it is my understanding
that for factors other than chemical constituents like grain
2-53
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National Sediment Bioaccumulation Conference
size or ammonia, this is about the typical response in
terms of the toxicity exposure for these animals. So, it is
consistent with what I am saying, which is that percent
mortality alone may not be a useful tool. Mortality has to
be put into a more ecologically relevant context And I
agree with your statement that a healthy benthic commu-
nity does not necessarily indicate whether or not there is
a potential for bioaccumulation.
Q (Edward Zillioux, Florida Risk-Based Priority Coun-
cil): Dr. Mount, I noticed that you said you limited your
data collection to fish and invertebrates. I realize that
this is a tremendous undertaking and there may be
logistical reasons thatyou did not go further. But I would
recommend that you consider including wading birds,
because not only do they provide useful residue effect
relationships that are in the literature, but they could also
be a good link to higher trophic levels. We looked at this
for mercury and found quite useful relationships that
showed up in work conducted by Don Porcella and Jani
Benoit. And we also found that the residue effect rela-
tionships derived from the field samples correlated fairly
well with residue effects derivedfrom laboratory studies
with a typical white rat and mallards.
David Mount:
You raise a good point. I should emphasize that our
decision to limit our database to aquatic species was not
any sort of biological judgment, but purely a logistical
decision. And you are absolutely right that there are lots
of issues regarding bioaccumulation that extend well
beyond the aquatic community.
Q(Arthur Asaki, U.S. Army Center for Health Promotion
and Preventive Medicine): Dr. Mount, I congratulate
your work in this area. It is something that has been
needed for a long time, and I am glad somebody has done
it. I looked at your data, your effect data and no-effect
data, graphically represented. You had yellow squares
for no-effect data and red diamonds for effect levels.
There was quite a bit of overlap in those datapoints, which
is to be expected. Later in your presentation, you showed
a table for chlorpyrifos andkepone where the lowest effect
level and the highest no-effect level did not overlap.
Could you explain that?
David Mount:
I will try to explain what I think you are asking. The
figure I presented included all data that were reported for
that chemical, regardless of whether it was just one data
point or several datapoints. The tables showed results of
individual studies. If you look at the sheepshead minnow
data for kepone, you will see several entries for sheeps-
head minnow in the table with different values for differ-
ent studies. Each line of the table corresponded to a single
study. The comparisons were reduced to just effect/no-
effect pairs, in a sense kind of culling the data set, which
probably reduced some of the variability. But all sources
of variability, such as intra-species and intra-experiment,
were represented in the figure.
Q (Maurice Zeeman): This question is for Dr. McCarty.
There is a lot of talk going on today about dose-
response relationships and tissue residue-based para-
digms for toxicity assessment. I was wondering if we
are going to have to start looking at some of these old
chemicals in new ways, because of some new ways of
looking at endpoints. Endocrine disrupters research
is getting to be very interesting and it is suggesting, in
essence, that dose-response relationships may not be
all that important for these kinds of chemicals. When
you are exposed to this trivial level of chemical maybe
more important than giving it to an adult later on at a
much higher level or at different levels. What effects
do you think that will have, if any, in terms of looking
at dose-response relationships, tissue residue concert-.
trations, and bioconcentration?
Lynn McCarty:
I do not think that the endocrine modulator people
really believe they are going to modify the basic
assumptions of toxicology. The description, you pre-
sented is that their perception of dose response is
giving a strong dose and getting a strong response.
Everything is clear and understood. I think it is even
more important in the sorts of things they are talking
about for low level responses. We are still talking
about a dose response. It is just down at low doses and
at different endpoints than what we have previously
looked ati I do not think it is any different at all. The
standard lexicological paradigm applies. We do not
have to throw out the paradigm because we do not
understand the specifics of this case. I think the
paradigm applies; we just have to get a greater under-
standing of what is going on. I think we see the echoes
of this problem with PAHs. The residue for PAHs is no
longer a marker of exposure for the organism, because
it is so readily metabolized that what you measure
today is not what the organism got a year ago. It may
not be the dose that was reflective of what is causing
effects to the organism today. That is the very same
problem that the endocrine people are talking about,
and it is simply the next level of effort. We have been
very lucky in that we have many organic chemicals
which are very recalcitrant to degradation, arid so they
can serve as their own markers of exposure. For these
chemicals, the tissue residue that we see today is fairly
reflective of the exposure that the organism received in
the past and, therefore, is recently attributable to the
effect that we see today. But we know there are situa-
tions where that does not occur. However, it still does
not negate the need to know what the dose was at the
time that the effect was initiated, and we have to
develop procedures for estimating that. But I think
there are people suggesting to simply bypass the whole
scientific process and assessment of this. I think there
is good science to be done and, if you throw out dose
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Proceedings
2-55
response, then you throw out all science that is appli-
cable to things. That certainly can be done, but I am
not suggesting that. .
Q (Peter Chapman): All chemicals are not the same for
a variety of reasons. Do you think it is possible that we
will be able to develop body burden-to-effect relation-
ships for all chemicals within a reasonable time frame
with reasonable effort? Or should we dedicate our
efforts to those chemicals we think we will be able to do
that for? Some of them may require so much effort and
time it may not be worthwhile.
Lynn McCarty:
We are'not going to look at every chemical. There
is no question about that. I used the example I took from
the EPA laboratory in Duluth on the modes of action. I
think it is a brilliant piece of conceptual work in saying
that we, as lexicologists* have been oppressed by the
chemists for so long, because they are the.people doing all
of the chemical work and they always tell us the chemical
relationships in terms of chemical descriptors. Well, I am
a toxicologist and I want to have groupings according to
toxicology groupings. I do not care what the structure of
the chemical is. I want to know about the chemical based
on effects. That is.the first step in going hi that direction.
I think as we apply this tissue residue approach, it is going
to allow us to get better estimates of those things and
begin to categorize things on the basis of the effects that'
they have. We will be able to classify those effects into
mechanistically related groups. It will also allow us the
ability to look at mixtures, and hopefully that will allow
us to address larger, groups of things, conserve the limited
resources available, and still improve curability to do the
tasks that have been set for us.
Q (Phillip Rury, Arthur D. Little, Inc.): Burt, since the tissue
screening concentration (TSC) method seems to have vali-
dated the pertinence of aquatic water quality criteria to
protecting aquatic biota from residue effects, how would
you respond to Lynn McCarty's assertion that the superior-
ity of chronic tests as a basis for regulatory criteria is a
"myth?" ,
Burt Shephard:
I do not know if I would totally call it a myth. We
are really measuring different sides of the same coin. If
we expose the animal to the same concentration of chemi-
cal for a longer time, you begin to see chronic effects first
And if you keep exposing that hypothetical animal to that
saine concentration for a longer and longer time, you
keep bioaccumulating more and more chemical. Eventu-
ally you will begin to run into acute toxicity, where you
will reach a lethal body burden and the animal will expire.
So, I think what we are really looking at is a temporal
difference involving how long organisms are exposed to
a given concentration. This is especially the case for
chemicals that just keep on bioaccumulating the longer
we expose them. You can start to see chronic effects at
low tissue residues. As you gain more and more residue,
you begin to get mortality.
Q (Phillip Rury): Lynn had not really elaborated on that
comment, that zinger up there about it being a myth, and
• perhaps he would care to take this time to do so now?
Lynn McCarty:
What I was trying to caution against was the feeling
that all we need is more chronic toxicity data and We will
be able to solve all our problems. I definitely think that,
is not the case. And I think that there are better ways of
obtaining'that information than doing chronic toxicity
testing in the way that we are doing it now. The point I
am trying to make is that I think there are better ways of
achieving the same end more cost-effectively using our
knowledge,"rather than having to create specific data
points for every chemical and every situation that we
want to look at. Chronic toxicity testing will not be our
salvation and it is not the holy grail. It has to be taken into
context. .
Q (Peter Chapman): When I look at chemicals, including
organics thai come in via lipids and metals that are taken
up via evolutionary mechanisms for uptake, I view them
for our purposes here in two ways. Some chemicals that
accumulate in organisms can be measured and this
information may tell us something we can relate to
effects. An example would be PCBs. Other chemicals,
such as PAHs, accumulate in some organisms, but not in
others because they are metabolized. Either we can look
at the metabolites for organisms that metabolize the
parent compounds or, as Jay pointed out, we can measure
these chemicals in an organism that does not metabolize
them. But in addition to that, within the group of
chemicals that accumulate in organisms without forming
metabolites, there are also chemicals that are regulated
and those that are not. For instance, consider the
essential metals. I think Burt made my point very well in
his talk when he mentioned that copper and zinc proved
to be problems for him. They proved to be problems
because he was using bioconcentration factors that will
not work for essential metals. These organisms must take .
up the essential metals to survive, and they will fight,
against the concentration gradient to retain them. I am
wondering if we really should not look at the way the
chemical acts. Maybe certain chemicals work better than
others and we shouldfocus our attention on these. Some
chemicals may be a lost cause, and we should not put our
effort into them for a variety of reasons. They have got
complications that we should leave until later to address.
Is that a reasonable way to look at this situation, or do
you think, as a panel, that we should just go for it as a
whole lot? What are your feelings?
Lynn McCarty: • • '
I think that the sort of thing you want to do is what
Burt has done. I only wish that I had done what he has
done. I would have at least liked to have had the
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National Sediment Bioaccumulation Conference
opportunity, because I think it is an excellent example of
how you both improve the understanding of the situation
and point out the limitations. You have the opportunity to
see where things work and, more importantly, to under-
stand why they work. It also allows you to focus on the
exceptions, yet they happen to be particularly problematic
based on other information. So, I think the general danger
in doing any of this residue-based approach is simply that
we are looking at the basic paradigm of toxicology dose
response and are trying to get a better understanding of the
dose so we understand where our response comes from.
There are situations where trying to make the methodol-
ogy apply to all chemicals will make it so incredibly
complicated and expensive that it is almost impossible to
do. We basically do as is done in the sediment program by
applying a tiered-testing approach. Essentially you focus
on chemicals that can be addressed by simple assumptions
with simple approaches. You only use more complicated
evaluations and approaches to address the chemicals that
do not fit into a simplified scheme. Understanding that
they all are basically surrogates, it is simply a matter of not
picking the right surrogate. This is related to Maurice's
point earlier about hormone modulators. It does not
negate the whole concept of the dose response in toxicol-
ogy. It simply means that the dose surrogate you were
using is not good enough for this particular situation.
Q (Peter Chapman): I know, but I think you are simply
adding to my point that we need to be very careful and not
delude people. If we do go to a tissue residue versus effects
relationship, this is not going to work for everything.
Tliere are going to be some exceptions, and I think some
very important exceptions. People get deluded in their
thinking when they look at some of the data, because we
are not always clear that we are talking about organics,
lipids, and relationships that may be a little easier, than
say, for the essential metals. And we have to be very clear
about this. I agree with you whole-heartedly about the
tiering approach, but I think my working hypothesis at this
point is that we are going to reach the end of the rainbow.
Eventually, we will develop a relationship for some chemi-
cals under some circumstances, between effects and tissue
body burdens. But we will not successfully do it for a
number of others for a variety of reasons.
Lynn McCarty:
I appreciate that, but I just wanted to point out that
I recognize that problem. I have been very careful hi
writing about this to try not to make it a be all and end all.
The appropriate cautions or caveats are hi there. Whether
people actually see them, when they read it, is another
story. But at least I think it is very, very important to do
exactly what you said. The worst thing that could happen
is to present this as the solution to everything, because it
is not.
Burt Shcphard:
I just might add to that a little. There is certainly no
holy grail in this business. Clearly, the tissue residue
approach is not going to work for everything. If we want
to take the time and effort and money to quantify residues
of metabolites of PAHs that are related to adverse effects,
we can certainly do that. But if, on'the other hand, we
already have an approach in sediment quality criteria that
seems to be pretty protective of our biological resources
from the effects of PAHs, why do we need to look at
metabolites at all? We have a method that works, so we
should use it. If we need to use multiple methods for the
laundry list of chemicals that we have to look at in this
business, I certainly do not have a problem with using
multiple methods. We should use sediment criteria
where they are appropriate. If tissue residues work better
for some chemicals or some situations, we should use
them.
Q (John Connolly, HydroQual, Inc.): I have a comment
and then a question that I think is related to the comment.
The comment is that we have been using the term "eco-
logical risk assessment" a lot, and yet everything I have
heard is really referring to some sort of screening to
evaluate chemicals of potential concern. I do not know if
that is ecological risk assessment as much as it is just
deciding whether or not there is a potential problem at a
site. I think we need to make that distinction. The
question is directed to Dave Mount. When we look at
body burden relationships to toxicity, there have been
some studies that have looked at relationships across the
population, and they have shown that there is a range of
body burdens. So there is a sensitive organism that
responds at a low body burden, and then there is a very
hardy organism that does not respond until you get to a
very high body burden. That distribution of body burdens
gives us information about population response that
presumably would allow us to take the step beyond the
screening tool to evaluate whether or not body burdens
are potentially going to have a population effect. Given
the way are you structuring the database, are you going
to incorporate some of that kind of information that may
allow us to take that step?
David Mount:.
The answer, of course, is yes and no. There are several
issues that you bring up. One is where there were ranges of
concentrations for individual organisms within the popula-
tion that were evaluated. You can consult the original
citation to get more information on the ranges given in the
database. There is also some variation in the literature.
Studies either analyze the organisms that died, those that
survived, or some combination thereof. Those notations are
made hi the database, so we may be able to use this hi our
analysis. I really believe that one of the critical uses of the
database will be more as a pointer to answer specific
questions and less as the endpoint hi itself.
I might diverge a little bit and address the previous
question. Certainly we are looking very actively at tissue
residue-based approaches, but I think you have to bear in
mind a couple things. One is they are most effective when
you already have the tissue residue, which indicates they
are directly applicable. An example would be a
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yrpceedlngs
2-57
bioaccumulation test that is done as part of a dredged
material management monitoring program. A lot of the
decisions that get made are not related, or are not dealt
with, at the level of the tissue residue. You still have to
bridge back to environmental concentrations that relate
to, those residues. And that reopens the whole bag of
worms that we were trying to avoid by jumping to tissue
residues. So, we cannot fool ourselves that there are no
problems, just because some data that seemed disparate
collapse when we look at it on the basis of tissue residue.
There is still the fact that those chemicals that collapse on
the basis of tissue residue did not necessarily collapse on
the basis of environmental exposure.
So, the tissue residue approach is not so much a
direct interpretive tool, but it may teach us about
groups of chemicals or making estimates of acute or
chronic effect thresholds for chemicals that we have
relatively little data for. It does straighten out some
QS AR relationships that were formerly based on water
concentrations, but. were muddled by differences in
uptake or something else. And to me that is the real
scientific importance of the concept. I think the direct
regulatory significance is almost secondary. We need
.to make use of all the information we have. But there
are a relatively small number of instances where that
information is necessarily directly relevant. For ex-
ample, in a risk assessment, if you have extremely high
residues, you have some information about existing
risk, Almost always what is of interest in a risk
assessment is future risk or risk under various manage-
ment alternatives. And unless you can link those up, it
will not do all the good you want it to.
Q (Hector Laguette, Brown and Root Environmental): A
considerable amount of the discussion so far on tissue
residues has been-based on lipid-normalized values, and
I wonder if any consideration has been given to the
possible effect of the contaminants themselves on the
lipid metabolism of the organisms prior to the moment
when we do this normalization of concentrations. How
may this artifact be affecting some of the approaches that
we are talking about? ' • -
Burt Shephard:
On the database that we compiled, less than 25 per-
cent of the papers that we compiled reported the lipid
content of the species. So, it is really hard to make a
judgement, at least on what I have looked at. I do not
know how Dave feels about that.
David Mount:
Very true. Somebody mentioned this morning that
if they report lipid data, there are some issues of how it
was measured and how relevant that measure may be. To
support your point, I think Peter Landrum presented data
this morning to show exactly how lipid metabolism
affectedinterpretationofresidue-baseddata. In that case,
lipid normalization tended to explain the variation rather
than confound it. 'But, it is a relevant point.
Lynn McCarty:
One of the things I have a great deal of concern
about is actual lipid normalization of toxicity test results.
It is perfectly reasonable to do it for bioaccumulation
purposes, but when you normalize whole body residue
levels to a standard lipid content, you are making the
assumption that the whole body lipid content is reflective
of the lipid content at the site of toxic action. This is not
an assumption I would care to make. And we have very
little information about that sort'of thing. So, I think you
have to be very cautious in normalizing the data when you
are talking about toxicity. However, Burt has done this
and I think it has worked out. But we are doing it out of
ignorance, not necessarily out of knowledge. The fact that
it worked is not a reflection of whether it is right or not.
Maybe we were just lucky that time. Until we understand
that, we will have to be very careful about normalizing
toxicity data to lipid content.
Burt Shephard:
I am not sure I would agree that it was luck. There
is good reason to suspect that it would work out, but it is
an assumption. I will grant you that.
Q (Hector Laguette): I guess just from the point of view
of ecological risk assessment, it is one more of those things
that ends up being in the uncertainty analysis. It is
something that should be considered at the end.
Burt Shephard: • '. '
Another problem with lipid normalization is that
the lipid content of many species varies seasonally or
annually, so how do you take that into account as well?
The types of lipids also vary. There are a lot of
assumptions. I do not know if I was lucky or if the
EPA data that I based my data on was good. It might
be a little bit of both. In this case, it seemed to work
out, but there is. certainly some concern about lipid
normalization.
David Mount:
I think one of the issues that really comes to the floor.
when we start talking about all these other variables is that
some of these principles work very well, in general, and
they make good predictions of mean responses across
groups of chemicals. But there are subtleties in organisnial
factors, physical and chemical factors, or all sorts of other
things that cause individual chemicals to deviate from that
behavior. In a lot of regulatory programs, that deviation
is not considered acceptable. Making your best estimate
and constructing a worst reasonable case are two very
different tasks. There are exceptions that people consider
to be quite relevant. Some of these exceptions are not
accounted for in some of the very generalized models that we
useinthissortofanalysis. We all use log log plots, and the
noise around a log log plot is important to the decision that
gets made.
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National Sediment Bioaccumulation Conference
Bart Shephard:
The decision is also based in part on what you are
going to use your data for. Dave and I both did literature
reviews, but, in some cases, we had very different criteria
as to how we decided a paper could or could not be used in
ourliteraturejustbecause we had different uses forthedata.
Q (Tom O'Connor, NOAA): I did have a question for
Burt Shephard that addresses this issue of how extensive •
the problem of coastal contamination is. Your toxic
threshold concentration for cadmium, as I recall, was
about 0.04 parts per million. If I convert that to a dry
weight number, that is something like 0.2 parts per
million. I think that number is exceeded by most of the
mussels and oysters in the United States. Are we to
conclude that the contamination has put all these animals
at risk?
Burt Shephard:
We have run into the same problem. I will use
cadmium as an example. I have spent part of the summer
up in the Aleutian Islands where very few point sources
occur. We have some blue mussel data from up and down
the Aleutian Island chain that we have been collecting for
background information for use in a risk assessment at a
military base closure site in the Aleutians. As fate would
have it, the typical cadmium concentrations are about
half a part per million. We have a number of mussels
from various sites with no known point sources over one
part per million. That may be just the natural background.
For some reason, the mussels seem to be doing fine there.
Something I did not talk about at all, especially for
metals, is naturally occurring compounds. It is very
important in the risk assessment to do a proper back-
ground comparison with your site data. Background
comparisons can be done several ways. You can do the
mean of your sample population versus your background
population. You can also do, for lack of a better term, hot
spot comparison, comparing a high end mussel versus
some part of your distribution. You asked if I thought the
mussels are contaminated nationwide and showing ef-
fects. No, I do not. But very clearly, some other species
is going to show an effect at half a part per million. I
mentioned earlier that if you have species specific infor-
mation, that is obviously the best way to do a risk
assessment. If you havearange of data for blue mussels,
and you know thathalf a part per million cadmium causes
no adverse lexicological or ecological effect on blue
mussels, then you would certainly use that in preference
to a tissue screening number.
David Mount:
I think that addresses a real hazard and what I
consider a real abuse of a lot of assessment tools. We had
a discussion last week about one-tailed and two-tailed
criteria. If you are below a one-tailed criteria, for ex-
ample, you are confident mat there is no effect. But there
is no implication of effect if you exceed that. If you look
at the derivation of the tissue screening number, they are
entirely one-tailed from the way that they were devel-
oped. There is no reason to infer effect from an exceed-
ance. In fact, if you look at the way water quality criteria
were developed and the way they were written, they are
really one-tailed criteria. But people consistently infer
effect from an exceedance of a criterion, which is not
completely wrong. You should recognize, though, that
when you make that inference, you are buying into a set
of assumptions that may or may not apply. So, the
exceedance of one of the screening levels hi a healthy
organism should not come as a surprise to any of us. The
question is whether or not you consider the generaliza-
tions that went into the derivation of that number.
Q (Tom O'Connor): In that light at the other extreme, Jay
Field had a lot of data for PCBs in the fishes of the
Hudson River. Jay, what did you have for effects of these
PCBs?
Jay Field:
We were comparing tissue concentrations of PCBs
to literature-derived effect concentrations for total PCBs
and dioxin, using dioxin equivalent values for coplanar
PCBs. We did not measure effects in Hudson River fish
directly.
Q (John Haggard, General Electric Company}: Jay, one
of the things we are planning on the Hudson River is to
investigate and remediate active water column sources of
PCBs. We believe they are influencing the top surface
sediments. The subject of a lot of the- debate over the
years on remediation has been buried sediments, which
have different PCB congener signatures. In your work,
Jay, with the congeners and the fish, have you been able
to sort out the sources of the PCBs based on the congener
distributions, or are you still working on that?
Jay Field:
No, we did not attempt to distinguish among water
column, surface sediment or subsurface sediment sources.
I think you need other information to do that. You have
in-place sediment, recent releases of material through
ground water or non-aqueous phase layers as you have at
Bakers Palls. You also have sediment that is resuspended
and/or transported down river in every spring flood. So
separating out what is coming to the fish via the water
column (either suspended or dissolved) from recent re-
leases or sediment transport from past years is difficult to
determine based on congener pattern alone. But the
congener patterns in fish show a clear signal of what they
are exposed to at different locations along the river
gradient.
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National Sediment Bioaccumulation Conference
Session Three:
Modeling Bioavailability of
Sediment Contaminants
Nelson Thomas, Panel Moderator
U.S. EPA, Office of Research and Development,
Duluth, Minnesota
Dominic M. Di Toro
HydroQual, Inc,
Mahwah, New Jersey
Equilibrium Partitioning and Organic Carbon
Normalization
Victor A. McFarland
U.S. Army Corps of Engineers
Waterways Experiment Station,
• Vicksburg, Mississippi
Estimating Bioaccumulation Potential in Dredged
Sediment Regulation
Philip M. Cook
U.S. EPA, Office of Research and Development,
Duluth, Minnesota
Development of Bioaccumulation Factors for
Protection of Fish and Wildlife in the Great Lakes
Mary C. Reiley
U.S. EPA, Office of Science and Technology,
Washington, DC
From Modeling to Criteria: Integrated Approach to
Criteria Development
3-1
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National Sediment Bioaccumulation Conference
Equilibrium Partitioning and Organic
Carbon Normalization
Dominic M. Di Toro and Laurie D. De Rosa
HydroQual, Inc., Mahwah, New Jersey
Establishing sediment quality criteria (SQC) requires
a determination of the extent of the bioavailability
of sediment-associated chemicals., A full discus-
sion of the Equilibrium Partitioning (EqP) approach to
developing SQC is presented elsewhere (Di Toro et al.,
1991; USEPA, 1993). The main focus of this presenta-
tion is field observations of partitioning in sediments.
Consider a sediment sample that is segregated into vari-
ous size classes after collection. The particles in each
class were in contact with the pore water. If sorption
equilibrium has been attained for each class, then letting
Cs(j) be the particle chemical concentration of the jth size
class, it is true that
(D
where foc(j) is the organic carbon fraction for each size
class j, KOC is the partition coefficient for sediment organic
carbon, and Cd is the pore water concentration. On an
organic carbon-normalized basis, this equation becomes
where Cjoc(j) =
(2)
Tnis result indicates that the
organic carbon-normalized sediment concentration of a
chemical should be equal in each size class because Koc
and Cd are the same for each size class. Thus a direct test
of the validity of both organic carbon normalization and
EqP would be to examine whether C (j) is constant.
across size classes in a sediment sample.
Data from three field studies, Prahl (1982), Evans
et al. (1990), and Delbeke et al. (1990), can be used to
test this prediction. In Prahl's study, sediment cores
were collected at three stations near the. Washington
State coast (Stations 4, 5, and 7). These were sieved into
a silt-and-clay-sized fraction (<64 |jm) and a sand-sized
fraction (>64 |im). This latter fraction was further
separated into a low-density fraction (<1.9 g/cm3) and
the remaining higher-density sand-sized particles. The
concentrations of 13 individual polycyclic aromatic
hydrocarbons (PAHs) were measured in each size fraction.
It is important to realize that these size fractions are
not pure clay, silt, or sand, but are natural particles in the
Organic Carbon Fractions
100.0
10.0
.1.0
0.1
• Sta. 4
D Sta. 5
• Sta.'7
LOW SAND SILT/CLAY
Sediment Fraction
Source: Prahl, 1982
Figure 1. Organic carbon fractions:
Sediment fraction.
size classes denoted by clay, silt, and sand. The organic
carbon fractions, shown on Figure 1, range from
0,2 percent for the high-density sand-sized fraction to
greater than 30 percent for the low-density fraction. This
exceeds two orders of magnitude and essentially spans
the range usually found in practice. For example, 90
percent of the estuarine and coastal sediments sampled
for the National Status and Trends program exceed
0.2 percent organic carbon (NOAA, 1991).
Figure 2 (top) compares the dry weight-normalized
clay/silt-sized fraction sediment PAH concentrations,
Cs(j), to the sand-sized high- and low-density PAH conr
centrations on a dry weight basis. The dry weight-
normalized data have distinctly different concentrations—
the low-density high-organic carbon fraction is highly
enriched, whereas the sand-sized fraction is substantially
below the clay/silt fraction concentrations. Figure 2
(bottom) presents the same data but on an organic carbon-,
normalized basis, Csoc(j). In contrast to dry weight
normalization, the PAH concentrations are essentially
3-3
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3-4
National Sediment Bioaccumulation Conference
Dry Weight Normalization
Sand vs Clay/Silt Low Density vs Clay/Silt
1000
?
$ 100
i 10
1
10 100
PAHfrgfgdiywt)
1000
10000
1000
•100
10
10 100
PAHfpg/gdiywt)
1000
Organic Carbon Normalization
100000
g-10000
Sand vs Clay/Silt
Low Density vs Clay/Silt
1000
100.
100
1000 10000 100000
PAH (na'g oc)
Source: Prahl, 1982
100
Figure 2. Dry weight normalization and organic carbon normalization.
the same in each size class, as predicted by Equation 2.
The lines in Figure 2 represent equality and have been
added as a visual aid.
In the field data from Evans et al. (1990), sedi-
ments were collected at five sites along the River
Derwent, Derbyshire, United Kingdom, and separated
into six sediment size classes. The size
classes were representative of clay and
silt (<63 |im) to coarse sand (1.0 to 2.0
mm). Organic carbon content and total
PAH were measured in each sediment
size class. Figure 3 presents the size
classes and associated organic carbon
content. Evans et al. attribute the bimor
dal distribution of f^. to two types of
organic matter. Organic matter in the
1.0 to 2.0 mm size class may be from
fragmentary plant material, while the
size classes less than 500 pm have organic
carbon content that is'the result of aging
humic material. The organic content in
this study ranges from 2.0 to 40 percent.
Figure 4 presents a comparison of
PAH concentrationfordifferentsediment
classes for dry weight normalization and
organic carbon normalization. The top
left panel compares PAH concentrations
on sand (63-500 |im) and clay/silt
(<63 um) on a dry weight basis. The
top right panel compares PAH
dry weight basis. The data indicate
that the PAH concentration is higher
in the coarse sand fraction of sedi- '
ment. Recall from Figure 3 that the
clay/silt and coarse sand fractions
contain higher fraction organic car-
bon content. The bottom panels of
Figure 4 present the organic carbon-
normalized comparison of PAH con-
centrations by sediment class. For
both panels, the organic carbon-nor-
malizedPAH concentrations are simi-
lar regardless of the sediment size
class as predicted by Equation 2. The
lines in Figure 4 represent equality and
have been added as a visual aid.
Lastly, Delbeke et al. (1990)
collected sediments from seven sites in
the Belgian continental shelf and the
Scheldt estuary. These sites were
analyzed for eight polychlorinated
biphenyl (PCB) congeners and organic
carbon in the bulk sediment and clay/
silt (<63 um) sediment fraction. In
addition, analyses of the samples were
done to determine the percent of size
fractions ranging from 500 um to 3 um
that made up the sample. The PCB
- congeners tested for in this study were
IUPAC numbers 28,52,101,118,153,138,170, and 180.
Using concentrations reported for bulk samples,
concentrations for clay/silt samples, and percent size
fractions of each sample, calculations were done to
estimate concentrations on the >63 um portion of the .
sample. Similar calculations were done to determine
1000 10000 100000
PAH (ng/g OC)
Organic Carbon Fractions
10
J
DstaC 0StaH
• staDa IZJStaK
BstaG
63 ^m 63-125 \m 125-250 pm 250-500 pm ,0,5-1 mm 1-2 mm
SEDIMENT SIZE CLASS
Source: Evans et al., 1990
concentrations on coarse sand p. 3 Q carfe fractions. Sediment size class.
(0.5-2.0 mm) and clay/silt (<63 um) on a 6 &
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Proceedings
3-5
Dry Weight Normalization
1000
100
Sand vs Clay/Silt
I
1
10
0.1
1000
=- 100
Course Sand vs Clay/Silt
10
0.1
0.1
1 10 100
PAH (tig/g dry wt)
1000
0,1 1 10 100
PAH(ng/gdrywt)
1000
10000
_ 1000
1 ioo
10
Organic Carbon Normalization
Sand vs Clay/Silt Course Sand vs Clay/Silt
E O 63-125 urn
- A125-250 (i
-V 250-500 urn
10000
_ 1000
!
I
100
10
10 100 1000
PAHfrg/gOC)
10000
Source: Evans et al., 1990
10 100 1000
PAH (ng/g OC)
.10000
Figure 4. Dry weight normalization and organic carbon normalization.
Figure 5 presents the
percent organic carbon on the
<63 nm portion of the sample
(blackbar)andonthe>63 um
portion of the sample (white
bar). Comparisons of the PCB
congener concentrations on a
dry weight basis (top) and on
an organic carbon basis (bot-
tom) are shown in Figure 6.
Organic carbon content in the
>63 um class size at stations
2 and 4 is 0.01 percent and
0.06 percent, respectively, as
indicated in Figure 5. The
data for these stations are
shown on Figure 6 using
filled symbols. Though an
foc >0.2 percent has been pre-
sented as the value for which
organic carbon normalization
applies; normalization at
' these f^ values seems appro-
.priate for this data set.
The top panel of Fig-
ure 6 indicates no evident re-
lationship between PCBs in
the <63 um sample andPCBs
in the >63 |jm sample oh a dry
weight basis. When concen-
Organic Carbon Fractions
100 F
10 ;
1 =
J
0.01
0.001
= 1 1
1 1 1 1 =
: P >63nm • • -
I
1 <
63
\im
-
-
-i •'
' =
0.1 2 3 4 56 7-8
Station
Source: Delbeke et al., 1990
Figure 5. Organic carbon fractions: Station.
organic carbon content on the >63 um portion of the
sample. Organic content varied from 0.01 percent to
10 percent inclusive of both <63 um and >63 jam portions
of the sediment.
trations in either class size, are normalized to organic
carbon content, the concentrations are similar for both
class sizes as shown in the bottom paneL This indicates
that PCB concentrations are similar across sediment class
sizes, which supports organic carbon normalization. The
lines in Figure 6 represent equality and have been added
as a visual aid.
.The data from Figures 2, 4, and 6 are analyzed to.
quantify the reduction in variability when the data are
carbon-normalized. The variation of the y-axis values
from the line of unity presented hi Figures 2, 4, and 5
represents the residual difference 6f the y values from the-
x values. Coefficients of variation for these residuals are
presented in Figure 7 for dry weight- (black bar) arid
organic carbon-normalized (gray bar) data. The coeffi-
cients of variation are reduced significantly. It can be
concluded from the data of Prahl (1982), Evans et al.
(1990), andDelbeke etal. (1990) that the organic carbon-
normalized PAH and PCB concentrations are relatively
independent of particle size class and that organic carbon
is the predominant controlling factor hi determining the
partition coefficient of the different sediment size par-
ticles hi a sediment sample. The organic carbon concen-
tration of the high-density sand-sized fraction in Prahl's
data (0.2 to 0.3 percent) suggests that organic carbon
normalization is appropriate at these low levels. The data
from Evans et al. suggest that EqP can be applied to
organic carbon originating from more than one source, '
that is, fragmentary plant matter and aging humic material.
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National Sediment Bioaccumulation Conference
Dry Weight Normalized
CO
to
A
100
10
0.1
o 0.01
o.
Q QQ-| IX I tllHtK 1 MMfHI I I M I1W I I I IMHI 1 I.
0.001 0.01 0.1 1 10
I1H
100
PCB (ng/g) <63 |
Organic Carbon Normalized
0.1 1 10 100 1000 10000
PCB (ng/g OC) <63 urn
Source: Delbeke etal., 1990
References
Delbeke, K., RJ. Claude, and M. Bossicart. 1990.
Organochlorides in different fractions of sedi-
ments and different planktonic compartments of
the Belgian Continental Shelf and Scheldt Estuary.
--Environ. Pollut. 66:325-349.
Di Toro, D.M., C. Zarba, DJ. Hansen, W. Berry, R.C.
Swartz, C.E. Cowan, S.P. Pavlou, and H.E. Allen.
1991. Technical basis for establishing sediment
quality criteria for nonionic organic chemicals us-
ing equilibrium partitioning. Environ. Toxicol.
Chem. 10:1541-1583.
Evans, K.M., R.A. Gill, andP.WJ. Robotham. 1990. The
PAH and organic content of sediment particle size
fractions. Water Air Soil Pollut. 51:13-31.
NOAA. 1991. National Status and Trends Program—
Second summary of data on chemical contami-
nants in sediments from the National Status and
Trends Program. NOAA Technical Memorandum
NOS OMA 59. National Oceanic and Atmospheric
Administration, Office of Oceanography and Ma-
rine Assessment, Rockville, MD.
Prahl, F.G. 1982. The geochemistry of polycyclic
aromatic hydrocarbons in Columbia River and
Washingtoncoastalsediments. Ph.D.thesis. Wash-
ington State University, Pullman, WA.
USEPA. 1993. Technical basis for deriving sediment
qualify criteria for nonionic organic contaminants
for the protection of benthic organisms by using
equilibriumpartitioning. EPA822-R-93-011. U.S.
Environmental Protection Agency, Office of
Water, Washington, DC.
Figure 6. Dry weight normalized and organic
carbon normalized.
1000
Prahl, 1982 Prahl, 1982 Evans et al., 1990 Evans etal., 1990 Delbeke et at., 1990
Sand vs Clay/Silt Low Density vs Clay/Silt Sand vs Silt/Clay Coarse Sand vs Clay/Silt >63 urn vs <63 urn
B- Dry Wt Normalized Concentrations
- Organic Carbon Normalized Concentrations
Figure 7. Coefficients of variation.
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National Sediment Bioaccumulatlon Conference
Estimating Bioaccumulation Potential
in Dredged Sediment Regulation
Victor A. McFarland
U.S. Army Corps of Engineers Waterways Experiment Station, Vicksburg, Mississippi
The bioaccumulatipn potential of neutral organic
chemicals in dredged sediments is estimated from
sediment chemistry.. A simple model is used in
which concentration data are normalized on sediment
organic carbon and organism lipid and a biota/sediment
accumulation factor (BSAF) is applied. This presenta-
tion describes an experiment comparing predicted with
actual measured tissue concentrations of polynuclear
aromatic hydrocarbons (PAH) bioaccumulated from sedi-
ments by the clam Macoma nasuta.
Testing Requirements
Open water disposal of sediments dredged for
navigation purposes in the United States is regulated
under provisions of section 103 of the Ocean Dumping
Act (Marine Protection, Research, and Sanctuaries Act,
MPRSA, of 1972) and section 404 of the Clean Water Act
(CWA of 1972). Both laws require that the potential for
bioaccumulation of toxic chemicals associated with
dredged sediments be assessed as part of the regulatory
process when such chemicals are suspected or known to
be present. The guidance manuals for Implementation of
the laws use a tiered approach (USEPA/USACE, 1991,
1994). In the first tier, historical data, if it exists, is used
to judge whether there is a reason to believe that
bioaccumulating chemicals may be present and may be,
bioavailable to exposed organisms. In the second .tier,
bioaccumulation potential is estimated from sediment
chemistry data. If the potential for bioaccumulation
appears to exist, then 28-day laboratory' exposures of
benthic organisms and analysis of their tissues may
follow in the third tier. A fourth tier exists for special
situations in which a decision could not be made in any
earlier tier.
Theoretical Bioaccumulation Potential
The Tier II sediment screening test is referred to as
"Theoretical Bioaccumulation Potential" (TBP) and is
based on equilibrium partitioning. TBP is used only for
neutral organic chemicals and is simply the application of
a BSAF to sediment concentration data in order to estimate
the concentration that would result in an organism ex-
posed to the sediment as its only source of contamination.
In aquatic systems, neutral organic chemical contami-
nants such as the PCBs, PAHs, dioxins, etc. primarily
partition to the organic carbon of sediments and the lipids
of biota. Recognition of this fact led to the convention of
normalizing concentrations of neutral chemicals in sedi-
ments on the basis of their total organic carbon (TOC)
content and similarly normalizing concentrations in biota
on the basis of their lipid content. BS AFs are the ratio of
the normalized concentrations. Multiplying the TOC-
normalized concentration of a neutral chemical in sedi-
ment by the BSAF provides an estimation of the steady-
state body burden of that chemical in a sediment-exposed
organism:
TBP = 4(Cs/%TOC)%L
(1)
where Cs = concentration in- whole sediment, L = tqtal
ex'tractabie lipids in an organism of interest, and "4" is the
value assigned representing a generalized BSAF for all
neutral chemicals and biota.
In theory, the BS AFs for individual neutral chemi-
cals should not differ greatly from one another and can be
approximated by a single value. However, the model is
a simplification that does not accOunt for differences hi
bioavailability, the metabolism of compounds, disequi-
librium and non-constancy of exposure, organism feed-
ing behavior, or any of the other kinetic or measurement
processes that influence bioaccumulation. As such, TBP
is protective but not necessarily predictive.
Empirical BSAFs
B S AF data are compiled in a database accessible by
modem through an electronic Bulletin Board System at
the U.S. Army Corps of Engineers Waterways Experi-
ment Station, Vicksburg, MS (The Contaminants BBS,
601-634-4380). Entries include data on organism lipid
content, lipid extraction method, organic carbon content
of sediment, length of exposure, etc., and the source of the
data is given. The data are severely skewed, with most
3-7
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3-8
National Sediment Bioaccumulatlon Conference
BSAF values reported as less than 1.0. The frequency
distribution of all BSAF entries presently in the database
is shown in Figure 1. These data contrast sharply with the
universal AF used in the Tier IITBP calculations. The
universal BSAF (4) is at the 94th percentile of the
database and is about 12-fold greater than the median. .
Table 1 shows the medians and the interquartile ranges of
the BSAFs in the database by group. It can be seen that
the medians for the chlorinated groups (PCBs, dioxins/
furans, other chemicals) did not differ statistically. How-
ever, the median PAH BSAF ranged 16- to 22-fold lower
than any of these and is lower than the universal BSAF by
a factor of 125. The BSAF data were compiled with the
expectation that their use in Tier II dredged sediment
bioaccumulation potential calculations would provide
more predictiv^estimations than does the current practice.
This assumption was tested using the priority pollutant
PAH data of two studies conducted at the Waterways
Experiment Station (McFarland et al., 1994a, 1994b;
McFarland, 1995).
Field Study
Sediments and their resident infaunal and benthic
polychaetes and bivalve mollusks were collected at a
location on the continental shelf of the New York Bight
Apex. The location had low, but in most cases detectable,
concentrations of PAH compounds. Sediment TOC
content averaged 0.5 percent in the four samples taken.
The biota were pooled by taxonomic group and their
tissues analyzed for PAHs and for lipids. Three to five
replicates of the seven taxonomic groups were possible,
resulting in a total of 24 samples. The sediment and
organism PAH data were used to calculate BSAFs for the
15 individual PAHs and for the total of the 15 using
"Bootstrap" estimation methods (Manly, 1991).
Laboratory Study
Two sediments were collected in the San Francisco
Bay system. One was surficial material from the central
Bay (designated "Reference") and the other was from an ,
inner harbor turning basin known to be contaminated
(designated "Contaminated"). The total PAH concentra-
tion of Reference was about 1.6 (jg g"1 and that of
Contaminated was about 50 |ag g'1. TOC contents were
similar (0.926 and 1.10 percent). Bentnose clams,
Macoma nasuta, were collected from a clean area
(Tomales Bay, California) and exposed to the sediments
in a flow-through facility for 28 days. Exposures were to
either bedded sediment or to sediment continuously
suspended at about 50 mgL"1. At the end of the exposures
the tissues of the clams were analyzed for the 15 priority
pollutant PAHs, as in the field study sediments and
organisms. Lipids were also measured.
Bioaccumulation potential of the PAH compounds
in the San Francisco Bay sediments was estimated using
the TBP model and the PAH BSAFs generated by the
New York Bight field study. The lipid input data were
the mean concentrations of lipids in the Tomales Bay
clams at the end of the 28-day exposures in each treat-
ment. The predicted (TBP) PAH concentrations are
plotted against the concentrations measured at the end of
the 28-day exposures in Figure 2 for the Reference
sediment and Figure 3 for the Contaminated sediment.
Vertical and horizontal bars and caps are standard errors.
The diagonal line represents perfect agreement between
predicted and observed concentrations. Observations
falling below the line are cases in which measured values
exceed predicted. Observations above the line are the
reverse. Overestimates and underestimates are nearly
. equal in the Reference sediment exposures (15 and 17,
respectively) and are equal in the Contaminated sediment
exposures (16 and 16).
Figure 4 identifies the PAH compounds and shows
the distribution of the ratioed means. In the Reference
sediment exposures, 56 percent of the predicted concen-
trations were within a factor of 2 of the measured concen-
trations. In the Contaminated sediment exposures,
63 percent were within a factor of 2. For the Reference,
72 percent were within a factor of 3 and 75 percent of the
Contaminated were within a factor of 3. PAH compounds
for which the predicted/measured concentration ex-
ceeded or was less than a factor of 3 were acenaphthylene,
naphthalene, fluorene, dibenz[a,h]anthracene, andpyrene
in the Reference sediment exposures. In Contaminated
sediment exposures similar results were observed for
acenaphthylene, anthracene, fluorene, and indeno[ 1,2,3-
cd]pyrene. Only for anthracene, fluorene, and naphtha-
lene were statistically significant (P<0.05) differences
found when t-tests were performed comparing the boot
strap mean ,TBPs with the mean measured 28-day
concentrations.
Although there were individual cases showing large
differences between predicted and measured concentra-
tions, Figures 2 through 4 reveal numerous close corre-
spondences. In the case of the total (of the 15) PAH, the
'effect of averaging over- and underestimations results hi
very good correspondence. For the totals, the poorest
correspondence was 0.76 for the suspended Contami-
' nated sediment exposures, and the closest correspon-
dence was a ratio of 0.97 for total PAH in the suspended
Reference sediment exposures.
Acknowledgments
This work was sponsored by the U.S. Army Corps
of Engineers Long-term Effects of Dredging Operations
Program. Permission was granted by the Chief of Engi-
neers to publish this information.
References
Manly, B.F.J. 1991. Randomization and Monte Carlo
methods in biology. Chapman and Hall, New York,
NY.
McFarland, V.A. 1995. Evaluation of field-gen-
erated accumulation factors predicting the
-------
Proceedings
3-9
bioaccumulation potential of sediment-
associated PAH compounds. Technical Report
D-95-2. U.S. Army Corps of Engineers Waterways
Experiment Station, Vicksburg, MS.
McFarlarid, V.A., G.H. Lutz, and F.J. Reilly, Jr. 1994a.
Bioaccumulation data and analysis for selected
contaminants in sediments and biota of the New
York Bight Apex Mud Dump Reference Site. Re-
port to U.S. Army Engineer District, New York.
McFarland, V.A., J.U. Clarke, C.H. Lutz, A.S. Jarvis,
B. Mulhearn, andFJ. Reilly, Jr. 1994b. Bioaccu-
mulation potential of contaminants from bedded
and suspended Oakland Harbor Deepening Project
sediments in San Francisco Bay flatfish and bi-
valve mollusks. Miscellaneous -Paper EL-94-7.
U.S. Army Corps of Engineers Waterways Experi-
ment Station, Vicksburg, MS.
USEPA/USACE. 1991. Evaluation of dredged material
proposed for ocean disposal (testing manual).
EPA-503/8-91/001. USEPA Office of Marine and
Estuarine Protection, Washington, DC.
USEPA/USACE. s [1994]. Evaluation of dredged mate-
rial proposed for discharge in inland and near
coastal waters (draft) (Inland testing manual).
USEPA Office of Water, Washington, DC. In
review.
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3-10
National Sediment Bioaccumulation Conference
TABLE 1. DESCRIPTIVE STATISTICS
AND COMPARISONS OF GROUPED
DATA
Group
All BSAF
Invertebrates
Fish
Field Studies
Laboratory Studies
PCBs
PAHs
Dioxins/Furans
Other Chemicals
n
689
608
81
492
197
404
110
129
46
Median
BSAF
0.520
0.440
1.600
0.337
0.670
0.718
0.032
0.514
0.598
25%ile
0.139
0.101
0.735
0.065
0.428
0.230
0.006
0.269
0.065
75%ile
1.453
1.120
2.600
1.525
1.393
1.820
0.299
1.275
1.800
t-test
on
rankits
A*
A
B
A
C
C
D
C
AC
*Groups with same letter are not significantly different, P < 0.05
FIGURE 1. FREQUENCY DISTRIBUTION OF BIOTA/SEDIMENT
ACCUMULATION FACTORS (BSAF) IN CONTAMINANTS BBS DATABASE
140
UJ 100-1
H
5 so :
111
CQ 40
&
Z> 20 -
0
n = 689
median = 0.520
_TL
0.0
1.0
2.0
3.0 ' 4.0
BSAF
5.0
6.0 .7.0
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Proceedings
3-11
FIGURE 2.TBP-PREDICTED vs MEASURED PAH BIOACCUMULATION IN
CLAMS EXPOSED TO REFERENCE SEDIMENT
Bedded Sediment
Suspended Sediment
0.01 0.1 1 10
Measured Concentration, ng g"
FIGURE 3. TBP-PREDICTED vs MEASURED PAH BIOACCUMULATION IN
CLAMS EXPOSED TO CONTAMINATED SEDIMENT
8
=0"
10000
O)
O) 1000 -
£=
.g
CO 100 -
•I— •
I
o
O
10 -
1 H
0.1
0.1
• Bedded Sediment
• Suspended Sediment
Line of Unity
10
100
1000
10000
Measured Concentration, ng g
,-t
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3-12
National Sediment Bloaccumulation Conference
FIGURE 4. AGREEMENT BETWEEN PREDICTED AND MEASURED
BIOACCUMULATION: TBP/TISSUE CONCENTRATIONS
acenaphthene
acenaphthylene
anthracene
benz[a]anthrace
benzo[a]pyrene
benzo[b+k]fluor
benzo[g,h,i]per
chrysene
dibenz[a,h]ant
fluoranthene
fluorene
indeno[1,2,3-cd]
naphthalene
phenanthrene
pyrene
Total of 15 PAH
- D AJ7
O
a
a
P)
- (D
OL$7
O
. a o
^ o
A
D REF-BEDDED
O REF-SUSPENDED
A CONTAM-BEDDED
V CONTAM-SUSPENDED
AV
a
o
-101 2 3 4 5 6 7 8 9 10 11 12 13 14
PREDICTED/MEASURED BIOACCUMULATION
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Proceedings
3-13
ESTIMATING BIOACCUMULATION
POTENTIAL IN DREDGED SEDIMENT
REGULATION
Victor A. McFarland
USAE Waterways Experiment Station
Vicksburg, Mississippi
OPEN-WATER DREDGED
MATERIAL DISPOSAL IS
REGULATED BY:
• Section 103 of PL-532 of 1972, the
Marine Protection, Research and
Sanctuaries Act (coastal waters)
! -
• Section 404 of PL-530 of 1972, the
Clean Water Act (inland and coastal
waters)
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3-14
National Sediment Bioaccumulation Conference
THE IMPLEMENTATION MANUALS
USE A TIERED-TESTING APPROACH
TIER I
TIER II
TIER III
TIER IV
HISTORI
"REASON
28-DAY BIOACCUMULATION TEST
(MEASURE OF RELATIVE
BIQAVAILABILITY) J „
DEFINITIVE BIOACCUMULATION
(STEADY STATE}
APPROPRIATE USE OF TBP:
"The TBP calculation in Tier II is applied
as a coarse screen to predict the magnitude
of bioaccumulation likely to be associated
with nonpolar organic contaminants in the
dredged material."*
'Draft Inland Testing Manual, June 1994, p. 120.
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Proceedings
3-tS
TBP:
Is based on equilibrium partitioning
Applies only to neutral chemicals
Uses sediment chemistry data
Normalizes concentration data on:
> Organic carbon in sediments
> Lipid in exposed organisms
EQUILIBRIUM PARTITIONING
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3-16
National Sediment Bioaccumulation Conference
SOLUBILITIES OF SOME ORGANIC SOLUTES
IN ORGANIC SOLVENTS OR IN WATER, g/mL
NAPHTHALENE
PHENANTHRENE
LINDANE
DDT
TOLUENE
OR
BENZENE
0.29
0.42
0.29
0.78
OLIVE OIL
OR
PEANUT
OIL
0.13
NA
NA
0.11
CHLORO-
FORM
0.50
NA
0.24
NA
•
CARBON
TETRA-
CHLORIDE
0.50
0.42
NA
'0.45
WATER
8.80E-7
1.06E-9
1.70E-9
3.10E-12
TBP = 4(Cs/%TOC)%L
TBP = Estimated tissue concentration
4 = An "appropriate" bioaccumulation
factor
Cs = Chemical concentration in sediment
TOC = Sediment total organic carbon
L = Organism lipid
#The factor, 4, is a universal
biota/sediment accumulation
factor (BSAF)
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Proceedings
3-17
DESCRIPTIVE STATISTICS AND
COMPARISONS OF GROUPED DATA
Group
AH BSAF
Invertebrates
Fish
Field Studies
Laboratory Studies
PCBs
PAHs
Dioxins/Furans
Other Chemicals
n
689
608
81
492
197
404
110
129
46
Median
BSAF
0.520
0.440 '
1.600
0.337
0.670
0.718
0.032
0.514
0.598
25%ile
0.139
0,101
0.735
0.065
0.428
0.230
0.006
0.269
0.065
75%ile
1.453
1.120
2.600
f.525
1.393
1.820
0.299
1.275
1.800.
t-test
on
rankits
A*
A
B
A
C
C
D
C
AC
*Grdups with same letter are not significantly different, P < 0.05
TWO STUDIES:
East Coast
Field study
Collected benthic infauna
and sediments
Analyzed both and
calculated BSAFs
West Coast
Lab study.
Collected high and low
contamination sediments
and analyzed
Collected mussels and
clams from clean site
Used field study BSAFs to
calculate TBPs
Exposed bivalves to the
sediments
Compared TBP estimations
with actual bioaccumulation
-------
3-18
National Sediment Bloaccumulation Conference
MEANS COMPARISONS
• Performed t-tests on bootstrap mean TBP
and measured mean 28-day tissue
concentration for each compound in each
treatment
• 5-6 replicates of each treatment
• 1,024 bootstrap iterations for each
comparison
• only anthracene, fluorene, and naphthalene
were significantly different at P < 0.05
CONCLUSION
• For PAH compounds and probably for
other neutral organics empirical
BSAFs can provide reasonably good
estimates of bioaccumulation
potential
• Estimates for total PAHs are very
good
-------
National Sediment Bioaccumulation Conference
Development of Bioaccumulation
Factors for Protection of Fish and
Wildlife in the Great Lakes
Philip M. Cook and Dr. Lawrence P. Burkhard
U.S. Environmental Protection Agency, Office of Research and Development,
Duluth, Minnesota .
Bioaccumulation factor (B AF) development for ap-
plication to the Great Lakes, and in particular for
the recent Great Lakes Water Quality Initiative
(GLWQI) effort of U.S. EPA and the respective Great
Lakes states, illustrates the importance of the linkage
between sediments and the water column and its influence
on exposure of all aquatic biota. This presentation in-
cluded a discussion of the development and application of
. bioaccumulation factors for fish, both water-based BAFs
and biota-sediment accumulation factors (BSAFs), with
emphasis on the role'of sediments in bioaccumulation of
persistent, hydrophobic non-polar organic chemicals by.
bothbenthic and pelagic organisms. Choices of bioaccu-
mulation factors are important because they will strongly
influence predictions of toxic effects,in aquatic organ-
isms, especially when chemical residue-based dose-re-
sponse relationships are used.
There were two principal bioaccumulation factor
expressions used by the GLWQI. TheBAFfis based on
Upid-normalized concentration of the chemical in the
organism,with respect to the.concentration of freely
dissolved (bioavailable) chemical in the water. The BSAF
is the lipid-normalized concentration hi the organism
with respect to organic carbon-normalized concentration
in the sediments. BSAFs were used to determine BAFf s
for chemicals with concentrations which have not been
measured in Great Lakes water but are detectable hi
sediments and fish. Equilibrium partitioning of persis-
tent non-polar organic chemicals generally occurs be-
tween sediments and benthic invertebrates and a thermo-
dynamic equilibrium or fugacity approach is useful for
describing the degree of equilibrium (or disequilibrium)
associated with bioaccumulation in fish. However, mea-
suredB AFf s and BSAFs generally indicate a state of non-
equilibrium partitioning from sediments to fish. BAFfs
and BSAFs may be determined and applied as steady-
state relationships which incorporate degrees of disequi-
- librium, such as normally present between water and
sediment or between fish and water due to the
biomagnification phenomenon. ;,
The bioaccumulation cube (Figure 1) is a concep-
tual model which includes the most important generic
factors that must be considered when predicting bioaccu-
mulation from measured or predicted concentrations of
chemicals in the water and sediments of the ecosystem.
The bioavailability considerations that remain, after in-
corporating the influence of organism lipid, organic car-
bon in water and sediments, and trophic level into B AFf s
and BSAFs to reduce uncertainty for site-specific
bioavailability conditions, are shown on the z-axis. Ba-
sically, this residual bioavailability factor is the chemical
distribution between water and sediment .which can vary
between ecosystems or vary temporally and spatially
within an ecosystem. Chemical properties which influ-
ence bioaccumulation are shown on the x-axis. The
octanol-water partition coefficient (Kow) is the primary
indicator of chemical hydrophobicity and bioaccumula-
tion potential. A second chemical factor is metabolismby
organisms in the food chain. Metabolism is strongly
related to chemical structure as well as the presence or
absence of specific metabolizing enzymes in different
organisms in the food chain. The rates of metabolism of
a bioaccumulative chemical by the different organisms in
a food chain will determine the.extent to which rates of
elimination of the chemical will be faster than that pre-
dicted on the basis of Kow in the absence of metabolism.
Conceptually, the cumulative effect of metabolism in the
food chain can be equated to a factor K^^ which could
be subtracted from Kow to correct for the degree of reduced
bioaccumulation associated with metabolism.
Ecosystem conditions, such as riverine/lacustrine
character, temperature, and trophic condition, as illus-
trated on the y-axis of the bioaccumulation cube, may be
an important consideration when trying to extrapolate
from one ecosystem to another. The degree to which
quantitative differences in bioaccumulation may be at-
tributable to particular ecosystem conditions, apart from
the influence of organic carbon which is handled as a
bioavailability variable, is not well known. Bioaccumu-
lation data of the quality neededfor quantitative measure-
ment of these relationships for different ecosystems are
very limited. Finally, recognition that the food chain has
to be.defined when modeling bioaccumulation and
biomagnification creates a fourth dimension, the trophic
3-19 ,
-------
3-20
level, within the bioaccumulation cube; i.e. the bioaccu-
mulation cube exists for each trophic level or more spe-
cific definition of food chain.
The procedures used in the GLWQI for predicting
bioaccumulatation are reported in the form of a technical
support document (U.S. EPA, 1995) which is available
from NTIS. Although bioaccumulation factors can be
specific for ecosystem conditions and for the structure of
the food chain, they may be less site-specific hi regard to
bioavailability conditions. However, in the GLWQI,
BAFf s were developed based upon the concentration of
freely dissolved chemical in water because this greatly
reduces bioavailability conditions as a source of variabil-
ity between sites. The fraction of the chemical in water
which is not partitioned to particulate organic carbon and
dissolved organic carbon (fraction freely dissolved) is
considered to be the fraction which is bioavailable. The
fractionfreelydissdlved(ff'1) chemical can beestimated as:
(1)
where POC is the concentration of particulate organic
carbon, DOC is the concentration of dissolved organic
carbon.andK^andK^ are therespectiveorganic carbon-
water partition coefficients. FortheGLWQI, K was set
equal to Kow for each chemical, and K^, basecfon Great
Lakes water data, was set equal to one-tenth of K
reflecting the lesser partitioning power of dissolved or-
ganic carbon.
The distribution of chemicals between the sedi-
ment and water column can be characterized with a
sediment-water concentration quotient (TI^J which is
the ratio of the organic carbon-normalize'd'concentra-
tion in surface sediments to the freely dissolved chemical
concentration in water. With Lake Ontario data (Oliver
and Niimi, 1988) and the POC and DOC partitioning
model (equation 1), U^ can be related to the degree of
chemical equilibrium or disequilibrium (Figure 2). The
values of log E^, for chemicals with varying log K are
above the line which represents a fugacity ratio of one,
or AW eg"31 to !°g K • This reflects a degree of
chemical disequilibrium in Lake Ontario which is prob-
ably common to most of the Great Lakes since the early
1970s. Based on linear regression, the H value for
these data would be about 25 times Kow, or about 25-fold
theoretical disequilibrium between the sediment and the
water column under recent conditions in Lake Ontario.
A significant portion of this disequilibrium may be an
ecosystem characteristic as a consequence of the differ-
ence between the fraction of organic carbon in sediments
and the fraction of organic carbon associated with par-
ticulate material in the overlying water.
BAFfpredictionsforchemicalswithlogK s greater
than 5 are quite sensitive to variations in II when II /
Kw = 25 (Figure 3). Using the Gobas bScumulatton
model (Gobas, 1993), Burkhard (1997) demonstrated that
a 10 percent increase in the Lake Ontario fl^, which is
National Sediment Bioaccumulation Conference
the same as increasing the sediment concentration by 10
percent while holding the water column concentration
steady, results hi nearly a 10 percent change in BAF^s.
Predictions of bioaccumulation in the form of the BAFfds
for organisms throughout the food chain are strongly
influenced by change in the 11^ value when water is at
disequilibrium with surface sediments (Burkhard, 1997).
In other words, B AFf s for chemicals with log K s > 5 are
strongly benthicaUy linked under this condition of dis-
equilibrium, even when the benthic food chain connec-
tion may be small. If the ratio of U^ to Kow is close to one
(equilibrium between the water and sediment which theo-
retically could occur in other locations), the sensitivity of
to6 nso™is quite different (Figure 4). The relationship for
sculpin is more sensitive, reflecting its stronger benthic
connection to the sediments. The BSAF sensitivity to
change in IIsocw is the opposite of the BAFf sensitivity;
i.e., when the BAFf sensitivity is large, the BSAF sensi-
tivity is small. This is not surprising since H equals the
ratio of theBAFf totheBSAF. In summary (figure 5) the
sensitivity of BAFf s and BSAFs to II30CW depends on the
Kow of to6 chemical, the benthic/pelagic relative contribu-
tion to the food chain, and the degree of disequilibrium
between the sediment and the overlying water. The
relative sensitivity of BAFf s and BSAFs to IIS could be
an important determinant, under particular site-specific
conditions and chemical Kows, of whether a water-based or
a sediment-based bioaccumulation factor should be used
for prediction of bioaccumulation.
SelectionofBAFfsfortheGreatLakesWaterQual-
ity Initiative involved a tiered approach. Preference was
given to high-quality, field-measured values. Unfortu-
nately, for many chemicals these values do not exist.
Second preference was given to BAFf s predicted using a'
BSAF methodology, which is described below. The third
and fourth tier procedures involved calculation of food
chain multipliers to account for biomagnification. In the
third tier, the food chain multiplier is multiplied by a
measured bioconcentration factor (BCF) and, in the fourth
tier when BCFs are not available, the octanol-water parti-
tion coefficient is used as a surrogate for the lipid-normal-
ized bioconcentration factor based on freely dissolved
chemical in water (BCFf).
The second tier method, which uses BSAFs to cal-
culate BAFf s, was derived using the following relation-
ship between BAFf, BSAF, and H :
n =
•socw BSAF
(2)
For many chemicals hi the Great Lakes, under present-day
conditions, ratios of U^ to Kow (fugacity ratios between
sediment and water) are similar:
/ en ),
socw a _ socw
(3)
-------
Proceedings • :
With this condition, equation 2 can be substituted into
equation 3 and, following rearrangement, the resulting
equation 4 can be used to calculate (BAFfs)j for
chemicals (I) such as TCDD which cannot be routinely
measured in water at this time:
fd _
(BAF, ){-
TheBSAF method uses reference chemicals (r), such
. as PCB congeners, for which (BAFf )rs carioften be accu-
rately measured. If areferencechemicalthathasthesame ,
K as the unknown chemical is chosen, the Kpw ratio in the
equation becomes one and the calculation is simplified
further. Figure 6 illustrates BAFf s calculated from Lake
Ontario data with the B'S AF method. The distribution of
the PCB congener B AFf s (circles) provides the expected
increase in bioaccumulation and biomagnification with
respect to magnitude of Kow. In contrast, the dioxins and
furans are predicted to have quite smaller bioaccumulation
factors (on the basis of Kow). This is primarily because of
the effect of metabolism in fish which is effectively
measured by theBSAFs and incorporated into theBAFfs.
Even though metabolism rates are slow, the increase in
elimination rate of the parent chemical is significant and
dramatically reduces the bioaccumulation potential with
respect to PCB s with the same Kow.
To evaluate the BSAF method, BAFf s measured in
Lake Ontario were compared to predicted BAFf s calcu-
lated from Lake Ontario BSAFs (Figure 7) and were in -
good agreement. A further evaluation was performed by
comparing BAFf s calculated from BSAFs for PCBs. in
Lake Ontario for trout to B AFf s independently calculated
fromBSAFsinGreenBay forbrowntrout(Figure8). These
values were also in agreement despite the disparate eco-
systems and measurements involved. >
The determination of food chain multipliers (ratio
of BAFf to Kow) for prediction of BAFf s from Kows was
accomplished with a food chain model (Gobas, 1993)
' using Lake Ontario data and conditions. The objective
was to calculate food chain multipliers for bioaccumulative
organic chemicals and use : them .with Kow to estimate
BAFfds. Figure 9 illustrates how the predictions with food
chain multipliers compared to measured B AFf s with the
datareportedby Oliver andNiimi (1988) for Lake Ontario.
The agreement is very good, particularly for the higher Kow
chemicals which are not metabolized, which in this case
are primarily PCBs. The food chain multipliers that were
calculated using the .Gobas 'model reflect -a biomag-
nification potential that is a function of Kbw for the two top
trophic levels of predator fish and forage fish. Under the
conditions of the model, the zooplankton are considered
to be at equilibrium with respect to the water and benthic
invertebrates at equilibrium with respect to the sediment.
Bioaccumulation factors can facilitate bio-
accumulation predictions in ecological risk assessments
involving impacts of complex mixtures of chemicals. The
joint toxicity of chemicals that share similar structure and
common mode of toxic action with TCT3D (2,3,7,8-
tetracholorodibenzo-rp-dioxin) can be predicted with an
3-21
additivity model using the TCDD toxicity equivalence
approach. TCDD toxicity equivalence factor's (TEFs) are
essentially toxicity potency estimates relative to TCDD
such that a chemical with a TEF of 1 has a potency equal •
to that of TCDD* The toxicity equivalence concentration
(TEC) is calculated as the sum of the products of the TEF , ,
times the concentration for each chemical in a mixture.
Often a key question involves what media the concentra-
tions should be based upon. TECs have been calculated
based on chemical concentrations in effluents, sediments,
or water. TECs based on concentrations of the chemicals
in tissue are preferable because of the direct connection
between concentration in the tissue and the dose-response
relationship for a toxic effect. If a TEC associated with a
contaminant mixture in sediments is desired, the TEC can
be expressed in terms of the concentrations expected in a
fish as a result of bioaccumulation (TEC^). TheTEC^h
can be directly related to the potential for toxic effects in
the fish (Cook etal., 1997a),ortowUdlifeorhumans,that.,
eat the fish, arid is calculated as the sum of products of the
brgariic carbon-normalized concentration in sediment
(C ) tunes the BS AF (equation 5) and the TEF for each of
n chemicals. The fraction lipid(f) in the fish is included
.when the TECfish is calculated on the basis of whole fish,
rather than lipid-normalized concentration. A TECf]sh can
similarly be calculated for chemical concentrations in
water with B AFf s.
) f (BSAFfish) i (5)
Equation 5, as adapted for lake trout eggs, was used
retrospectively to determine the influence of TCDD and.
related chemicals on lake trout reproduction and popula-
tion dynamics of lake trout in Lake Ontario since 1920
(Cooketal., 1994,1997). Radionuclide-dated sediment
sections from sediment cores were essential for construc-
tion of a historical exposure record which was then linked
to effects on lake trout through the lake trout egg TCDD
dose-early life stage mortality response relationship
(Walkeretal., 1994). The use of the lake trout egg TCDD
.dose-response relationship requires use of TEFs and
BSAFs basedonconcentrationsofchemicalsintrouteggs
to calculate TCDD toxicity equivalence concentrations
which were based on lake trout eggs (TECeggs). Figure 10
summarizes the information that was generated by this
analysis. The y-axis represents the chronology in years for •
Icmincrementsfromthekeyreferencesedimentcorefrom
eastern Lake Ontario which were analyzed by high reso-
lution gas chromatography/high resolution mass spec-
trometry. This core was selected to represent trends in
Lake Ontario exposure conditions in this century. The
toxicity equivalents of the more important congeners
present in the 1 cm increments of sediment are plotted
cumulatively on the x-axis such that each horizontal bar
represents the TECe predicted for lake trout on the basis
of equations. Thee§SAFeggs were adjusted to accommo-
date the effect of differences in [!„„,, attributable to greater
chemical loadings to the lake prior to 1970.
11
-------
3-22
The relationship between predicted TEC s and
predicted degree of lake trout early life stage mortality is
also indicated in Figure 10. For example, during the
period from the 1940s to the 1970s, 100 percent early life
stage mortality is predicted for this very sensitive fish
species. The epidemiological records from Lake Ontario
are consistent with this prediction, despite complications
associated with the presence of non-chemical stressors
such as sea lamprey predation and over-fishing during the
period in which the lake trout population declined to
virtual extinction by 1960. During the period of recovery
of Lake Ontario after 1970, when lake trout were stocked
and large populations of adult trout were restored, natural
reproduction has not been achieved. However, eggs were
collected from the stocked fish, fertilized, and early life
stage development and survival monitored under labora-
tory conditions. The incidence of mortality due to blue-
sac syndrome associated with TCDD was observed in the
laboratory and is in good agreement with the percent
mortality predicted with the TECe model. After 1985,
measured concentrations of TCDD8and related chemicals'
in lake trout eggs were below the threshold for mortality
associated with the blue-sac syndrome, and field observa-
tions of lake trout sac fry presence on spawning reefs
increased with the first observations of 1- to 2- year old
lake trout from natural reproduction occurring in 1994.
BAFjds and BSAFs can be critical components of
water and sediment criteria development. For example, to
create a sediment criterion for the protection of future lake
troutpopulations in the GreatLakes, the following factors
should be considered: (1) the concentration of TCDD in
the eggs that would be associated with no adverse effects
to early life stages of lake trout (this includes effects at
sublethal exposures that reduce survival of sac fry and
alvins) and (2) theBSAF s for lake trout under a IT
condition expected during the time period of interest. The
concentration of TCDD in sediment that would be associ-
ated with a lack of adverse effects (sediment criterion) can
be calculated from the concentration of TCDD in the egg
associated with the threshold for toxic effects divided by
the BS AF . Similarly, a water criterion can be calculated
using the BAFf for TCDD.
To relate these TCDD criteria, whether they be
sediment criteria or water criteria, to organisms exposed
to complex mixtures of TCDD and related chemicals,
differences in bioaccumulation must be considered along
with the differences in toxic potency as expressed with
TEFs. Bioaccumulation potentials of the different chemi-
cals contributing to dioxin toxicity risks can be referenced
to TCDD as with TEFs. In the GLWQI these were named
bioaccumulation equivalency factors. The sum of TCDD
toxicity equivalents is directly comparable to the water
quality criterion or sediment quality criterion for TCDD
under the TCDD toxicity equivalence model.
In conclusion, BAFfs and BSAFs are essential for
application of chemical-residue-based criteria in risk as-
sessments and are interrelated through the sediment-water
concentration quotient (fl^J, particularly for the more
National
:Bic
hydrophobic organic chemicals. They can incorporate
elements of site-specific bioavailability. They are a spe-
cific interface between exposure assessments and effects
assessments. They are a primary output in food chain
bioaccumulation models used for validation of the mod-
els and comparisons to field data. Finally, measured
bioaccumulation factors are effective for prediction of
bioaccumulation in association with water or sediment
quality criteria when used appropriately with time-aver-
aged exposure estimates for persistent organic chemicals,
especially those with a higher K
0 ow
References
Burkhard, L.P. 1997. Comparison of two models for pre-
dicting bioaccumulation of hydrophobic organic
chemicals in a Great .Lakes food web. Environ.
Toxicol. Chem., in press.
Cook, P.M., B.C. Butterworth, M.K. Walker, M.W.
Hornung, E.W. Zabel and R.E. Peterson. 1994.
Lake trout recruitment in the Great Lakes: Relative
risks for chemical-induced early life stage mortal-
ity. Soc. Environ. Toxicol Chem. Abstr. 15: 58.
Cook, P.M., E.W. Zabel and R.E. Peterson. 1997a. The
TCDD toxicity equivalence approach for character-
izing risks for early life stage mortality in trout. In
Chemically-induced alterations in the functional
development and reproduction of fishes, eds. R.
Rolland, M. Gibertson and R. Peterson, Chapter 2.
SETAC Press, Pensacola, FL, in press.
Cook, P.M., D.D. Endicott, J. Robbins, P.J. Marquis, C.
Berini, J J. Libal, A. Kizlauskas, P.D. Guiney, M.K.
Walker, E.W. Zabel, and R.E. Peterson. 1997b.
Effects of chemicals with an Ah receptor mediated
mode of early life stage toxicity on lake trout
reproduction in Lake Ontario: Retrospective and
prospective risk assessments. Submitted for publi-
cation.
Gobas, F.A.P.C. 1993. A model for predicting the
bioaccumulation of hydrophobic organic chemi-
cals in aquatic food-webs: Application to Lake
Ontario. Ecological Modeling 69: 1-17.
Oliver, E.G. and A.J. Niimi. 1988. Trophodynamic
analysis of polychlorinatedbiphenyl congeners and
other chlorinated hydrocarbons in the Lake Ontario
ecosystem. Environ. Sci. Technol. 22: 388-397.
U.S. EPA. 1995. Great Lakes Water Quality Initiative
technical support document for the procedure to
determine bioaccumulation factors. EPA-820-8-
005, NTIS PB95187290, 185pp.
Walker, M.K., P.M. Cook, A.R. Batterman,
B.C. Butterworth, C. Berini, J. J.Libal, L.C. Hufhagle
and R.E. Peterson. 1994. Translocation of 2,3,7,8-
tetrachlorodibenzo-p-dioxin from adult female lake
trout (Salvelinus namaycush) to oocytes: Effects on
early life stage development and sac fry survival.
Can. J. Fish. Aquat. Sci. 51: 1410-1419.
-------
Proceedings
3-23
Figure 1.
Framework for Predicting Bioaccumulation Factors
Applicable to Different Aquatic Ecosystems
• Food
Chain
Model
/EcosystemS
V Conditions/
4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5
log (K0^ - Kmetab)
(Chemical Properties)
Figure 2.
10
JTe
Sediment-water column chemical concentration quotient
for Lake Ontario data of Oliver and Niimi (1988)
Pesticides Cl-benzene^C.-to.uenes pCBCongenere
• . O *
LogKow
DOC = 2 mg/L & Kdoc= Kow/10
Sediment organic carbon content = 2.7%
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3-24
National Secttment Bioaccumulatton Conference
Figure 3.
1.2
1
0.8
0.6
1 0.4
.1
w
0.2
o
(0.2)
(0.4)
2
Sensitivity of Food Chain
to nsocw (+1 0%) (Gobas 1 993 Model)
HSOCW /Kow = 25
1 Sensitivity = ...^
IIsocwABAFf //?
(-0.1)nSOCw-BAFjd ///
// /
// •/'
// ,.'
,/,'.-•'
-«^-:-'
Zooplankton Dlporeiasp. Sculpin' Atewifa Smelt Piscivorous Fish
' ' ' ' ' ' ' ' ' ' • |
3 4 5 '6 7 8 9
Log Kow
Rgure 4.
1.2
1
0.8
0.6
.-&
4» 0-4
* 0.2
0
(0.2)
^n /IN
lu-iv
2
Sensitivity of Food Chain
to nsocw (+1 0%) (Gobas 1 993 Model)
nsocw/Kow= 1
- . ... , nsocw • ABAFjd
Sensitivity™ •
^ ""'. (-O.I)nsocwBAFf1 ^ '
/
1
..-.r.-.rvr....
•• #•*' •"».•-...
/ f .„..„..„.....-..— _._.— ,.T-Si.^,.r.:.r..'.r.:.
_-l— ^^"
Zooplankton Diporeiasp. Sculpin Alewife Smelt Piscivorous Fish
— — - -..._..
1 1 1 1 . l.l.i. |
3 4 5 6 789
Log Kow
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Proceedings
3-25
Figure 5
Sensitivities of BAFJjd s and BSAFs to changes in nSOcw depend on:
1. Kow of chemical
2. Benthic/pelagic contribution to food chain
3. Disequilibrium between sediment and overlying water (SOC - POC - C™)
Predicted Lake Ontario Lake Trout BAFs
PCDDs.PCDFs chlordanes/nonachlors
* • •
3
Referenced to O-N BAF for PCB 52
Doc=2mg/L & Kdoc=Kow/10
-------
3-26
National Sediment Bioaccumulation Conference
Figure 7.
Lake Ontario Salmonid BAFs
Correlation of Measured BAFs to BSAF Predicted
OKvor & NUml - Refereread to BAF for PCB 52
Doo=2mgrt. & KdociKbwflO
6 7 8
Oliver & Niimi measured log BAFs
10
Figure 8.
10
Correlation of L. Ont. & G. Bay log BAFs
5 6 • 7 8
Mean Lake Ontario log BAFs from BSAFs
ERLD GB B.Trout Region 3A/3B BAFs rsf. PCB 52 ' '
Doc=2-5mg/L & Koc=Kow/10
10
-------
Proceedings
3-27
Figure 9.
Measured and Predicted BAFs for Piscivorous Fishes
• Measured BAFs from Oliver and Niiml (1988)
* *
Pesticides
• ' •
Cl-benzenes, Cl-toluenes
&HCBD
. 'O; •
PCB Congeners
*
BAFs Predicted using
FCMs
8
Figure 10.
Lake Ontario Lake Trout Egg RTEC Retrospective
Contribution of Individual Chemicals .
D 2378 TCDD
• PCB 126
E3 23478 PeCDF
• T2378PeCDD
• 123478 HxCDF
H PCB 77
• 2378 TCDF
GO Other •
50 100 150 200 . 250
CUMULATIVE TCDD TEQ (pg TCDD/g egg)
300
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National Sediment Bioaccumulation Conference
From Modeling to Criteria: Integrated
Approach to Criteria Development
Mary C. Reiley
U.S. Environmental Protection Agency, Office of Science and Technology, Washington, DC
JPB^he Office of Water's Water Quality Criteria Program
I (CWA Section 304(a)) is at a major crossroads in its
.M. evolution. The national program currently develops
chemical criteria from the priority pollutant list (CWA
Section 307(a)) based on toxicity testing with little or no
consideration of mixtures, bioaccumulative potential, or
exposurepathway. Individual criteria (aquaticlife, human
health, sediment, andwildlife) were developed for a host of
chemicals, often with the result of several criteria types for
a given chemical. The most stringent of these criteria, was
then used to derive the water quality goals of an aquatic
system or a permit limit. To develop assessment methods
and criteria that will align more closely with the stated
objective of the Clean Water Act,"... to restore and main-
tain the chemical, physical, and biological integrity of the
Nation's waters," the program would like to integrate
criteria development using the risk assessment paradigm. '
The goal is to develop criteria and methods more efficiently
and with more insight into the effects of chemicals on
aquatic systems (including-those terrestrial organisms
which are aquatic dependent, e.g., fish eaters).
The Office of Science and Technology (OST) pro-
poses to develop water quality criteria by evaluating the
different possible pathways of exposure and determining
the pathway that is most critical for a particular chemical.
To accomplish this task, OST will develop a strategy to
merge the technical and programmatic aspects of water
quality criteria programs (human health, drinking water,
aquatic life, wildlife, sediments, biocriteria) to address
ecosystem threats for a specific chemical (or class of
chemicals). Theproductdevelopedunder this strategy will
be a multi-pathway model(s) for establishing human health
and ecological criteria, with particular attention paid to the
most sensitive pathway. The program is working with the,.
Society for Environmental Toxicology and .Chemistry
(SETAC) to design a Pellston Workshop that will address
the state of the science and research needed to be able to
construct integrated assessment tools. The figure below
is a conceptual diagram of how this may be achieved.
Integrated Pathways to Criteria
Target Organism
(NOEL for: Wildlife Effects
Human Health
Aquatic Life)
Current
Water Quality
Prey Quality
(Tissue concentration
that protects target)
BSAF
SLSA
Regulatable
Sediment or
Water Quality
Value/Method
Program & Knowledge
Models
\
Source
Control
Implementation
Guidance
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National Sediment Bioaccumulation Conference
From Modeling to Criteria:
Integrated Approach to Criteria
Development for
Bioaccumulative Chemicals
5 Types of Water Quality Criteria
Aquatic Life
Human Health
Sediment Quality
Wildlife
Biocriteria
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Proceedings
3-31
Integrating Criteria
Chemicals
Designated Use/Target Organism
Fish Tissue
Measurement Media
Regulatory Implementation
Research and Implementation Issues
Incorporate metabolism into the model(s).
Change residue values into acceptable loadings.
Account for multiple sources.
What level of protection do we strive for?
Package model(s) and guidance for practicality.
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National Sediment Bioaccumulation Conference
Day One: September 11, 1996
Session three:
Questions and Answers
A
fter each session, there was an opportunity for
questions and answers and group discussions per-
taining to the speakers' presentations.
.Q (Bob Barrick, PTI Environmental Services): Dom, I
was going to just sit here and listen, but you brought up
Fred Praul 's work and it is such a central part of your talk
that I really need to speak. As you know I work with Fred.
His conclusions from his research are 100 percent oppo-
site of your conclusions.
Dominic Di Toro:
Exactly right. You can conclude what you like.
Q (Bob Barrick): I want to make three points here. One
is that when you are going ahead and using bulk organic
carbon to normalize sediments, it misses the fact that
organic carbon.is disproportionately found in the different
fractions. It is not a weighted average. Unless you quan-
tify the organic carbon in each of those size and density
fractions, you are going to come up -with the wrong
answer. Bulk organic carbon is not necessarily appropri-
ate, even if organic carbon works. That is also the case
with what Fred found, which was a disproportionate
amount of PAH versus organic carbon in those fractions.
Now, that is obscured a bit because Fred did present
arithmetic plots in his thesisandyou have converted those
to log plots, which has dampened down the variability. If
you take that out, it is a pretty big scatter in there.
Dominic Di Toro:
Bob, we have, as you know, organic carbon mea-
surements. He made measurements in each of the size
classes, so we know what the organic carbon concentra-
tion in each size class is. So, you divide, by the organic
carbon concentration in each size class.
Q (Bob Barrick); Dom, my point was that Fred did it
properly. What I am saying is that when you are taking
the organic carbon fractions and applying them out in the
real world, where everybody has a TOC number, that
number is not according to a particular compartment
within the sediment. It is abulk sediment number, andto use
that to measure against some kind of chemical that may be.
foundonlyinonecompartmentisnotwhatFredfound.IfFred
found that, that may be an erroneous way to proceed.
Dominic Di Toro:
Let me just comment on the comment. If you
actually take the bulk organic carbon concentration and
take the chemistry per unit carbon, it also works for all the
size fractions. That is because it is the same in each
fraction. So, if you add up the same numbers, you get the
same number.
Q (Bob Bar rick): It works better if you put it analog plot.
The third thing I wanted to say was that in discussing all
these things, it also ignores the difference in something
else that Fred found in his research. This was the differ-
ence between labile and refractive panicles, even though
you may be able to extract organic compounds out of both
of those using organic solvents in a laboratory. In fact,
in nature where exposure is actually happening, there
may be no exchange from the refracted particles and
considerable exchange from labile particles. And to use
the data to say that it supports equilibrium in the environ-
ment, when it is looking at -an organic 'carbon-extracted
system, is also making a little simplification. The only
reason I really wanted to bring, this 'up is because it is
something that is now a part of your talk, and it is really
counter to the conclusions of his dissertation work.
Dominic Di Toro:
I think the data analysis stands on its own. And you
are right.. Fred concluded exactly the opposite, which
struck us as a little peculiar since the data seemed to
indicate what I presented to you. There is a problem, by
the way, with bioavailability. All organic carbon is not the
same and all phases of sediments and chemicals are not the
same. The issue is whether the difference is so large as to
make organic carbon normalization useless, or are we
arguing about the extent to which we can collapse, responses
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National Sediment Bioaccumulation Conference
and understand what we are seeing? If the variability was
so large as to be useless, then I would say fine, use dry
weight normalization. In fact, why not use wet weight
normalization in sediments? People have used it for biota.
Why is it not a good idea in sediments? The point is you
have to have some kind of database and theoretical
understanding of what you are doing. The data speak for
themselves.
Q(Dennis Leonard, Detroit Edison): Dr. Cook, couldyou
comment briefly on the development of the BAF for
mercury in the Great Lakes? The BAF model that you.
discussed required the steady-state assumptions to be
present. The mercury concentrations that we have in the
Great Lakes vary by about a factor of 100. Tributary
littoral concentrations are influenced by high concentra-
tions of mercury in rainfall. Open water concentrations
are affected by transfer of mercury back to. the atmo-
sphere; therefore, we have concentrations ranging from
about 15 ng/m3 to 0.5 ng/tn3 at any point in time and space.
Is the steady-state assumption really valid, and how do
you develop a mercury criterion when you have this
hundred-fold variation?
Philip Cook:
I would love to answer your question, but I cannot.
I do not know that much about the mercury bioaccumula-
tion. If there is someone else here who feels they have .that
knowledge, I would welcome their participation.
Bob Barrick:
We have done quite a bit of work on mercury and
mercury uptake. Mercury is a totally different animal
because how it is associated hi cells is quite different from
other metals. It is pretty complicated. There is literature
available, and I think there is a whole conference on
mercury that focuses on its uptake hi the environment.
Mercury does not fit neatly into these models. Consult the
literature because there is information on how that should
be done differently.
Philip Cook:
I can agree with that.
Q (Gayle Gorman, NOAA): lampleased to hear someone
talk about the fact that the environment is not really in
equilibrium. Yet you are still making an assumption of
steady state and this is for the Great Lakes. Generally, I
workin estuaries andtheyare very dynamic systems. lam
wondering if you could comment on our assumptions of
steady state or equilibriumfor estuaries, and whether you
think the modeling-approach that you have taken for the
Great Lakes is applicable in an estuarine situation? ,
Philip Cook:
I certainly would not advocate using a steady-state
model where we know it would not produce a valid result.
There is obviously a need for nonsteady-state models. To
some extent, these empirical tools that I have discussed
here today may be usable, when necessary, in nonsteady-
state conditions. I think you have to get a good prediction
of an average exposure relationship, whether it be sedi-
ment or water, and then take into consideration the prop-
erties of the chemical that you are trying to model. If it is
a lower Kow chemical, I think the fluctuating exposure
problem becomes more severe.
O_(CharlesKovatch, University of'South Carolina): Could
you further explain your food chain multiplier model
parameter?
Philip Cook:
Essentially, the food chain multiplier is an expres-
sion for the organism that you are trying to model, which
represents the increase in the BAF over the octanol-water
partition coefficient. So, it is an expression of the total
effect (in the food chain) of biomagnification on the
bioaccumulation factor. It is applied when you do not
have the bioaccumulation factor specific for that chemi-
cal, so you use a bioconcentration factor or an octanol-
water partition coefficient as the surrogate for the equilib-
rium accumulation. The food chain multiplier, when
applied to either the BCF or Kow, predicts what the
biomagnification effect would be on the bioaccumulation
factor.
Q (Doug Hotchkiss, Port of Seattle): The comment was
, made in this last talk and in others that we have a lot of
data out there. When we make these lists of data, like the
compilations of data by URS and others, it looks like we
have a lot of data. I have been involved recently in trying
to use some of that data on a very site-specific regulatory
basis. This is just a word of caution and a note to
everybody out there. These lists may be very good for
screening purposes to identify what we should really
worry about. But when you apply them to regulating in
a site-specific situation, you need to take a really close
look at each individual paper. If you look at the specifics
of how that number was generated, you will find that some
of those numbers can be very soft for regulatory purposes.
For example, in a study using a spiked sediment, you
should check if they rinsed out the interstitial spike before
they ran the tests. Some of the numbers can also be listed
incorrectly from a paper. These lists can be a great help,
butyou ought to reexamine thevalues that are going to be
critical in the decision-making process for both the regu-
lated and the regulatory community. You should sit down
and take a critical look at what those numbers really mean
before just automatically moving ahead with them.
Q (Weldon Bosworth, Dames and Moore): I would like to
direct questions to Dr. McFarland and Dr. Di Toro. For
those of us that work in wetlands, we occasionally see
organic carbonlevels that are substantially higher than
the data you presented on your slides. There are also
substantial amounts of dissolved organic matter. When
we apply this on a screening level or for a Tier I risk
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Proceedings
3-35
assessment, weneedtodeterminewhatthepotentialisfor
bioavailability. Referring just to neutral chemicals, we
•might want to go to carbon normalization. How comfort-
able would you feel about applying your theoretical bioac-
cumulation potential estimate to something that would
range up to 30 or 40 percent organic carbon? What
empirical or theoretical data do you have to support your
answer?
Victor McFarland:
At 30 or 40 percent organic carbon, you might have
quite a lot of something that is not natural organic carbon.
But it could also be natural material like peat. What we
ordinarily encounter is what you see in ship channels. I
have riot tried to measure anything like you have de-
scribed. What we have done is to see how low you can go,
rather than how high you can go. In the types of situations
that we generally see, we have material containing up to
3 percent and occasionally up to 5 percent TOC. But, in
fact, I have had to search hard to find anything that I could
use in doing those kinds of studies that was much above
3 percent. We have some idea of how low you can go,
which kind of agrees with Dom, but I could not answer
about higher TOC ranges.
Dominic Di Tpro:
' Weknowaiittlebitaboutthat. The carbon fraction-
ation data that I showed you went as high as 10 or 20
percent. The theoretical limit is 40 percent, meaning that
40 percent on a dry weight basis of organic matter, sludge,
or other material is carbon. So, that is the upper limit.
Quite a bit of work has been done on partitioning of
hydrophobic chemicals to digested sewage sludge. We
used a fair amount of that data in the mid-1980s to
establish the partitioning relationships that we use. For
partitioning experiments and suspensions, I know that
carbon normalization appears to work up to 20,or 30
percent.
Q (Weldon Bosworth): I do not mean to suggest that
you could probably get away with a Tier 1 assessment
on a situation like that. The result of carbon normal-
izing and then adjusting bioavailability for that would
show that there would not be much that is bioavailable.
It becomes a critical issue, when you consider the
relative risks of leaving material there that may not be
bioavailable compared to tearing up the whole wet-
land and trying to restore it. There is not much work
being done on bioavailability in conditions when the
organic carbon is that high. ,
Q (PaulJacobson, Langhei Ecology, Inc.): I have to say I was
a bit bemused by Dom's comments regarding the role of
ecology in this whole process. I feel compelled to make a
short comment on that. I think it is true that toxicology was
developed as a science and applied to pollution control
decades ago, because ecology was really not up to the task.
However, I think that hardly validates the assertion that
ecology process and content really is not relevant toddy and
into the future. And I think that for the past 20 years or so,
pollution control has really been defined in toxicological
terms. The upshot of the Edgewater consensus was that the
approach of the last 25 years is not going to get us where
we need to go. There is aneedfora more ecologically oriented
perspective.
Dominic Di Toro:
I did not mean to say that I think ecology is
irrelevant. What I meant to say was I did not see ho w the
type of ecological work that I think is being thought
about would get us there any quicker. I think that simple
observations of disturbed ecosystems, with no idea of
what the causality is about and without the sort of
toxicological information that we have and need to
develop, is awasteof time. That was the caution, notthat
we should not do ecology, but rather if you look in the.
risk assessment paradigm and open the tool box to find
what methods actually exist to do this problem, you find
a remarkable lack of quantitative methods.
PaulJacobson:
Well, then, perhaps we are in complete agreement.
I think that the need is for good ecology.
Dominicpi Toro:
Yes, exactly right. I am railing against what I see as
a return'to an approach that I would call Victorian natural-
ism. That approach involves observing, making measure-
ments, and trying to make some elaborate arguments
linking observed changes to causation.
Q (Peter Landrum, NOAA, Great Lakes Environmental
Research Laboratory): twos inierestedinyour talk, Dom,
since we have done some of that particle size separation
and carbon normalization. I would say that the variance
in our laboratory-dosed 'sediments is somewhat larger
than what you showed on your log log plots. We see at
least an order of magnitude. And, in some cases, we see
the condition where the big organic particles do not seem
to adsorb as much material.
Dominic Di Toro:
I think what that says, Peter, is that your lab simula-
tions are not at equilibrium. The data I .showed you are
field data sets.
Q (Peter Landrum): Right, but I still thinkwhereyou have
bigger panicles, they are not necessarily going to be at
equilibrium. . '. *•
Dominic Di Toro: .
Well, I ask you to look at three data sets that strongly
suggest that large particles with high organic carbon
concentrations look just like small particles, and that kind
of equilibrium must have been there for that relationship
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National Sediment Bioaccumulation Conference
to work. That relationship tests two very interesting asser-
tions: that the system is at equilibrium and that carbon
normalization gets rid of the effect of other sedimentolpgi-
cal properties.
Q (Peter Landrurn): If you put that on a linear plot, you
will see that there is still quite a lot of variance there.
Dominic Di Toro:
There is no doubt about that, but put the raw data
on a linear plot.
Q (Peter Landrum): Well, that is what I do.
Dominic Di Toro:
Well, then it looks like hash. If you do not carbon
normalize, then it is all over the place.
Q (Peter Landrum): Carbon normalization actually
does, in most cases, reduce the variance. I will not say
in all cases. The other thing, though, that we have seen
is even though you look at that carbon normalization,
what we see for the bioavailability in the selection of
particles by the organism is that they are selecting
particles that we cannot even distinguish on a carbon-
normalizedbasis. We see this basedon the measurement
of concentrations in the fecal pellets, where they are
actually selecting particles at a much higher concen-
tration than we can measure relative to our bulk chemi-
cal measurements. That is another issue that needs to
be considered relative to what we get out of carbon
normalization relative to bioavailability.
Dominic Di Toro:
It occurs to me, Peter, that maybe the problem is
that you have to incubate your lab sediments long
enough to get equilibrium across the particle
spectrum.
Q (Bob Barrick): I am glad that Peter Landrum
spoke up because the major conclusions from Fred's
thesis directly support a particle-selective model.
It says the particles are important, and if there is
feeding on a particle^selective basis, then you will
have dramatically different results. His thesis di-
rectly supports that rather than supporting an equi-
librium perspective.
Dominic Di Toro:
My.only comment is Fred's data are what they are.
Q (Susan Kane Driscoll, Virginia Institute of Marine
Science): Dr. McFarland, I was interested in the BSAF
database that you showed where the median value for the
PAHs was lower than for the chlorinated compounds.
Do you have any impression about whether, it is more
important that there is metabolism of the PAHs, or if you
are seeing some sort of kinetic limitation to accumulation,
or if it is a bioavailability question like for soot particles?
Victor McFarland:
Well, fish certainly tear PAHs up, and I do not
think that the bivalves are totally devoid of some
metabolic capability there, too. But I do not think that
is the whole answer. Anthropogenic PAHs are associ-
ated primarily with soot. The chemical is going to be
distributed throughout the soot particle. In order to
desorb from the interior of a soot particle, I think you
would have to imagine something like a chromatogra-
phy column, where you have many steps of desorption,
sorption, desorption, and so on, which would make the
process quite slow. I think there is some evidence for this
in the literature. It is a complex process! There is
certainly much more to it than just one or two things that
determine bioavailability and the BSAFs that we have
measured for organisms and chemicals.
Q(G. Fred Lee, G. Fred Lee & Associates): I would like
to ask Mary, what, if any, timetable EPA has for putting
where we are now into a regulatory framework?
Mary Reiley:
A long one. If we look at the past history, it is a long
process frdm the time we have data and come up with the
theory, to moving that into something that can be prac-
tically implemented into a regulatory program, and then
to actually getting it implemented. There is an introduc-
tory period to get the research accomplished, about 5
years to make it practical, and then another 5 to 10 years
to get it implemented. I think a lot of people believe that
if we publish something today, it is implemented tomor-
row. That is not the way it works. It takes a lot of time to
get the bugs out. Five years would be nice, but I would
say to actually see it being implemented in a regulatory
program on a routine basis would take longer than that.
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National Sediment Bioaccumulatton Conference
Session Four:
Food Chain Models and
Bioenergetics
Lawrence Burkhard, Panel Moderator
U.S. EPA, Office of Research and Development,
Duluth, Minnesota
Frank Gobas
Simon Fraser University,
Burnaby, British Columbia, Canada
Food Chain Models for Predicting Bioaccumulation
John P. Connolly
HydroQual, Inc., .
Mahwah, New Jersey
Use of Food Web Models to Evaluate
Bioaccumulation Data
Robert V. Thomann
Manhattan College,.
Riverdale, New York
Bioaccumulation Modeling ofPCBs in the Hudson
Estuary: A Review and Update
. 4-1.
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National Sediment Bioaccumulation Conference
Food Chain Models for Predicting
Bioaccumulation
Frank Gobas
Simon Fraser University, Burnaby, British Columbia, Canada
Please contact the speaker for information on this presentation.
4-3
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National Sediment Bioaccumulation Conference
Use of Food Web Models to Evaluate
Bioaccumulation Data
John P. Connolly and David Glaser
HydroQual, Inc., Mahwah, New Jersey
Introduction
Atypical use of bioaccumulation factors is to derive
clean up levels or criteria/standards for water and
sediment. Thetargetsedimentorwaterconcentra-
tion (TSC or TWC) is established by dividing a maximum
allowable tissue level (MATL) by either a biota-to-sedi-
ment accumulation factor (BSAF) or a bioaccumulation
factor (B AF). Where possible, the BSAF and the B AF are
defined by measurement (USEPA, 1995). The implicit
assumption is that the BSAF and the B AF are estimates of
an invariant steady-state relationship between tissue con-
centration and sediment or water concentration. By that
we mean the following: the BSAF and BAF are applicable
to conditions that differ from the measurement conditions
such that achieving a sediment concentration equal to the
TS C or a water concentration equal to the TWC will result
in a tissue concentration, equal to the MATL.
Applicability of Measured BSAFs
and BAFs -
Measured BSAFs and BAFs can be applied to the
clean up level or criteria/standards problem only if they
describe the invariant steady-state relationship that is
implied by their use. Numerous examples exist where this
is evidently not the case.
BSAFs and BAFs vary with location
In the Hudson River, the polychlorinated biphenyl
(PCB) BAFs measured in 1990 for largemouth bass
decline from ca. 40xl06 to lOxlO6 L/kg lipid with dis-
tance from the PCB source. Conversely, the BSAFs
increase from about 1 to 2 g OC/g lipid (see page 4-9). In
Green Bay, the PCB BSAFs for carp increase with
distance from the source by factors of 5 to 10 (see page 4-
9). The ratio of ppDDE (p,p'-DDE) inkelp bass toppDDE
in white croaker from the Southern California Bight
increases with distance from the source, changing by
more than a factor of 7 (see page 4-10).
BSAFs and BAFs vary with time
At Stillwater in the upper Hudson River, large-
mouth bass BAFs vary among years from about
3xl06to 30xl06 L/kg lipid. Similarly, the BSAFs vary
,from about 2 to 4 g OC/g lipid (see page 4- 10).
BSAFs and BAFs vary among species at
similar trophic levels
Green Bay carp and alewife are at similar trophic
levels, as indicated by similar levels of PCB accumulation
relative to particles at the base of the food web (see
page 4-1 1). Yet, alewife have much lower PCB concen-
trations. Southern California Bight dover sole and white
croaker both consume benthic invertebrates, yet the PCB
and ppDDE BSAFs of the sole are 2 to 3 times lower than
those of the croaker (see page 4-11).
To explore the potential causes of the variability in
BSAFs and BAFs, consider that they are presumed to
reflect a steady-state relationship among contaminant
concentrations in biota (v), dissolved water (cdl), and/or
sediment (r2). In general, both sediments and water
column may contribute to fish contaminant loads, so
Because the use of a BSAF or a BAF implies an
invariant relationship between the biota and media consid-
ered (i.e., sediment or dissolved water), a constant relation-
ship must exist between dissolved water and sediment:
where Kws is the water-sediment partition coefficient.
These equations yield the following expressions for
BSAF and BAF:
BSAF = —+b
= a+bKws
The coefficients a and b are functions of food web
structure, bioenergetics, and toxicokinetics; The partition
coefficient KTO is a function of contaminant loading and all
4-5
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4-6
National Sediment Bloaccumulation Conference
of the fate and transport processes. Lack of steady-state
conditions is an obvious cause for BSAF and BAF vari-
ability. BS AF and BAF variation with location could also
be attributable to variations hi Kws or food web structure.
BSAF and BAF variation with time may result from
variations hi KM or in bioenergetics that result from
physiological changes (e.g., lipid content). BSAF and
BAF variation among species may be due to food web
structure, bioenergetics, or toxicokinetic differences.
Interpretation of BSAF and BAF data must involve
an assessment of whether the implicit assumption of an
invariant steady-state condition is accurate. Is a
measured BSAF or BAF value appropriate for regulatory
application or should it be adjusted or discarded? Such
interpretation is hampered because of the probable site-
specificity of BSAFs and BAFs and the many factors that
can invalidate the invariant steady-state assumption.
Use of Food Web Models to Validate
Bloaccumulation Data
Food web models provide a means for validation
because they mechanistically describe the bioaccumu-
lation process and can ascribe causality to observed rela-
tionships between biota and sediment or water. The utility
of models as validation tools for data is predicated on (he
accuracy of the models. Two issues are important: (1) is
the bioaccumulation process sufficiently well character-
ized to permit the use of models as diagnostic tools? and
(2) is the uncertainty of model calculations small enough
to allow discrimination among measured BSAF or( BAF
values? A model of PCBs in Green Bay and DDE and
PCBs in Southern California Bight illustrate the robust-
ness of the models. In Green Bay, a single model structure
with one set of bioenergetic and toxicokinetic parameters
accurately reproduced congener and SPCB concentra-
tions in five fish species in five locations that extend over
an order of magnitude gradient in exposure concentra-
tions (see page 4-14).
Monte Carlo analysis of a model of ppDDE in dover
sole indicates that model uncertainty is not greater than
the uncertainty of field BAF data, about a factor of
2 (see page 4-16).
Example
Green Bay carp PCB data were used as an example
of spatial variability in estimated BSAF values. To
interpret these data a bioaccumulation model was
developed using the same toxicokinetic parameters as
used for the other Green Bay species. The computed
BSAFs are consistent with those observed hi Zone 3B. hi
contrast, the model was not capable of reproducing the
Fox River and Zone 4 BSAF data while maintaining
parameter values within experimental limits (see
page4-17). Thus, the modeling suggests that the Zone 3B
data represent a steady-state relationship between carp
and sediment. Further, it appears that in the other zones
the carp were not at steady state with the sediments,
possibly because the sampled sediments do not properly
describe the exposure concentrations seen by the carp.
Southern California Bight ppDDE and PCB data
in three species of birds were used to assess from what
location the birds received their contaminants. To
interpret these data, a bioaccumulation model was
developed using the same toxicokinetic framework
for all three species! Measured prey and predator
concentrations were consistent for the peregrine fal-
con and bald 'eagle, suggesting that our view of the
feeding behaviors and feeding locations of these spe-
cies is reasonable. However, prey and predator levels
were not consistent for the double-crested cormorant
on Santa Barbara Island, suggesting that the cormo-
rants feed in less contaminated areas than previously
assumed.
Conclusions
• Food web models provide a means to interpret
bioaccumulation data.
• Models are necessary to test assumptions implicit
hi data-based BSAF and BAF values used for
regulatory purposes.
• Two potential applications of models are:
(1) to refine the database of BAF and BSAF values
used for regulatory purposes and
(2) to increase confidence in regulatory decisions
having substantial economic implications.
References
USEPA. 1995. Great Lakes Water Quality Initiative
technical support document for the procedure to
determine bioaccumulation factors. EPA-820-B-
95-005. U. S. Environmental Protection Agency,
Washington, DC.
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Proceedings
4-7
A typical use of bioaccumulation factors is in the
derivation of clean up levels or criteria/standards for
water and sediment:
Sediment Target Level (STL in mg/kg)
STL = vc/BSAF
Water Column Target Level (WTL in jjg/l)
WTL = v /BAF
' • C , •
Where possible, the BSAF and the BAF are defined by
measurement.
The implicit assumption is that the BASF and BAF
values are estimates of an invariant steady-state
relationship between tissue concentration and
sediment or water concentration
i.e., achieving a sediment concentration equal to the
STL or a water column concentration equal to the WTL
will result in a tissue concentration equal to vr
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National Sediment Bioaccumulation Conference
The steady-state relationship among contaminant
concentrations in biota (v), dissolved water (cd1) and
sediment (r2) is:
v = acd1 + br2
If a and b are both non-zero, an invariant relationship
requires that:
which yields:
BSAF = aK +b
ws
BAF=a+ _b
K
ws
and, thus, requires that a, b and Kwsare invariant
(2)
(3)
(4)
The constraints are restrictive, because:
• Equation (1) is only valid at steady-state
• a and b are functions of food web structure,
bioenergetics and toxicokinetics
Kws is a function of contaminant loading and all of the
fate and transport processes
Thus, it is probable that many BSAF and BAF values
calculated from measurements do not reflect an invariant,
steady-state condition.
How can we interpret BSAF and BAF data ?
-------
Proceedings
4-9
2500
2000
1600
1000
500
0
Sediment
1991
(ug/g OC)
Water Column
July 1990-June 1991
' (ng/L) '
200 190 180 170 160' 150
60
40
20
0
200 190 180 170 160 150
Largemouth Bass
BSAF
1991
(Kg OC/Kg lipid)
6
5
4
3
2
1
0
200 190 180 170 160 150
Largemouth Bass
BAF
1991
(x108L/Kg lipid)
200 190 180 170 160 150
River Mile
Total PCBs in the upper Hudson River: Spatial Patterns
Sediment, water column and largemouth bass in 1991
HydroQual, Inc.
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Log Kow
Bioaccumulation Factors for PCBs in Green Bay Carp
PCB .Congeners Grouped into 0.5 Log Kow Bins
Data are Arithmetic Means and 95% Confidence Intervals
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4-10
National Sediment Bioaccumulation Conference
£
§
CO
Q.
1.00
0.80
0.60
0.40
0.20
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-50 -25 0 25 50 75 100 125
Distance from Whites Point Outfall (km)
150
Ratio of (kelp bass)/(white croaker) lipid-based ppDDE
concentrations in the Southern California Bight.
Sediment
(ug/g OC)
2500
2000
1500
1000
500
Water Column
(ng/L)
1000
800
600
400
200
187S 1980 1965 1990 1995 2000
1975 1980 1985 1990 1995 2000
Largemouth Bass
BSAF
(Kg OC/Kg lipid)
1975 1980 1985 1990 1995 2000
Year
Total PCBs in the upper Hudson River: Temporal Patterns
Sediment, water column and largemouth bass from Stillwater
Largemouth Bass
BAF
(x106 L/Kg lipid)
1975 1980 1985 1990 1995 2000
HydroQual, Inc.
-------
Proceedings
4-ii
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-------
4-12
National Sediment Bioaccumulation Conference
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Water-Sediment partitioning for PCB homologs and congeners (L/kg OC)
-------
Proceedings
4-t3
How can we interpret BSAF and BAF data ?
By using food web bioaccumulation models.
Models provide this capability because:
• They describe the process of bioaccumulation and can
account for water & sediment exposure, time variability
and food web structure
• They are credible: capable of reproducing field data
using parameterizations that are supported by
experimental data and are consistent within and across
food webs
• Their uncertainty is not overwhelming
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4-14
National Sediment Bloaccumulatlon Conference
GREEN BAY WET WEIGHT-BASED CONCENTRATION
TOTAL PCBs
10
8
6
4
2
0
Walleye
Brown Trout
1 2a,b 3a 3b 4
Zone
I I I I T
I i
1 2a,b 3a 3b 4
Zone
1.0
0.8
0.6
0.4
0.2
0.0
III
Alewife
~i—i—i—r
1 2a,b 3a 3b 4
Zone
Zooplankton
i i i i r
1 2a,b 3a 3b 4
Zone
1 2a,b 3a 3b 4
Zone
Rainbow Smelt
"i—r~n—i—r
1 2a,b 3a 3b 4
Zone
50
40
30
20
10
0
Phytoplankton (ug/gOC)
—n—r~
T
I ^T—I 1
1 2a,b 3a 3b 4
Zone
Food Web Model Calibration. Computed and observed total PCB
concentrations, ng/g whole body wet weight, for all spatial zones.
Lines: model calculations. Filled circles: data.
-------
4-J5
GREEN BAY LIPID-BASED BAFs
Walleye
io9
Brown Trout
™6;r
io5;i
4 5 6 7 8 9
Log (Kow)
456 7 8 9
Log (Kow)
Gizzard Shad
10
io8i
10
10
10
10
5 6 789
Log (Kow)
Alewife
4 567 8 9
Log (Kow)
Zooplankton
4 56 78 9
Log (Kow)
Rainbow Smelt
4 56 7 89
Log (Kow)
Phytoplankton (UKgOC)
10
10
10
10
10'
10
i r i i
4-5 6.7 89
Log (Kow)
Food Web Model Calibration. Computed and observed lipid-based
bioaccumulation factors for zone 3A. l_/Kg lipid.
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4-16
National Sediment Bioaccumulatton Conference
O
I?
ij
0 I
o
a.
a.
DOVER SOLE
Year
Comparison of Predicted and Observed ppDDE Concentrations in Dover Sole
Solid Lines are Model Results
Dashed Lines are 95% Confidence Intervals around the Mean (Monte Carlo)
Data are Arithmetic Means and 95% Confidence Intervals around the Mean
Using a model to examine the Green Bay carp data we
conclude the BSAF values in the Fox River and zone 4
represent non-steady state between the fish and the
sampled sediment
• Differences in toxicokinetics and bioenergetics do not
account for the spatially variable BSAFs
• Differences in food web structure do not account for the
spatially variable BSAFs
-------
,PI
4-17
O
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Q.
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U- ™
FOX RIVER
EASTERN ZONE 3B
60.0
40.0
20.0
1 1 1 1 1 'III!
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80.0
60.0
40.0
20.0
0.0
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WESTERN ZONE 4! " „„„ EASTERN ZONE 4
' Log Kow
Bioaccumulatiori Factors for RGBs in Green Bay Carp
PCB Congeners Grouped into 0.5 Log Kow Bins
Data are Arithmetic Means and 95% Confidence Intervals
Conclusions
Models provide a means to interpret bioaccumulation
data
Models are necessary to test assumptions implicit in
data-based BAF and BSAF values
- to refine the database of BAF and BSAF values
used for regulatory purposes
-• *•«
- to increase confidence in regulatory decisions
having substantial economic implications
-------
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National Sediment Bioaccumulation Conference
Bioaccumulation Modeling of PCBs in
the Hudson Estuary: A Review and
Update
Robert V.Thomann and Kevin J. Farley
Manhattan College, Environmental Engineering Department, Riverdale, New York
Introduction
Theissueof polychlorinatedbiphenyl (PCB) accumu-
lation in the striped bass of the Hudson estuary
has been a matter of concern for several decades.
Early discharges of PCBs to the estuary resulted in total
PCB concentrations in the striped bass during 1978 to
1982 of 5 to 10 times the U.S. Food and Drug Adminis-
tration (FDA) action level of 2 (ig/g(wet). The fishery has
been closed to commercial harvesting since the mid-
1970s.
Bioaccumulation Model
A linked homolog-specific, physicochemical bib-
accumulation model was constructed (Thomann et al.,
1989,1991) to help address questions of the effectiveness
of upstream controls on PCBs in reducing the PCB con-
centration in the striped bass or, if no
action is taken, the time it would take to
reach acceptable levels in the fish.
Model calibration was accomplished
with stripedbassdatafrom 1978 through
1987 and indicated that more than 90
percent of the observed PCB' concentra-
tion was due to food web transfer. Pro-
jections were made of the expected de-
crease in PCB concentration in the
striped bass from 1987 to 2010. The
projections were based on a PCB ho-
molog-specific modeling framework
that included a time-variable, age-de-
pendent striped bass bioaccumulation
model. Those results indicated that
under a no-action scenario, the average
PCB concentration in the striped bass
in the mid to lower estuary would de-
cline below the FDA action level of
2 ug/g(wet) by about 1994 to 1995.
10
.«• 8
GQ
o
a.
1
Model Post-Audit
Data obtained by the New York State Department
of Environmental Conservation (as stored in TAMS ,1996)
are now available to check the projections up through
1994. Observed mean total PCB. concentrations in 2- to
5-year-old striped bass in the mid-lower estuary
(designated SB2 group) declined from about 3.5 ug/
g(wet) in 1988 to about 1.6 ug/g(wet) in 1994. A
correction of the original projection was necessary due to
a numerical error in exposure concentration hi Food Web
Region #4, the Long Island Sound and New York Bight
area. This correction resulted in a reduction of less than
about 0.5 ug/g(wet) from the original projection. Using the
original input load projections, the comparison to the
" observed data for SB2 is shown in Figure 1 and indicates
that the model underestimated the mean in 1989 and 1990
but adequately reproduced the means in 1992 and 1994.
The variability in the data is large with 5 to 95 percentile
o
1987
5% tile [4-
_i_
1988 1989 1990
1991
YEAR
1992 1993 1994 1995
Figure 1. Comparison of original (as corrected) model projection
(solid line) made in 1987 to observed data of striped bass (2-5 yr old),
Food Web Region #2.
4-19
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4-20
National Sediment Bioacci
Confe
range in individual samples of about an order of magni-
tude distributed approximately lognormally. Projections
of the percent frequency of samples below a target level
mean of 2 ug/g(wet) were also made, and comparison to
observed data (Figure 2) indicated that the original model
overestimated the frequency =< 2 fjg/g(wet) in 1990 but
tracked the general trend in the data of an increasing
frequency=<2 |ig/g(wet) in the years 1992 to 1994.
The model has been updated in two areas: assessment
of the effect on striped bass from a temporary increase in
upriver loading and an evaluation of a varying migration
pattern of the striped bass. To assess the effect of the
increase in loading, a fivefold increase over the originally
projected load from the upper river was added for the one year
of 1991. Preliminary results indicate a calculated increase of
total PCB concentration of about 0.4 to 0.8 ug/g(wet) for
1992 to 1994 in the SB2 group. The effects of theincreased
load are dissipated in about 5 years in the mid-lower estuary.
For the effect of varying migration, recent research
by Secor and Piccoli (1996), who estimated .the exposed
salinity regime in striped bass from measurements of the
Strontium/calcium (Sr/Ca) in the otolith, has indicated that
some male striped bass remain in the mid to upper estuary
anddonotmigratetotheocean. Figure 3 shows acomparison
of female and male SB2 total PCB concentrations from the
data base. The higher median concentration in the males is
observed, as well as considerably higher extreme concen-
trations in the male SB2 over the female SB2 group. The
model results for nonmigratory behavior, shown in Figure
4, indicate an approximate doubling of the concentration in
the striped bass and help explain the elevated concentra-
tions that have been observed.
Projections to Year 2010
Revised long-term projections based on varying
bass migration patterns and the original load projections
are shown in Figure 5 for the mean and Figure 6 for the
estimated frequency of occurrence =< 2 |ag/g(wet). The
revised projections indicate that by the year 2000, the
mean total PCB concentration is estimated to be between
0.8 and 1.8 ug/g(wet) with an estimated 75 to 95 percent
of the total PCB concentrations in the SB2 group =
< 2 ug/g(wet). However, for the mid-upper estuary, cal-
culated mean total PCB concentration is about
2.1 ug/g(wet) for 2- to 5- year-old bass, indicating that
this region can be expected to have elevated concentrations
over a longer a period of time than the mid estuary region.
Conclusions
Forthis work, which is still in progress, it is concluded
that the original model generally tracked the observed
decline in mean total PCB concentrations in the striped bass
for the mid to lower estuary although there are year-to-year
variations in the mean that are not captured by the model.
A simulation of a 1-year "pulse" load of five times the
estimated load in 1991 indicated that such an input persists
in the SB2 group for about a 5-year period. Migration
behavior is particularly significant and contributes to the
observed variability in the SB2 data. The revised projections
estimate that SB2 total PCB concentrations will continue to
decline to levels below the FDA action level. It should be
noted, however, that such projections are strictly related to
the projections of the load and, of course, the model itself.
Reevaluation of the loading using contemporary estimates
and model recalibration are currently under way. There is a
continual need to monitor the input PCB loads and the
concentration in the striped bass and couple such monitoring
with periodic model post-audits and updates.
References
1987
1994 1995
Figure 2. Comparison of observed vs. model exceedance frequencies
(%=< 2 pg/g). Striped bass (2-5 yr old), Food Web Region #2.
Secor, D., and Piccoli. 1996. Age and sex
dependent migrations of the Hudson
River striped bass population deter-
mined from otolith chemical
microanalsis. The Univ. of Maryland
System, Center for Environmental and
EstuarineStudies, CBL, Solomons, MD.
TAMS. 1996. Data base for the Hudson
River PCBs reassessment RI/FS. Data
base report, Vol. 2A. TAMS Cons.,
Inc. and Gradient Corp. USEPA Con-
tract No. 68592001. CD ROM.
Thomann, R.V., J.A. Mueller, R.P.
Winfield, and C-R. Huang. 1989.
Mathematical model of the long-term
behavior of PCBs in the Hudson River
estuary. Final report to the Hudson'
River Foundation, New York, NY.
Thomann, R. V., J. A. Mueller, et al.
1991. Model of the fate and accumu-
lation of PCB homologues in Hudson
estuary. ASCE, J. Env. Eng. Div.
117(2): 161-177.
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Proceedings
4-zr
10 •—.
30
20
10
FEMALE
MALE
Sf
30
20
10
86 87 88 89 90 91 92 93 94
86 87 88 89 90 91 92 93 94
YEAR
Figure 3. Variation in total PCS concentration in striped bass (2-5 yr old), Food
Web Region #2. Line in box = 50th %tile, box boundaries = 25th and 75th %tile,
symbols = outliers.
MIGRATION
OUT OF
ESTUARY
1987 1988 1989 1990 1991 1992 1993 1994 1995
YEAR
Figure 4. Calculated effect of varying migration of striped bass (2-5
yr old), Food Web Region #2.
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4-22
National Sediment Bioaccumulatlon Conference
1988 1990 1992 ,1994 1996 1998 2000 2002 2004 2006 2008 2010
YEAR
Figure 5. Long term model projection using original (1987) load projections
with varying migration by striped bass. Solid line: striped bass migrates out
of estuary; dashed line: fish remains in estuary. Striped bass (2-5 vr old),
Food Web Region #2.
1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
YEAR
Figure 6. Long term model projection of frequency of striped bass =< 2ug/g
with varying migration by striped bass. Solid line: striped bass migrates out
of estuary; dashed line: fish remains in estuary. Striped bass (2-5 yr old),
Food Web Region #2.
-------
National Sediment Btoaccumu/atfon Conference
Day Two: September 12, 1996
Session Four:
Questions and Answers
A
fter each session, there was an opportunity for
questions and answers and group discussions per-
taining to the speakers' presentations.
Q (Ron Sloan, NYS Department of Environmental Con-
servation): One of the things that Bob brought up, which
is very interesting from our standpoint as researchers in
a regulatory agency, is the possibility of regulating on the
basis of sex in fish. This would be very difficult to do, but
. it raises a very valid point in terms of male and female
differences, not only for accumulation and behavior in the
estuary, but also in other systems and for other species of
fish. Fora number of years we have noted tremendous sex
differences, with the males always being higher in con-
centration than the females for striped bass, American
shad, white perch, the Pacific salmon in Lake Ontario,
and a number of other species. Bob, isthereasmuchwork
going on with you and other researchers as it relates to sex
differences?
Robert Thomann:
I am not doing anything myself, but I have been
following the literature rather closely. There is a lot more
information now. I think John has done some work on
seals! Recently, the Dutch did some work on exposing
males and females and looking at bioaccumulation in the
laboratory, which showed significant differences. But I
have a question back to you. Did I understand your
opening comment to mean that you really are thinking
about regulating by sex? • . . J
Q (Ron Sloan): No, no. There is no real way to be able
to do that, but it is very bothersome that we do not have any
good explanation/or why the males are so much higher in
concentration, even controlling for gamete production
and the lipid consequences associated with voiding of egg
material from the females. The sex'differences are still
there and they are very dramatic.
Robert Thomann:
Well, I think it is because they are staying in the
estuary. '
Q (Ron Sloan): Maybe for striped bass, but even if you
look at the males in the lower part of the estuary that are
freshly migrating in from the ocean, the males will tend to
be higher in concentration. That still does not explain the
sex differences that we see very dramatically in Pacific
salmon and white perch. One of the reasons I raised the
point is because we have been looking the past few days
now at the uncertainties associatedwith BAFs andBSAFs,
and I think a lot of the uncertainty and the variability is
associated with sex differences when we start looking at
fish. •. •
Robert Thomann:
Well, I think that is true. The sex differences, atleast
for this case, do contribute significantly to the variation.
If you calculated BAFs here, they would be all over the lot. •
As John pointed out, part of it is the disequilibrium
between the fish and the water. This would be the same for
BSAFs. They would be very time variable and very
spatially variable.
Q (Ron Sloan): We have looked at that to some extent, and
we cannot really account for it because the lipid concentra-
tions are so low. Gamete loss cannot explain the differences.
/ ' ' ' •
John Connolly:
We have looked at a lot of data in a more generic
sense and it seems to be a mixed bag. We do see a
difference for some species, but we do not for other
species. You, particularily see it in aquatic mammals.
Milk production and the Joss due to' that explains the
differences for the. aquatic mammals. But I do not think
we understand the reason for those differences in fish.
Q (Ron Sloan): My primary reason for bringing this up as
a question or an issue is that, if we are interested in
explaining a lot of the variability that we are observing, we
need to take into account the sex differences.
Q (Nelson Thomas, U.S. EPA, Office of Research and
Development): This is a question for John and Bob. In
Frank's presentation, he alluded to an uncertainty factor
4-23
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4-24
National Sediment Bioaccumulation Conference
of 3 at the 95 percent confidence level. Did you look at
your 95percent confidence-level in your calculations and
figure out how far off you would be like Frank did?
John Connolly:
The one that I showed, which was for Dover sole,
was about a factor of 2. In a couple of other calculations,
where we have done uncertainty factors, the factor of 2 to
3 is pretty robust. That is what we are generally seeing in
these calculations.
Robert Thomann:
That is true. If you look closely at those percent
exceedance frequencies, you will see about the same kind
of variability.
Larry Burkhard:
John, I have a slide of the probability distribution
for the 2-year old flounders from your New Bedford
harbor model. This figure is from a publication in the
SETAC Journal. It illustrates the uncertainty that they
found using a Monte Carlo simulation for his model. You
can see here that a factor of 2 to 3 is right on line. I just
wanted to point out the kind of uncertainties that you have
with these models.
Robert Thomann:
I interpreted Nelson's question as asking what our
uncertainty was in the 95th percentile estimate, or hi other
words, in the tail of the distribution. We have the ability
to project or analyze for the 95th percentile to a factor of
about 2 or 3.
Q (Jay Field, NOAA): In situations where we have
vertical gradients in terms of sediment concentrations,
has anybody looked into the implications of biological
activity, which may vary seasonally or by location, and
the impact it might have on some of the models? How
would any effects that we see affect the way we collect
information?
John Connolly:
With some of the work I have done, I have seen more
location differences. I have not paid a lot of attention to
the seasonal differences that might exist. So, I cannot
comment on seasonal differences within a system. But
clearly, we see differences from system to system, de-
pending to a large extent on the type of organisms com-
prising the benthic infauna. In determining whether or not
we are worried about the top centimeter or the top 5
centimeters as being biologically available material, that
is more of an issue for higher level organisms. This is
something that again introduces considerable uncertainty,
both in models and into the B AF and BS AF. That was one
of the points I was trying to make with the Fox River. The
model results suggest that the carp are seeing material
recently deposited in the river, as opposed to material that
is buried a few centimeters down. If carp were exposed to
material a few centimeters down, they should have been at
much higher concentrations than they were.
Robert Thomann:
The only calculation I have done in that area was
associated with the cadmium and the blue crab in Foundry
Cove, where there was a considerable amount of sediment
mixing and sediment bioturbation. In that particular case,
bringing up deep sediment to the surface and then letting
that get into the food chain, actually retarded or slowed
down the recovery of the cove. Recovery was delayed
because you are just accessing higher concentrations over
a longer period of time. It is very interesting. It increases
the flux to the water column, so you are actually depurat-
ing out the sediment with a higher flux. But, because you
are also reaching down into higher concentrations, you
also retard the response.
Q (Ken Finkelstein, NOAA): Dr. Thomann, you presented
a figure early in your talk that showed the concentrations
in the striped bass with a no-action or as is. You also
showed on the same figure one that would indicate that
there was no change at all, even with some kind of
decrease in the load. Actually, I think you decreased it
down to zero, or in other words, it was remediation. I was
wondering if you could shed some light on that because it
puts some question in remediation plans, both there and
elsewhere. I have seen this at other sites with models
where the models do not show any kind of significant
change with drastic cleanup operations.
Robert Thomann:
What you are focusing on is the calculation that was
done in 1987 and 1988. There actually is a difference
between remediating the upstream sediment and the no-
action. The difference is only in the_sense that it takes you
a little bit longer to get to a certain percent'frequency
below 2, if you do not do anything. But eventually they
come together. The reason for that is we have projected in
the calculation, which I showed in the load projection, that
the upstream load will continue to decline whether you do
something or not in a no-action case. So, that was that
load projection going down. That is what we did in 1987,
and that is what we are still doing today. That is being
revised, but we are still in the process of doing that. That
load is declining, but there are also downstream loads,
including loads in the metropolitan area, nonpoint source
loads, and atmospheric loads. That calculation essentially
said that, after a period of time, the relative contribution
from the downstream sources became more dominant,
and the upstream source became less dominant. So, its
impact became less and less as time went on, and
remediating it had less and less of an impact.
Q (Ken Finkelstein): Maybe I can also relate a little bit of
a different experience that we have had in doing similar
types of calculations. Consider the case where the
-------
Proceedings
4-25
remediation is remote to where you are looking. For
example, you are remediating in the upper Hudson River
and looking at benefits in the lower Hudson River. In
many cases, you do not, see a big bang because that load ,
is not controlling the concentrations and the exposure in
the remote area. In the case of the lower Hudson, it may
be because there is another load. In other cases, it may be
that past historical discharges are controlling the system,
rather than the current discharges coming from an up-
stream area. In these cases, eliminating the upstream
source will not show an impact in the downstream area
since that source was not contributing to contaminant
levels in the fish downstream.
Robert Thomann: ,
That says nothing about the advantage of remediating
for the upriver area. There is a local benefit from that.
Q (Arnold Kuzmack, U.S. EPA, Office of Science and
Technology): I would like to make a couple of comments
of a somewhat philosophical nature. First, in terms of the
discussions of the uncertainty being within a factor 'of 2 or
3, I think we have to be careful of how we use the
terminology here, particularly when distinguishing be-
tween variability and uncertainty. Uncertainties tend to
deal more with things thai we do not know. For example,
lam sure when you were doing your original models in the
1980s, you assumed that the fish were homogeneous in a
^migration pattern. You probably did not realize you were
making that assumption. If you had listed your assump-
tions, that probably would not have appeared, there, and
it turned out to.be wrong. That is an example of uncer-.
tainty. There are other uncertainties in just how well can
we measure, what all we are including in the models, and
so forth. The second comment I would like to make relates
to John's discussion of the data versus modeling. I
absolutely agree with your comment that whenever you
use data you have some sort of implicit model. I would
indicate caution on the part where you said that the
models incorporate everything we know about the sci-
ence. I think almost by definition they do not include
everything. They include some sort of schematization and
rationalization of our knowledge. And we sort of discard
the things we do not understand that are in the data. I
think because of that we have to be careful to do ah
appropriate degree of ground truthing ~of the models,
which you all did in your research. I think 'one could
criticize regulatory agencies in perhaps putting too much
reliance on models that do not have that kind of ground
truthing, particularly for situations like some permit pro-.
cess applications or decision-making based on model results
that.are not clearly understood. I think in these sorts of
situations, you have to be pretty careful about having the
models run away with things, I think that is what probably
the data advocates are trying say. , '
Robert Thomann:
I think the other point, too, is deciding when a model is
useful for regulatory or management purposes. Who
makes the decision that models are'ready for use hi some
kind of decision-making process? I have always felt that
regulators and lawyers do not make that decision. They are
not in a position to evaluate it. The people who ultimately
make the determination of whether a model is suitable for
management purposes or decision-making are members
of this community. It is the scientific community that
determines when the model can account fpr all the impor-
tant factors and produce results that make sense relative to
the data. This is the group that throws holy water on it.
Q (Dave Michaud, Wisconsin Electric Power Company):
John, in looking at the carp data from the Fox River and
Green Bay system that you-presented, I am not surprised
about whatyousaw. The carp population in the Fox River
is a'restricted population that lives in a highly regulated
environment with a number of pools controlled by dams.
You see greater-variability in Green Bay becausethere is
an intense depositional gradient along the east coast, and
the carp can and do move freely between Green Bay and
Lake Michigan. I would guess that you were probably
sampling fish that were 10 to 15 years old) so they have a
unique uptake history relative to the alewife. That leads
me to my second comment. At one point in your presen-
tation you grouped alewife and carp together in terms of
trophic levels. I am not sure I understand the logic behind
•that. Except for an occasional amphipod or mysid,
alewife feed primarily on plankton. The food habits work
that we have done on carp in Lake Michigan suggests that
it feeds almost exclusively on benthic organisms. We have
found very little plankton in examining the gut contents. I
would not call these the same trophic levels. How would
you also factor in the obvious age differences in terms of
exposure? Typically, alewife live only 3years, while carp
can survive for more than 25 years.
John Connolly: .
The data that we had was for carp over a rather wide
range of ages, so we were not looking specifically at carp
that were 14 or 15 years old. When I was talking about the
Fox River, I was referring to the lower Fox River below
DePere Dam, where the carp are not confined in pools.
But you just raised a lot of questions that I think are all
valid. The point I was trying to make is that models .allow
you to explore those questions, as opposed to just using
them to generate a number you can run around and
extrapolate with.
Q (John Zambrano): This is a question for the panel from
a regulator. Yesterday Philip Cook described the work
that EPA did for the Great Lakes Initiative (GLI)for the
purposes of establishing BAFs for setting water quality
standards. What, does the panel think of that work,
particularly its applicability to the rest of the nation and
the use of a disequilibrium constant of 25?
Frank Gobas:
My understanding of the process is that they used a
bioaccumulation model for a particular system to derive
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National Sediment Bioaccumulation Conference
bioaccumulation factors, food chain multipliers, and
BSAFs. Then they applied these values to different
systems, assuming that they are applicable for these other
systems. What we try to do in our modeling is exactly the
opposite. We are providing people with models that allow
them to put hi site-specific factors so that they can derive-
these values, the food chain multipliers, BSAFs, and
BAFs, for various systems. We believe that not all
systems are the same and that you cannot extrapolate from
one system to another. So, my feeling is that the models
can be used much more effectively when they are applied
on a site-specific basis to work out these important
bioaccumulation properties.
John Connolly:
I think you have to put the GLI work into context.
What the GLI work was attempting to do was to develop
bioaccumulation factors that could be applied to the Great
Lakes. I do not think they had it in mind to use these
factors for national criteria. So, I do not think that there is
any intent to say that this approach is automatically
applicable nationwide. I think that the GLI documents are
very careful to point out a lot of the things that came out
in these talks, in terms of the cautions in the use of this
data. They are very clear in talking about site-specific
application. They provided a generic number because it
was their responsibility to do that. But they also provided
all of the cautions associated with the application of those
generic numbers.
Larry Burkhard:
I might add that in the GLI itself there is a tiering,
starting with field data from the Great Lakes and ending
with something that is totally model-derived from very
generic kind of parameters from Lake Ontario. That is
reflective of the knowledge that we had at the time that that
was constructed and advanced.
Q (Mike Kravitz, U.S. EPA, Office of Science and Tech-
nology): This is sort of along the lines of the last question.
What happens in terms of marine -waters? What is the
value of using things like BSAFs in systems that are so
dynamic? Will we be able to do that?
Robert Thomann:
BAFs and the BSAFs have served us well and
will continue to serve us well as kind of a first-order
screening. There will always be a utility to BAFs and
BSAFs combined with the kinds of calculations we
have been showing. So, I do not think it is totally a
question of discarding entirely the BAF and BSAF
concept. That is not the point. The point is to be aware
of the kinds of variability that can exist and the causes
of that variability in those two numbers. In marine
systems, I think ultimately we would get to the point of
looking much more specifically at fully time-variable
calculations, which, up to a point, are entirely
doable today by just about anybody. Again, we must
recognize all of the caveats and all of the assumptions
that have been made. But I think we may be heading
in the direction of working on those kinds of systems,
supplemented by the BAF and BSAF concepts.
Q(Gayle Gartnan, NOAA): I have spent most of my career
dealing with issues of whether a site should be remediated
and to what degree it should be remediated, particularly
sites with PCB contamination. So, I was particularly
interested in Dr. Thomann's presentation and his projec-
tions for the Hudson River. I found it a little disturbing
since it seems to imply that the PCBs in the Hudson River
are going to essentially be assimilated. Am I going to end
up doing calculations of assimilative capacity for PCBs?
I think about that and also about some data we have for
Puget Sound, which show that the salmon that return to
Puget Sound actually have higher levels of PCBs in their
tissue than the salmon that leave Puget Sound. So, I
wonder again, if your models are very accurate for the
little part of our system that you are modeling, but that
they do not show us what happens outside of that system.
I would like you to comment on that and what you
think your models imply for decisions about
remediation.
Robert Thomann:
Again, I think remediation has an impact locally.
There is no doubt about that, since that has been shown
any number of times. This was a question of remediating
an upriver site and its impact on a migratory fish popula-
tion. So that is the focus. One should not conclude from
the results that remediation does not affect a population or
the concentration of PCB sin a population. It does. But it
depends on its relationship to the target organism. I do not
mean to imply the question, why remediate? Why do the
PCBs seem to be declining? Fundamentally, what hap-
pens in this calculation is the PCBs ultimately are being
flushed out into the ocean and the exchange with the ocean
is diluting it. There is also a continual burial of PCBs. If
you look at the rate of decline of the striped bass over time
and make an estimate of average burial rates over that
period of time (and this is the crudest calculation), you
find out that PCBs are continually being buried. Also, the
assumption here is that the upstream load is declining.
Why is that declining? It is declining for similar kinds of
reasons. But remember, this is a long-term projection.
There are two issues you need to be aware of. One is this
calculation assumes that the loads to the system from point
sources and nonpoint sources will continue to decline.
That may not be the case. They may level off at some
point. The second is that this calculation assumes when
the fish goes out to the ocean, it sees zero PCBs. That is
what we did in the old days. We are revisiting that part of
the calculation, now that much better data are available for
what is going out into the ocean. So we send these larger
fish out 8 or 9 months of the year, and they see zero PCBs.
If the concentrations out there are now higher than zero,
which in fact they are, then those fish are going to come
back at a different concentration than we had originally
calculated.
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National Sediment Bioaccumulation Conference
Risk Assessment Overview
Dorothy Patton
U.S. Environmental Protection Agency, Office of Research and Development,
Washington, DC
Please contact the speaker for information on this presentation.
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National Sediment Bioaccumulation Conference
Session Five:
Human Health-Based Risk
Assessment
Marc Tuchman, Panel Moderator
U.S. EPA, Great Lakes National Program Office,
Chicago, Illinois
Judy L. Crane
MnnesotaPollutionControl Agency,
St. Paul, Minnesota
MethodologyfbrAssessingHumanHealth-Based'Risks
Amy Pelka
U.S. EPA Region 5,
Chicago, Illinois
Bioaccumulation Models and Applications: Setting
Sediment Cleanup Coals in the Great Lakes
Robert L. Paulson
Wisconsin Department of Natural Resources,
Madison, Wisconsin.
Use of Human Health- and Ecological-Based Goals in
Developing a Whole River Sediment Strategy: Fox
River, Wisconsin
Laura B. Weiss
Washington Department of Ecology,
Olympia, Washington
Development of Health-Based Sediment Criteria for
Puget Sound
Alex Lechich
U.S. EPA Region 2,
New York, New York
Development of Bioaccumulation Guidance for
Dredged Material Evaluations in EPA Region 2
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National Sediment Bioaccumulatioh Conference
Methodology for Assessing Human
Health-Based Risks
Judy L. Crane .
Minnesota Pollution Control Agency, Water Quality Division, St. Raul, Minnesota
^•Hhe purpose of this presentation is to discuss how and
• why human health risk assessments are conducted
M. at contaminated sediment sites. The main compo-
nents of risk assessments (i.e., site characterization,
toxicity assessment, exposure assessment, and risk
characterization) are described. In addition, the advan-
tages and limitations of using a risk assessment
approach, as it applies to bioaccumulative contaminants,
are discussed. The variety of methods by which human
health risk assessments can be conducted are described,
and these methods are illustrated with examples from
baseline and comparative risk assessments conducted as
part of the GreatLakes National Program Office's (GLNPO)
Assessment and Remediation of Contaminated Sedi-
ments (ARCS) program.
Why Use a Risk Assessment
Approach?
Risk assessmentprovides a scientific basis by which
estimates of noncarcinogenic and carcinogenic risks can
be estimated at a contaminated site. These risk estimates
can be used to address management questions about a
site; for example, what are the baseline (i.e., current) risks
to residents living in the Sheboygan River, Wisconsin,
Area of Concern (AOC)? or how would risks change at the
Buffalo River, New York, AOC if various remediation
alternatives were implemented? A risk assessment ap-
proach can also be used for regulation and enforcement
purposes, as well as for the selection of clean-up criteria.
In the United States, the triggers that initiate a risk
assessment include regulatory action leading to place-
ment on the National Priorities List or a state-equivalent
list of contaminated sites. Thus, human health risk
assessments are conducted at all Superfund sites. In,.
contrast, Canada has additional trigger mechanisms for
risk assessment, including real estate transactions, rezoh-
ing/redevelopment, regulatory placement on a priority
list, new legislation, or regulatory orders (Golder Asso-
• elates, 1993). .Canadians also have the option of using a
criteria-based approach instead of a risk-based approach
at contaminated sites.
The primary advantages of using a risk assessment
approach include the following:
• Provides a quantitative basis for comparing and
prioritizing risks.
• Improves the understanding of risk.
• Acknowledges the inherent .uncertainty in
estimating risk.
• Estimates clear, consistent endpoints (e.g., cancer).
• Separates risk assessment from risk management.
The limitations and uncertainties associated with
human health risk assessments are discussed in the
following sections.
Components of Human Health Risk,
Assessments
The specific components of human health risk
assessments are described in this section. The U.S.
Environmental Protection Agency (EPA) has developed
exposure and risk assessment guidance for use at
Superfund sites (USEPA, 1988, 1989a, 1989b, 1991)
which can be applied to other contaminated sediment
sites. Refer to this guidance for detailed information
about how to perform a site characterization, toxicity
assessment, exposure assessment, and risk characteriza-
tion for a contaminated site. A brief review of these steps
is given below. .
Site Characterization
Available site information is reviewed, and rel-
evant site samples are gathered, analyzed, and evaluated
for appropriate quality assurance measures in this step.
Potential site-related contaminants are compared with
background values. In addition, potential contaminants
of concern are identified, and a set of data is developed for
use in the risk assessment.
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5-6
National Sediment Bioaccumulation Conference
Toxicity Assessment
Verified toxicity values are obtained from EPA's
Integrated Risk Information System (IRIS) database. For
chemicals lacking a ''verified value," interim toxicity
values can be obtained fromEPA's Health Effects Assess-
mentSummaryTables(HEAST)andfromtheh'terature. The
reference dose (RfD) is the toxicity value used to evaluate
noncarcinogenic effects (e.g., neurotoxicity, reproductive
and developmental toxicity, immunotoxicty, organ-specific
toxicity). The slope factor is the toxicity value used in
evaluating carcinogenic effects. It quantitatively defines
therelan'onshipbetweendoseandresponse. TheEPAweight-
of-evidence classification scheme indicates the strength of
evidence that the contaminant is a human carcinogen.
Exposure Assessment
This component involves the greatest use of as-
sumptions and professional judgment when site-specific
information is lacking. The major parts of an exposure
assessment include the following: characterize the physi-
cal setting, identify potentially exposed populations,
identify potential exposure pathways, estimate exposure
concentrations, and estimate chemical intakes. The most
important exposure pathways identified at five Great
Lakes AOCs included the consumption of contaminated
fish and/or waterfowl (Crane, 1996). In addition, most of
the carcinogenic risk was due to elevated concentrations
of polychlorinated biphenyls (PCBs) in fish tissue. In the
exposure assessment, it is important to identify sensitive
subpopulations such as sport anglers, ethnic groups that
consume a greater proportion of fish in then- diet, and
pregnant women who consume contaminated fish. Dur-
ing the past few years, the Agency for Toxic Substances
and Disease Registry (ATSDR) hasiunded a Great Lakes
Human Health Effects Research Program that will pro-
vide more exposure information about sensitive sub-
populations in the Great Lakes area, as well as how fish
preparation and cooking practices can reduce bioaccu-
mulative contaminants in fish tissue.
Risk Characterization
In this step, the exposure and toxicity estimates are
combined into an integrated expression of human health
risk. Noncarcinogenic effects are evaluated by compar-
ing an exposure level over a specified tune period with an
RfD derived from a similar exposure period. • Carcino-
genic effects are estimated as the incremental probability
of an individual developing cancer over a lifetime as a
result of exposure to the potential carcinogen. This risk
is computed using average lifetime exposure values that
are multiplied by the oral slope factor for a particular
chemical. Noncarcinogenic and carcinogenic risk esti-
mates are summed separately for all chemicals in an
exposure pathway (e.g., fish consumption). The risk
estimates are then summed for multiple exposure pathways.
This summation does not account for any synergistic or
antagonistic effects that may occur among chemicals.
The risk characterization also includes an evaluation of
the uncertainties associated with the risk estimate.
Uncertainty is reduced by using as much site-specific
information as possible. Refer to USEPA (1989a), Colder
Associates (1993), and Crane (1996) for additional infor-
mation on evaluating uncertainties.
Risk Assessment Methodologies
Given the risk assessment framework described
above, human health risk assessments can vary in their
complexity and scope. Risk assessments can be conducted
in a qualitative, semi-quantitative, or quantitative way.
The level of detail and cost associated with conducting a
risk assessment increase as more quantitative results are
needed. The human health risk assessments conducted for
the ARCS program (Crane, 1996) were done in a semi-
quantitative way because uncertainty was expressed in a
qualitative way and quantitative risk estimates were esti-
mated. Semi-quantitative risk assessments compose the
greatest proportion of risk assessments conducted in the
United States.
Semi-quantitative risk assessments are conducted
using a deterministic approach (see Table 1). In this
approach, a single number is used from each parameter
set to calculate a single value of risk. Quantitative risk
assessments are conducted using a stochastic approach
(see Table 1), whereby a distribution of values for each
parameter set is used in the risk calculation and a distri-
. bution of risk is produced. Some jurisdictions, such as
British Columbia, are starting to require quantitative risk
assessments at some contaminated sediment/soil sites.
Human health risk assessments conducted for the
Superfund Program include baseline conditions and future
land use exposure scenarios. Future land uses do not need
to be considered if the management questions for the non-
Superfund site are concerned only with current risk
conditions to the public. Comparative risk assessments can
be conducted to assess the risk, relative to the baseline
risk, that would result from the implementation of various
sediment remedial alternatives. The ARCS Risk Assessment
and Modeling Workgroup developed a comparative risk
assessmentframewprk to integrate theresultsfrombaseline
risk assessments, field data, and mass balance modeling to
provide estimates of the potential impact of remedial
actions onhumanhealth, aquatic life, and wildlife (USEPA,
1993). A demonstration of this approach was conducted
for the Buffalo River, New York, AOC (Crane, 1995).
Problems with Current Risk
Assessment Practice
Risk assessment is an evolving science and is not
without its limitations. Some of the major problems
associated with human health risk assessments include
the following:
• Use of arbitrary exposure scenarios.
• Excessive credence to the carcinogen
classification.
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Proceedings
5-7
Table 1. Components of deterministic and stochastic risk .assessments (Golder Associates, 1993).
Deterministic
Low degree of public interest
Relatively low degree of site-specific uncertainty
Deterministic result is far from action level
Small-scale project (scope, budget, schedule)
Routine application
Large number of potential contaminants and/or
pathways (rapid screening or triggering tool)
Initial model development
Stochastic
>
High degree of public interest
Relatively high degree of site-specific
uncertainty ; :
Deterministic result is close to action level
Large-scale project (scope, budget, schedule)
Non-routine application
Small number of potential contaminants and/or
pathways
Model refinement
Quantification of uncertainty
Detailed value-of-information analysis (project
planning)
• Excessive reliance on findings from animal
cancer tests.
.• Lack of toxicity data for many components/me-
tabolites of bioaccumulative contaminants
(e.g., PCB congeners,, some PCB Aroclors,
polynuclear, aromatic hydrocarbons).
• • Lack of a quantitative level of risk that is
universally acceptable or unacceptable.
•. Poor assessment of noncarcinogenic health
effects.
• Uncertainty of risk estimate'may be poorly
characterized.
* Risks may not be communicated well to
the public.
• Environmental inequity not always considered
for low-income and minority populations.
Despite the above limitations, risk assessment has
been demonstrated as an effective way to prioritize how
scarce funding sources should be spent to provide the
most benefit to human and ecological health! EPA has
adopted a risk assessment approach, as has the Minnesota
Pollution Control Agency, for determining priorities and
shaping regulatory planning/policy making. As the sci-
entific and policy issues associated with conducting and
communicating human health risk assessments are
strengthened, the public will benefit from this increased
level of confidence in risk estimates.
References
Crane, J.L. 1995. Comparative human health and
wildlife risk assessment: Buffalo River, New York,
Area of Concern. EPA 905-R-95-008. U.S.
Environmental Protection Agency, Great Lakes
National Program Office, Chicago, IL.
Crane, LL. 1996. Carcinogenic human health risks
associated with consuming contaminated fish from
five Great Lakes Areas of Concern. J. Great Lakes
Res. 22:653-668.,
Golder Associates. 1993. Quantitative human health
risk assessment. Phase 1 - Review of methods and
framework recommendation. Prepared for
Ministry of Environment, Lands andParks, Victoria,
BC, by Golder Associates, Burnaby, BC.
USEPA. 1988. Superfund exposure assessment manual.
EPA/540/1-88/001. U.S. Environmental Protection
Agency, Office of Remedial Response, Washington,
DC.
USEPA. 1989a. Risk assessment guidanceforsuperfund:
Human health evaluation manual part A. Interim
final. OSWERDirective9285.7-01a.U.S.Environ-
mental Protection Agency, Washington, DC.
USEPA. 1989b. Exposure factors handbook. EPA/600/
8-89/043. U.S. Environmental Protection Agency,
Office of Health and Environmental Assessment,
Washington, DC. ^
USEPA. 1991. Risk assessment guidance for Superfund.
Volume I: Human health evaluation manual.
Supplemental guidance: "Standard default expo- '
sure factors." Interim final (March 25, 1991).
OSWER Directive 9285.6-03. U.S. Environmen-
tal Protection Agency, Washington, DC.
USEPA. 1993. Risk assessment and modeling overview
document. EPA 905-R93-007.. U.S. Environmen-
tal Protection Agency, Great Lakes National
Program Office, Chicago, IL.
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National Sediment Bioaccumulation Conference
Bioaccumulation Models and
Applications: Setting Sediment
Cleanup Goals in the Great Lakes
Amy Pelka
U.S. Environmental Protection Agency Region 5, Chicago, Illinois
Background
The Great Lakes, much of which is within Region 5
of the U.S. Environmental Protection Agency
(USEPA), has significant contamination of hydro-
phobic organic compounds such as PCBs and dioxins.
Because much of this contamination is found in sedi-
ments, consideration of bioaccumulation is required when
making environmental decisions. Regulatory actions
that deal with bioaccumulative hydrophobic organic com-
pounds are generally either waterway management (Clean
Water Act section 404) decisions or remedial decisions
under statutes such as Superfund, and the Resource
Conservation and Recovery Act (RCRA). The focus of
this talk will be on the latter category of remedial
decision-making.
The presentation will discuss the following:
• The need and precedent for the use of
bioaccumulation methods in a regulatory setting.
Region 5 evaluation of bioaccumulation
methodologies using Great Lakes data
(sediments to fish workgroup, or S2F).
• S2F-recomfnended process of using bioaccum-
ulation methods in combination with risk
' assessment.
• Case studies and lessons learned.
Summary
Environmental decisions often require that sedi-
ment cleanup goals be developed. Issues such as what
level is safe to leave behind, which sediments need to be
removed for it to be safe, and which remedial option
offers the best risk reduction, need to be addressed at the
many sites with bioaccumulative hydrophobic organic
compounds. In general, there are few sediment regula-
tory levels that directly address human health. PCBs, a
frequent contaminant in the Great Lakes, are regulated
under the Toxic Substances Control Act at 50 ppm or
greater, which is not, however, considered to be health-
based. In some cases there are mandates to return to
background levels, and there are also the ecological
guidelines developed by the Province of Ontario and the
National Oceanic and Atmospheric Administration
(NOAA). While these are all useful and relevant, there
was. a perceived gap in having actions that use these as
cleanup goals to be protective of human health.
A Regional workgroup was formed that sought to
address the issue of how to address bioaccumulative
compounds such as PCBs and dioxins in order to be
protective of human health. To promote consistency
and clarity on the topic, the workgroup developed Re-
gional guidance based on their deliberations. Because.
of the concern about PCB bioaccumulation, the scope of
the workgroup's efforts was always on hydrophobic
organic compounds. Because in general it is not appro-
priate to extrapolate methods or recommendations to
other contaminants that behave differently in the envi-
ronment (such as metals), the workgroup and document
only addressed methods appropriate to hydrophobic
organic compounds. The workgroup, named Sediments
to Fish, or S2F, contained technical staff from several
disciplines and areas of the agency. The goal of the
workgroup was to: (1) review relevant literature on
bioaccumulation; (2) evaluate various methodologies
using Great Lakes data and include a discussion of data
issues; and (3) recommend how best to develop cleanup
goals or, more accurately, how to best use bioaccumu-
lation methodologies in regulatory actions.
A draft guidance document was completed in
1994. The basic structure of the document is:
• Overview.
• Review and discussion of methods.
• Evaluation and validation of methods (includes
discussion of data issues).
• Recommended process for how to use the biota-
to-sediment accumulation factor (B SAP) method
with risk assessment procedures for specific use
in a regulatory setting.
. The document was reviewed extensively, includ-
ing Region 5 states, the State of Washington, USEPA
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National Sediment Bioaccumulation Conference
Headquarters, and NOAA. Overall, the reviews were
supportive and recommended refining the document fur-
ther and adding more information. The document has
been revised based on this review, and changes include a
new appendix on BSAFs found in the literature,(values
were checked in the primary reference) and additional
case studies. Currently, one of the case studies is being
revised to incorporate additional data made available
recently. When this revision is made, the document will
go through academic peer review.
It is clear that the best way to accurately assess
bioaccumulation is to use more complex models utilizing
pharmacokinetic parameters. However, for purely prac-
tical reasons, they were hot considered to be useful at
present in a regulatory setting where the data needs of
these models would not be met and time would also be
insufficient. Three methods, then, were analyzed in
detail—BCF, BAF, and BS AF. It is useful to note that in
general the BCF and BAF methods relate fish tissue
levels to the water column, whereas the BSAF method
relates fish contamination to sediment (often the medium
where levels need to be set and where contamination
more likely lies).
Methods were tested by comparing predicted fish
levels (using the various methods) with actual fish data.
This was done at four locations—Saginaw, Michigan;
Buffalo, New York; Ontario, Canada; and Manistique,
Michigan. Data needs were.considerable for this process;
data were needed to input into all methods (water column,
sediment, etc.) and a separate data set was needed to
determine site-specific BSAFs. Conclusions from this
process were as follows:
• When considering all case studies as a whole,
BSAF consistently gave the most reliable esti-
mates of fish tissue concentrations relative to
other methods. However, for specific case stud-
ies, some of the other methods were slightly more
or about as accurate (e.g., BAF—using a mea-
sured BAF and dissolved values in the Buffalo
case; and BCF—using a measured BCF and total
concentration values in the Saginaw case).
• In all of the studies, the modified BAF was the
least accurate method.
• How data were used was found to have a signifi-
cant impact. Accuracy in predicting fish levels
depended on whether all data were available, how
one decided to handle heterogeneously distrib-
uted data, and which bioaccumulation factors
were used and how they were developed. From
this limited review, it appears that site-specific or
field-derived bioaccumulation factors improve
the accuracy of the results.
• In general, BCF tended to underestimate fish
levels and BAF tended to overestimate fish levels.
Another important conclusion from this method
validation chapter was how to appropriately use data.
Major recommendations are shown in Table 1. Specific
results of the data validation using Great Lakes data are
shown in Tables 2 through 4.
The document also discusses how to incorporate
human health issues, applying the BSAF method, in
conjunction with risk assessment. In this way, one can
develop options in a regulatory setting such as setting
sediment cleanup goals. The general process for setting
cleanup goals is shown in Figure 1. Essentially, using the
basic exposure and risk equations from the Risk
Assessment Guidance for Superfund (RAGS), a target
level in fish is set It is important to note that the process
shown assumes that the contaminant of concern (PCBs,
or other hydrophobic organic compound) is appropriate,
and no other compound that would not be assessed in this
way is important in making a cleanup decision. It also
assumes that the only pathway of concern is ingestion of
contaminated fish. (No other pathway is discussed here,
such as ingestion of sediment or surface water.) Note, in
addition, that setting the target level in fish using risk
assessment requires decisions be made regarding
acceptable levels of risk (e.g., 10"6). The target fish level
can also be a regulatory level such as a threshold for
setting a fish advisory (e.g., 0.05 ppm).
The target fish level is put into the BSAF equation
and solved for concentration in sediment. Important
issues to consider when doing this analysis are: (1) choos-
ing a BSAF, which can be site, specific or can be chosen
from the literature (variations will arise and can have
great impact on results); (2) quality of total organic
carbon (TOC) data, which can have a great impact on
results as well; (3) using appropriate species of fish and
keeping species-specific considerations throughout
(lipid values, range, etc.); and (4) applying the risk
assessment process carefully and considering many
options, such as different exposure scenarios for different
fishing behaviors.
This process has been applied in several cases in
Region 5. Two that will be discussed are Saginaw and
Manistique. Results shown were used in decision-
making in Saginaw, as part of a Natural Resource
Damage Assessment (NRDA). USEPA looked at current
health risks, developed cleanup goals, and assessed how
a possible action could address human health risk. The
lower Saginaw River is characterized as having wide-
spread lower level (less than 5 ppm on average) sediment
contamination at the surface and somewhat more
contamination at depth in sediment. Site-specific BSAFs
were calculated for two species, walleye and carp.
Although a range of BSAFs could be calculated
depending on data considerations (averaging of
sediment data, etc.), they can be summarized as being 0.3
for walleye and 0.6 for carp. This information is
contrasted to Manistique, which is characterized as
having localized sediment "hot spots" of PCB
contamination, the majority of which is not at the
surface. Site-specific BSAFs were also calculated al-
though sediment and fish data were somewhat more
limited. Again a range of site-specific BSAFs were
considered due to possible data handling choices, but
they can be summarized as 0.4 for carp and .07 for
walleye. Sediment cleanup goals for these two sites
obviously follow from the BSAF differences. Saginaw
cleanup goals are much lower than those calculated
from Manistique, Michigan. A summary is provided in
Figure 2.
-------
Proceedings
5-J]
Table 1. Data Issues and Recommendations for Sediment to Fish Predictive Methods
Data Issue
Averaging offish or sediment data (geometric vs.
arithmetic mean)
Use of sediment organic carbon data
Handling of non-detect data
Uneven clustering of sediment samples
Calculating site specific BSAF value using sediment
and fish data
Type of fish sample
Bioaccumulation method
Recommendation
Geometric Mean
Point normalize
Use one-half the detection limit
Surface area weighting
Temporarily matched sediment and fish data
Filet (human health endpoint)
Whole fish (ecological endpoint)
BSAF
Table 2. Comparison of Predicted Fish Tissue Concentrations (from draft S2F document)
All values shown are ppm PCBs
BCF (meas./total)
BAF (meas./diss.) .
BAF (meas./total)
BSAF
Actual
Saginaw (walleye)
1.4
38
38
1:4
1.5
Buffalo (carp)
0.35
0.42
3.5
-0.871
2.8
(Using geometric means of relevant data)
-------
5-12
National Sediment Bioaccumulation Conference
Table 3. (from draft S2F document)
Manistique, MI
WATER-TO-
FISH
OR
SEDIMENT-
TO-FISH
PREDICTIVE
MODEL
BAF-modified
TBP (pf=4)
BSAF
(value in
parentheses is
site-specific
BSAF used)
Actual Fish
Tissue
Concentration
PREDICTED FISH CONCENTRATIONS IN CARP (in rag/kg)
SAW
SEDIMENT;
ARITHMETIC
MEANS
390 - 550
88
9.0
(0.41)
6.5
SAW
SEDIMENT;
GEOMETRIC
MEANS
380-550
86
8.6
(0.40)
6.2
ARITHMETIC
POINT-
NORMALIZED
SEDIMENT;
ARITHMETIC
MEANS
520 - 740
120
13
(0.45)
-
6.5
"•
ARITHMETIC
MEANS FOR
ALL
PARAMETERS
230 - 330
52
4.6
(0.35)
6.5
GEOMETRIC
MEANS FOR
ALL
PARAMETERS
79-110
18
2.9
(0.64)
6.2
'SAW = surface area weighted
'Values in this column are the same regardless if sediment data are normalized before or after calculating geometric means.
Table 4. (from draft S2F document)
Manistique, MI
WATER-TO-
FISH
OR
SEDIMENT-
TO-FISH
PREDICTIVE
MODEL
BAF-modified
TBP(pf=4)
BSAF
(value in
parentheses is
site-specific
BSAF used)
Actual Fish
Tissue
Concentration
PREDICTED FISH CONCENTRATIONS IN WALLEYE (in mg/kg)
SAW
SEDIMENT;
ARITHMETIC
MEANS
200-340
24
0.99
(0.16)
0.34
SAW
SEDIMENT;
GEOMETRIC
MEANS
180-310
, 22
0.87
(0.16)
0.25
ARITHMETIC
POINT-
NORMALIZED
SEDIMENT;
ARITHMETIC
MEANS
270 - 460
33
1.5
(0.18)
0.34
ARITHMETIC
MEANS FOR
ALL
PARAMETERS
120 - 204
15
0.51
<0.14)
0.34
GEOMETRIC
MEANS FOR
ALL
PARAMETERS
37-64 •
4.6
0.29
• (0.25)
0.25
'SAW = surface area weighted
'Values in this column are the same regardless if sediment data are normalized before or after calculating geometric means.
-------
Proceedings
5-13
1) Set acceptable contaminant level in fish
•i set risk target level (i.e. lO"6 cancer, HI=1)
determine appropriate exposure parameters
for fish ingestion pathway
2) Calculate total organic carbon (TOO in the area
determine fish exposure area
use most recent sediment data
use surface samples
3) Determine fish which are consumed
Consider:
local fish consumption patterns
at least two species to target '
species-specific lipid levels
4) Calculate/Select BSAF
use site-specific data to.calculate BSAF
and/or
choose literature value from Appendix £
(match species and site)
5) Calculate sediment cleanup goal
Cs = Cf (I) x TOC (2)
BSAF (4) x Lipid (3)
Figure 1. Recommended Methodology for Determining Sediment Cleanup Goals.
Cancer Risk
Level
10E-6
10E-5
10E-4
Exposure
Assumptions
sport fisher
eating average of
20 g walleye/day,
25% from site
sport fisher
eating average of
15 g walleye/day,
25% from site
subsistence fisher
eating average of
75 g walleye/day,
50% from site
Site
Saginaw
Manistique
Saginaw
Manistique
Saginaw
Manistique
CUGs for
PCBs (ppm)
0.06
1
0.8
13
0.8
13
[
•
Figure 2. Comparison of Saginaw and Manistique Cleanup Goals (CUGs).
-------
5-14
National Sediment Bioaccumulation Conference
Bioaccumulation Models and Applications: ijy
Setting Sediment Clean Up Goals in the Great Lakes
Overview
• need and precedent for use of bioaccumulation methods
in regulatory setting (linking sediment levels with
health endpoint)
• Region 5 evaluation of bioaccumulation methodologies
• Region 5 recommended process in use of methodology and
in linking with risk assessment
• Case Studies/lessons learned
National Bioaccumulation Conf.
A.E.. PeOca
9/12/96
Bioaccumulation Models and Applications H^
4 Need and precedent for bioaccumulation methods 1
for regulatory purposes 1
• assessing bioaccumulation potential
• setting cleanup goals
• evaluating remedial options
• estimating risks when limited data are available
9/IW6
-------
Proceedings
5-tS
Bioaccumulation Models and Applications
Alternative Clean Up Goals/Remedial Targets for \
Contaminated Sediments
. TSCA (50 ppm for PCBs)
Ontario Sediment Quality guidelines
NOAA Sediment Thresholds
\
background
If gap in having actions protective of human health
9/12/96
Bioaccumulation Models and Applications
Region 5 Workgroup - Sediments to Fish (S2F)
• multi-media and-division
• focused on hydrophobic organic compounds
- e.g., PCBs, PCB-like compounds, dioxins
• Guidance document
-reviewed literature and several methodologies
-tested methods using Great Lakes data
-recommended process using BSAF
• draft completed in 1994, reviewed by States and
Federal agencies; significant revisions;
interim final by end 1996; academic peer review.
9/1V96
-------
National Sediment Bioaccumulation Conference
Bioaccumulation Models and Applications
S2F Workgroup:
John Dorkin
Al Fenedick
Diane Ragler
Lee Gorsky*
Linda Hoist*
Gary Kohlhepp*
Amy Pelka*
Marc Tuchman
Dolly Tong
(Lara Pullen)
* authors of the guidance document
9I1W6
Bioaccumulation Models and Applications
Key Questions/Issues that Emerged from S2F J
O Which methodology is most accurate in predicting fish
tissue concentrations?
O Appropriately handling data
O Science Policy Issues
9/12/96
-------
Proceedings
Bioaccumulation Models and Applications
5-17
Methodologies Available to Assess Bioaccumulation of
Contaminated Sediments
BAF
BCF
BSAF
relates fish tissue concentration to water column
relates fish tissue concentration to sediment
biokinetic models -requires pharmacokinetic parameters
9/12/96
Bioaccumulation Models and Applications
Testing methodologies I
The ability of the various models to accurately predict fish tissue
concentrations were tested using actual fish tissue, water column,
and sediment data from the following sites:
• Saginaw
•Buffalo
• Ontario
• Manistique .
9/12196
-------
5-18
National Sediment Bioaccumulation Conference
Testing Methodologies |
Data needs were considerable
-need data to input into all methodologies (BAF, BCF, BSAF)
and solve for cone, in fish
-compare estimated level in fish to actual fish data
ter column \
+ •/
BAFs
BCF
BSAF
•^ conc.infish
/
bioacc. factors
ra separate data set was needed to develop site-specific
bioaccumulation factors
9/1V96
Bioaccumulation Models and Applications
PS*
L «•**•> /
fc.,,«aa
t^Equations used for Evaluating Bioaccumulation Methods:
BCF = Cf
cw
BAF = Cf Modified BAF => Cf =
cw
c^ ' •
(BCF*FC)*C0
f * K
•''OC "^OC
' where: Cf = concentration in fish; Cw=concentration in the water column;
Cs concentration in the sediment; FC=food chain multiplier;
f^ =fraction organic carbon;
Koc= partitioning coefficient (between water and organic carbon)
-------
5-19
Bioaccumulation Models and Applications
K^^
m
i^ Comparison of Predicted Fish Tissue Concentrations
from draft S2F document
. • all values shown are ppm
PCBs
>•
BCF dneas./total)
BAF (meas./diss.)
BAFdneas./total)
BSAF
Actual
Saginaw
(walleye)
1.4
38
38
1.4
1.5
Buffalo
(carp) .
.35
.42
3.5
.87-1.7
2,8.
(Using geometric means of relevant data)
9/12/96
Bioaccumulation Models and Applications
•
^Predicted PCB carp tissue concentrations
for the Manistique River
(from draft S2F document)
•
WATER-TO-FISH
CHI SEDIMENT-TO-FISH
PREDICTIVE MODEL
BSAF
(value in paientheses is site-
specific BSAF used)
Actual Fish Tissue
PREMCTED FISH CONCENTRATIONS (in vug/kg
SAW1 SEDIMEOT:
ARITHMBmC
MEANS
390-550
88
9.0
(0.41)
6.5
SAW SEDIMENT:
GEOMETRIC
MEANS
380-550
86
.8.6
(0.40)
6.2
ARITHMETIC PCHNT-
NOKMAUZED
SEDIMENT:
ARITHMETIC MEANS
520-740
120
13
(0.45)
6.5
ARITHMETIC
MEANS FOR ALL
PARAMETERS
230-330
52
4.6
(0.35)
6.5
GEOMETRIC2
MEANS FOR ALL
PARAMETERS
79-110
18
2.9
(O.M)
6.2
*^A**
m
1 SAW = surface area weigned
2 Values in thiscotam are die sanEreganHess if sediment data are nonnalized before or after calculating geometric means. a/ring
-------
5-20
National Sediment Bloaccumulation Conference
Bioaccumulation Models and Applications
!51
C^ Predicted PCS walleve tissue concentrations
for the Manistique River
(from draft S2F document)
3
WATER-TO-FISH
OR SEDJMENT-TO-FISH
PREDICTIVE MODEL
BAF.modifKd
TBP(pf-4)
BSAF
(vtlue in Duaxbaes is she-
spccific BSAF used)
Acaul Fish Tissue
Conccncruion
PREDICTED FISH CONCENTRATIONS (in mg/kg)
SAW1 SEDIMENT:
ARITHMETIC
MEANS
200-340
24
0.99
'(0.16)
0.34
SAW SEDIMENT:
GEOMETRIC
MEANS
180-310
22
0.87
(0.16)
0.25
ARITHMETIC POINT-
NORMALIZED
SEDIMENT:
ARITHMETIC MEANS
270-460
33
1.5
(Oil 8)
0.34 '
ARITHMETIC
'MEANS FOR ALL
PARAMETERS
120-204 '
0.51
(0 14)
SAW - ui&ce uea weighted
V«lu« in tlis coiunm ire the sune regardless if sediment data are nonnalized before or after calculadnu geometric means.
GEOMEtRIC1
MEANS FOR ALL
PARAMETERS
0.29
(0 25)
-
9/1W6
Bioaccumulation Models and Applications
Cj^ Data Issues & Recommendations |
.
Data Issue
Averaging data
(geometric vs. arithmetic mean)
Use of sediment
organic carbon data
Non-detect data
Uneven clustering of sediment
samples
Calculating site specific BSAF
Type of fish sample
Bioaccumulation method
Recommendation
Geometric Mean
Point normalize
Use one-half the detection limit
Surface area weighting
Temporally matched sediment and fish data
Fillet (human health endpoint)
Whole fish (ecological endpoint)
BSAF
tH
9/12/96
-------
Proceedings
5-21
Bioaccumulation
iioaccumulation Method Evaluation Conclusions:
•when evaluating all the case studies as a whole, BSAF consistently
gave reliable estimates; although other methods in some cases were
slightly more or as accurate as BSAF
•estimates using measured values for bioaccumulation factors
were more accurate than those using calculated factors
•accuracy in predicting fish levels strongly depended on data quality,
availability, and handling of data (e.g., heterogeneously distributed
data) -
•in most cases: BAF-modified was least accurate, BCF tended to
underestimate, and BAF tended to overestimate
9/12/96
Bioaccumulation Models and Applications
Recommended Methodology for Determining
Sediment Cleanup Goals
1) Set acceptable contaminant level in fish ,
2) Calculate total organic carbon (TOC) in the area
3) Determine fish which are consumed
4) Calculate/Select BSAF
5) Calculate sediment cleanup goal
= Cf(DxTOC(2)
BSAF (4) x Lipid (3)
9/12/96
-------
5-22
National Sediment Bioaccumulation Conference
Bioaccumulation Models and Applications
Evaluating Remedial Options I
• Consider several options, for example:
-dredge sediments greater than 50 ppm, 10 ppm
-leave sediment in place
-other options
4 Calculate surface area weighted sediment concentration
for each scenario under evaluation
[Cs]
• Determine BSAF for representative fish specks
(literature, site specific)
[BSAFJ
Bioaccumulation Models and Applications
Evaluating Remedial Options, cont'dl
• Use BSAF to model contaminant
concentration in fish under each scenario
Cf = (BSAF) x (C«) x T
(Organic Carbon)
4 Use exposure equation to calculate human
intake of contaminant
4 Use toxicological risk information (IRIS) to
calculate, human health risk under each scenario
9/12196
-------
Proceedings
5-23
Bioaccumulation Models and Applications
••.%
Determining an Appropriate BSAF Value I
Species Specific Issues , I
Issue
Foraging Range '•"'•
Pisciverous vs.
Bottom Feeding
Lipid Content
Presence of Species •
at Site
Consumption of
Species :-
Consideration
Consult with fish biologist to help confirm that
the average contaminant concentration in the
sediment is representative of the fish's range.
Bottom feeding fish will likely have a Higher
BSAF and thus should be included to represent
• a more conservative scenario.
Fatty fish tend to accumulate more contaminants
and thus inclusion will add a more conservative
scenario. .
Choose a species endpbint that is actually found
at the site. ..••''•.
Choose a species which is being consumed by
the local population.'
- i>*rs
: . k2tf
Bioaccumulation Models and Applications
Critical Science Policy Decisions
• Choice of bioaccumulation model
Choice of fish species (e. g. pelagic, bottom-feeding)
Choice of BSAF value
Determining appropriate sediment concentration term
• Defining fish exposure area/site boundary
9/12&6
-------
5-24
National Sediment Bioaccumulation Conference
Bioaccumulation Models and Applications
Critical Science Policy Decisions, cont'd
4 Handling of "non-detect" data
4 Choice of fish consumption rate
4 Determination of endpoints of concern
4 Accurately estimating TOC
**$*
feT^a
USEPA Region 5
Current Potential Health Risks
(MDEQ 1986-1993)
Species
jvra
lleye^ ,
carp
\bass
[whitegsh
£erch_
pjjce
\ trout
Concentrati on | Cancer Risk Range
0.43
3.1
0.21
0.04
0.13!
0.15J
0.08
3.04E-05
2.19E-04
(2.64E-03
1.90E-02
1.46E-05 1.27E-03
2.94E-06J 2.55E-04
9.16E-06
i.07E-65
5.64E-06
7.94E-04
9.25E-04
4.89E-04
HQ Ranee
0.20
1.42
0.10
0.02
0.06
0.07
0.04
17.11!
123.371
8.241
1.65!
5.161
6.01!
o i o 1
j 1 O '
-------
5-25
USEPA Region 5
22-Mile Surface- Present
Average
90% UCL /
"i
95% UCL /
cV iX"^-^
/~ >v H:'...,.: .^ . .
V, . '"'""I.- ,
Is -^, , ,
.^;^ "S,. •
pt.jflorm PCB(mg/kg)
78.2
96.6
104.7
USEPA Region 5
22-Mile Surface - Post Dredge
pt. norm P
TOC(%)
Average 55.8p
90% UCL 7i6
*&
, •£
95% UCL ,-^ /82.2
2.3
4.1
4.6
-------
National Sediment Bioaccumulation Conference
USEPA Region 5
Calculating Risk-Based Cleanup Goals
- Set Target Fish Tissue Level
,E!o4jrweight
Afcep^leRiskjLevel j 1.00E-06r l.OOE-06]
cancer slope factor 1 7.7! 7.7!
(kg)
Averaging time (days)
Ingestion rate (kg/day)
Fraction ingest ion (%)
Absorption (%)
••-
Exp. frequency (days/year)
Exposure duration (years)
Concentration in Fish
I
70J 70?
25550
255501
0.02f OJ3|
. 0.25
365
9
~0.6l41~
._-| _
365J
30J
0.00021
1 1 !
Haz. Index • -l! 1
^Ref. Dose lOO&OSl ioO&OS
70i 70
. ^Jo^Sl "70950
6.02! OJ3
0.25! _ _J_
365! 365
30! 30
I ' b"28i b.oio&
1 ,,__,
USEPA Region 5
Calculating Risk-Based Cleanup Goals
Input Target Fish Levels into BSAF=>CUGs
Sediment Qeanup(»oa] ->
^nccr(&6
fetl-i
carp
'
CF itoc
ab'iii'i'iV
, f
CF itoc
00301632
„ | .
iBSAF
..?:.?1...9^J9693
1
iBSAF
2.3: 0^319693
Csi5tocxCF)/(BSAJFxlirid) '
lipid
lipid
d I i INoncanc
i.ys
122
I.Vdl
122
CS
0.0583901
0.0050116
CS
5.783&05
walleye
carp
AWCT
babsK," .
( walleye
•carp
er (HI=n j
028
028,
•f. I
I CF toe
f 00107692,
00107692:
" BSAF
i
i lipid
23_ 02813299^
23* 05319693*
i
BSAF ilioid
23 02813299
2.3* 05319693
196
198
198
I 9R
....
CS
1.1679221
CS
-------
Proceedings
5-27
Rgh USEPA Region 5
Post-Remediation Health Risks
- Input Sediment Levels into BSAF=>Resulting Levels in Fish
range walleye CS I toe Ilipid 1BSAF
, 0.9! .2.3! 1.961 0.28
1.3! 2.3! 1.96! 0.28
55.81 l! 6.0196! 0.28
812! l! 0.0196! 0.28
CF
0.2157678
0.1558323
0.3076849
0.4532563
'. . I ' ' ! 1 ''I ' •
1 • !. 1 ' -M
range carp CS Itoc ' Ilipid IBSAF
0.9! 2.3! 12.2! 0.53
1.3| - . 2.3J_ , 12.2! _ 0.53
; '" ™ ."*"" """~55.8[ " 1! o!l22|~~ . 6.53
82.2! 1! •;'•' 0.122! a53
CF
2.5395752
1.8341377
3.6214343
5.334801
(normal)
(normal.)
(normal)
(normal)
*|p USEPA Region 5 , ' • '.
Post-Remediation Health Risks
Define Exposure Scenarios and Calculate Risk
walleye §£Sf6!Sti<% low high
CF _ 0307685 0453256^
!BW • 1 70! . 70|
AT 25550^ 25550
IR 002' 013,
JFI * 025__ l'
"AB " V i
" EF~" f 365"" 3~65,,
ED * 9, 30,
slope 7?' 77
RISK 218E-05 278E:03_
••''.' carp ftas^^"'low high
CF 3 621434_ 5334801
BW 70~ 70
,AT " 25550 25550*
. llR ' 1 0.021 0.13i
FI _ 025 1
^AB 1_ _ 1
IED ? 9! " "so?
Aslope 7 7_ 77
IRISK ! 0.000256! 0.032695i
l^^tl
JCF ___ j
IBW 1
,AT
IR
JEF "" T
JED 1
?RfD .!
_„. HQ _ _,
- .C* ',
BW !
AT
im !
FI , ;
AB
?EF ]
"IED" "" "T
,RfD
!HQ 1
ow 'high !
0.307685J 0.45325_6i
?6l " io
25550, 25550
002! 013
___0.25! 1
~ ~~365p ' 365|
9! 30|
2.00E-051 2.00E-05
0 M128_£_18 03775
X
f •;
3 621434^ 5 334801
70° 70
25550 25550
0.02! 0.13
025 L
1_ 1
365J _ 365J
"9]"" 30!
000002^ 000002
1.662903 1 212.3033
-------
5-28
National Sediment BJoaccumulation Conference
JWpacoim^^
^ Exposure Assumptions used at Manistique
Variable
Value
-mgestion rate
(kg/day)
-fraction ingested
from area
-exposure frequency
(days/year)
-exposure duration
(years)
-body weight
(kg)
-averaging time
(days)
.015 - .054
.075 - .130
25%
50%
100%
365
9
30
70
3285
10950
25550
-recreation "average" - "high end"
-subsistence "average" - "high end"
-recreation "average"
-recr. "high end" & subsis. "avg."
-subsistence "high end"
(IR's are daily rates)
"average" scenarios
"high end" scenarios
"average" noncancer
"high-end" noncancer
cancer
Bioaccumulation Models and Applications
*
^Manistique Sediment Cleanup Levels Summary (PCBs)
Cancer
Recreational
fishing
Subsistence
fishing
"Average" Scenario
risk target sediment
level (ppm)
10'6 1.3
Iff4 130
10"° 0.13
10"4 13
"High End" Scenario
risk target sediment
level (mm)
10'6 0.0096
lO'4 0.96
10'6 0.002
W4 0.2
Noncancer
(Tmmuno-
toxicitv and
Reproductive
Effects)
Haz, Index - 1
Recreational
fishing
Subsistence
fishing
"Average" Scenario
target sediment level
(ppm)
25
2.5
"High End" Scenario
target sediment level
(ppm)
0.63
0.13
H
9/1206
-------
Proceedings
5-29
'• ITS'
fe8>'
] USEPA Region 5 ''.'', ...•'' ' ' :
Comparison of Saginaw and Manistique
Cleanup Goals (CUGs)
Cancer Risk
Level
10E-6
10E-5
Exposure
Assumptions
sport fisher
eating average of
20 g walleye/day,
25% from site .
sport fisher
eating average of
15 g walleye/day,
25% from site
Site
Saginaw
Manistique
Saginaw
Manistique
CUGs for
PCBs (ppm) I
0.06
1
0.8
13
10E-4
subsistence fisher
eating average of
75 g walleye/day,
50% from site
Saginaw
Manistique
0.8
13
X
I
USEPA Region 5
Biota To Sediment Accumulation Factors
(BSAFs) in Saq'maw and Manistique
Carp Saginaw 41.6/78.2
Manistique 102.2/245
Walleye Saginaw v 22/78.2
Manistique 16.7/245
Carp
Walleye
I Saginaw
i Manistique
0.2 0.4
BSAF
0.6
-------
5-30
National Sediment Bioaccumulation Conference
Conclusions:
-bioaccumulation models applied in a regulatory setting, with careful
consideration, appear to provide reasonably accurate results and
allow actions to consider human health
[note: models evaluated for hydrophobic organic compounds only]
-data quality and quantity clearly are critical to usability and accuracy
-important considerations include:
-accurately estimating: TOC, fish species differences (% lipid,
range, etc.), concentrations of contaminant at the surface that fish
are/were exposed to, and bioaccumulation factors;
-fish ingestion rates,
-setting acceptable risk levels (cancer vs noncancer)
-critically and clearly communicating limitations, assumptions,
and uncertainties.
9/12/96
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National Sediment BioaccumuJation Conference
Use of Human Health- and Ecological-
Based Goals in Developing a Whole
River Sediment Strategy: Fox River,
Wisconsin
Robert L. Paulson
Wisconsin Department of Natural Resources, Madison, Wisconsin
^•ffhe Wisconsin Department of Natural Resources
I (WDNR) has been working with the Fox River
M. Coalition (FRC), a planning and implementation
group composed of local, state, and federal partners, to
develop a whole river sediment strategy. It was evident
early in the process that numeric criteria alone would not ,
suffice in developing a cost-effective whole river sedi-
ment strategy. Numeric criteria alone cannot address .
issues regarding loc'al benefits of remediation in numer-
ous riverreach'es or evaluate benefits of reducing PCB
transport to Green Bay in lieu of local fish tissue reduc-
tions. Other techniques that could factor in the size of the
existing problem and unique features of the Fox River
Basin were needed, t
This presentation reviews one alternative approach.
The approach relies on the tools and data generated
during the Green Bay Mass Balance Study (GBMBS) to
help identify and prioritize remediation areas and at-
tempts to quantify the benefits of remediation in terms of
reduced PCB transport to Green Bay and reductions in
fish tissue concentrations. To date, efforts have focused
on developing a basic set of remediation scenarios that
illustrate the environmental benefit and implementation
considerations of varying levels of sediment remediation.
The next step will be to develop preliminary costs for
these scenarios. With "ballpark" costs linked to the
associated environmental benefits and implementation
issues, these scenarios will help the FRC and WDNR
develop a whole river sediment strategy: The strategy
will strive for cost-effective progress toward achieving
established water quality goals and elimination of fish
consumption advisories.
The Fox River and Green Bay were studied as part
of the 1989 Green Bay Mass Balance Study (GBMBS)
(Beltran, 1992). The study focused on the transport and
fate of PCBs from the outlet of Lake Winnebago through
the entire Lower Fox River and into Green Bay, as well
as the accumulation of PCBs in the aquatic food web of
Green Bay and the Fox River downstream of DePere.
One significant conclusion of the GBMBS is that the
source of essentially all (>99 percent) of the PCBs trans-
ported by the river originates from the river sediments.
Further, a 1989 inventory of sediment PCBs estimates the
Fox River sediments contain 4,000 kg (8,800 Ibs) and
26,000 kg (57,200 Ibs) of PCBs upstream (32 miles) and
downstream of the DePere dam (7 miles), respectively. ,
Sediment remedial action scenarios for the Fox
River were simulated by using the WASPS model (Water '
Quality Analysis Program) for the Fox River upstream of
DePere (WDNR, 1995) and the IPX (In-Place Pollutant
eXport) model for downstream of DePere (Velleux et al.,
1996). These water quality models developed during the
GBMBS were useful tools for evaluating how PCBs
moved through the Fox River/Green Bay System during
1989. As demonstrated through a post-auditing proce-
dure, the Fox River water quality models can predict PCB
concentrations to within 20 percent to 30 percent of
observed PCB concentrations. The post-audit results
indicate that the Fox River models are excellent tools for
evaluating the impact and effectiveness of proposed sedi-
•ment remediation efforts.
With the intent of making model simulations real-
istically represent implementation issues, two assump-
tions were made. The post-remediation residual PCB
concentration used for the simulations was set to 2.5 ppm
for the uppermost sediment layer. Also, to simplify the
simulation of multiple remediation scenarios, all
remediation was assumed to occur at one point in time—
July 1, 2000. July 1, 2000, was chosen to represent the
midpoint of a 5-year period from early 1998 through th&
end of 2002.
The Fox River PCB transport models were used to
predict PCB concentrations in fish for different reaches
of the river as well as PCB mass transported over the
5-31
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5-32
National Sediment Bioaccumulation Conference
DePere dam and to Green Bay from January 1,1996, to
December 31,2020. Both models predict surface sediment
PCB concentrations and PCB mass transport over time.
Predicted surface sediment PCB concentrations were
used to calculate PCB concentrations in fish tissue using
a simple model, biota-sediment accumulation factor
(BSAF)(DiToroetal., 1991). The BSAF is a measure of
site-specific bioaccumulation potential of fish from ex-
posure to contaminated sediments. The model is rela-
tively simple, and describes bioaccumulation based on
the lipid (fat) content in fish and the amount of contami-
nation and organic carbon content of the sediment. A site-
specific BSAF can be calculated as:
BSAF= (C/f,)/(C/fJ
(1)
where Cf is the pollutant concentration in fish, f, is the
fraction of lipid content in fish, Cs is the pollutant concen-
tration in sediment, and f^. is fraction of organic carbon in
sediment. For ease of evaluating the remedial scenarios,
the BSAF was applied instantaneously to simulated sur-
face sediment PCB concentrations to simulate fish tissue
concentrations over the 25-year model simulation. The
fraction of lipid in fish and the fraction of organic carbon
in sediment were assumed to remain equal to
preremediation conditions.
Site Selections
A nonparametric statistical model, based on fuzzy
set theory, was employed to prioritize contaminated
Table 1. Variables used for fuzzy set ranking of contaminated sediment sites
PCB mass
PCB mass/area
PCB mass/volume
Mercury concern
River position
Bioavailability Index (OC-normalized PCB in top layer)
PCB mass remaining—25-yr "no action" scenario
PCB mass delivery during Mass Balance Study year
PCB mass delivery under a modeled 100-yr storm event
PCB mass delivery—25-yr "no action" scenario
individual model's configuration. Upstream of DePere,
the sites were prioritized byriver segment. ThelPXmodel
used downstream of DePere artificially divides the last 7
miles of river into 96 Sediment Management Units (SMU).
Site prioritization downstream of DePere was by SMU.
Upstream of DePere, the five top-ranked river segments
contain Deposits A, POG, C, D/E, N, and EE/GG/HH.
Deposits A, C, D/E, and POG are all within the first river
reach from the outlet of Lake Winnebago, which is locally
known as Little Lake Butte des Morts (LLBdM).
The site rankings were used to assemble four sedi-
ment remediation scenarios that attempt to accommodate
remediation upstream of DePere while balancing the
importance of reducing PCB bioaccumulation into fish
tissue downstream of DePere with reductions of PCB
transport to Green Bay. The four scenarios are:
• No Action [Figure 1 (1)].
• Deposits A, C, POG upstream of DePere and the 3
top SMUs downstream of DePere [Figure 1 (2)].
• Deposits A, C, POG upstream of DePere and the 17
top SMUs downstream of DePere [Figure 1 (3)].
• Deposits A, D/E, POG, N upstream of DePere and
the 50 top SMUs downstream of DePere
-- [Figure 1 (4)].
Endpoints
To provide a base level of communication that
should be easily recognized and understood by the major-
ity of the public, changes in risk associated with the three
scenarios were expressed in terms of allowable fish con-
sumption rates. The pro-
posed Uniform Great
Lakes Sport Fish Con-
sumption Advisory Pro-
tocol (GLSFATF, 1993)
was selected because it
recognized the limita-
tions and inadequacy of
the FDA tolerances for
marketplace fish and set
sediment sites both upstream of DePere and in the 7 river
miles downstream of DePere. This fuzzy set analysis
provides a systematic technique for comparing a set of
alternatives and identifying more preferable ones based
on multiple decision criteria or factors (Table 1).
In general, PCB mass delivery under a simulated
25-yr "no action" scenario
and bioavailability were Table 2. Proposed uniform Great Lakes sport fish consumption advisory levels.
the most important vari-
ables while river position
and mercury were the vari-
ables of least importance.
forth a protocol based on
a weight-of-evidence health protection value. The pro-
tocol provides a range of consumption advice expressed
in consumption terms, which provides adequate protec-
tion but also allows people to selectively eat sport fish as
often as they wish. The advisoiy categories for PCBs are
listed in Table 2.
The prioritizing of
sediment sites was con-
ducted separately for up-
stream and downstream
of DePere based on the
Consumption Rate (227g/meal)
Tissue PCB concentration
Unrestricted consumption (225 meals/year)
One meal per week
One meal per month
Six meals per year
Do Not Eat
<0.05 ppm
0.05 to 0.22 ppm
0.22 to 0.95 ppm
0.95 to 1.89 ppm
> 1.89 ppm
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Proceedings
5-33
To incorporate ecological concerns into the evalu-
ation of the three remediation scenarios, fish tissue con-
centrations that would be protective of fish-consuming
birds and mammals were also included. Using method-
ologies from the Great Lakes Water Quality Initiative
(USEPA, 1995), an ecologically protective fish tissue
concentration of 0.023 ppm derived from mink data was
included in the evaluations of the scenarios.
Typical Model Simulation Results
Figure 1 illustrates the type of results generated
by this modeling approach. Results have been limited
to single fish species in only two distinct river.segments
(LLBdM and downstream of DePere) and PCB
transport to Green Bay. Similar results can be generated
for any parameter listed in Table 1 (except river
position) in any particular river reach. Other fish
species or tissue types (i.e., whole fish) can be easily
substituted for the species analyzed provided there are
enough data to estimate the average PCB concentration
around 1990 for locations above DePere and around
1995 for below DePere.
Conclusions
General conclusions of the modeling done to date
include:
• The problem is large and environmental benefit
of sediment remediation is directly proportional
to the effort expended.
• Remediation of select "hot spots" upstream of the
DePere dam has little influence on transport to
Green Bay.
• Remediation upstream of .the DePere dam has little
influence on fish tissue downstream of DePere.
• Remediation of large areas with low PCB
concentrations achieves greater reductions in
transport with similar reductions in fish tissues.
• Remediation of areas downstream of DePere has
greatest influence oh fish tissue concentrations
downstream of DePere and PCB transport to
Green Bay.
Remediation decreases the time necessary to
achieve a specific fish tissue endpqint.
Next Steps
With the goal of a cost-effective whole river sediment
strategy in mind and the environmental benefits of these
scenarios in hand, attention will shift toward developing
total costs of these scenarios. Critical to this step will be
developing unit costs for the remedial techniques most
likely to be used. These costs could be applied across the
board to each scenario, resulting in "ballpark" costs.
Alternatively, each scenario could be reviewed in detail
and specific techniques and costs applied to each sediment
area or group of areas. Most likely, an iterative combination
of these approaches will be attempted. Ultimately, with
discussions focused on the cost of achieving specific
environmental benefits, a cost-effective whole river strategy
can be refined from this basic set of scenarios.
References
Beltran, R.F. 1992. The Green Bay/Fox River mass
balance study - management summary. USEPA
GLNPO, Chicago, IL. 24pp.
DiToro,D.M.,etal. 1991. Technical basis of establishing
sediment quality criteria for nonionic organic chemi-
cals using equilibrium partitioning. Environ.
Toxicol. Chem. 10:1541-1583.
GLSFATF. 1993. Protocol for a uniform Great Lakes
sport fish consumption advisory. Great Lakes Sport
Fish Advisory Task Force Protocol Drafting Com-
mittee, September 1993. 81 pp.
USEPA. 1995. Final water quality guidance for the
GreatLakes system. 40 CFRParts 9,122,123,131
and 132.
Velleux, M., J. Gailani, and D. Endicott. 1996.
Screening-level approach for estimating contami-
nant export from tributaries. J. Env. Engrg. Div.,
ASCE 122(6), 503-514.
WDNR. 1995. A deterministic PCB transport model for
the Lower Fox River between Lake Winnebago and
DePere, Wisconsin. WDNR PUBL WR 389-95.
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5-34
National Sediment Bioaccumulation Conference
Cumulative PCB Transport to Green Bay
6000
1995 2000 2005 2010 2015 2020
Year -
PCB in LLBdM 20" Walleye Fillets
0.1
8
0.01
0.001
1995 2000 2005 2010 2015 2020
Year
Ave 20-25" Walleye Fillet Below DePere
2000
2005 2010
Year
2015' 2020
Figure 1. Typical remediation simulation results.
_
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National Sediment Bioaccumulation Conference
Development of Health-Based
Sediment Criteria for Puget Sound
Laura B. Weiss
Washington State Department of Ecology, Olympia, Washington
Problem Statement
Discharge of many industrial, agricultural, and
domestic chemicals into Puget Sound has
resulted in sediments with elevated levels of pol-
lutants, especially in urban bays and estuaries. Many of
these pollutants accumulate in fish and shellfish. As a result,
there is concern that. contaminated sediments pose a
health threat to humans through the consumption of sea-
food that has bioaccumulated chemicals directly or indi-
rectly from sediments.
To address the problem of contaminated sediments,
the Washington State Department of Ecology (Ecology)
adopted the Sediment Management Standards (SMS)
(Chapter 173-204 WAG) in 1991. The purpose of these
standards is to "reduce and ultimately eliminate adverse
effects on biological resources and significant human
health threats."
Sediment Management Standards
(SMS) Background
The SMS currehtly establish 47 chemical-specific
sediment quality standards (SQS), which are designed to
protect benthic organisms. No human health-based
criteria were available for inclusion at the time of SMS
adoption. As a result, standards for the protection of
human health from contaminated sediments are being
developed on a case-by-case basis. To increase consis-
tency and allow for more timely decision-making, Ecol-
ogy is developing human health-based sediment quality
criteria (HHSQC) that will be incorporated into the cur-
rent SMS.
Once adopted into the SMS, human health criteria
will be used in conjunction with existing ecological
criteria to make cleanup, source control, and dredging
decisions. The rule presently includes two levels of
criteria: (1) the Sediment Quality Standards (SQS), which
set a goal of "no adverse impacts," and (2) a higher
Regulatory Limit (RL), which allows for "minor adverse
impacts." Regulatory decisions are made on a site-
specific basis in the range between these two levels. The
HHSQC will also include two criteria levels, based on
different levels of risk.
Implementation Framework
Ecology's proposed construct for human health
criteria relies on a tiered approach. "Tier I" is intended to
allow for an initial evaluation to determine if sediment
chemical concentrations pose a significant human health
risk. If so, additional site-specific analysis would be
available under "Tier II" to verify the results of the tier I
analysis and to take into account any uncertainties asso-
ciated with Tier I values. In addition, Ecology is propos-
ing the use of tissue data as a confirmatory step under
Tier H to validate assumptions regarding bioaccumula-
tipn potential.
Criteria Calculation/Methodology
The primary human route of exposure to contami-
nated sediments is via the consumption of contaminated
fish and/or shellfish. Human health criteria are devel-
oped by applying U. S. EPA's risk assessment methodol-
ogy to calculate risk from consumption of potentially
contaminated fish/shellfish. To quantitatively establish
the link between sediment and biota, a biota-sediment
accumulation factor (BSAF) is used.
The following formula and input parameters are being
proposed to develop HHSQC for carcinogenic compounds:
where:
HHSQC = R*BW* AT* 1000
CPF * ED * ER * BSAF * FL
R = risk level of 10-6for SQS (a lO'5 risk level is
proposed for the RL)
B W = adult body weight of 70 kg
AT = averaging time of 75 years
CPF = chemical-specific cancer,potency factor as
defined by EPA (IRIS)
ED = exposure duration of 30 years
IR = fish ingestion rate of 52 grams/day (based on
results of consumption studies of Native American
populations in the Puget Sound region (Toy, 1995))
BSAF = chemical-specific biota-sediment
accumulation factor
FL = fish lipid of 3%
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5-36
National Sediment Bioaccumulation Conference
Technical Development Work
Several technical reports have been completed to
support the development of HHSQC. One of these, Tier
I Report: Development of Sediment Quality Criteria for
the Protection of Human Health, completed by the Wash-
ington State Department of Health (DOH), investigated
technical issues related to the development of health-
based sediment criteria (DOH, 1995). The report de-
scribes four areas of research: (1) determination of back-
ground concentrations; (2) a prioritization of chemicals
of concern; (3) development of recommended BSAFs;
and (4) fish consumption rates and recommendations.
DOH identified over 200 potential chemicals of
concern based on data In Ecology's SEDQUAL database.
These chemicals were prioritized into one of three groups
(Groups I,' 2, and 3) based on whether they had EPA
toxicity values (CPFs or RfDs), the frequency with which
they were detected in urban areas, and their ability to
bioaccumulate in aquatic biota (as measured by their Kow).
Ecology is focusing its efforts on developing
HHSQC for six organic chemicals or chemical groups
from the Group 1 chemicals of concern list which are of
primary human health concern in Puget Sound and for
which our confidence in the toxicity and the BSAF is the
highest. These chemicals are known to bioaccumulate,
have been found in Puget Sound fish or shellfish, and are
likely to present a risk to humans at levels that are lower
than current ecologically based sediment criteria. These
chemicals are:
DDT and metabolites
Hexachlorobenzene
Hexachlorobutadiene
HPAHs (high molecular weight polycyclic aro-
matic hydrocarbons)
PCBs
Polychlorinated dibenzodioxins and furans
There are other chemicals of concern for which a
scientifically defensible BSAF could not be developed at
this time, including several inorganic compounds such as
mercury. For these chemicals, Ecology is proposing to
develop target tissue levels that can be used to make
source control and cleanup decisions in the absence of an
HHSQC.
BSAF Development
Initial efforts by DOH focused on the use of a
bioenergetics-based equilibrium-partitioning model
(Thomann et al., 1992). However, an empirically based
approach, relying on information from both the pub-
lished and gray literature, was developed "and recom-
mended. This was due to the availability of empirical
data as well as a lack of appropriate Input parameters for
the model. This approach is described in the final DOH
Tier I Report (DOH, 1995).
DOH compiled empirically derived. BSAF values
from a variety of sources for a range of aquatic species
and chemicals. Over 1,200 BSAFs for upper trophic
level fish were identified for a set of organic chemicals of
concern. These BSAFs were primarily field-derived and
represent both marine and freshwater species.
DOH derived BSAFs from these literature values
using descriptive statistics based on grouping chemicals
by chemical class and log Kow. DOH recommended the
use of the 75th percentile BSAF values for criteria
development.
To provide additional support for BSAF develop-
ment, Ecology hired an outside contractor (PTI Environ-
mental Services) to analyze the data set compiled by
DOH. PTI used linear and nonlinear multiple regression
analysis to investigate the effects of chemical-specific
and species-specific characteristics on BSAF values and
to estimate BSAFs (PTI Environmental Services, 1995).
Based on the results of the multiple linear regres-
sion analysis, separate BSAF calculation equations were
developed for different chemical classes, feeding types,
and taxonomic groups. A variety of upper confidence
limits were calculated for these prediction equations.
Regressions were found to be statistically significant for
PCBs and dioxins in finfish and for PAHs and PCBs in
shellfish. However, the R2 ranged from 0.70 for dioxins
in finfish to 0.058 for PAHs in shellfish.
Using the results of the DOH and PTI analyses,
Ecology has developed preliminary HHSQC. BSAFs
developed by regression analysis for PCBs and dioxins in
finfish, as well as those for PAHs in shellfish, are being
applied. BSAFs for other compounds, such as DDT and
metabolites, are based on the results of a descriptive
statistical analysis (using the 90th upper confidence limit
on the mean).
Technical/Policy Implications
Several technical andpolicy issues have been raised
in the process of developing HHSQC. Debate over
criteria development has focused primarily on three input
parameters: (1) level of risk for cancer-causing chemi-
cals, (2) fish consumption rates, and (3) BSAFs. Each of
these issues involves both technical and policy decisions.
Because of the controversial nature of these crite-
ria, Ecology has been working closely with an advisory
committee made up of representatives from industry,-the
environmental community, tribes, ports, and other gov-
ernment agencies, in the development of the criteria. The
committee has been providing input on Ecology's technical
development work and the related implementation issues.
In addition to questions about the technical/scien-
tific methods being applied, concerns about the cost and
liability implications of the HHSQC have been expressed
by some potentially affected groups. In an attempt to
respond to these concerns, Ecology is currently conducting
"case studies." These case studies are areview of existing
sediment cleanup site decisions to assess the potential
impact of the HHSQC on these (and other) sites. The case
studies will also allow the agency to improve the imple-
mentation strategy based on lessons learned in the field.
After completion of the case studies, Ecology ex-
pects to continue with the rule'development process,
which includes proposal of a draft rule in mid-1997 and
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Proceedings
'5-37
completion of a cost/benefit analysis '(as required by state
law). Ecology is looking toward adoption of HHSQC by
the end of 1997.
References
DOH (Washington State Department of Health), 1995.
Tier I report: Development of sediment quality
criteria for the protection of human health. Office
of Toxic Substances, Olympia, WA.
PTI Environmental Services. 1995. Analysis ofBSAF
values for nonpolar organic compounds in finfish
and shellfish, final report. Prepared for the
Washington State Department of Ecology, Central
Program, Environmental Review and Sediments
Section.
Thomanri, R., J. Connolly, and T. Parkerton. 1992.
An equilibrium model of organic chemical accu-
mulation in aquatic food webs with sediment
interaction. Environ. Toxicol. Chem. (ll):615-629.
Toy, K.A., G.D. Gawne-Mittelstaedt, N.L. Polissar, and
S. Liao. 1995. A fish consumption survey of the
Tulalip and Squaxin Tribes of the Puget Sound
region (draft). Tulalip Tribes, Natural Resources
Department, Marysville, WA.
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National Sediment Bioaccumulation Conference
Development of Health-Based
Criteria for Sediments in
Puget Sound
WASHINGTON STATE
DEPARTMENT OF
ECOLOGY
Laura B. Weiss, M.P.H.
Washington State Department of Ecology
Environmental Review and Sediments Section
Sediment Management Standards
Application Model
"Minor
Adverse
Effects"
Goal:
"No Effects"
Regulatory
Limit
Sediment
Quality
Standard
Increasing Sediment
Contamination
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Proceedings
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HHSQC Implementation Framework
Initial Sediment Characterization:
Compare to Tier I HHSQC
Optional Tier II Analysis:
Collect Site-Specific Data
Exceed Standards:
Regulatory
action initiated
Meet Standards:
No regulatory
action required
Derivation of Health-Based
SQC for Carcinogens
Sediment
Risk x BW x AT
Concentration = CPF x BSAF x IR x FL x ED
where:
Risk = 1 in a million (1Q-6) /1 in 100,000 (10s)
BW - body weight of 70 kg
AT = lifetime of 75 years
CPF = chemical-specific cancer potency factor (IRIS)
BSAF = chemical-specific biota-sediment accumulation factor
IR = fish ingestion rate of 52 grams/day
FL = fish lipid of 3%
ED = exposure duration of 30 years
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National Sediment Bioaccumulation Conference
Technical Development Work
Tier I Report (DOH, 6/95)
Use of Distributional Analysis (Male, 6/94)
Fish Tissue Regulatory Options Paper
(Male, 9/94)
Analysis of BSAFs for Metals (PTI, 10/95)
Analysis of BSAFs for Organics (PTI, 11/95)
Chemicals of Concern Analysis/Display
(PH, 10/95)
DOH Tier II Report (DOH, 5/96) -
BSAF Validation for Puget Sound (PTI, 9/96)
Tier I Report (DOH, 1995)
Patrick, McBride, Hardy and LaFlamme
• Areas of Research:
- Determination of background concentrations
- Chemicals of concern (3 groups)
- BSAF development
- Fish consumption review and recommendations
• SQC calculated based on DOH
recommendations
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Proceedings
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Chemicals of Concern = All chemicals detected in
Puget Sound sediments (SEDQUAL) .
no
EPA Toxicity Value?
yes
>5% Detection Frequency in
Urban Bay Sediments?
yes
no
logKow>3.5?
V- yes
( Group 1
Human Health
Chemicals of Concern
* Aldrin
• DDD, DDE, and DDT
• Hexachlorobenzene
• Hexachlorobutadiene
• HPAHs(TEQ)
• PCBs
• Pentachlorophenol
• Polychlorinated dibenzodioxins and furans (TEQ)
(Note: This list includes only Group 1 organic chemicals with the highest '
bioaccumulation potential. Confidence in calculated BSAF values for these 8
chemicals or chemical groups ranges from high to low.)
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National Sediment Bioaccumulation Conference
Approaches for
BSAF Development
• Thomann Food-Web Model
- Requires further data collection
- Validation recommended
• Empirical, Literature-Based Values
- Regression analysis
. - Descriptive statistics
• Use Fish Tissue Data
to Validate
BSAF Analysis for
Nonpolar Organics — DOH
Compiled data from:
- Parkerton (1991)
- COBIAA (1992)
- EPA GLWQI (1994)
Mostly field data, from marine and freshwater
1,200 BSAF values for upper trophic level fish
- Grouped by chemical class
• Found too much variability among chemicals
- Grouped by Kow and chemical class
• Accounts for important chemical characteristics
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.Proceedings
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An Alternative BSAF Analysis
for Nonpolar QrgaBics
Alternative statistical analysis of data compiled by
DOH (linear and non-linear regression analysis)
Included a total of 1,5.91 data points (finfish and
shellfish)
Found significant regressions for PCBs and dioxins in
finfish and for PCBs and PAHs in shellfish (variable
'
Results for PCBs in finfish consistent with DOH
Less consistency for other chemicals of concern
Managing Uncertainty
Criteria Development
- Monte Carlo Analysis
Implementation
- Two Tiers allow for site-specific
data collection and analysis
- Tissue collection and analysis
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National Sediment Bioaccumulatlon Conference
HHSQC, Ecological Criteria and
Background Concentrations
1000 n
100
10 -
1 -
0.1 -
0.01
D Ecological
Criteria
mHHSQC
(preliminary)
• "Background"
Concentrations
HCB
Hcbd
PCBs B(a)P
Issues/Concerns Raised
Technical/scientific methods
Consistency between Ecology programs
Liability and cost associated with cleanup
Statutory authority
Implications for source control
Environmental equity
Speed of rule development
Protection of resource and future
generations
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Proceedings
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What Next?
•Case Studies:
To answer specific questions about
implementation and rule impacts
• Draft rule proposal in mid-1997
• •
• Complete cost/benefit analysis
• Rule adoption in late 1997
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National Sediment Bioaccumulation Conference.
Development of Bioaccumulation
Guidance for Dredged Material
Evaluations in EPA Region 2
Alex Lechich
U.S. Environmental Protection Agency Region 2, New York, New York
Introduction
The work described here was done under the auspices
of the New York/New Jersey Harbor Dredging
Forum, which was convened in the Summer of 1993
by the U.S. Environmental Protection Agency Region 2
(Region 2), the New York District Corps of Engineers
(NYDCOE), the New York State Department of Environ-'
mental Conservation (NYSDEC) and the State of New
Jersey Department of Environmental Protection (NJDEP).
The Forum was convened to try to solve the serious prob-
lems facing dredgrng'and disposal of dredged material from
the Harbor. The problems stem from the implementation of
revised dredged material testing procedures, which resulted
in many more proposed projects being found not suitable for
ocean disposal, and the lack of regional alternatives to ocean
disposal. The Forum drew together representatives of all of
the local interested parties, including government, industry,
shipping, labor, and public environmental interests. In early
Forum meetings, eight general areas to be addressed, were
identified and defined by the participants, and workgroups
were assembled which were tasked to address these specific
areas. .
The Disposal Criteria Workgroup, chaired by Mario
Del Vicario, Chief of the Place-Based Protection Branch
in Region 2, was tasked to address the perceived "gaps" in
criteria for evaluating tests for ocean disposal of dredged
material. The workgroup initially identified eleven issues
to address. The issue of evaluation of bioaccumulation
test results was number one on the list. In prioritizing all
eleven issues, however, the workgroup realized that some
of the other eleven issues could be resolved more quickly
and would address outstanding issues relating to the
regional testing manual. After some of these issues were
addressed, the Bioaccumulation Subgroup of the Disposal
Criteria Workgroup was formed in the Spring of 1994,
and began to seriously address bioaccumulation after
evaluating the status of other ongoing efforts, including
national efforts. The subgroup included a representative
each fromRegion 2, NYDCOE, NYSDEC, NJDEP, Exxon
Biomedical Services (as an industry representative), and
from a consortium of environmental groups that included
the Environmental Defense Fund, the American Littoral
Society and Clean Ocean Action.
This discussion will describe the methods that were
developed by the subgroup, the current status of the work,
including other related work on development of BS AFs
from project test results, and the actions that are antici-
pated in the future. -
General Approach
The workgroup decided to develop information in
two general areas, risk-based evaluation methods and
field background data on benthic invertebrate tissue
residues from areas around the ocean disposal site. This
approach follows the general guidance on evaluation of
bioaccumulation test results in the Green Book (1991),
using eight guidance factors for' evaluating
bioaccumulation results (see 1991 Green Book
Bioaccumulation Factors on page 5-53). Of these eight
factors, the workgroup felt there were important informa-
tion needs for factors four and eight, the. toxicological
importance of contaminants which exceed reference ma-
terial and exceedance of concentrations found in organ-
isms living hi the vicinity of the disposal site.
The various toxicological measures of a contami-
nant (i.e., human health, ecological endpoints) are the
most important indicators of its potential for adverse
effects, while information on background concentrations
in benthic organisms is necessary to evaluate the potential
for significantly degrading the existing conditions in the
area around the disposal site. The toxicological impor-
tance of a contaminant needs to be related to the potential
risk to an end receptor, which, for dredged material
evaluations, is measured at the benthic invertebrate level
of the food chain. The workgroup decided to use a
method for estimating human health and wildlife risk
proposed and developed by John Zambrano of NYSDEC
with workgroup involvement. The method is a "stan-
dards"-based assessment, as opposed to a site-specific or
5-47
-------
5-48
National Sediment Bioaccumulation Conference
case-specific risk assessment. Since the workgroup had
been tasked to develop an approach on its own resources,
a phased approach was recommended that initially used
available information and established methods where
possible. Information was readily available in the EPA
IRIS (1994,1995) database and elsewhere to derive risk-
based guidance values with the principles that EPA used
to derive water quality criteria. This would be compared
to other risk-based information and field background
tissue data, and combined in an overall strategy for evaluation
of test results. As new information or national guidance
values became available, the approach would be modified.
Depending on the level of confidence that could be
placed on guidance values synthesized from the risk-
based and background information, an overall evaluation
strategy would probably still be necessary. This is because
the level of confidence hi guidance values that would be
appropriate for passing or failing a proposed ocean disposal
project based on exceedance of, for instance, one con-
taminant (essentially setting "bright line" standards) would
be difficult to achieve, given the uncertainties and
assumptions in the available methods. A weight-of-
evidence type strategy would be necessary if the resulting
guidance values do not have this level of confidence. The
overall approach, then, would include a human health and
ecological (aquatic and wildlife) risk-based component,
a field background tissue component and a combined
evaluation strategy.
Human Health Approach
The risk-based approach for carcinogens starts with
effects data and, after consideration of consumption and
other exposure factors, ends with concentration-related
levels of risk. In a site-specific approach, actual "project"
concentrations are used through hazard and exposure.
assessments to result in a description of levels of risk for
the project. For noncarcinogens, reference doses (RfDs)
are used with the same exposure factors as hi the cancer
risk method The standards approach usedbroad assumptions
regarding exposure, although the method does include
site-specific information that was developed for a repre-
sentative food chain and wildlife species at potential risk.
The human health model first calculates an accept-
able lexicological dose for carcinogens by dividing a
selected cancer risk by the cancer potency factor and
multiplying by a 70 kg body weight and a 103 unit
conversion factor (see Human Health Method on page 5-
53). For noncarcinogens, an RfD is multiplied by body
weight. Toxicological data was obtained from IRIS, and
information from the National Toxics Rule (1992) was
used for a total PCB reference dose (RfD). An acceptable
concentration in seafood is calculated by dividing an
acceptable lexicological dose by a seafood consumption
factor. This is then converted to an acceptable concentration
in benthic invertebrates using a food chain factor, a whole
fish-to-filet ratio, and a lipid adjustment (to 2 percent
lipid).
EPA has recommended 6.5 g/day,as a national
average fish consumption rate in its guidance to the states
and has utilized that value in the National Toxics Rule
(1992). It is recognized that other values may be appro-
priate to reflect any regional differences; however, there
was no effort made to determine a different regional rate.
This issue involves extensive consideration of either re-
gional survey data or comparable data, and of average
versus higher percentile consumers. The Workgroup felt
that, for this initial effort, the procedures in the method
includes other cancer and noncancer risk components that
can account for geographic variables and population
extremes.
Trophic Transfer
Initially, the workgroup evaluated food chain mul-
tipliers (FCMs) used in the EPA Water Quality Standards
Handbook, which used a food chain model developed by
Thomann (1989). Scientists from EPA's Office of Re-
search and Development (ORD) recommended that the
Gobas model (1993) be used-, which was used in the EPA
Great Lakes Initiative (GLI). The ORD recommendations
came in a meeting held in Region 2 that was chaired by
Bob Huggett, EPA Assistant Administrator for ORD, and
included researchers from various ORD research labora-
tories as well as representatives from several EPA Head-
quarters offices and Regions to support Region 2 in this
effort. The Gobas model assumes equilibrium partition-
ing in benthic organisms, and it was determined that this
model reasonably represented field study data for the GLI.
To use the Gobas model in our effort, a regional food chain
with representative lipid values and organism masses for
all trophic levels needed to be developed. A representa-
tive coastal ocean demersal food chain for the region was
developed in consultation with National Marine Fisheries
Service and other experts. It includes information on lipid
and mass for each trophic level organism, as well as
average values by trophic level for input into the model.
Larry Burkhard .of EPA's Mid-Continent Ecology
Division (Duluth, MN) performed the model runs. The
resulting multipliers are applied on the basis of log Kow,
which were obtained from EPA guidance for the GLI
(1993). Humans were assumed to eat primarily from the
fourth trophic level, so the multipliers from level 2 to 4
were used to calculate the increase in concentration from
benthos to human seafood (see Tables 5 and 6 on
page 5-55). Since the Gobas model is considered appli-
cable for lipophilic organics mat do not metabolize, it is
not applicable for metals and PAHs. For cadmium, it was
assumed that bioaccumulation occurs through water, and
biomagnification does not occur. The trophic transfer
factor for methyl mercury was obtained from the GLI
(1995). PAHs are metabolized in many higher trophic
organisms, but not in some benthic organisms. A trophic
transfer factor of one was initially assumed; however,
since there is little evidence for the potential of a signifi-
cant pathway to humans, the workgroup has not as yet
decided whether to include PAHs in the human health
method. Information from several studies on PAHs in
lobsters, including hepatopancreas concentrations, is be-
ing evaluated with respect to modeling a potential human
pathway. An ingestion rate adjustment, as well as
-------
5-49
adjiistments according to EPA PAH Toxic Equivalences,
will probably be used if the workgroup decides to include
the carcinogenic PAHs in the human health method.
These adjustments would result in higher human health
guidance values than were initially calculated (see Table 7
on page 5-56).,
Whole Body/Met Ratio
A whole body-to-filet ratio was used hi the human
health method. New York State data indicated a range of
1.2 to 1.5 as being applicable to lipophilic substances. The
mid-range of 1.35 Was used in the model for all lipophilic
substances. A value of one was used for cadmium and
methyl mercury. A lipid adjustment to 2 percent lipid was
used to reflect the average lipid content of trophic level 2
in the representative demersal food chain.
Wildlife Approach
Initially, the workgroup considered developing
wildlife protection values similarly to the human health
model, but including adjustments for less stringent effects
protection and reflecting the need to protect populations
instead of individuals. There was no consensus reached
by the workgroup on appropriate adjustments. Also;
recommendations by ORD GLI reviewers to address their
concerns related to mis technique could not, in the opinion
of the workgroup, be implemented within the scope of this
effort. Therefore, the workgroup decided to calculate
wildlife reference doses (WRfD) from the GLI informa-
tion for three compounds common to the GLI and regional
contaminants being addressed, DDT, PCB and mercury.
The WRfDs were calculated using the test doses and
uncertainty factors from the GLI Tier 1 wildlife criteria
equation and criteria documents for protection of wildlife.
The WRfDs are conceptually equivalent to the human
RfDs. An acceptable lexicological dose is calculated by
multiplying the WRfDs by the body weights of species to
be protected (see Wildlife Method and related informa-
tion on pages 5,-56 through 5^57).
Representative wildlife species information was
developed that included body weight and fish consump-
tion rate at each trophic level. A variety of sources were
used to develop the wildlife species information, includ-
ing discussions with marine observers and scientists and
the EPA Wildlife Exposure Factors Handbook.
Based on observations and review of studies in the
area, it was determined that the harbor seal would be a
good representative mammal potentially at risk, since it
has been observed in the dump site vicinity.- Other marine
mammals and sea turtles were not determined to be at
much risk in this scenario, based on information from
sightings regarding their regional residence times and
feeding behavior. Studies of food consumption and
weights of harbor seals in the wild were not available, so
mformation was obtained from the NY Aquarium, which
has held several specimens at different times.
Discussions were held with seabird observers, in-
cluding the Mahomet Observatory and Cape May,
Observatory in New Jersey, and available information on
avian species potentially at risk was compiled. A critical
factor for evaluating species at risk was the ability to feed
from the demersal food chain at the depths found at the
Mud Dump Site (50-80 feet). Cormorants, old squaw
duck and red-throated loons were observed in the area and
can dive to these depths. Since there was no information
available on body weights or food consumption for these
species, input parameters used in the GLI for the belted
kingfisher were used hi the model. Although it is ac-
knowledged that these birds have different body weights
and probably different ingestion rates than the -belted
kingfisher, the ingestion rate to body weight ratios, which
are used in. the'model, are probably within reasonable
limits. The herring gull data as used in the GLI was used
directly for New York Bight apex gulls to compare with
the other wildlife results., A full description and assess-
ment of the above information is available upon request.
, The food chain for wildlife was assumed to be
similar to the one constructed for humans. Wildlife values
for individual species are calculated using the acceptable
doses, aquatic food consumption rates and trophic transfer
factors. The trophic transfer factors are weighted according
to the relative food consumption at each trophic level. As
was done in the GLI, the final wildlife value is considered
the most stringent of the mammalian and avian results.
Aquatic Risk-Based Approach
An aquatic risk-based approach was also proposed
that would estimate risk levels-for finfish, which were
considered the upper trophic level predators in the aquatic
system. In this approach, toxicity mformation in the EPA
AQUIRE (Aquatic Toxicity Information Retrieval) and
other databases would be evaluated and the appropriate
data compiled and manipulated to yield benthic organism
guidance levels (see Aquatic Risk-Based Approach on
page 5-58). An order of preference for acceptability of
toxicity mformation was developed, with the key prefer-
ence being tissue residue-based lexicological data. Un-
certainty factors would be obtained from Calabrese and
, Baldwin (1993). Bioconcentration factors, if necessary,
would be obtained from the GLI or other sources, as
available. The food chain multipliers developed for the
other risk-based approaches would be used here also., ,
Additional databases are currently being reviewed for
tissueresidue-based toxicity information, since the amount
of information that has been identified thus far is meager
for many compounds. It is hoped that information on
aquatic risk will be completed in the near future and can be
incorporated with any additional information or modifi-
cations that are identified for the overall evaluation strategy.
Background Tissue Residue Database
There were benthic tissue contaminant data avail-
able from various studies that had been conducted in the
vicinity of the Mud Dump Site. This information was
preliminarily evaluated and summarized, but it was
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5-50
National Sediment Bioaccumulation Conference
determined by the workgroup that a dedicated sampling
survey should be conducted to get a better representation
of overall field background benthos concentrations. Sam-
pling stations for this effort were located farther from the
disposal site than the existing studies, but included areas
of potential contamination from other sources. Surveys
were conducted in the Spring and Summer of 1995. The
data has been evaluated by the workgroup, and the appro-
priate statistical representation and use of the data will be
determined. An interesting finding in this effort is that,
although the preliminary information was carefully se-
lected to exclude data from potentially contaminated
sediments, the more recent data is generally lower in
concentrations for most contaminants. This seems to
indicate a general improvement in the benthic conditions
of the New York Bight apex since cessation of sewage
sludge disposal in June 1992. This is, in fact, the determi-
nation of NOAA's National Marine Fisheries Service
laboratory in Sandy Hook, New Jersey, from studies
conducted in the area since cessation of sludge disposal
(NOAA.1995).
Future Actions
An example of the issues that will need to be
resolved in completing an overall evaluation strategy is
illustrated by the results for PCS and DDT. For DDT, the
lower bound (10*) human health risk level at 20 ppb is
within reasonable proximity to the wildlife value and the
background range. For PCB, however, an approximation
to these other values is only seen at the upper bound risk
range of 70 ppb. For many of the contaminants, the risk
levels are in the range of the more recent (lower) background
levels. For PAHs, as was noted above, if it is decided that
PAHs should be included in the human health risk method,
application of other factors would raise the preliminary
human health risk levels. The upper bound risk levels
would then range considerably greater than background
values. These varying factors will have to be weighed by
the workgroup in completing an evaluation strategy.
Bioaccumulation tests are expensive and time-
consuming. Biota-sediment accumulation factors
(BSAFs) are being developed from some of the regional
testing results. This could enable the estimation of
bioaccumulation in benthos from sediment chemical
analyses using the theoretical bioaccumulation potential
(TBP) relationship, expressed as
TBP = AF (Cs/%TOC) %L ,
where TBP is expressed on a whole-body wet weight basis
in the same units of concentration as Cs, and
Ca = concentration of nonpolar organic contami-
nant in sediment
%TOC = total organic carbon content of sediment
expressed as a decimal fraction
%L = organism lipid content expressed as a decimal
fraction
A suite of tests that were conducted for federal
navigation projects in New York/New Jersey Harbor has
produced a large and comparable data set. Preliminary
results are promising; calculated BSAFs for 2,3,7,8-TCDD
in sandworms were in the range of 0.11 to 0.19, with a
standard deviation of 0.03. Pruell et al. (1993) conducted
a long-term bioaccumulation study using sediments with
high dioxin content (-600 pptr 2,3,7,8-TCDD) and sev-
eral benthic species, anddetermined the time to steady state
and accumulation factors for PCBs, dioxins and furans. Ap-
plying an empirically derived 28-day to steady-state expo-
sure ratio factor for sandworms (~4.0) from this study, the
calculated 28-day BSAFs compare closely to the steady-
state accumulation factor for sandworms (0.46) derived
from the 1993 study.
As additional data for other projects are incorporated
for dioxin and other contaminants, the level of confidence
in the ability to accurately estimate tissue accumulations from
sediment concentrations should be such as to greatly reduce
the need to conduct individual bioaccumulation tests.
References
Calabrese, E.J., and L.A. Baldwin. 1993. Performing
ecological risk assessments. Lewis Publishers,
Chelsea.
Gobas, F.A. 1993. A model for predicting the
bioaccumulation of hydrophobic organic chemi-
cals in aquatic food webs: application to Lake
Ontario. Ecological Modeling 69: 1-17. Elsevier
Science Publishers B.V., Amsterdam.
NOAA. 1995. Effects of cessation of sewage sludge
dumping at the 12-Mile Site. NOAA Technical
Report NMFS 124.
Pruell, R.J., N.I. Rubenstein, B.K. Taplin, J.A. LiVolsi,
R.D. Bowen. 1993. Accumulation of polychlbri-
nated organic contaminants from sediment by three
benthic marine species. Arch. Environ. Contam.
Toxicol. 24: 290-297.
Thomann,R.V. 1989. Bioaccumulation model of organic
chemical distribution in aquatic food chains. Envir.
Sci. Technol 23: 699.
USEPA. 1992. Water quality standards; establishment of
numeric criteria for priority toxic pollutants; states
compliance. Federal Register 57:60848-60923.
USEPA. 1993. Derivation of proposed human health and
wildlife bioaccumulation factors for the Great Lakes
Initiative. Draft. U.S. Environmental Protection
Agency, Washington, DC.
USEPA. 1994 and 1995. On line. Integrated Risk
Information System (IRIS). Office of Research and
Development, Environmental Criteria and Assess-
ment Office, Cincinnati, OH.
USEPA. 1995. Great Lakes Water Quality Initiative
technical support documentfor the procedure to deter-
mine bioaccumulation factors, Appendix E. U.S. Envi-
ronmental Protection Agency, Washington, DC.
USEPA/USACE. 1991. Evaluation of dredged material
proposed for ocean disposal - Testing manual.
EPA-503/8-91/001.
-------
Proceedings
5-51
NEW YORK/NEW JERSEY HARBOR
DREDGING FORUM
EPA REGION 2
NEW YORK DISTRICT CORPS OF ENGINEERS
NEW YORK STATE DEPARTMENT OF
ENVIRONMENTAL CONSERVATION
STATE OF NEW JERSEY DEPARTMENT OF
ENVIRONMENTAL PROTECTION
REPRESENTATIVES FROM GOVERNMENT, INDUSTRY, PUBLIC
ENVIRONMENTAL INTERESTS, SHIPPING, LABOR
Disposal Criteria Workgroup
(Chair/Mario Del Vicario, EPA Region 2)
Bioaccumulation Subgroup
EPA REGION 2 - Alex Lechich
NYD CORPS OF ENGINEERS - Lisa Rosman/Oksana Yaremko
NEW YORK STATE DEPT. OF ENVIR. CONSERVATION -
John Zarnbrano
STATE OF NEW JERSEY DEPT. OF ENVIR. PROTECTION -
Ruth Prince, Ph.D. ,
EXXON BIOMEDICAL SERVICES - Tom Parkerton, Ph.D.
(Industry representative)
RAMAPO COLLEGE - Angela Christini, Ph.D.
(Representing public environmental interests including Environmental
Defense Fund, American Littoral Society and Clean Ocean Action)
-------
5-52
National Sediment Bioaccumulation Conference
CRITERIA WORKGROUP
BIOACCUMULATION STRATEGY DEVELOPMENT
THREE COMPONENTS:
1. Human health & ecological (aquatic and wildlife) - risk-based
2. Field benthic (background) tissue level
3. Combined evaluation strategy
NY DREDGED MATERIAL FORUM CRITERIA WORKGROUP
(BIOACCUMULATION SUBGROUP)
GENERALLY USED GREEN BOOK PROCEDURES:
IF STATISTICALLY ABOVE REFERENCE, GO TO 8 FACTORS
FOCUSED ON COMBINATION OF FACTORS ASSOCIATED WITH TOXICOLOGI-
CAL IMPORTANCE AND TISSUE LEVELS IN VICINITY OF DISPOSAL SITE
(BACKGROUND) COMPARISON
WORKGROUP DECIDED ON "STANDARD" AS COMPARED TO "SITE SPECIFIC"
RISK-BASED APPROACH BECAUSE OF TIME AND RESOURCE CONSTRAINTS
INFORMATION FROM THIS EFFORT CAN BE USED TO LATER "FEED INTO" A
SITE SPECIFIC RISK APPROACH
TOXICOLOGICAL INFORMATION USED IN RISK-BASED APPROACHES FOR
HUMAN HEALTH (CANCER AND NON-CANCER)
AQUATIC RESOURCES
WILDLIFE RESOURCES
ALL APPROACHES BEGIN WITH CALCULATION OF ACCEPTABLE CONCEN-
TRATION IN FISH, THEN APPLICATION OF ADJUSTMENTS FOR TROPHIC
TRANSFER, LIPID AND OTHERS, RESULTING IN BENTHIC INVERTEBRATE
TISSUE LEVEL •
-------
5-53
1991 GREEN BOOK BIOACCUMULATION FACTORS
(1) number of species in which bioaccumulatiori from the dredged material is statistically greater
than bioaccumulation from the reference material
(2) number of contaminants for which bioaccumulation from the dredged material is statistically
greater than bioaccumulation from the reference material
(3) magnitude by which bioaccumulation from the dredged material exceeds bioaccumulation
from the reference material ;
(4) toxicological importance of the contaminants whose bioaccumulation from the dredged
material exceeds that from the reference material
(5) phylogenetic diversity of the species in which bioaccumulation from the dredged, material
statistically exceeds bioaccumulation from the reference material ,
(6) propensity for the contaminants with statistically significant bioaccumulation to biomagnify
within aquatic food webs
(7) magnitude of toxicity and.number and phylogenetic .diversity of species exhibiting greater
mortality in the dredged material than in the reference material
(8) magnitude by which contaminants whose bioaccumulation from the dredged material exceeds
that from the reference material also exceed the concentrations found in comparable species living
in the vicinity of the proposed disposal site. (
HUMAN HEALTH METHOD
ACCEPTABLE TOXICOLOGICAL DOSE
.1. CANCER - CANCER RISK LEVEL X BODY WEIGHT
CANCER SLOPE FACTOR
2. NONCANCER - (RfD) (BODY WEIGHT)
ACCEPTABLE TOXICOLOGICAL DOSE = ACCEPTABLE CONCENTRATION IN FISH
FISH CONSUMPTION
(ACCEPT. CONG. IN FISHY (WHOLE BODY/FILET FACTORY = ACCEPTABLE
(TROPHIC FACTOR) ! CONCENTRATION IN
BENTHIC INVERTE-
BRATES
BODY WEIGHT -70 Kg
FISH CONSUMPTION - 6.5 g/day
WHOLE BODY/FILET RATIO -1.35 •
LIPID ADJUSTMENT - to 2%
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5-54
National Sediment Bioaccumulatton Conference
FOOD CHAIN MODEL
INITIALLY USED FCMs IN EPA WATER QUALITY STANDARDS (1993) HAND-
BOOK - THESE USED THOMANN 1989 FOOD CHAIN MODEL
- DOES NOT INCLUDE BENTHIC COMPARTMENT
- USED 10% LIPID FOR ALL TROPHIC LEVELS
BOB HUGGETT (AA, ORD) MEETING HELD ON MARCH 22-23, 1995 WITH ORD
SCIENTISTS, HQ OFFICES AND REGIONS IN SUPPORT OF REGION 2 EFFORT
- RECOMMENDED USE OF GOBAS 1991 MODEL
GOBAS MODEL
- ASSUMES EQUILIBRIUM BETWEEN SEDIMENT AND BENTHOS
- EPA FOUND GOOD CORRELATION FOR EQUILIBRIUM AND USED MODEL IN
THE GREAT LAKES INITIATIVE (GLI)
- CONSIDERED APPLICABLE FOR LIPOPHILIC ORGANICS THAT AREN'T
METABOLIZED - WASN'T ASSUMED APPLICABLE FOR METALS OR PAHs
• FOR CADMIUM, BIOAC THRU WATER, NO BIOAMAG TTF =1
• FOR MERCURY, TTF FROM GLI TSD, APPENDIX E
• FOR PAHs, METABOLIZED IN MANY HIGHER ORGS TTF == 1
Adjusted results to reflect two percent lipid - as was found for trophic level two (benthos)
in the representative food chain
moraic LEVEL
ifoo4 prtftnixti)
11.IV
•
•
•
•
•
Hole (summer floonder)
(and hue. juvenile fish.
mrsldlfcrtap)
hake (rak red. silver, othera)
(UM« crabs, myslds.
btarvee, pefyduetes)
blstCah
0Wv trniH crita, iqyaidi.
poiydfflettt, squid)
UtttOf
(ratnute, benides. mytEds.
cntx)
ktcter (hepito+muiele)
livtanddodllih,
fnsJttilVt*
%LIPID
(»ret wt)
1.2
LI
11
3.8
6
•Wna.^nJT «
•
•
ffrn*
TLB
•
•
•
Juven^e flnflili/iaadlmtce
(ocpepods, my^dt.
cbdoeom, fkh eg^.
nollittca bcvae)
oiutaceani (crabi, ihriin[))
(unall pdyehacM* 4t
Rothliis, d^xxtleduid
•uapendcd organic mutter.
smaller cnutoceana)
•unjt
potychies. (Nq*ty>)
Cdeposn and >edlm«nt
kvestinK or organic matter.
eimirorea of mintite
bivalve noNu^cx (Nucule.)
(decnik acid filer [cedera-
pbYtopSinktoR, orjanlc
cnutacdant (Crancoo, roysids)
(deposit and filler feeders-
decriliK. carnivores of
Ealnuw orsiinisina)
ivtnte
4.2
43
*A
2.0
3.0
1.0
2
MASS(gms)
(vretwt)
500
200
1000
800
500
600
10
10
10
I
0.1
0.1
OA
-------
Proceedings
5-55
Log Kow
4.0
4.1
' : 4.2 '
4.3 ••'-.'
• 4.4
4.5
4.6
4.7
4.8 •
4.9
5.0
5.1 '
, 5.2
5.3
5.4
5.5
,5.6
. . 5.7
5.8
5.9,
6.0
6.1 .
6.2
6.3
. .: ,6.4-
6.5
TableS
TROPHIC TRANSFER FACTORS
-- • • vs. •• : . • •
LOG KOW
Level 3 to 2
1.0
• 1.0
•:•-,. i.o
1.0 '
1.0
1.0
1.0 •
1.0,
. 1.0
,1.0
1.0 .....
1.0 .
: ••1-° '
'•". .• . ' ' -• ' ' s u • . •
••••• • '•••''• . 1:1 •• :
l.l
'l.l " '
• •• "1.1 "..•""• •"
1.1
- •. • . 1.1 • . '.-•-••
1.1 .-•-....
' - • • . - • - 1.2
1.2 . .
Level4to2 '
1.0
1.1
1.1
1.1
,1-1
1.1
1.2
1.2 •
1.3
1.3
1.4
1.5
, 1.5
• 1.6 -
1.8
1.9
2.0
2.1
. 2.3 "
2.4
2.6
2.7
2.8
2.9
3.0
3.0
Substance
aldrin
anthracene-
benzo(a)anthracene
benzo(k)fluoranthene
benzofluoranthene, 3,4- ,
benzo(a)pyrene
cadmium - i '• .
chlordaneS.8
chrysene -
ODD
DDE
DDT
dibenz(a,h)anthracene
dieldrin
fluoranthene
fluorene -
heptachlorS.O
heptachlor epoxide :
inden(l,2,3-cd)pyrene
methyl mercury
,PCBs
pyrene
Table 6
Trophic Transfer Factors
Trophic Transfer Factor
Log Kow Level 4 to 2 Levek3'to2
6.0
•• . • 1
-
- .
,
-
1
2.3
1
6.1
6.4
6.2
-
5.0
-
1
1.4
4.1
."
.
6.1
., - - •
2.6 1.1 .
1
1 1
1- 1
1 1
1 1
1
1-1
1
2.7 1.1
2.9 1.2
2.8 1.1
1 1
1.4 1.0
' 1 1
, 1 .
1.0 .
1.1 1.0
'1 • 1
6.3 1.3
2.7 1.1
1 1
'Factors for trophic level 4 to 2 are used to derive the criteria for human health.
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National Sediment Bioaccumulation Conference
Substance
aldrin
benzo(a)anthracene*
benzo(k)fludranthene*
benzofluoranthene,3,4*
benzo(a)pyrene*
cadmium
chlordane
chrysene*
ODD
DDE
DDT
dibenz(a,h)anthracene*
dieldrin
heptachlor
heptachlor epoxide •
indeno(l,2,3-cd)pyrene*
methyl mercury
PCBs, Total
Table?
PRELIMINARY BENTHIC ORGANISM GUIDANCE VALUES, ug/kg
(Human Health)
Cancer (10-6)
0.3
2*
2*
2*
2*
5
2*
20
10
20
2*
0.7
2 .
1
2*
0.7
Noncancer
200
10,000
300
1,000
500
5,000
200
200
100
*NOTE: Values for 7 carcinogenic PAHs will be either revised upward (by incorporation of lower ingestion rate - based on Quincy
Bay study of lobster hepatopancreas consumption - and application of TEFs), or will not be included in human health assessment.
WILDLIFE METHOD
INITIALLY, CONSIDERED USING ADJUSTMENTS TO HUMAN HEALTH METHOD, FOR LESS STRINGENT OVER-
ALL EFFECTS PROTECTION AND REFLECTING NEED TO PROTECT POPULATIONS INSTEAD OF INDIVIDUALS
-NO CONCENSUS; IMPRACTICAL
USED EPA GREAT LAKES INITIATIVE (GLI) INFORMATION
FOR 3 COMPOUNDS (DDT, PCS, MERCURY) IN THIS EFFORT
CALCULATED WRfDs WITH TEST DOSES AND UFs FROM GLI
TIER 1 WILDLIFE CRITERIA EQUATION AND CRITERIA DOCUMENTS FOR PROTECTION OF WILDLIFE
Species
mammalian
avian
DDT
80
9
Calculated WRfDs fug/kg-dl
PCS Mercury
30
200
16
13
harbor seal 9600
belted kingfisher 1.4
herring gull 9.9
(WrfD)(body weight) = Wildlife Acceptable Dose
Wildlife Acceptable Dose fug/d")
3600 1920
30 2
220 14.3
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Proceedings
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WILDLIFE PARAMETERS
Aquatic Food
Ingestion Rate (F), (kg/day)
Troph.Lev.3 ,
0
0.0672
. 0.192
troph.Lev.4
9.6
0
>0.0480
Selected 'Adult Body
Species ' , Weight (Kgl
Harbor Seal ' 120
Belted King Fisher 0.15
HerringGull 1.1
Example Computation .
Acceptable Doses (AD), divided by the aquatic food consumption rates (F) and the trophic transfer (TT) factors. The
trophic transfer factors are weighted according to the relative food consumption at each trophic levels An example ,
computation is presented below for the Herring Gull and DDTr.
Species Criterion =
(Gull, DDTr)
Species Criterion =
(Gull, DDTr)
AD
[(FTL3)(TT3.2)+(FtM)(TT4r2)]
9.9
[(0.192)(1.1)+(0,0480)2.8]
Species Criterion (Gull, DDTr) = 29.2 ug/kg,
WILDLIFE GUIDANCE VALUES fug/kg)
Individual Species
DDTr Mercury
Harbor Seal
Belted King Fisher
Herring Gull
357
18
29.2
31.7
22.2
26
134
405
637
DDTr
Mercury
PCBs, Total
PRELIMINARY
FINAL WILDLIFE VALUES (ug/kg)
20 •'•".. ,
20
100- '• f '..'_
DDT and PCB values are based on two percent lipid. Concentrations are based on wet weight.
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National Sediment Bioaccumulation Conference
AQUATIC RISK-BASED APPROACH
1. Using EPA AQUIRE (Aquatic Toxicity Information Retrieval) database, searched for information on BCCs encompassing all finfish species -
(Class Osteichthyes - bony fishes)
-also used review chapter in CRC Critical reviews in Aquatic
Sciences, entitled "Effects of Environmetnal Pollutants on Early
Fish Development"
2. AQUIRE Data: Order of Preference
Chemical Reporting:
1. Tissue Concentrations
2. Water Concentrations
Effects Reporting:
1. Reproductive Endpoints
a) Embryonic or Larval Malformation
b) Egg Production
c) Hatchability/Survivorship
d) Embryonic or Larval Mortality
2. Adult Chronic
3. Adult Acute
Endpoints Reporting:
1. NOAEC
2. MATC
3. LOAEC
4. Effects Concentrations
5. EC50.LC50
- UFs from Calabrese and Baldwin
(1993). Performing Ecological Risk Assessments
- BCFs from GLI Derivation of Proposed HH and
WldlfBCFsforGLI
40°40'-
40°30'-
40°20'
40°10'-
73°40' 73°30'
. May 1995 Station
Reference Site
Mud Dump Site
11^
Long Island Inshore •
• 20 4,19
~-~
.14
15
• IChristiaerisen *
.Basin I
. ' * i Cholera ^1
* I 16 Bank W
10 I -m „_
New Jersey \
Inshore |
r
\
Hudson Shelf
Valley
\
Figure 1. Map showing the five New York Bight Apex Regions and sampling locations for
May 1995 Body Burden Survey.
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Proceedings
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ISSUES TO BE ADDRESSED
try to reach concensus on appropriate statistical use of background data
try to reach concensus on contaminant-specific guidance values that include human health,
ecological and background values .
how do they compare?
in some cases, roughly comparable @ 10'6 HH care, risk level .
for PCBs and PAHs, HH care, values are comparable only @ 10'5 - 10"4 risk levels
will evaluate comments from peer/public review on acceptability of approach and on deriva-
tions and conclusions
Biota-Sediment Accumulation Factors
From Regional Dredging Projects
(draft) results of bioaccumulation tests of nine NY/NJ Harbor dredging sites (federal
projects) plus a reference site
BSAF = (Tc/L)
Sc/TOG
Dioxin/Furan 28-day BSAFs
TCDD- 0.11 -0.19 (mean 0.14, SD 0.03) ,
TCDF- 0.14 - 0.28 (mean 0.20, SD 0.04)
Comparable to Pruell et al. 1993 AFs for dioxins/furans 28-day and steady state results
Validation with other project results , .
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National Sediment Bioaccumulation Conference
COMPOUND
PCB
DDT
HUMAN HEALTH
10-4 10-6
70 0.7
2000 20
WILDLIFE
1 2
300 110
20 260
FIELD BKGRD
(rough approx.)
50-150
10 - 20
Wildlife:
1. Sub-group effort
2. New York State Dept. Of Envir. Conser. - Niagara River Biota Contamination Project: Fish
Flesh Criteria for Piscivorous Wildlife, Newell, et al., July 1987
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National Sediment Bioaccumulation Conference
Day Two: September 12, 1996
Session Five:
Questions and Answers
A
fter each session, there was an opportunity' for
questions and answers and group discussions per-
taining to the speakers' presentations.
Q (John Connolly, HydroQuol, Inc.): Amy, in your work
•with BSAFs, are you assuming that if you cut the sediment
concentration in half, the fish concentration -will drop by
a factor of 2? How do you know that is true?
AmyPelka, U.S. EPA Region 5:
It probably is not true. It depends on where the site
is. The BSAFs are not linear at one site that has 20,000
parts per million PCBs! Here, as the concentration in-
creases, it does not go up with the BSAFs. Similarly, as
the concentration decreases, it does not go down by half.
Looking at this further, we decided that it is very Impor-
tant to consider when arid where you are taking your
sediment sample. This sample represents what you.think
^presently and in the future or what you are trying to create
theoretically. I am not sure whether we can do that,
because we do not always'have the data. We are seeing
that there is some kind of curve where the concentration
tops out and the BSAF is not going to increase or
decrease. The way to deal with this issue presently is by
deciding whether the samples represent what we think are
steady-state levels. Sometimes we have looked at caged
fish data from upstream to see if that represents what the
bioaccumulation might look like at these low levels
versus the high levels. You do not want to do BASFs on
a hotspot, for example. You would want to look at
something lower. ' .
Q (John Connolly): My big concern is that it is not a
conservative assumption. For example, suppose there
are sources you do not know about, as in Puget Sound. We
.have contaminated fish, and we say we are going to go in '
and remove sediment and expe,ct contaminant levels in
the fish, to decrease.. But what we do not realize is that
some residual sources are contributing to the problem.
, We remove, sediment and it does not get better, because
we did not address those sources. If we are talking about
particular issues that may have significant economic.
costs (for example,- dredging that costs $50 million or
$100 million), is it worth spending $500,000 or $1
million to find out that cutting the sediment concentra-
tion is going to be protective of the ecosystem and human '
health, before you make the decision based on the son of
routine procedure that has been outlined?
Amy Pelka:
I agree that you should be clear about where your
sources are before you go about trying to attack a problem
and setting cleanup goals. And you are right that it is not
a conservative assumption. I do not know if it was clear,
but for Saginaw there were very low levels of PCBs on the
surface. I showed you only normalized numbers, but, on
average, the Saginaw levels are only 2 parts per million.
The fish are a lot more contaminated there than they were
in Manistique, which was much more contaminated. The
curve for this example actually flattens down at the,
bottom as well as at the top. I am trying to show that, if
- you get a lot of contamination, it does not mean there will
be more bioaccumulation at the bottom.. It never really
goes away. You need to see where you are and look at the
system to decide what you are going to do. Sometimes
that is a question of whether just modeling should be
done. There are a lot of Superfund sites in Region 5 where
this is a problem, and you may not have the option of
modeling to come up with an answer due to the high cost.
It may not reduce enough of the uncertainty. So you could
spend nothing, if you consider me free, or you could
spend $12 million like they did to model Green Bay. In
some cases that make sense and, in other cases, it does
not. It really depends on the circumstances.
Q (John Connolly): I thinkyou do have to approach it on
a case-by-case basis. I have one last question. You
mentioned offhandedly that mass removal was a good
thing. I am not sure why that is true.
Amy Pelka:
I wanted to make it clear that risk assessment is one
way to look at whether or not a site has bioaccumulation
at levels of concern, but it is not the only way to assess
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National Sediment Bioaccumulation Conference
whether or not you have a problem. In some cases, you
wiU not see the differences in a risk assessment. For
example, with Saginaw, the levels are not going to
decrease in the surface concentrations in sediment and
the levels in fish populations probably will not decrease
significantly either. From a risk assessment perspective,
this is because the uncertainty is too large when estimat-
ing the different ingestion rates associated with risk
assessments. Therefore, it is appropriate to look at mass
as well. Maybe it is appropriate for EPA or a state agency
to remove PCBs because they do not want loadings to the
Great Lakes. I do not want people to think risk assessment
is the only approach, because sometimes mass can be a
reasonable approach.
Q (John Connolly): For your case in Saginaw, consider
an example where you may have 2 parts per million on the
surface and 100 parts per million at depth. If you go in
and dredge, you may end up with a residual concentra-
tion of 5 parts per million. In this example, you may have
made the problem worse.
Amy Pclka:
The goal of the removal project is to remove the
surface material. But there are cases where dredging
probably will increase the surface concentrations, and
how do we mitigate that? The problem with Saginaw
was that it had 22 miles of contamination at 2 parts per
million. There would not be enough money to pay EPA
Region 5 to bring it down to 0.5 parts per million. That
was the point. I agree with you. We worry about that a
lot. Sometimes with the dredging, what you actually
think you are going to get as a result will often be
higher than what you started with. A big issue is
whether that is good.
Robert Paulson, Wisconsin Department of Natural
Resources:
It can also certainly affect transport into the future
with whatever residual you leave behind, if the residual
is at a level that will work itself up into the system a little
bit more. You can reduce significantly the transport into
the future by dealing with just mass. This is just one
variable.
John Connolly:
I agree, but I think that is really on a case-by-case
basis. If your contaminants are high 2 feet down, they
may really be locked away forever. But you have to
evaluate that on a site-by-site basis.
Q (Robert Paulson): Are they really all locked away
forever? This is the point we are questioning.
Amy Pelka:
There is another set of modeling you can do. With
the risk assessment, you can try to determine whether or
not certain storm events are going to reveal that and what
the bioaccumulation will be after that. So, you can torture
yourself with that consideration, too, if you want to.
Q (EdPfau, Ohio EPA): My question is directed to Laura
Weiss. "You had mentioned that, as part of your uncer-
tainty analysis, you had gone back and revisited the
numbers using uncertainty analysis with the stochastic
model. You alluded to the fact that it was surprising that
your point values came out at about the 80th percentile
from the final stochastic analysis. What particular inputs
in the equation in the algorithm did you use distributions
for, and were the distributions from the same original
database that the point values were derived from?
Laura Weiss, Washington Department of Ecology:
We distributed as many input parameters as we
could that were appropriate to be distributed. S orne param-
eters were fairly simple and obvious like body weight and
exposure duration. We also distributed fish consumption
rate, fish lipid, and BSAFs. We kept risk level constant and
evaluated one of the more controversial factors, the cancer
potency factors (CPFs). A consultant was hired to evaluate
CPFs. This is something EPA has been grappling with over
time as Monte Carlo analysis has become more popular.
The results of this analysis showed that there was too much
uncertainty and none of the approaches that were evaluated
were really defensible. So, ultimately the toxicity factor
was held constant as well.
Q (Ed Pfau): Was the database for the point values
basically the same from which the distributions were
drawn?
Laura Weiss:
Yes, it basically was. We relied on local data as
much as possible, especially for parameters like fish
consumption rate.
Q (EdPfau): You talked about using various methodolo-
gies to determine an effective concentration both in fish
tissue and for sediments. You also talked about the
surface area weighted average and use of geometric
means. Is it appropriate at some point in the future, if the
stochastic approach becomes more viable, that use of the
distribution with its appropriate shape of distribution
would be a reasonable substitute for either one of those
methods of trying to average out concentrations in fish
tissue or in sediment concentrations?
Laura Weiss:
On a site-specific basis, it is a potential option we
might want to look at. There might be a place for it in the
Tier 2 analysis. However, I think it affects the other
programs in our agency as far as how they deal with
Monte Carlo analysis, particularly how the results are
analyzed and whether the input parameters are appropri-
ate. We will need to develop guidance for its use.
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Proceedings
5-63
Amy Pelka:
You want to make sure the set of data that you have
is representative of what you want to look at, which may
be the sediment concentration at the surface. If you have
varying spacial intensities where there are several samples
around the rot spots, your distribution still is not repre-
sentative of the true distribution, even if you have run a
Monte Carlo analysis. It all depends'on how the distribu-
tion was done. A distribution, or Monte Carlo analysis, is
not inherently evil. It just depends on how it is used. It can
be useful.
Q (Ed Pfau): So the surface area weighting is to remove
the bias in sampling, and that would not be something
that would be addressed in a Monte Carlo distribution?
Is that correct?
Amy Pelka:
I am not sure that just because you have a surface
area weighting means that you cannot use a Monte
Carlo distribution. I do not think Monte Carlo takes
away that bias in sampling. If it shows you the mean
and if you are still using a distribution that is based on
a small subset of the data, you are still going to have the
same problem.
Q (Malcolm Watts, Zeneca, Inc.): I am pleased that
one person, Mr. Paulson, did at least mention cost in
passing, and I am very upset that the cost issues have
largely been ignored. I am part of the handful of
people here from the regulated community, and we see
these models being generated with inordinate'costs
possibly associated with the results. This is very dis-
turbing. The methodology of the models seems to be
quite good, except when conservative factors are in-
troduced which build upon one another to give inordi-
nately cautious results. In particular, with those sites
that I have been involved with, I have found the
science base is not worth anything. The data that Ms.
Pelka referred to as being very difficult to find and
evaluate, I believe, is characteristic of the basis on which
the decisions are made. This produces results which
cause high costs. I propose to you to use the models and
the data you have, and see what the results are. If they are
easy to work with, like no action or modest action, then
that is fine. If, on the other hand, the costs are very high,
you should reverse tracks. You should find the most
sensitive parameters, look at the data for those param-
eters, and focus the research on that. The scientific
community is not doing bad work. It is just that they are
not being funded to do it correctly, so scientists often
make do with what they have, not with what they should
have.
Victor McFarland, U.S. ACE, Waterways Experi-
ment Station:
between neutral chemicals and their concentration in
sediments and in organisms based on organic carbon and
lipid normalization, we called that a preference factor.
Later, the preference factor was changed to an accumula-
tion factor, which was essentially the same thing. Then it
became a biota-sediment accumulation factor, and we
were still talking about the same thing, although the term
got stretched to include a disequilibrium situation for fish
instead of applying it to just-invertebrates and such. Now
wearetalkingaboutaBSAFformetals.andlam unable to
figure out how things are going to be done or what the
rationale is. .
Laura Weiss:
I assume you are addressing me regarding the slide
that alluded to BS AFs from metals. That was probably an
oversight in terms of the terminology. The report focused
on the bioaccumulation of certain metals, such as meth-
ylmercury and tributyltin. These chemicals are of concern
from a human health perspective as they are known to
bioaccumulate in aquatic biota. The definition of BSAF
includes TOC and lipid normalization, and clearly that is
not appropriate for metals. Therefore, that was an error on
my part since the term BSAF is not strictly applicable to
metals. •
Q (Victor McFarland): Is it too late to change it and
call it something else like a biota/sediment metals
factor? *
Laura Weiss:
I am interested in some terminology for that. Like
I mentioned, it seems that our biggest challenge is quan-
tifying the factor so a sediment level can be determined to
protect human health.
Q (Philip Cook, U.S. EPA, Office of Research and Devel-
opment): Amy, I am concerned about one part of your '
presentation, which dealt with the comparison of predic-
tions from the site-specific BSAFs to predictions from
BAFs. You described the BAFs as being consistent with
the Great Lakes Water Quality Initiative methodology.
However, if I followed your equations correctly, my
impression was that you were applying those BAFs to
predicted concentrations in the water and that resulted
from an assumption that there was an equilibrium be-
tween the sediments and the water. How didyou calculate
the water concentration so that you could apply the
BAFs?
Amy Pelka:
I did not do those calculations. For Buffalo and
Saginaw, I.think we had water column concentrations
that came from the ARCS program. The water column
concentrations were measured.
I would like to mention a word about terminology.
When we first started talking about the relationship
Q (Philip Cook): Were those water concentrations based
on freely dissolved chemicals?
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National Sediment Bidaccumulation Conference
AmyPelka:
Both. When it was available, we looked at freely
dissolved and total.
Q (Philip Cook): How didyou calculate freely dissolved?
Amy Pelka:
I am not sure of that. I think that would have been
operationally defined, where freely dissolved was what
passed through a filter. \
Q (Philip Cook): The point I would make, in conclu-
sion, is that the BAFs that you used are based on freely
dissolved chemicals. You have to be very concerned
about what model you use to predict that exposure
concentration. In this case, fluctuations in concentra-
tions over time have to be considered, and, if there is
a disequilibrium between the sediments and the water
column, that would factor into the analysis. So, I have
some concern that the high values you predicted for
some of the fish may have resulted from improper use
of BAFs.
Amy Pelka:
I would have to go back and look more carefully
at those specific calculations. I want to make sure I
understand your point. Your point is that the BAFs are
based on the dissolved portions, and we should be
consistent in terms of the water measurements that
are used.
Philip Cook:
Yes.
AmyPelka:
I believe that was taken into account, but those
calculations were done a while ago. You are right, though.
It is important to be consistent.
Laura Weiss:
I would like to address Mr. Watts. I believe you
made a comment about cost, and I would like to
reiterate that, in Puget Sound, cost does play a role in
our decision-making process. In addition, before we
can adopt criteria, we have to go through a cost-benefit
analysis as required by our legislature. Cost is some-
thing we cannot ignore.
Amy Pelka:
. Cost is also considered in the Superfund remedial
process. The costs and implications for different cleanup
goals and remediations are an important part of the
negotiation discussions. They are, by no means, forgot-
ten in any sense of the word.
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National Sediment Bioaccumu/atton Conference
Session Six;
Ecological-Based Risk Assessment
James Andreasen, Panel Moderator
ILS. EPA, Office of Research and Development,
Washington, DC
Wayne R. Munns, Jr.
U.S. EPA, Office of Research and Development,
Narragansett, Rhode Island .
Use of Bioaccumulation Date in Aquatic Life Risk
Assessment
David Charters . .
U.S. EPA, Office of Solid Waste and Emergency Response,
Edison, New Jersey
WildlifeRiskAssessment
6-1
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National Sediment Bioaceumufation Conference
Use of Bioaccumulation Data in
Aquatic Life Risk Assessment
Wayne R. Munns, jr.
U.S. Environmental Protection Agency, Office of Research and Development,
Atlantic Ecology Division, Narragansett, Rhode Island
Introduction
Problems of sediment contamination are being
viewed increasingly from a risk assessment per-
spective. Environmental managers with regula-
tory responsibility for hazardous waste sites, sediment
dredging and disposal, and similar problems are begin-
ning to use the tools and approaches of risk assessment to
evaluate adverse effects associated with chemical con-
centrations measured in sediments. In the most general
sense, accurate estimation of ecological risks requkes both
quantification of environmental exposure conditions and
understanding of the biological and ecological effects
resulting from that exposure. Ecological risk involving
chemical stressors is a function of chemical concentration.
or dose at the site of toxic action (DSTA) and the biologi-
cal or ecological effects occurring at that chemical con-
centration. Historically, external exposure has been used
in aquatic toxicology as a surrogate for internal dose.
Body burden and tissue residue data are thought to
provide more direct measures of DSTA. Without com-
plete understanding of the internal dynamics of chemical
stressors and their mechanisms of toxic effect, however,
these measures are still but estimates (although hopefully
improved) of DSTA. .
So what, then, are the uses of bioaccumulation and
tissue residue data in assessing ecological risk? The
value of this kind of information obviously is limited to
assessments involving chemical stressors. Further, the
data confer insight solely about exposure, just one part of
the risk assessment puzzle. Sediment risk assessments in
which bioaccumulation is an issue presently focus on the
biological responses of individual organisms or. their
component cells and tissues. However, organismal re-
sponse can be extrapolated to population-level impacts,
and given the appropriate ecological relationships, bio-
accumulation can be related to community and ecosystem
responses. Assessments involving these levels of ecologi-
.cal organization require trophic transfer models and mod-
els involving species interactions. '. •
The objectives of this presentation are threefold;
(1) to describe ecological risk assessment and to present
EPA's approach for conducting such assessments; (2) to
identify how bioaccumulation and tissue residue data are
used in each of the steps of ecological risk assessment
with respect to aquatic life; and (3) to highlight some of
the key uncertainties associated with uses of bioaccumu-
lation data in making risk-based management decisions.
Although EPA's framework is by no means the sole
approach used to evaluate risks, description of this para-
digm will help to illustrate the uses of bioaccumulation
data in the various components of any risk assessment.
By enumerating uncertainties, I hope to identify general
areas of future research that could improve the utility of
bioaccumulation information in evaluating the ecologi-
cal risks of contaminated sediments. Much of the infor-
mation provided here is obvious; yet it is important to.
keep these ideas in the forefront of discussions concern-
ing bioaccumulation to ensure that misconceptions are
not propagated as part of environmental management and
the communication of risks.
Ecological Risk Assessment
Ecological risk assessment can be described as a
process for estimating the likelihood of adverse ecological
impact resulting from anthropogenic stress. Risk assess-
ments can be retrospective, prospective, or a combination
of both. In the context of sediment contamination,
retrospective assessments attempt to quantify the impacts
of past releases of contaminants on sediment-associated
receptors to enhance understanding of current ecological
condition. This often is the type of application used when
evaluating impacts associated with hazardous waste sites.
Prospective assessments involving sediment contamina-
tion attempt to predict future impacts based upon the
nature and behavior of chemical stressors and potentially
exposed ecological systems. Prospective assessments
have utility, for example, when selecting among various
dredged sediment disposal options. A combination of
both retrospective and prospective approaches is useful
for evaluating risks of in-place contaminated sediments
when both current and future conditions (for example,
under various remediation scenarios) are cogent
6-3
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National Sediment Bloaccumulatlon Conference
As proposed by the U.S. Environmental Protection
Agency'sRiskAssessmentForum(USEPA, 1992,1995),
ecological riskassessmentconsists of three primaryphases
or steps: Problem Formulation, Analysis, and Risk Char-
acterization (Figure 1). Some of the goals of Problem
Formulation are (1) to evaluate existing information
concerning stressors, receiving ecosystems, and potential
ecological effects; (2) to identify assessment endpoints
(valued ecological conditions or processes) to be pro-
tected; and (3) to develop a conceptual model describing
potential risks to assessment endpoints. Discussions
among the risk assessors, environmental managers, and
other stakeholders are crucial in the process to ensure that
the assessment addresses the important regulatory and
societal concerns and that the information generated is
useful in making environmental management decisions.
The Analysis step involves characterization of exposure
conditions in time and space, as well as evaluation of
ecological effects potentially resulting from those levels
of exposure. Analysis involves a variety of empirical and
modeling activities, with the ultimate goal of developing
profiles of exposure andeffect. These profiles are synthe-
sized into estimates of ecological risk during the Risk
Characterization step. Characterization activities may be
either qualitative or quantitative, and are directed toward
providing the information necessary to make informed
environmental management decisions. An analysis of the
uncertainties associated with the assessment is a critical
part of Risk Characterization. EPA's framework is
intended to be general with respect to the nature of the
stressor(s) and the ecological systems involved in any
given assessment. It is therefore useful in assessments
involving either chemical or nonchemical stressors, and
all types of ecological systems. How bioaccumulation
and tissue residue data are used in the specific steps of risk
assessment is described in the next three sections.
Uses in the Problem Formulation Phase
Bioaccumulation and tissue residue data play three
somewhat related roles in Problem Formulation: (1) to
identify those stressors which may impact biological
receptors, particularly at higher trophic levels (including
humans); (2) to aid in initial descriptions of the potential
extent and magnitude of sediment contamination; and
(3) to assist in identifying the range of potential biologi-
cal and ecological effects resulting from exposure. Infor-
mation concerning important stressors, their concentra-
tion distributions, and the effects they potentially elicit
supports development of a conceptual model that focuses
the remainder of the risk assessment.
Appreciation of bioaccumulation potentials can
lead to identification of contaminants that might be
available to biological receptors, and may affect organisms
at higher trophic levels. The potential for highly lipophilic
organic compounds to bioaccumulate, for instance, identi-
fies trophic transfer as an important exposure route when
these compounds are present. Not only does this suggest
that ecological receptors removed from immediate contact
with the.sediment should be considered, but it also leads
to hypotheses concerning the biological transport of
Ecological Risk Assessment
PROBLEM FORMULATION
ANALYSIS
Characterization i Characterization
of ! of
Exposure ' Ecological
I Effects
RISK CHARACTERIZATION
Discussion Between Risk
Assessor and Risk Manager
Data
Acquisition,
Verification,
and
Monitoring
| Risk Management \
Figure 1. EPA's framework for ecological risk assessment (from USEPA, 1995).
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Proceedings
6-5
contaminants away from the immediate site of contami-
nation. Conversely, chemicals with low potential to
bioaccumulate (some metals, for example), cannot be
eliminated as stressors of concern, since die toxic effects
of some chemicals are not tightly linked to body burden.
A requirement for adverse impact is the co-occur-
rence of the stressor with biological receptors. For
chemical stressors associated with sediments, environ-
mental exposure (external to biological receptors) is
controlled by a number of geochemical factors. Histori-
cally, environmental exposure had been quantified as the
chemical's bulk concentration in the sediment. Recent
advances in understanding the partitioning of chemicals
among various environmental phases has enhanced the
accuracy of predictions of the availability of chemicals to
biological receptors, particularly those in intimate con-
tact with the sediment. In many cases, tissue residue data
provide independent verification of these predictions
and support description of the extent of contamination.
As importantly, tissue residues support, evaluation of the
extent of exposure to those receptors somewhat removed
from direct contact with the sediment. For example,
elevated contaminant levels.in deployed blue mussels or
pelagic finfish indicate contaminant transport from the
sediment to the water column or through trophic transfer.
This in turn implies that ecological effects may not be
limited to benthic organisms.
Knowledge of the degree to which contaminants
bioaccumulate, and the tissues in which they accumu-
late, can provide insight to potential biological effects.
PCBs, for example, are known to accumulate in lipid-rich
tissues such as gonads and have been associated with
reproductive impairment. They also can be transferred
during oogenesis to potential offspring, and can cause a
number of developmental and survival effects. Thus, hi
addition to effects resulting from trophic transfer, poten-
tial transgeneratipnal effects may be possible.
In combination, the information above can be used
to define a conceptual model of exposure leading to
potential ecological effects. The conceptual model can
incorporate hypotheses of how contaminants move
through the physical environment and biotic food webs,
thereby identifying key exposure pathways and exposure
media for further evaluation. Figure 2 illustrates
a generalized conceptual model relating potential
contaminant sources in a watershed to ecological receptors
in an estuary. In this model, a chemical released to the
environment through anthropogenic activity enters the
estuary via surface water, ground wafer, and atmospheric
routes. Phase partitioning, water movement, and transport
of particulates redistribute the chemical to various
environmental compartments (including sediments)
within the estuary, leading to potential exposure of a
variety of aquatic organisms. Geochemical and biological
processes influence uptake of the chemical by biological
receptors, which in turn may result in its transfer to
organisms at higher trophic levels. In addition to
providing a description of environmental exposure pathways
(primarily transport and fate), fully developed concep-
tual models communicate hypotheses concerning the
potential adverse effects that may result from
exposure. This often requires greater detail in,
Exposure Pathway Analysis
Bioconcentration ,
> ^^ *~ * > ^
,^'ssf -~~r* f -- -
, _ , ,„„ Redistribution in " [
^"{f'','•.''^ ^~'\ Aquatic Environment "
Figure 2. Generalized conceptual model relating contaminant sources to estuarine receptors.
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6-6
National Sediment Bioaccumulatlon (Conference
the description of chemical uptake by receptors, and can
involve conceptual understanding of the toxicokinetics
and toxicodynamics of the contaminant within receptor
organisms (Figure 3).
When developed on an assessment-specific basis, the
conceptual model can be used to guide the activities in the
Analysis phase. Forinstance, should the chemical of interest
be persistent and display a high potential for biological
uptake, me conceptual model would dictate analysis of
trophic transfer (either empirically or through modeling
efforts). Conversely, conceptual models hypothesizing
little potential of risk to key consumer organisms, as a result
of low bioaccumulation potential or the absence of impor-
tant trophic pathways, may focus analysis activities on the
direct toxicological effects on benthic organisms.
Uses in the Analysis Phase
The Analysis phase of ecological risk assessment
involves characterization of exposure and characteriza-
tion of ecological effects. Legitimately, bioaccumulation
data are primarily restricted to evaluations of exposure.
Tissue residues can be used, however, as independent
variables in models relating exposure to effects.
As discussed previously, bioaccumulation data can
help define the availability of chemicals to receptor
organisms, improving the accuracy of estimates of exposure
over bulk measures made in sediments. For some
contaminants, tissue residues can be used to quantify
exposure along pathways leading to consumer organisms
(including humans). This information is most useful in.
models of trophic transfer. Residue data also support
analysis of the fate of chemical stressors when significant
biotransformation or biological transport is possible.
These kinds of information support development of a
profile describing the nature, extent, and severity of
exposure to contaminants found in sediments.
Use of bioaccumulation data to characterize effects
in the Analysis step is limited to quantifying internal dose
in development of dose-response relationships. These
models relate the degree of exposure to levels of biologi-
cal/ecological response, typically generated through
laboratory or field experimentation. Although true
DSTA-response models theoretically provide the most
accurate predictions of likely biological effect, exposure-
response and residue-response models can also be useful.
Promising approaches for developing relationships be-
tween residues and toxicity have been proposed by
McCarty (see McCarty and Mackay, 1993) and others,
and several efforts are under way to construct databases
containing residue-effects information. Extrapolations
to threshold residue values from ambient water quality
criteria (Shephard, this conference) and similar toxicity-
based benchmarks also hold promise. However, attempts
to relate internal dose of chemical stressors to biological
effects have met with varying degrees of success.
Bioaccumulation usually is considered a phenom-
enon relevant to individual organisms, and past
assessments of contaminated sediments have tended to
focus on effects manifested in individuals (mortality,
reproduction, growth, and development). Residue data
can also be linked to responses at higher levels of ecologi-
cal organization. For instance, Munns et al. (1997) used
a modeling approach to extrapolate survival and reproduc-
tive effects of PCBs on mummichogs (Fundulus
heteroclitus) to estimates of population growth rate as
Bioconcentration
& Trophic Transfer
Figure 3. Detail of conceptual model showing contaminant kinetics within an organism.
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Proceedings
6-7
a function of liver PCB burden (Figure 4). Despite
involving many assumptions, such approaches can be
subjected to verification through manipulative laboratory
and field experimentation. Similar extrapolations can be
made to responses manifested athigher levels of ecological
organization (for example, shifts in community structure
and function mediated by direct toxic effects on individu-
als and indirect effects resulting from changes in species
interactions) by applying ecological models that incorpo-
rate residue-response relationships. .
Uses in the Risk Characterization Phase
The exposure and ecological effects profiles devel-
oped during Analysis ultimately are used to develop under-
standing of the risks posed by contaminated sediments. The
utility of bioaccumulation and tissue residue data in this
process therefore plays out directly from the exposure and
effects analyses. Similarly, the limitations on their use
alluded to above also apply in Risk Characterization.
. Both qualitative and quantitative methods have
been used to characterize risk. One of the qualitative
approaches involves calculation of simple ratios of the
environmental exposure concentration (measured or
modeled) to biological benchmark concentrations.
Biological benchmarks can be receptor-specific toxicity
thresholds, sediment quality criteria or standards, or
other sediment quality assessment guidelines. Critical
body residues or other derived toxicity thresholds based
on residue burdens offer a means to incorporate
bioaccumulation data into this characterization approach.
This so-called risk or hazard quotient approach is most
useful in screening-level assessments, since "the
magnitudes of likely impact are difficult to ascertain
from simple ratios. Other qualitative techniques include
weight-of-eyidence approaches that base conclusions
about contaminant-associated risks on the preponder-
ance of information evaluated during the assessment.
Residue data are often included as evidence of exposure.
Quantitative characterization methods attempt to
provide information concerning the realized or expected
severity of impact, often in terms of the probability of
a "particular level of effect. Dynamic simulation
modeling, static assessment, and distributional analysis
are examples of techniques providing quantitative estimates
of impact, Most complete with respect to analysis of the
. full range of impact are simulation models that incorporate
both direct (toxicity) and indirect (species interactions)
responses potentially resulting from contaminant exposure.
Trophic transfer submodels are useful in this context
when the effects of oral dose can be described. Quantitative
techniques are often useful for evaluating the conse-
quences of various remediation alternatives.
Key Uncertainties and Areas for Future
Research
As reported during this conference (and
elsewhere), our understanding of environmental
processes leading to contaminant availability and uptake
has improved substantially over the past 5 to 10 years.
We have a fairly firm grasp of the sediment factors and
partitioning dynamics which influence bioavailability,
can model uptake and depuration kinetics with plausible
accuracy, and can describe transfer of contaminants from
HI
1 -
s
o
0.96
C 0.92 -
a.
O
Q.
0.88
—i—
10
—i—
20
30
PCB LIVER BURDEN (ug/g)
Figure 4. Population-level effects on mummichogs as a function of PCB liver burden (from Munns et al.,
1997). • •'"" "" ; ". • ' " •• . •, .-,: ; • •
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National Sediment Btoacoumulation Conference
prey to predator with reasonable confidence.
Although additional research is still needed in these areas,
perhaps the greatest uncertainties associated with the use of
bioaccumulation data hi risk-based environmental man-
agement are associated with linking tissue residues to
biological/ecological effect. While advances are being
made in this area (for example, the critical body residue
and similar empirical approaches), risk assessments will
continue to rely primarily on appropriately normalized
sediment concentrations as the measure of exposure until
this nut is cracked.
In a general sense, factors that hinder our ability to
develop residue relationships include: the rates at which
contaminants are metabolized or eliminated; the toxici-
ties of intermediate metabolites relative to parent com-
pounds; dose-related induction of enzymatic systems;
the modes and time course of toxic action; homeostatic
processes resulting hi immobilization/sequestration; and
the environmental factors that mediate toxic effect.
Toxicokinetic and toxicodynamic studies would appear
to be fruitful approaches for addressing these issues.
These, then, are some of the areas on which future
research should focus.
Acknowledgments
W. Berry, D. Hansen, R. Johnston, and T. Dillon
helped develop some of the ideas hi this presentation.
W. Berry, G. Pesch, and B. Brown kindly provided timely
reviews of this paper. NHEERL AED Contribution no.
1807. Mention of trade names or commercial products
does not constitute endorsement or recommendation for
usebyUSEPA.
References
McCarty, L.S., and D. Mackay. 1993. Enhancing
ecotoxicological modeling and assessment: Body
residues and modes of toxic action. Environ. Sci.
Technol. 27:1719-1728.
Munns, W.R., Jr., D.E. Black, T.R. Gleason, K. Salomon,
D. Bengtson, andR. Gutjahr-Gobell. 1997. Evalu-
ation of the effects of dioxinandPCBs onFundulus
heteroclitus populations using a modeling ap-
proach. Environ. Toxicol. Chem. 16:1074-1081.
Shephard, B.K. 1998. Quantification of ecological risks
to aquatic biota from bioaccumulated chemicals.
This conference.
USEPA. 1992. Framework for ecological risk assess-
ment. EPA/630/R-92/001. U.S. Environmental
Protection Agency, Washington, DC.
USEPA. 1995. Proposed guidelines for ecological risk
assessment. EPA/630/R-95/002B. U.S. Environ-
mental Protection Agency, Washington, DC.
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National Sediment Bioaccumulation Conference
Wildlife Risk Assessment
David Charters ,- "
U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response,
Superfuhd Program Environmental Response Team Center, Edison, New Jersey
This presentation will cover the Superfund ecologi-
cal risk assessment process and an ecological risk
assessment conducted at the LCP Chemicals site in
Brunswick, Georgia by the Superfund Program. The
focus will be on the. wildlife risk assessment part of the
much larger ecological risk assessment conducted at the
site under the Superfund removal program. Ecological'
risk assessment is the process that evaluates the likelihood
that adverse ecological effects may occur or are occurring
as a result of exposure to one or more stressors. The risk
assessment process at this site involved applying the
eight-step draft Superfund risk assessment guidance
(USEPA, 1997) at the site to obtain information to answer
important risk questions. This approach contrasts with the
former process of collecting extensive data initially at a
site and playing what was once referred to as "Million
Dollar Jeopardy." The result of the past process was that
the Superfund Program literally spent millions of dollars
on sites to collect data, but often made decisions based on
, a small fraction of relevant data.
Risk Assessment Process
The current approach to risk assessment'in the
Superfund Program is for the risk assessors to work with
risk managers during the initial site assessment to meet
two objectives: (1) to identify the questions theriskmanagers
need to have answered and (2) to build the scientific
framework to support the risk assessment. This up-front
planning will avoid the pitfall of reaching the end of the
risk assessment process with only the general conclusion
that it is a bad site where something needs to be done. The
outcome of the ecological risk assessment should be
cleanup goals, not lines around the site that define areas
where everything inside the boundaries must be cleaned up.
In the Superfund ecological risk assessment process
there are eight steps and five decision points which are
referred to individually as a scientific management deci-
sion point (SMDP). At each decision point, it is the risk
assessor' s j ob to explain to the risk manager what has been
done. It is critical that the risk manager understands all the
information. This is also an appropriate time to share the
assessment information with the community and other
stakeholders in the process. The risk assessor must be able
to communicate clearly to the public what is being done on
the site and why it is being done.
The eight-step ecological risk assessment process
for Superfund can be summarized as follows:
1. Preliminary problem formulation and eco-
logical effects evaluation
2. Preliminary exposure estimates and risk
calculation . •
3. Problem formulation
4. Study design and data quality objective process
5. Field verification of sampling design
6. Site investigation and analysis phase
7. Risk characterization
8. Risk management
Below is a brief description of each step in the risk
assessment process.
The process begins with a preliminary risk assess-
ment (steps 1 and 2) which is the equivalent of a screening
risk assessment. The first step in the preliminary assess-
ment includes the site visit, problem formulation, and
toxicity evaluation; the second step involves develop^
ment of preliminary exposure estimates and risk calcula-
tion. A preliminary assessment normally includes about
240 chemicals. These chemicals are run through a very
preliminary and conservative screen initially to elimi-
nate all the chemicals that show no indication that they
need to be considered in the full risk assessment. In rare
cases, a preliminary risk as ses sment can result in termina-
tion of the risk assessment if data indicates that there is no
significant risk at the site. Both the risk assessors and the
risk managers must agree on this determination. This
determination is the first scientific management decision
point.
The decision to continue the risk assessment
initiates the'full risk assessment process which is
described in program-specific guidance, but follows the
Agency framework for risk assessment (USEPA, 1997). •
The decision to continue the risk assessment
initiates the full risk assessment process, beginning with
problem formulation (step 3). The problem formulation
phase involves several activities including toxicity evalu-
ation, selection of assessment endpoints, and devel-
opment of the conceptual model and testable
hypotheses. The second SMDP occurs at the end of prob-
lem formulation. At this point the involved parties must
agree on the assessment endpoints, the conceptual model,
the exposure pathways, and questions or risk hypotheses.
The risk asssessment continues with development
of the study design and identification of data quality
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National Sediment Bioaccumulation Conference
objectives and statistical considerations (step 4). This
process produces a work plan and sampling and data
analysis plan. Agreement on the content of both plans
constitutes the third SMDP.
The fifth step in the risk assessment process is
verification of the field sampling plan. Field activities
during this step will determine sampling feasibility.
This step ends with the approval of the work plan and
the sampling and analysis plan which is the fourth
SMDP. With work plan approval, the risk assessment
moves into the site investigation and analysis phase
(step 6). The plans define how these activities will be
conducted, but they may require modification depend-
ing on circumstances such as changing field condi-
tions. An additional SMDP may be necessary to ap-
prove plan modifications.
The risk assessment process continues with the risk
characterization (step 7). The three primary components
of risk characterization are risk estimation, risk descrip-
tion (threshold for effects on assessment ehdpoints and
other risk information), and uncertainty analysis. And
finally, the process culminates in risk managers using the
results of the risk characterization to make the record of
decision (ROD). This decision is the final SMDP.
Site Summary
The LCP Chemicals site in Brunswick, Georgia
offers a case study for Superfund wildlife risk assessment.
The site initially contained a petroleum refinery which
operated for more than 10 years. In 1955 it was sold to a
chemical company that built a chloralkali plant on the
property to manufacture caustic soda, chlorine, and hy-
drochloric acid. The plant continued to produce these
chemicals at the site through the 1980s. Early in the risk
assessment process some highly contaminated areas were
identified within the site that all parties agreed needed
remediation. PCBs measuring in the thousands of parts
per million (ppm) were found hi sediments from these
areas. The Superfund removal program initiated some
actual cleanups in these areas prior to the completion of
the risk assessment Elevated levels of mercury and lead
were also found in sediments near the site.
The site is tidally influenced with a tidal range of
.about 8 feet. The tidal marsh at the site covers about 500
acres. It provides a very diverse habitat for wildlife,
including a number of endangered species. Contaminants
from the outfall area have been released through tributar-
ies into the marsh. The question being addressed here was
what needed to be done to restore the habitat not only for
aquatic life, but also for wildlife. In this case, the primary
objective was to restore and maintain the ecological
health of the salt marsh community, particularly with respect
to the structure and function of the marsh.
Assessment Endpoints and Results
The assessment endpoints are what risk assessors
and managers target for ecological protection. Results
from other sites indicate that current wildlife assessment
endpoints are not particularly good. The Superfund
Program is providing additional resources to ecologists to
determine more specifically the critical ecological func-
tions that require protection to maintain diverse wildlife
habitats such as salt marshes. This information would
allow risk assessors to derive better assessment endpoints
and to define better measurement endpoints for wildlife
risk'assessment.
[Dr. Charters discussed how they evaluated con-
taminant concentrations in wildlife at the LCP Chemicals
site, particularly for terrapins, otters, and racoons. His
discussion focused on evaluation of mercury measure-
ments. Selected data sets and related graphics presented
at the conference are not available for publication in this
paper. Please contact Dr. Charters directly for further
information on the site-specific wildlife data for this
Superfund site in Brunswick, Georgia. For additional
information on EPA's Environmental Response Team,
you may visit their website on the Internet at http://
www.ert.org]
Summary
The LCP Chemicals site is one of the first Superfund
sites to undergo evaluation using the eight-step risk as-
sessment process. It is a site where the Superfund Pro-
gram expanded the scope of the risk assessment to con-
sider impacts to semi-aquatic and terrestrial animals living
around the aquatic environment. That was a point of
departure from the normal EPA approach of being heavily
oriented to protection of aquatic organisms. The Superfund
Program has recognized that a lot of sites have some
terrestrial component associated with them. The program
is working very hard to come up with appropriate numbers
to use for screening aquatically or terrestrially. This
would allow the program to do a better job of identifying
semi-aquatic and terrestrial species that are •significantly
impacted by bioaccumulative compounds at these sites.
Going through the eight-step process, the Superfund
Program is starting to address some of the issues that have
been addressed in the aquatic community up to the fish
level. The program is beginning to focus on higher
species that utilize fish as forage and introduce contami-
nation into the terrestrial envkonment, including ones that
have not been evaluated in the past. Sediment bioaccumu-
lation is an important part of the wildlife evaluation not
only from a question of sediment uptake directly into
these species, but also from the view that significant
impacts can result from contaminant-induced changes in
behavior.
References
USEPA. 1997. Process for designing and conducting
ecological risk assessments—interim final. EPA
540/R-97/006. U.S. Environmental Protection
Agency, Office of Emergency and Remedial Re--
sponse, Washington, DC.
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6-ri
Ecological Risk Assessment
Guidance for Superfund:
Process for Designing and
Conducting Ecological Risk
Assessments
David W. Charters, Ph.D.
Mark D. Sprenger, Ph.D.
Ecological Risk Assessment Framework (U.S. EPA, 1992a)
PROBLEM FORMULATION
fl
ft
Characterization
Characterization
Ecolog cal Effects
RISK CHARACTERIZATION
I
(Q
&EPA
Discussion Between the Risk Assessor and Risk Manager (Results)
" "A": ''• "
Y
Risk Management
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National Sediment Bioaccumulatlon Conference
Eight-Step Ecological Risk
Assessment Process for
Superfund
liEZI;
O
—
STEP1:
PRELIMINARY
Site Visit
Problem Formulation
Toxicity Evaluation
a
ii* Tu^u- ™
i<§ :
i "S !
ill i
STEP 2: PRELIMINARY
Exposure Estimate
Risk Calculation
STEP 3: PROBLEM FORMULATION
Toxicity Evaluation
Assessment Endpoints
Conceptual Model
Exposure Pathways
Questions/Hypotheses
STEP 4: STUDY DESIGN AND DQO PROCESS
Lines of Evidence
Measurement Endpoints
Work Plan and Sampling and Analysis Plan
STEP 5: VERIFICATION OF FIELD SAMPLING PLAN
STEP 6: SITE INVESTIGATION AND DATA ANALYSIS
STEP 7: RISK CHARACTERIZATION
STEP 8: RISK MANAGEMENT
\fj&i*ftf ' '•'**->" *• f
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Proceedings
6-13
STEP1: PRELIMINARY
• Site Visit
• Problem Formulation
• Toxicity Evaluation
STEP 2: PRELIMINARY
• Exposure Estimate
• Risk Calculation
STEPS: PROBLEM
FORMULATION
Toxicity Evaluation
Assessment
Endpoints
Conceptual Model
Exposure Pathways
Questions/Hypotheses
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Ncitional Sediment Bioaccumulation Conference
r>
STEP 4: STUDY DESIGN AND
DQO PROCESS
• Lines of Evidence
• Measurement Endpoints
Work Plan and
Sampling Analysis Plan
-a
'
STEPS: VERIFICATION OF FIELD
SAMPLING PLAN
STEP 6: SITE INVESTIGATION
AND DATA ANALYSIS
STEP 7: RISK
CHARACTERIZATION
STEP 8: RISK MANAGEMENT
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National Sediment Bioaccumulation Conference
Day Two: September 12, 1996
Session Six?
Questions and Answers
A
fter each session, there was an opportunity for
questions and answers and group discussions
^pertaining to the speakers' presentations.
Q (Arnold Kuzmack, U.S. EPA Office of Water): Dave, I
could not tell on your mercury charts whether you were
distinguishing .inorganic from organic mercury. You
really should.
David Charters:
We are not. That is a nice toxicological issue, but
it is not a cleanup issue.
Q (Arnold Kuzmack): Whether or not the hazard quotient
is really greater than one, I think, compels -what kind of
mercury it is. In terms of the process you are laying out,
I noticed that at the step of risk characterization there
was not a scientific management decision point (SMDP),
and it strikes me as extremely important to have one.
David Charters: ;
The difference there is that the discussion on what
is risk characterization is pretty much the risk assessors
trying to figure out how it is done. In risk management,
it is more consideration of the risk communication issues.
We need to keep these separate. ,We do not want risk
management and risk communication to be confused any
more than has historically been done. So it is the same
thing once again. It is whether it is in step seven of in step
eight.
Q (Todd Bridges, COE Waterways): David, you did not
say what you did with the threatened and endangered
species. Did you treat them in the same way that you did
the raccoon?
David Charters:
No, the threatened and endangered species were
done through the two trust agencies, U.S. Fish and
Wildlife and NOAA. We do not have a legal responsibil-
ity there, but we must comply with the spirit of that law
in working with Fish and Wildlife and NOAA. It is not
a unilateral EPA decision. At this point, those decisions
have not been made.
Q (Participant): I noticed you used a LOAEL when you
were calculating your hazard quotient rather than a
NOAEL.
David Charters: .
We had better information on the LOAEL. We also
have the no-observed-adverse-effect level (NOAEL) and
we can take it down to that. This was for illustration
purposes. It is not the standard way that is taken. If you
want to turn those into NOAEL numbers, multiply them
by 10. What we .are really looking for is not only to be
reasonable, but also to use the best data available to
address the question, "Is there a realistic probability of an
adverse impact or not?" This is the real part of the risk
assessment, not the'screening anymore. We felt that we
were working with the best information and that it was
very solid.
6-15
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National Sediment Bioaccumulation Conference
Session Seven:
Integrating Bioaccumulation Results
into EPA's Decision-Making Process
Elizabeth Southerland, Panel Moderator
U.S. EPA, Office of Science and Technology,
Washington, DC
Opening Remarks
Michael Kravitz
U.S. EPA, Office of Science and Technology,
Washington, DC
Bioaccumulation Testing and Interpretation for the
Purpose of Sediment Quality Assessment: Status
and Needs
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National Sediment Bioaccurnulation Conference
Opening Remarks
Elizabeth Southerland
U.S. Environmental Protection Agency, Office of Science and Technology, Washington, DC
During the first two days of the conference, we
heard technical presentations. Today we will be
focusing on policy. I would like to review
today's agenda. We will open with speakers from four
regulatory programs in EPA that use bioaccumulation
data. The speakers will describe the current use of this
data in their regulatory programs. After the program
presentations, I will begin the panel discussion by asking
the panelists to identify barriers to using bioaccumula-
tion data in their programs and additional needs to allow
more efficient use of bioaccumulation data. Once each
panelist has had an opportunity to address those issues,
I will.open the discussion up to the entire audience.
During mis time you can share your ideas about future
needs and comment on any of the information that has
been presented. • '
Before we begin the panel presentations,' I will
give a brief overview of the programs in EPA that use
bioaccumulation data. Then Mike Kravitz from my,
Division in the Office of Science and Technology will
talk about an EPA report-that is currently under develop-
ment on bioaccumulation testing and interpretation for
assessing sediment quality. The report is being devel-
oped by an Agency workgroup that is co-chaired by the
Office of Water and the Office of Solid Waste.
The program representatives speaking today will
explain how bioaccumulation data is used in EPA regu-
latory programs. The data may be from laboratory
assays that we heard abput on the first day of the
conference, or it may be from field studies similar to
those presented on the second day of the conference.
Once these programs have collected the data, their pri-
mary concern is determining what it means in the context
of their regulations. The interpretation issue has been
raised a number of times at this conference. There are
fundamental questions that we are still trying to answer
about bioaccumulation data. One of the critical issues to
help resolve these questions is to define tissue residue
levels of concern for regulatory programs. All of us feel
that we need to have a better idea of how to interpret this
data. Once we can interpret it by applying better scien-
tific information, we can move to the next step and
determine how to use it in regulatory decision-making.
Our panelists today are representatives of the Super-
fund remediation program in the Office of, Emergency
and Remedial Response, the industrial chemicals pro-
gram in the Office of Pollution Prevention and Toxics,
and the permitting (National Pollutant Discharge Elimi-
nation System) and dredged material programs in the
Office of Water. Again, they will be giving you an
overview of how they currently use bioaccumulation
data in these, programs. But before we hear from our
panelists, let me introduce Mike Kravitz, who is our
Office of Water chair of the Bioaccumulation Analysis
Workgroup. He will tell us about the bioaccumulation
report that the workgroup is preparing.
BIOACCUMULATION DATA
What does it mean?
Interpretation
How is the information used in EPA decision-making?
Remediation
z
Permitting
Pesticides
\
Risk Management
Toxic
Substances
Dredged
Material
7-3
-------
-------
National Sediment Bioaccumulation Conference
Bioaccumulation Testing and
Interpretation for the Purpose of
Sediment Quality Assessment: Status
and Needs
Michael Kravitz
U.S. Environmental Protection Agency, Office of Science and Technology, Washington, DC
Problem Statement
I ediments serve as both a sink and a reservoir for
sistent chemical contaminants, some of-which
bioavailable or .become bioavailable as condi-
tions change naturally or anthropogenically. For instance,
metals bioavailability can change in estuaries depending
on seasonal changes in the influences of riverine flows and
oceanic tides (Geesey et al., 1984). Bioturbation (mixing
and movement of sediments by organisms) can also affect
bioavailability of sediment contaminants by increasing
oxygen and nutrient exchanges, and increasing exchange
of contaminants with overlying water. Increased or
sufficient bioavailability of contaminants can result in
bioaccumulation and^ depending on the contaminant and
level of bioaccumulation, can also result in toxicity
and/or in transfer to consumers through dietary uptake. In
the case of certain contaminants (i.e., arsenic, mercury,
methyl mercury, PCBs, DDT, DDE, toxaphene),
biomagnification up the food chain can occur,
affecting higher trophic levels (Suedel et al., 1994;
USAGE, 1995). .
Bioaccumulation of toxic persistent organic con-
taminants by aquatic organisms is a concern for several
federal agencies, including the U.S. Environmental Pro-
tection Agency (EPA), U.S. Army Corps of Engineers
(USAGE), National Oceanic and Atmospheric Adminis-
tration (NOAA), U.S. Fish arid Wildlife Service (FWS),
and'U.S. Geological Survey (USGS). EPA's National
Sediment Quality Survey (USEPA, 1997a) has shown
that these contaminants are widely distributed in sedi-
ments throughout the United States. The National Study
of Chemical Residues in Fish (USEPA, 1992a) has
demonstrated that^ these compounds are detectable in
fish tissues, and many states have issued fish consump-
tion bans as a result of bioaccumulative compounds
reaching concentrations in fish tissue that may pose a
threat to humans that consume them (USEPA, I997b).
For these reasons, EPA and other Federal and State
agencies have -identified a need to find solutions to
problems associated with bioaccumulative compounds
in sediments.
Scope of the Document
The EPA document, "Bioaccumulation Testing and
Interpretation for the Purpose of Sediment Quality As-
sessment: Status and Needs" is intended to summarize the
current status of our knowledge of bioaccumulation and
recent developments in bioaccumulation research that
might improve our ability to use bioaccumulation testing
to evaluate sediment quality. Chapter 2 discusses the
information compiled in chemical-specific summary tables
(Appendix) mat represent bioaccumulation research con-
ducted during the past 10 years. The .summary tables
cpntain information associating the presence and quantity
of potentially bioaccumulative chemicals in sediment
with uptake in the tissues of aquatic and terrestrial organ-
isms and with the effects of those chemicals on the
organisms. Chapter 3 discusses factors affecting the bio-
availability of sediment-associated contaminants. Chap-
ter 4 describes methods and techniques that have been
developed for measuring and modeling bioaccumulation.
Chapter 5 presents brief synopses of current research on
and uses of bioaccumulation testing in several Federal
' agency programs to support regulatory activities. Finally,
Chapter 6 summarizes further research needs for the
development of guidance for interpreting bioaccumula-
tion of persistent organic pollutants to assist in protecting
aquatic and terrestrial biota and humans from toxic effects
of bioaccumulative chemicals in sediments.
7-5
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7-6
National Sediment Bioaccumulation Conference
Purpose
A number of sediment assessment methods have
been developed to determine the bioaccumulation poten-
tial of contaminants in sediments, but overall guidance on
interpretation of test results in the evaluation of ecological
and human health effects, is lacking. To begin to address
this concern, EPA's Office of Science and Technology
(OST) and Office of Solid Waste (OSW) formed a "Bio-
accumulation Analysis Workgroup" consisting of
40Headquartersandregionalparticipants. Thisworkgroup
has overseen the production of the present "status and
needs paper," the purpose of which is to provide back-
ground information and report on the status of bioaccu-
mulation testing and interpretation in various EPA pro-
grams (and other federal agencies). EPA's Office of
Water envisions that the paper will serve as the basis for
EPA-wide cross program guidance on interpretation of
bioaccumulation tests for the purpose of sediment quality
assessment. Ultimately, integration of interpretable bio-
accumulation tests into a regulatory decision-making
framework will be required, with the understanding that
this would be subject to case-specific modifications based
on individual program needs.
Regulatory Uses
A brief synopsis of possible uses of bioaccumula-
tion data in EPA programs implementing a variety of
statutes is presented on page 7-9. More detailed informa-
tion on how bioaccumulation data is used by various
programs is provided in Chapter 5. Typical applications
of bioaccumulation guidance might be the characteriza-
tion of sediment contamination at Superfund sites, the
verification of contaminants of concern in sediment for
purposes of NPDES permitting, or the selection of dis-
posal options for dredged material.
The Office of Enforcement and Compliance Assur-
ance (OECA) is responsible for developing and imple-
menting enforcement and compliance assurance strate-
gies for the National Environmental Policy Act (NEPA)
and other federal regulations. As such, OECA may use
bioaccumulation data under a broad range of statutes to
determine the environmental acceptability of proposed
Federal actions.
The Office of Prevention, Pesticides, and Toxic
Substances (OPPTS) uses the results of bioaccumulation
tests to support review of new arid existing chemicals
under the Toxic Substances Control Act (TSCA) and the
registration/re-registration of chemicals under the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA). In
addition biaccumulation information may be used to
provide guidance on the design of new chemicals to
reduce bioavailability and partitioning of toxic chemicals
to sediment.
The Office of Solid Waste and Emergency Re-
sponse (OSWER) is responsible for controlling hazard-
ous wastes and remediating hazardous waste sites under
the Resource Conservation and Recovery Act (RCRA)
and the Comprehensive Environmental Response
Compensation and Liability Act (CERCLA). Under
CERCLA, the Office of Emergency and Remedial Re-
sponse (OERR)—the Superfund Program—uses sedi-
ment assessment methods, including bioaccumulation
data, as a standard part of initial sampling during the
preliminary site assessment and the more in-depth reme-
dial investigation/feasibility study for Superfund sites
where sediment contamination may be present. Under
RCRA, OSW is preparing a rule that addresses listed
hazardous wastes, and mixtures of and residues derived
from managing the hazardous wastes that pose low risks
to human health and the environment. The rule will
establish chemical-specific concentrations in wastes to be
eligible for a self-implementing exemption from the haz-
ardous waste management system requirements under
Subtitle C of RCRA. A risk-based methodology is under
development that will be used as the basis for the exit
concentrations. The methodology considers the bioaccu-
mulative potential of relevant chemicals in the evaluation
of potential exposures from multiple pathways, in multi-
media, and from a variety of waste management units.
In response to the Hazardous and Solid Waste
Amendments of 1984 (HSWA), which amended RCRA,
and the Pollution Prevention Act of 1990 (PPA), EPA
released the Waste Minimization National Plan (WMNP)
in November 1994. The WMNP focuses on reducing the
generation and subsequent release to the environment of
the most persistent, bioaccumulative, and toxic chemicals
in hazardous wastes. One of the objectives of the WMNP
was to develop a flexible risk-based screening tool that
would assist stakeholders in identifying source reduction
and recycling priorities. EPA committed to fulfill this
objective by developing a tool mat would prioritize chemi-
cals based on their persistence, bioaccumulation poten-
tial, toxicity, and quantity. This screening tool—the
Waste Minimization Prioritization Tool (WMPT)—has
been developed by OSW and the Office of Pollution
Prevention and Toxics (within OPPTS). It is currently
under public review.
The Office of Water (OW) is responsible for EPA's
water quality activities, which represent a coordinated
effort to restore the nation's waters. The functions of this
program include developing national programs, technical
policies, and regulations relating to drinking water, water
quality, and ground water; establishing environmental
and pollution source standards; and providing for the
protection of wetlands. In addition, this Office furnishes
technical direction, support, and evaluation of regional
water activities; enforces standards; and develops pro-
grams for technical assistance and technology transfer.
The Office oversees the provision of training in the fields
of water quality, economic and long-term environmental
analysis, and marine and estuarine protection.
OW and the USAGE developed joint technical
guidance for evaluating the potential for contaminant-
related impacts associated with the discharge of dredged
material in the ocean under the Marine Protection, Re-
search, and Sanctuaries Act (MPRSA) (USEPA and
USAGE, 1991). Similar updated guidance has been
drafted for evaluating dredged material discharges in
fresh, estuarine, and saline (near-coastal) waters under
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Proceedings 1_
Section 404 of the Clean Water Act (CWA) (USEPA and
USACE, 1994). These documents employ a tiered testing
protocol in which bioaccumulation data figures promi-
nently.
Under Sections 301,304,306, and3Q7 of theCWA,
the Office of Science and Technology (OST) (within OW)
promulgates technology-based national effluent limita-
tions guidelines that control the discharge of toxic chemi-
cals and other pollutants by categories of industrial dis-
chargers. Bioaccumulation data and modeling are used in
support of this effort. .
In response to the Water Resources Development
Act (WRDA) of 1992 requirement that EPA conduct a
national survey of data regarding sediment quality in the
United States, OST prepared the National Sediment Qual-
ity Survey (NSQS) (USEPA, 1997a). For calculations
related to bioaccumulation, the Survey makes use of fish
tissue residue data, and models bioaecumulation from
sediment using the theoretical bioaccumulation potential
approach. A national database containing information in
the NSQS, i.e., the National Sediment Inventory, will be
maintained and updated on a regular basis so that it can be
used to assess trends in both sediment quality and the
effectiveness of existing regulatory programs at the Fed-
eral, State, and local levels.
Section 403 of the CWA requires determination of
the quantities of and potential for bioaccumulation of
released chemicals, the potential for pollutant transport,
potential harm to biological communities, and direct and
indirect effects on humans. The "CWA Section 403:
Procedural and Monitoring Guidance" (USEPA, 1994)
developed by the Office of Wetlands, Oceans, and Water-
sheds (OWOW) (within OW) discusses the qualities of
target, species and methods for assessing bioaccumulation;
monitoring program design, including sampling of caged
or indigenous indicator species; the type of tissue to be
analyzed in invertebrates and fishes; and techniques for
extracting and analyzing chemical contaminants. USEPA
(1995) provides additional information on some of these
topics.
EPA's National Estuary Program (NEP), autho-
rized under CWA Section 320, is a national demonstration
program that uses a comprehensive watershed manage-
ment approach to address water quality and habitat prob-
lems in designated estuaries on the Atlantic, Gulf, and
Pacific coasts and in the Caribbean. OWOW developed
guidance for this program (USEPA, 1992b) which is
similar to that for Section 403 (above) and which includes
the design and conduct of bioaccumulation monitoring
studies to link exposure and effects and to examine risks
to target species and humans.
Section 402 of the CWA authorizes the National
Pollutant Discharge Elimination, System (NPDES) per-
mitting program, administered by the Office of Wastewa-
ter Management (OWM) (within OW), to regulate the
discharge of pollutants from point sources into navigable
waters. Bioaccumulation screening methods can be used
to identify chemicals of potential concern in the sedi-
ments, followed by chemical-specific analysis for confir-
matory purposes. Until the States adopt numeric criteria
into their standards for sediment contaminants based on
7-7
•bioaccumulation, the NPDES program would not require
permitting authorities to include, in their NPDES permits,
sediment bioaccumulation-based numeric limits. However,
States have the discretion to include such limits in permits
based on an interpretation of thek narrative standards for
toxics. To establish such permit limits, it will be necessary,
for permitting authorities to develop Waste Load Alloca-
tions (WLAs) for the relevant sediment contaminants.
Section 118(c)(2) of the CWA (Pub. L. 92-500 as
amended by the Great Lakes Critical Programs Act of
1990 (CPA), Pub. L. 101-596, November 16, 1990)
required EPA to publish proposed and final water quality
guidance on minimum water quality standards,
antidegradation policies, and implementation procedures
for the Great Lakes System. In response to these require-
ments, EPA developed the Final Water Quality Guidance
for the Great Lakes System; Final Rule, 40 CFRpart 132;
Federal Register, Thursday, March 23,1995. The Guid-
ance incorporates bioaccumulation factors (BAFs) in the
derivation of criteria and values to protect human health
and wildlife.
Section 118(c)(3) established the Assessment and
' Remediation of Contaminated Sediments (ARCS) Pro-
gram to assess.the extent of sediment contamination in the
Great Lakes and to demonstrate bench- and pilot-scale
treatment technologies for contaminated sediment. Un-
der the ARCS program, the Great Lakes National Program
Office (GLNPO) used bioaccumulation data and models
to estimate comparative human health risks associated
with direct and indirect exposures to contaminated sedi-
ments in the lower Buffalo River under selected remedial
alternatives. It was shown that risks could be reduced
under the different remedial alternatives compared to no
action, particularly if dredging was the selected option.
Ongoing work in the State of Washington provides
an example of the use of bioaccumulation data to imple-
ment a state regulation. Sediment Management Standards
(SMS) for the State of Washington were promulgated by
the Washington State Department of Ecology under Chap-
ter 173-204 WAC in March 1991. The purpose of these
standards is to "reduce and ultimately eliminate adverse
effects on biological resources and significant human
health'threats" resulting from contaminated sediments.
The State of Washington is developing human health
sediment quality criteria for bioaccumulative compounds
in Puget Sound sediments which will be incorporated into
the State's existing SMS. These criteria (not to be con:
fused with Sediment Quality Criteria for the Protection of
Benthic Organisms proposed by, EPA in the Federal
Register in 1994) are based on standard risk assessment
methodologies in conjunction with empirically derived
biota-sediment accumulation factors (BSAFs).
Important Issues Involved in
Generating and Interpreting
Bioaccumulation Data
The following general and specific issues should be
addressed before agencies can effectively consider bioac-
cumulative compounds when developing guidance on
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7-8
National Sediment Bioaccumulation Conference
sediment contamination. Each of these issues will be
addressed in the "status and needs" paper.
General Issues
• What are the assumptions, applications, and limi-
tations for each bioaccumulation methodology?
• What are the major uncertainties related to the
assessment of bioaccumulation of sediment-asso-
ciated contaminants?
• Do these uncertainties affectregulatory decisions?
Will they be resolvable in the near term or will
they require a much longer period for resolution?
• How can bioaccumulation assessment results be
effectively applied to human health and ecologi-
cal risk assessments?
Specific Issues
• What are the most appropriate definitions of terms
related to bioaccumulation?
• What are the requirements for selecting species for
bioaccumulation testing?
• What species are potentially available for use in
testing?
• What are the most appropriate methods for testing
bioaccumulation?
• Are there alternative tests that can be considered
for assessing bioaccumulation?
• How can tissue-specific residue levels be coupled
with chronic toxicity response data to develop
dose-response relationships for bioaccumulative
contaminants?
• How can bioaccumulation methods be used to
assess population level effects (i.e., in order to
allow for regulatory cost-benefit analysis)?
• How should we account for the bioaccumulation
of metabolites of contaminants, such as PAHs?
• When should theoretical models be used rather
than testing to assess bioaccumulation?
• How much site-specific information is required to
apply models to predict bioaccumulation?
• What model parameters are more broadly appli-
cable rather than site-specific?
• What bioaccumulation model components are es-
sential for food chain modeling?
• Is contaminant partitioning behavior related to
biomagnification?
• Can log K^ help determine the trophic level at
greatest risk from bioaccumulation of specific
sediment contaminants?
• How should we account for differential partitioning
of bioaccumulative contaminants among tissues?
• Do steady-state equilibrium model assumptions
represent prevailing conditions in the long term
for risk assessment purposes?
• What are the most sensitive exposure parameters
that drive the outcome of human health and eco-
logical risk assessments?
How are different programs using bioaccumula-
tion data and what do they need from the data to
address their program responsibilities?
References
Geesey, G.G., L. Borstad, and P.M. Chapman. 1984.
Influence of flow-related events on concentration
and phase distribution of metals in the lower Fraser
River and a small tributary stream in British Colum-
bia, Canada. Water Res. 18:233-238.
Suedel, B.C., J. A. Boraczek, R.K. Peddicord, P. A. Cliffort
and T.M. Dillon. 1994. Trophic transfer and
biomagnification potential of contaminants in
aquaticecosystems. Rev.Enviwn. Contam. Toxicol.
136:21-89.
USAGE. 1995. Trophic transfer and biomagnification
potential of contaminants in aquatic systems. Envi-
ronmental Effects of Dredging Technical Notes,
EEDP-01-33 January 1995. U.S. Army Corps of
Engineers, Waterways Experiment Station,
Vicksburg, MS.
USEPA. 1992a. National study of chemical residues in
fish. Volume I. EPA 823-R-92-008a. U.S.Environ-
, mental Protection Agency, Office of Science and
Technology, Washington, DC.
USEPA. 1992b. Monitoring guidance for the National
Estuary Program. EPA 842-B-92-004. U.S. Envi-
ronmental Protection Agency, Office of Water,
Washington, DC.
USEPA. 1994. CWA Section 403: Procedural and
monitoring guidance-. EPA 842-B-94-003. U.S.
Environmental Protection Agency, Office of Wa-
ter, Washington, DC.
USEPA. 1995. Guidance for assessing chemical con-
taminant data for use in fish advisories. Volume 1.
Fish sampling and analysis. Second edition. EPA
823-R-95-Q07. U.S. Environmental Protection
Agency, Office of Water, Washington, DC.
USEPA. 1997a. The incidence and severity of sediment
' contamination in surface waters of the United
States, Volume 1: National sediment quality sur-
vey. EPA 823-R-97-006. U.S. Environmental Pro-
tection Agency, Office of Science and Technology,
Washington, DC.
USEPA. 1997b. Listing of fish and wildlife consumption
advisories. EPA-823-C-97-004. "U.S. Environ-
mental Protection Agency, Office of Science and
Technology, Washington, DC.
USEPA and USAGE. 1991. Evaluation of dredged
material proposed for ocean disposal - Testing
manual. EPA-503-8-91-001. U.S. Environmental
Protection Agency and U.S. Army Corps of Engi-
neers, Washington, DC.
USEPA and USAGE, 1994. Evaluation of dredged
material proposed for discharge in waters of the
U.S. - Testing manual (Draft). Inland Testing
Manual. EPA-823-B-94-002. U.S. Environmental
Protection Agency and U.S. Army Corps of Engi-
neers, Washington, DC.
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Proceedings
7-9
Some Major Issues Involved in Generating
and Interpreting Bioaccumulation Data
Laboratory vs. field methods of assessing
bioaccumulation •
Feeding during testing
Uncertainties in test procedures
Lack of test organisms
Relationship between contaminant body burdens and
adverse ecological effects
Relationship between bioassay organisms and
procedures and natural populations
Relationship between bioassay organisms and human
health
Some Major Issues Involved in Generating
and Interpreting Bioaccumulation Data
(cont.)
Need to take home range/foraging area into account
when estimating exposure concentrations
Weight to give to various effects endpoints
Presence of bioaccumulative chemicals in sediments
may pose risks to aquatic life, wildlife, and humans
Overall guidance on interpretation of bioaccumulation
data in the evaluation of ecological and human health
effects is lacking
To begin to address this concern, EPA formed a
Bioaccumulation Analysis Workgroup consisting of 40
Headquarters and regional participants
-------
7-10
National Sediment Bioaccumulation Conference
Bioaccumulation Analysis Workgroup is
Overseeing the Production of:
• "Bioaccumulation Testing and Interpretation for the
Purpose of Sediment Quality Assessment: Status
and Needs"
Document will:
• Provide background information and summarize
current research that might improve our ability to use
bioaccumulation data to evaluate sediment quality
• Report on the status of bioaccumulation testing and
interpretation in various EPA programs for the
purpose of sediment quality assessment
Contents
Executive Summary
1. Introduction
• The Problem
• Purpose and Scope of the Document
• Major Issues Involved in Generating and
Interpreting Bioaccumulation Data
• Uncertainties
2. Important Bioaccumulative Chemicals
• Rationale for Choice of Chemicals
• Factors Affecting Bioavailability
• Potential Toxicity of Bioaccumulative Chemicals
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Proceedings
7-11
Contents (cont.)
3. Methods for Assessing Bioaccumulation
• Introduction
• Field and Laboratory Methods for Measuring
Bioaccumulation
• Approaches for Modeling Bioaccumulation
4. Summary of Agency Information on Bioaccumulation
Data Collection and Interpretation
• U.S. Environmental Protection Agency
• Other Federal Agencies
• International Efforts
• Similarities and Differences
Contents (cont.)
5. Further Research Needs for Understanding
Bioaccumulation and Sediment Quality
• Data Gaps
• Uncertainties
• Improvements Required
• Summary and Conclusions
APPENDIX A. Chemical-specific Summaries of
Bioaccumulation Information
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7-12
National Sediment B^oaccumulatjon' Conference
Biaccumulation Summary Cadmium
Chemical Category: METAL (Divalent)
Chemical Name (Common Synonyms): CADMIUM CASRN: 7440-43-9
Chemical Characteristics
Half-Life:
Log K^.:
Human Health
Confidence:
Solubility in Water:
Log Kow:
OralRfD:
Critical Effect:
Oral Slope Factor:
Carcinogenic Classification:
Wildlife
Partitioning Factors:
Food Chain Multipliers:
Aquatic Organisms
Partitioning Factors:
Food Chain Multipliers:
Tbxicitv/Bioaccumulation Assessment Profile
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Proceedings
7-13
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-------
National Sediment Bioaccumu/ation Conference
Session Seven:
Panel Presentations
Lawrence Zaragoza
U.S. EPA, Office of Emergency and Remedial Response,
Washington, DC
Bioaccumulation Results and Decision-Making:
The Superfund Program-
James Pendergast
U.S. EPA, Office of Wastewater Management,
Washington, DC
Sediment Bioaccumulation—-A National
Pollutant Discharge Elimination System (NPDES)
Program Perspective
Thomas Murray
U.S. EPA, Office of Pollution Prevention and Toxics,
Washington, DC
Integrating Bioaccumulative Results into EPA's
Decision-Making Process
Maurice Zeeman
U.S. EPA, Office of Pollution Prevention and Toxics^
Washington, DC
U.S. EPA/OPPTand Sediments: Screening New
and Existing Chemicals for Potential Environmental
Effects
Craig Vogt ,
U.S. EPA, Office of Wetlands, Oceans, and Watersheds,
Washington, DC ,
Dredged Material Management Program
Mario Del Vicario
U.S. EPA, Region 2,
New York, New York
Dredged Material Management: A Regional Perspective
7-15
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National Sediment Bioaccumulation Conference
Bioaccumulation Results and
Decision-Making:
The Superfund Program
Lawrence Zaragoza
U.S, Environmental Protection Agency, Office of Emergency and Remedial Response,
Washington, DC \ -
I have been following sediment issues -with Betsy
Southerland and other people at EPA for a number of
years. During that time I have been involved with a
variety of sediment projects, including the Agency's '
Contaminated Sediment Management Strategy and sedi-
ment quality criteria. It has been an interesting experi-
ence. What I will try to do.for the next several minutes is
provide you with a reflection of my experience in working
through these issues with the Office of Water and with the
EPA Regions:
I am sure that many of you are familiar with the
Superfund Program. The Superfund Program is designed
to protect both public health and the environment, so we
are interested in looking holistically at environmental
issues for all media. This means we are concerned with ,
air, water, and soil. In dealing with the environmental
issues at Superfund sites, we try to be consistent in our
approach to assessment of risks and cleanups. We also .
seek to be consistent with the activities of other program
offices. That is one of the reasons why we look to the
Office of Water to provide direction for the type of
approaches, we should apply for contaminated sediments.
The places where we tend to do some innovative
things are generally areas that bridge between different
program media. We especially need to consider how to
focus between different program media and how to make
sure that we are looking at everything in a consistent
manner. Coming to the decision about what is actually
going to be protective can also be challenging. You have
to look at what happens under different programs with
different statutes, and it can be difficult to reconcile issues
from a technical perspective that have different legislative
histories and requirements.
Superfund reauthorization has been a subject of
discussion over the last couple of years. One of the most
striking points that I have heard expressed at some of the.
reauthorization meetings is that Superfund is a program
thatprovides significantcleanup leverage for other.cleanup
programs. We are told that the EPA's efforts complement
stateefforts and that EPA work is especially useful on some
of the larger and more difficult sites.
Superfund reauthorization activities have been
going on for several years. Bills have been drafted that did
not make it through the political process. We hope to see
a reauthorization bill passed in the next year.
What about bioaccumulation data? If we are really
seeking to effectively assess risk to public health in the
environment, we should be looking at all the available
information to assist us hi making better decisions. This
would include bioaccumulation information,
bioavailability data, information on exposure, and infor-
mation on routes of exposure to either humans or sensitive
species. One of the activities that we are encouraged to see
moving forward is the work,that Mike Kravitz in the
• Office of Science and Technology is undertaking to assess
the different methodologies that exist for measuring bio-
accumulation and to build scientific consensus on these
methods so they can be used more broadly. Right now,
each program is usually faced with having to synthesize
• that kind of information on a case-by-case basis.
I would like to briefly describe Superfund's hazard
ranking system (HRS), which is the primary tool we use
to screen sites for placement on the National Priorities List
(NPL). The HRS was revised and published as a Federal
Register Notice on December 14, 1990. We track the
number of sites hi the Superfund universe through a
database called CERCLIS. Last year, we removed 28,000
sites from CERCLIS, which left about 13,000 sites in the
database. As of June, 1997, we have further reduced the
-number of sites in CERCLIS to 10,735. These steps have
. helped to identify those sites mat need additional assess-
ment and possible cleanup. Within the CERCLIS uni-
verse, the NPL represents those sites that are.likely to
require long-term cleanup efforts. Over 1,200 sites are on
the NPL. These sites tend to be complex and costly to
clean up and many include sediment contamination. The
HRS screening process for these sites relies on readily
available information, because we want the process to be
7-17
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7-18
National Sediment Bioaccumulatton Conference
cost effective in identifying sites that warrant further
attention. Sites undergo an in-depth evaluation once they
are listed. Bioaccumulation is included in this evalution,
but only the surface water exposure pathway is evaluated
for humans and other sensitive species.
Under the HRS, three factors are examined for con-
taminants at a site. We use bioconcentration data to
determine whether contaminants accumulate up food
chains. We look at water solubility data, particularly the
logarithm of the octanol-water partition coefficient Kow ,
to consider the potential for and consequences of chemical
partitioning. We also distinguish between freshwater and
saltwater environments and the resulting impacts on the
receptors (humans or other sensitive organisms) being
evaluated. Since the budget for an HRS evaluation is very
limited, the data must be collected over a relatively short
period of time.
Risk assessments for Superfund sites involve a
longer and more costly process than a HRS evaluation.
Depending on the site, a risk assessment can cost a few to
several hundred thousand dollars. Human health risk-
assessments are conducted more frequently than ecologi-
cal risk assessments. The risk assessment stage involves
more extensive data collection and detailed analysis of the
data. Results from standard bioassays and other assess-
ment techniques discussed at this conference are used at
this stage of analysis. These comprehensive studies are
performed atNPL sites and other areas to assess the impact
of contaminated materials on humans and other sensitive
species.
Finally, I would like to mention a Government
Accounting Office (GAO) study that was conducted a
couple of years ago. The report included a summary of
results that we got on risk information for a number of
different pathways. We found it interesting for sediments
which drove the cleanup for 14 out of about 200 sites that
were evaluated. Traditionally, the Superfund Program
has been driven by impacts to ground water. I definitely
see some changes that have taken place in scoring sites
using the revised HRS, which allows for more equal
consideration of risks among all media. We are also trying
to be much more comprehensive about evaluating all the
potential risks from all the media. Some of the bases for
cleanups at Superfund sites include maximum contami-
nant levels (MCLs), MCL goals, Resource Conservation
andRecovery Act (RCRA) risklevels, and state standards.
In some instances, state standards are more restrictive than
federal criteria. You may end up being more protective in
some states than you would be in others because of the
differences in state standards. These are all issues that will
be debated significantly during reauthorization. The costs
and complications of dealing with sediment problems are
often significantly more challenging than many of the
other media. This is true not only from a risk assessment
perspective, but also from the perspective of what to do
with the material once you determine that it is a problem.
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Proceedings
7-iV
What is Superfund?
Protect health and the environment as outlined in
the Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA) as
amended by the Superfund Amendment and
Reauthorization Act of 1986 (SARA)
To be consistent with the legislative direction and
the policies of other EPA offices (e.g., the National
Air Quality Standard for lead), OSWER lead policy
has targeted protection
Available scientific information to establish
protective levels plays a key role in policy
formulation
Superfund complements State cleanup programs
and has been reported to provide an incentive for
responsible parties to dean up environmental
problems
Superfund is in the process of reauthorization—we
hope within the next year
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National Sedirhent Bioaccumulatioh Conference
What is Needed to Use
Bioaccumulation Data?
The Superfund Program seeks to effectively assess
risks to health and the environment
Costs and feasibility may preclude some
assessments for bioaccumulation or risks
The expectation is that Superfund will seek to
improve risk assessments and the confidence that
can be placed in risk assessment results
How Does the Superfund Program
Use Bioaccumulation Data?
Protect health and the environment as outlined in
the Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA) as
amended by the Superfund Amendment and
Reauthorization Act of 1986 (SARA)
Superfund is in the process of reauthorization—we
hope within the next year
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Proceedings
7-21
Assessing Bioaccurnulation within
the Hazard Ranking System
• The Hazard Ranking System (MRS) is a screening
tool :
• The MRS is the primary tool for supporting the
addition of sites to the National Priorities List (NPL)
• The MRS employs readily available information and
information that can be collected
• Bioaccurnulation is evaluated in the human food
chain treat and environmental threats within the
Surface Water Pathway
A Tiered System is Used to
Determine Bioaccurnulation
Potential
Logarithm of the n-octanol-water partition coefficient
OogKow) ,
Water solubility data
Direction is provided to distinguish between fresh
and saltwater
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7-22
National Sediment Bloaccumulation Conference
Risk Assessments Provide for a
Detailed Examination
Bioassays and site specific Sediment Quality
Criteria are assessed
The types of standard bioassays employed by
others support risk assessments
SUMMARY OF THE BASIS FOR
CLEANUP
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National Sediment Bioaccumulation Conference
Sediment Bioaccumulation—A
National Pollutant Discharge
Elimination System (NPDES)
Program Perspective
James Pendergast
U.S. Environmental Protection Agency, Office of Wastewater Management, Washington, DC
I am going to. talk briefly about what the National
Pollutant Discharge Elimination System (NPDES)
Program does in the area of sediment and bioaccumu-
lation and what we think we are going to be doing in the
future. For all of you who have dealt with the NPDES
Program, you may believe that half of the program staff
are engineers and the other half are attorneys. You could
.probably ask why these people are talking about bioaccu-
mulation and whether they know enough to talk about it
in the first place. We would respond that bioaccumulation,
is of interest to us both in terms of setting permit limita-
tions and collecting information that may be needed for
making future watershed assessments.
I am going to spend most of my time talking about
both of these, but will preface my talk with a couple
important points. One is that what I will be talking about
is going to be in the future. And the future does not mean
tomorrow and maybe not even next year. In a couple of
instances, I will be referring to what is occurring now, but
in most cases I will be talking about activities in the 5- to
10-year horizon. That is when the majority of permits
may have to be .dealing with these considerations where
necessary. The second is a point of clarification that, in
contrast to the Superfund Program which deals with
remediation, the NPDES Program deals with discharges
today. By that I mean we take care of current point source
pollutant discharges in the waters of the United States.
For example, a facility that had discharged high levels of
pollutants in their wastewater years ago may be discharg-
ing very good quality wastewater today. We regulate
their discharge today without taking into account dis-
charges that polluted the environment 10 to 20 years ago.
In the ideal surface'water protection program, water
quality criteria are first developed by a combination of
Agency research and program staff. The Of fice.of Science
and Technology's (OST's) Health and Ecological Criteria
Division (HECD) is responsible for criteria development.
States then use that information to adopt water quality
standards. States are assisted in this process by the EPA
Regions and program staff in OST's Standards and
Applied Science Division (S ASD). The next step is to take
that information and devise a total maximum daily load
(TMDL) and a waste load allocation (WLA) using water
quality models. That process will produce a number in
terms of how many pounds of a pollutant a facility can
discharge without exceeding water quality standards.
Finally, the NPDES permit writer incorporates that infor-
mation into the terms of the permit to be issued.
The problem with the ideal world is that it is so
seldomrealized. In the last 22 years of my experience, the
three steps prior to issuing permits are not always there.
For example, we do not have water quality criteria for
every pollutant. We especially do not have criteria for all
the pollutants that bioaccumulate". We may have some raw
data and results from some good studies conducted at
universities, but we do not have criteria for every contami-
nant. Even where we have the criteria, the states may not
have adopted a numeric water quality standard mat in-
cludes all those criteria. There is a catch-all phrase in
water quality standards called a narrative standard. It is
worded something like this: "There should be no toxics in
toxic amounts." This gives the states a standard that can
be used, but it puts the burden on someone to figure out
what "toxic" and "toxic amounts" mean.
Not many waste load allocations have been devel-
oped for the bioconcentratable, bioaccumulative types of
pollutants. This means that permit writers now have to
figure out what to do. All of a sudden, they have to become
'someone who knows water quality criteria, who knows
how things bioconcentrate, and who knows the chemistry
and biology behind that. They must also become a math-
ematical modeler and figure out how pollutants cycle
through the environment. And, of course, they do not
usually have the training for that, except for a 5-day course
that the Permits Division conducts. But nevertheless, that
is the type of information they must learn to integrate.
Let us consider how sediments fit into the permit-
ting process. In dealing with sediments, we look at
bioaccumulation data when we try to interpret the nar-
rative for those "no toxics in toxic amounts" standards.
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National Sediment Bioaocumulation Conference
If you have sediment quality criteria, and you can figure
out the fate and transport, you can walk through the same
process of interpreting nontoxic and toxic amounts,
figuring out the cause-effect relationships, and deter-
mining which facilities are discharging which pollut-
ants that are causing problems in the sediments. But you
also have to recognize that when you are dealing with
the impact of discharges on sediments, you are having
to take into consideration a number of different factors
from discharges into water. For sediments, you have to
consider important factors like the physical composi-
tion of the sediment and chemical interactions with
. sediments. If you find a hot spot below a facility, you
also need to determine whether it is due to the facility's
discharge or to something that happened 20 years ago
that just got washed downstream in the last flood.
Bioaccumulative pollutants in sediments may not al-
ways originate from point source discharges. They may
originate from agricultural uses where there is runoff and
erosion from farms. This is another factor that the permit
writer must consider.
When we look at the information we have available
to address sediments today in the NPDES Program, we
have some challenges or barriers to overcome. No official
sediment criteria have been published, although we have
five proposed criteria. We do not find TMDLs that deal
with sediments because you have to have sediment crite-
ria to develop them. It is a difficult challenge to factor hi
unquantified nonpoint source contributions. It is also
difficult to accurately define fate and transport when you
deal with physical things that scour during flooding
events. The calculations done by the typical NPDES
permit writer are steady-state calculations, and storm
events do not fit into a steady-state calculation. So what
do we do?
Right now we are focusing more on the aqueous part
of the equation. We are not doing much with sediments
in our program today. On the aqueous side, we have put
out some guidance on how to deal with that "no toxics in
toxic amounts" phrase. We have two sources of informa-
tion that we refer people to. One is a technical support
document produced in 1991 for water quality-based
toxics control. In there, we have laid out the equation
similar to the water quality criteria program approach
where they are primarily protecting human health from
adverse affects for either a cancer or noncancer endpoint. .
We start out with how many ounces of fish a person can
eat a year, the typical weight of an American who eats that
fish, etc. From that information, you can determine what
a water quality standard should look like. The technical
support document also talks about a bioconcentration
factor. Since that was 1991, we know the information
needs to be updated. In the intervening years, we have
been working on how to bring bioaccumulation into that
evaluation process.
Through some work with our Office of Research
and Development, we have worked out how to estimate
or calculate bioaccumulation factors that can be added
to the equation. The best source of that information
today is the Great Lakes Initiative (GLI) rule. The rule
only applies to the Great Lakes basin, but the science in
it is universal and can be used across the country. So, this ,
is the type of guidance that we point people to when they
want to use bioaccumulation in making assessments in
the NPDES Program. There is also some discussion in the
GLI rule about what to do with fish tissue data. If you
have nothing in your aqueous phase chemistry, but you
find fish tissue that is high in a certain pollutant, can you
make regulatory decisions based on the fish tissue data?
The GLI rule shows how to translate the fish tissue data
and determine what its equivalent water quality concen-
tration would be.
That is where we are today. We are trying to work
out a companion process for dealing with sediments hi
developing permits. Some of the focus is on simplifying
modeling that currently works on a large mainframe
computer to an assessment tool that an average permit
writer can use. This could take five to ten years. Another
important area of focus is to conduct evaluations on a
watershed scale rather than the traditional approach of
evaluating each individual facility.-The NPDES Program
was initiated under the Clean Water Act of 1972 to permit
facilities to reduce pollutants. At this time, it was easier
to identify major sources of pollutants. The program
targeted the most obvious sources of pollution from the
big pipes or from areas with signs of pollution like foam
on the rivers. The program was successful in getting
treatment technology established at plants to combat
pollution. Now the program is in a more difficult stage.
Every two years the states are required to provide assess-
ments of their water quality that are compiled in the
305(b) reports. Lately, they are indicating that nontradi-
tional sources are causing more problems. These are
either urban point sources such as discharges from a storm
sewer or a combined sewer overflow (CSO) or nonpoint
source runoff from agricultural lands or forestry sites.
Now we are having to open our doors for the first time and
begin talking to programs in the Bureau of LandManage-
ment and the Forest Service to decide how we are going
to apply a holistic approach hi protecting our waters.
Working with programs that are entirely voluntary to
develop responsible water quality management is per-
haps our biggest challenge. NPDES is still part of the
equation, but no longer the primary part of the equation.
Sediments come into play in this process. We need to
identify watersheds where sediment contamination is the
greatest source of impairment and to work with other
agencies to deal with the sources of sediment problems.
And we may find out that, in some cases, NPDES may not
be the answer.
What do we expect today? We still expect that the
permit writers use their best judgement on how to deal
with bioaccumulation and sediments. And best judge-
ment does not mean to find an ounce of science and start
leaping miles ahead of that. What best judgement means
is taking the current science, taking the current data, and
using it responsibly to take a look at watershed-based
water management decisions: If in looking at this infor-
mation, a permit writer determines that a point source is
not the cause of the problem, then their best professional
judgement will say, "Don't deal with it." But if the permit
writer finds that a point source is discharging a
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Proceedings
7-25
biocohcentratable or bioaccumulative pollutant at lev-
els causing impairment today, then they should use the
information to include the right requirement in the permit
to limit that pollutant.
We do believe that NPDES permits still need to
be issued. We do not want to spend 25 years studying
•ssues before we can take any action. But we also
recognize that issuing permits on time does not neces-
sarily mean every 5 years regardless of the situation.
Issuing permits on a timely basis means doing it when
you have enough data that it makes good sense. And
that we will do.
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National Sediment Bioaccumulation Conference
WHY IS A NPDES PROGRAM MANAGER
TALKING ABOUT SEDIMENT
BIOACCUMULATION?
Is sediment bioaccumulation a permitting
issue?
Is sediment bioaccumulation strictly a
monitoring issue?
PERMIT ISSUANCE (WITHOUT SEDIMENT
CONTAMINATION FACTORED IN)
Permit Writing Factors:
• Develop criteria
Adopt Water Quality Standards (WQS)
• Develop Waste Load Allocation (WLA)
• Issue permits, based on the WLA, for each point.
source
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Proceedings
7-27
'* PERMIT ISSUANCE (WITH SEDIMENT
*f CONTAMINATION FACTORED IN)
Sediment Characteristics to Consider:
• Different sediment types (physical and chemical
composition)
• Sediments are not stationary
(Fate/Tranport Issue)
• Sediments may
have pre-existing contaminant
contributions from:
natural, point or non-point sources
'*
PERMIT WRITER'S CHALLENGE
Permit Writer's Challenges When Developing a
Permit with Sediment Contamination Factored in:
• No sediment criteria, therefore no WQS for sediment
• No total maximum daily loads (TMDLs)
• Non-point source contributions not factored in
• Transport-Fate issues are not addressed
for sediments
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National Sediment Bioaccumulation Conference
ADDRESSING THE CHALLENGES
What's Available:
• National Guidance
Technical Support Document (TSD)
(pages 36-44)
Great Lakes Initiative (GLI)
(pages 15400- 15406)
• Watershed Permitting Approach
PERMITTING BY WATERSHEDS
Land-Use Categories
Forestry
I I Agriculture
NPDES Facility
© CSO Stormwater Facility
/\ _ Watershed Number
~>-' Watershed Boundary
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7-29
\ WHAT IS EXPECTED FROM EPA, STATE,
** AND TRIBAL PERMIT WRITERS?
Minimum:
Using all available EPA permitting guidance, issue
permits based on Best Professional Judgement
(BPJ).
Issue NPDES Permits on time.
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, National Sediment BioaccumuJation {Conference
Integrating Bioaccumulative Results
into EPA's Decision-Making Process
Thomas Murray
U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington, DC
Premanufacture Notifications (PMNs) are required
under section 5 of the Toxic Substances Control
Act (TSCA) from anyone who intends to manufac-
ture or import a new chemical substance. A new
substance is defined as one not on the Chemical Inven-
tory created under TSCA section 9. Once the U.S.
Environmental Protection Agency (EPA) receives a
PMN document, Agency staff normally have 90 days to
review it. First, the PMN substance is sent through an
initial screening-level risk assessment process. A major
objective of this review process is to determine whether
the PMN substance may present an unreasonable risk of
injury to human health or the environment during its
lifetime. . . ,
.. The Office of Pollution Prevention and Toxics
(OPPT) uses a similar process for those chemicals al-
ready in the marketplace. Priorities are established for
selecting existing chemicals from the chemical inven-
tory for review. There is no statutorily imposed time
schedule for these reviews.
Coming out of the screening-level risk assessment
process, those chemicals which are found to present the
potential for unreasonable risk to human health or the
environment are scrutinized more thoroughly. OPPT
sometimes requires testing in response to identified
concerns before reaching a decision for a chemical under
review. ,
Professionals from many different disciplines take
part in reviewing the various aspects of the life cycle of
a chemical under review. In his remarks, Maurice
Zeeman describes those things considered when assess-
ing risk to ecological communities. My remarks will
focus on the human health exposures. ,
When a chemical is introduced into OPPT's risk
screening process, a Structure Activity Team convenes
to discuss its potential health and eco.toxicity concerns.
This Team provides, direction to the review, process that
follows. Of concern to us in this discussion are those
chemicals which result in human exposures through
surface water. Here, OPPT engineers quantify surface
water releases of these chemicals-from point sources or
estimate these releases where monitoring data are ab-
sent. We do not routinely assess nonpoint sources.
OPPT chemists then assess the fate of these chemicals
and describe likely or known transport processes. Asses-
sors then use these fate estimates to assess the potential
human health risks associated with the expected releases.
The process of evaluating each potential route of
exposure can be complicated. To perform the calcula-
tions necessary for exposure evaluations, assessors make
use of simple formulas, complex mathematical models,
and a number of basic assumptions. Sound monitoring
data are always preferred but are rarely available. Much
of the work involved in the assessment process involves
frequently encountered exposure scenarios. This has
allowed OPPT to standardize most of the assessment
•process. A number of thresholds have been developed
which help .determine whether a given chemical or
exposure route will present significant:potential expo-..
sures. OPPT relies heavily on the efforts of other EPA
program offices and academia in updating its exposure
assumptions and models. .
Sediment/Bioaccumuiation Results
When a chemical under review is believed to have
the potential to pose a risk to human health through the
surface water pathway, several exposure assessment
steps are set in motion. First, a fate review is done to ,
determine, among other things, how much of the chemi-
cal is likely to be removed in the wastewater treatment
process. With an: estimate of chemical loading to the
receiving stream, instream processes (hydrolysis, pho-
tolysis, biodegradation, etc.) are explored to assess the
ultimate fate of the chemical. Exposure models are then
deployed to track the. chemical downstream to drinking
water facilities. The fate chemists will also calculate the
Bioconcentration Factor (BCF) for the chemical if expo-
sure through fish ingestion is indicated. Potential Dose
Rates are calculated through this pathway only when the
log BCF is greater than 2. When the BCF is less than 100
(or the log BCF is less than 2), the resulting human
exposure is considered negligible. If the log Kow is
greater than 8, human exposure is not calculated. Values
for log K that are higher than 8 are considered
7-31
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National Sediment Bloaccumulation Conference
unreliable; therefore, the BCF estimate is deemed
unreliable and is not used.
OPPT has also determined that in addition to
having the potential to bioaccumulate, the chemical
must also remain in the environment long enough to be
absorbed into fish tissue. For our purposes, degradation
of the chemical must be estimated to take months or
longer to allow uptake by fish tissue to occur. Potential
dose rates (PDR, a measure of exposure) for fish inges-
tion are calculated using the stream concentration of the
chemical at mean flow (see pages 7-33 and 7-34). For
discharges to saline waters, chronic mixing zone dilu-
tion factors are used, when available. OPPT currently
assumes a fish ingestion rate of 16.9 grams per "day. To
be consistent with the most recent draft of the Exposure
Factors Handbook, we will adjust this rate. For subsis-
tence fishers a rate of 140 grams per day can be used; for
sport fishers 39 grams per day is reasonable.
Where our calculations indicate that potential
exists for unreasonable risk to humans through fish
ingestion, we can reach several decisions. Oftentimes,
we will require testing by the industry to refine our fate
estimates. Dialogue with industry is routinely employed
and frequently leads to other refinements in our assess-
ment process. In extreme cases where sufficient risk is
anticipated and uncertainty low, TSCA allows OPPT to
initiate actions to limit or ban the production or use of a
chemical.
Most recently, where potential risk is indicated,
we engage industry in discussions designed to encour-
age voluntary efforts to reduce or eliminate the risk.
These range from suggestions to recycle waste or seek
disposal practices other than wastewater discharge to
intensive efforts to work with industry to redesign their
processes to eliminate problems upstream in the process
through chemical substitution or process change.
As science advances our understanding of the fate
and transport processes of chemicals in the environment
and as new testing protocols are developed and standard-
ized, OPPT will embrace these new developments and,
where appropriate, will update its assessment process
accordingly.
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Proceedings
7-33
WATER RELEASE CYCLE
PART 4: FISH INGEST10N PDR'S
DOES SAT
REQUIRE (FISH)
INGESTION PDR'S?
ISPMNIN
EXPOSURE-BASED
(YX) REVIEW?
IS MOLECULAR
WEIGHT <1,000
DALTONS?
IS THE LOG OF BCF \ NO
GREATER THAN 2 AND
LESS THAN 6?
NOTE ON CONCENTRATION
PAGE AND CONTINUE
IS BIODEGRADATION
RATED MONTHS OR
LONGER?
GO TO PART 5:
CALCULATE FISH
INGESTIONPDR
AQUATIC SPECIES
NOTES:
Calculate fish ingestion PDRs for releases to saline, tidal, or "still" waters
using chronic mixing zone dilution factors when available.
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National Sediment Bioaccumulation Conference
PDRf = C * ING. * BCF * FQ * IE'6
where
Csw = concentration in surface water (ug/1)
ING{is = ingestion rate
BCF = As calculated
FQ = frequency of exposure (days/year)
Decisions
•Testing
•Dialogue
•Voluntary Actions
•TSCA Regulatory Actions
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National Sediment Bioaccumulation Conference
U.S. EPA/OPPT and Sediments:
Screening New and Existing
Chemicals for Potential
Environmental Effects
Maurice Zeerrian, jerry Smrchek, Joseph Nabholz, and Donald Rodier
U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington, DC
Introduction
Since 1976, the Office of Pollution Prevention and
Toxics (OPPT, formerly the Office of Toxic
Substances, OTS) at the U.S. Environmental Protec-
tion Agency (U.S. EPA), has been the office that is
responsible for assessing new and existing industrial
chemicals. Prior to a reorganization within OPPT in
1997, the Environmental Effects Branch was the princi-
pal ecological group within that office, hi the past, that
group had been concerned primarily about the ecological
effects of industrial chemicals in the water column
(Zeeman and Gilford; 1993; Zeeman, 1995). However,
in the last five to ten years, there has been more and more
concern expressed about the possible effects of industrial
chemicals upon organisms in the sediments (Clements et
al., 1994; U.S. EPA, 1994; Nabholz et al., in press;
Smrchek et al., 1995; Smrchek and Zeeman, 1997;
Zeeman, 1993; Zeeman et al., 1995 and in press).
Following is a brief introduction to the U.S. EPA,
the responsibilities of OPPT, especially the new and
existing chemical programs, and the kind of assessments
of these chemicals that are required under the Toxic
Substances Control Act (TSCA, the law under which
OTS [now OPPT] was formed in 1976). After this is a
description of how OPPT went about requiring and
getting sediment toxicity testing for a new industrial
chemical. And finally, an example is presented on how
OPPT developed a methodology that was used to Screen.
thousands of existing chemicals to try to develop a list of
higher priority chemicals for possible ecological testing
concerns, including possible sediment testing.
Background
For those who think of the U.S. EPA as some sort
of monolithic agency, it is not. .It has about 17,000 to
18,000 employees in numerous, programs and offices that
were each set up at different times and for different
purposes. The Agency's various programs and offices
address responsibilities defined by several different envi-
ronmental laws that were passed over decades by differ-
ent legislative actions (Clean Air Act, Clean Water Act,
TSCA, etc.). The Offices in the U.S. EPA were organized
under broad legislative or environmental categories,'such
as Ak and Radiation, Water, Pesticides and Toxic Sub-
stances, Solid Waste and Emergency Response
(Superfund), and Research and Development. The fig:
ures on page 7-40 [U.S. EPA, OPPT] illustrate how,.the
U=S. EPA is organized, with OPPT residing within the
Office of Prevention, Pesticides, and Toxic Substances
and the Environmental Effects Branch (EEB) residing
within OPPT. v-
The ecological hazard and risk assessment func-
tions of that Branch used to be in the Health and Environ-
mental Review Division (HERD), and those functions
now reside in the newly formed Risk Assessment Divi-
sion (RAD, formed hi 1997 from the combination of the
staff and functions of'both HERD and the Chemical
Screening and Risk Assessment Division, CSRAD)- The
Economics, Exposure, and Technology Division (EETD)
contains the staff responsible for performing the engi-
neering and exposure assessment portions of the ecologi-
cal risk assessments that are done in OPPT. .
Why does/should OPPT care about bioaccumula-
tion, bioconcentration, and sediments? Because there are
industrial chemicals which adsorb strongly to sediments
and which are quite likely to also bioaccumulate or
bioconcentrate. When introduced into the food chain,
they could be detrimental not only for those organisms in
the sediment and water column environments, but also
for humans. TSCA was passed in 1976 to regulate
industrial chemicals, those chemicals used in commerce
that were not regulated by other statutes, meaning that
they are not pesticides, pharmaceuticals, food additives,
or substances covered under other laws (see figure on
page 7-41 [watering can]). For example, industrial
7-35
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7-36
National Sediment Bioaccumulation Conference
chemicals are substances like solvents, plastics, dyes,
adhesives, detergents, monomers, and polymers. They
are chemicals that are widely used in commerce and are
around us all of the time. An independent calculation of
a partial sum of the 1989 production volumes of industrial
chemicals in the United States was around 6 trillion pounds
and it is undoubtedly even more now (Zeeman, 1997).
One of the first activities after TSCA was passed in
1976 was to develop an inventory of the industrial chemi-
cals already in commerce in the U.S., the existing chemi-
cals (see figure on page 7-42 [TSCA (Passed 1976)]).
After more than two years, over 60,000 chemicals were
identified as being in commerce and these became the
TSCA Inventory of existing chemicals. These chemicals
were basically grandfathered and the Agency was to look
at them for environmental concerns on an ongoing basis.
By definition, anything that was not an existing
chemical (i.e., on the Inventory) was a new industrial
chemical, and if anyone wanted to make it or import it into
the U.S., they would have to submit an application for its
assessment to the U.S. EPA. This assessment program is
not a registration program. Industry (the potential manu-
facturer or importer) submits a notice to OPPT called a
Premanufacture Notification (PMN). OPPT receives a
large number of these notices from industry each year (see
figure on page 7-42). They need to submit only the data
that they have or know about. They do not have to do any
testing. OPPT then has 90 days to make a decision based
on the available information or provide risk-based reasons
for not allowing it to be made or imported.
The number of new chemicals that have gone
through this process in OPPT and have become existing
chemicals on the TSCA Inventory is currently around
15,000, which brings the Inventory total to about 75,000.
OTS/OPPT has received around 30,000 new chemical
notices from 1979 to 1996. From 1986 to the present, the
average has been about 2,300 new chemical notices per
year. ThatisalmostSOnoticesperweekor lOperworkday
that are received and must be assessed hi a short lime frame.
As mentioned earlier, OPPT does not receive a lot
of information. What is required to be submitted with
these PMNs? Manufacturers must furnish information
such as the name of the chemical, the chemical structure,
the amount to be produced, disposal and human exposure
information, and any available test data since testing is
not required (see figure on page 7-43 [Required Submis-
sion]). Nevertheless, OPPT staff must make these risk-
based decisions in 90 days or the manufacturer will be
able to make or import that chemical unless a risk-based
case is made by OPPT that they should not.
The consistent experience of OPPT is that we sel-
dom receive the land of data that is needed for ecological
risk assessment. About 95 percent of the PMNs received
by OPPT contain no ecotoxicity or environmental fate data
(Zeeman and Gilford, 1993; Zeeman, 1995; Zeeman etal.,
1995). The engineers and fate chemists in OPPT only get
physical, chemical, or environmental fate data about 1 to 5
percent of the time (Zeeman et al., 1993 and 1995). They
seldom get any bioaccumulation or bioconcentration data.
A retrospective was performed on the ecotoxicity
data received for new chemicals and it was found that
OPPT received ecotoxicity data less than five percent of
the tune, and the vast proportion of the data received was
acute toxicity data (Zeeman, 1995). That means that 19
out of 20 times no ecotoxicity data are provided for new
chemicals. Therefore, OPPT has been forced to rely
heavily upon a modeling approach that uses structure-
activity and quantitative structure-activity relationships
(S AR/QS AR, or (Q)S AR) to estimate chemical properties,
chemical fate, and the ecotoxicity of a chemical to organ-
isms hi the aquatic environment (Clements, 1988 and
1994;Nabholzetal., 1993; Zeeman etal., 1993 and 1995).
How does OPPT make decisions for ecological risk
assessment in the new chemical program? A number of
PMNs for new chemicals are received each week and they
are generally assessed in groups. Within two or three
weeks of receipt of a group of PMNs, OPPT holds what
is called a FOCUS meeting (see figure on page 7-43
[Flow Chart]). That is the first level of risk assessment
where a comparison is made of the hazard assessments,
i.e., toxicity profile, and the exposure assessments for
each chemical. What is important for ecotoxicity is
whetherthe predicted environmental concentration (PEC,
from the exposure assessment) exceeds what is called the
concern concentration (CC, hazard assessment value(s)
adjusted for uncertainty). In at least 90 percent of the
cases, the PEC is not exceeded and a risk is not inferred.
These chemicals are dropped from further evaluation. In
the remaining five to ten percent of the cases, we proceed
to standard review or a request for testing and perhaps
through risk management, which can result in iterations
to obtain additional data (Wagner et al., 1995).
Sediment Assessment of an OPPT
New Chemical
Portions of the following specific new chemical
sediment assessment example have been previously pre-
sented at a Society of Environmental Toxicology and
Chemistry (SETAC) national meeting (Zeeman, 1993),
and were also used as one case study of ecological risk
assessment methods used by the Agency (U.S. EPA,
1994). Further elaborations of this sediment assessment
will also be corning out soon as publications, hi both a
SETAC book on Uncertainty in Ecological Risk Assess-
ment (Nabholz et al., in press), andin a White House OSTP
publication on Ecological Risk Assessments in the Federal
Government (Zeeman et al., in press).
The following describes the decision-making pro-
cess for a specific new chemical where OPFI was able to
get aquatic toxicity data, some generic and site-specific
data (so predictions could be made on whether or not it
would get into the sediments), and some sediment toxicity
data. The figure on page 7-44 shows the physical and
chemical properties of the chemical. This new chemical
would be produced at the level of 100,000 kg per year, so
it is not a trivial compound in terms of how much is going
to be manufactured or imported. It is an alkylated diphe-
nyl, and was classified into the SAR chemical class of
neutral organic chemicals. OPPT is very comfortable in
using its structure-activity relationship and quantitative
-------
Proceedings
7-37
structure-activity relationship [(QJSARJ models for mak-
ing predictions on neutral organic chemicals (Clements,
1988 and 1994; Nabholz et al., 1993; Zeeman et al., 1993).
B ased upon the chemical structure, an estimate was
made of the Kow value (the octanol to water partition
coefficient, often used to estimate both ecotoxicity and
bioconcentration ability) and it was fairly high. An
'estimate of the K^ value .(the water to organic carbon
partition coefficient, often used to estimate ability to
partition to sediments),was also made, and it was rela-
tively high. The water solubility was estimated to be
fairly low. These are all strong indications that this
chemical will be very likely to distribute selectively.from
the water column and into the sediments.
A hazard assessment (stressor-response) or toxic-
ity profile for this chemical was prepared (see the figure
on page 7-44). OPPT's structure-activity methods
(Clements, 1988 and 1994; Nabholz et al., 1993) were
used tq predict the acute and chronic aquatic toxicity and
to make a risk-based case'that eventually resulted in test
data. From this estimation information, OPPT inferred
that this new chemical would be a highly toxic compound
on a chronic exposure basis and that it would be very
likely to be transported to sediments. A case was subse-
quently made through refined exposure assessment esti-
mates that sediment toxicity testing was needed, and it
was eventually provided (see below).
How well did the OPPT (Q)SAR estimates predict
aquatic toxicity to fish and aquatic invertebrates? It was
estimated that there would be no effects at .saturation for
acute toxicities, which was confirmed by the testing.
Such short-tenn tests do not provide a long enough,
exposure time to observe any acute effects. It was also
estimated that the longer term chronic toxicity values
would be somewhere in the low parts per billion (ppb)
range. The test data subsequently received confirmed
that the OPPT (Q)S ARs were very accurate with the actual
chronic values of 13 ppb for fish and 7 ppb for daphnids
being very close to the predicted ecotoxicity results.
OPPT went through a number of iterations to
characterize the risk associated with this new chemical
(see the figure on page 7-45 [Summary...]). Initially it
was thought that fish would be the most sensitive species.
This did not turn out to be the case. However, the concern
concentration (CC, the level in the water below which
OPPT would not take any regulatory action) turned out to
be around 1 ppb using either the fish or the aquatic
invertebrate toxicity data. A risk-based pase was then
made through our. initial and subsequent iterations as-
sessing exposures. Generic production data and some
site-specific data were then obtained to improve the input
for our exposure models. The resulting estimates of
exposure were contrasted with estimates of benthic tox-
icity and the estimates of risk to organisms indicated that
the manufacturer should consider chronic testing in sedi-
ments. The manufacturer did perform a 28-day sediment
.toxicity test with chironomids, which showed that there
would be a moderate level of toxicity.
What risk management decision was made about
this new chemical? It was decided that this new chemical
could be used only at the three sites for which they
provided specific information and that they should limit
the water column concentrations of the chemical to 1 ppb
or less. OPPT also warned the manufacturer that this
chemical would, over the years, be likely to accumulate
in sediments. .. -
Existing Chemicals and Sediments
The TSCA Inventory of existing chemicals con-
sists of about 75,000 chemicals that include polymers,
mixtures and salts, organometallics, and discrete organic
chemicals. A focus on discrete organics was used for an
approach that was developed by OPPT for screening
possible persistent bioaccumulative chemicals on the
TSCA Inventory. Using this approach, thousands of
discrete existing chemicals were screened to identify
those that might have the chemical characteristics to be
persistent and bioaccumulate, and therefore, have poten-
tial for concern for selectively partitioning into sediments
(Zeeman etal., 1995).
In. 1990, OPPT asked the EPA research laboratory
in Duluth, MN to screen the TSCA Inventory for discrete
organic chemicals which could have log Kow values
greater than 3.5. For this screening effort, the Duluth lab
created a database and estimated the log Kow (also known
as log P). They started the screening process with about
20,000 chemicals and ended it with 6,668 chemicals with
log Kow values greater than 3.5 (see figure on page 7-45
[Screening for Persistent Bioaccumiilators]). The log
K value of 3.5 was chosen as a lower limit because it
represents a fish bioconcentration factor of about 250,
which was derived'using an equation from research
performed at the Duluth lab (Veith and Kosian, 1982).
That limit approximately defines the subset of chemicals
that should be cause for moderate or greater concern for
bioconcentration in aquatic organisms such as fish.
After this initial screening, OPPT continued with a
series of steps to reduce the list of chemicals to a more
manageable size. The first step was to do an intersection
between the Duluth database and the OPPT Chemical
Update System (CUS) database, which includes about
8,600 industrial chemicals that industry reports produc-
ing in quantities of more than 10,000 pounds per site per,
year (see figure on page 7-46). The intersection resulted
in the identification of about 1,000 chemicals with this
level of production and log Kow values greater than 3.5.
The next levelof assessment was to consider chemicals
with log Kow values between 3.5 (initially 4.3 was used)
and 8.0 to focus on those chemicals that had the highest
probability of causing the most critical problems. Then
persistence was evaluated using a degradation half-life of
greater than 30 days as the threshold. This reduced the list
to about 80 chemicals. Finally, we considered chemicals
that were being produced in quantities greater than 1
million pounds per year. Applying this final criterion, a
list of 34 chemicals resulted and these chemicals were
examined further because they could be of concern for
•persistence, bioaccumulation, and partitioning into sedi-
ments (Zeeman et al., 1995).
What are the next steps? Obviously, one of the
things that would be important is to obtain information on
actual environmental loadings. It has been suggested that
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National Sediment Bioaccumulation Conference
OPPT list some of these chemicals on the Toxics Release
Inventory (TRI) to find out if those chemicals that were
proposed to be only chemical intermediates were actually
being released into the environment. When this list of 34
chemicals was presented at a SETAC Workshop on the
Environmental Risk Assessment of Organochlorine
Chemicals (Clements et al., 1994), one of the chemicals
was supposed to be a chemical intermediate that would
not be released into the envkonment. A researcher from
Canada came up after the presentation and said that they
had been finding this chemical in gull eggs along the
Great Lakes.
OPPT has also developed a sequence of tests that
persistent bioaccumulative chemicals should be consid-
ered for (see figure on page 7-46 [Potential Testing...]).
First, we would like to determine whether or not these
chemicals are likely to degrade in a sediment and water
system. Chemicals that do not degrade should be evalu-
ated further for bioconcentration in fish. Finally, for the
chemicals whose results indicate that they can
bioconcentrate, then these chemicals need to be consid-
ered for testing to estimate their chronic toxicity to
aquatic and sediment dwelling organisms (e.g., see figure
on page 7-47 [Preliminary Testing Scheme ...], adapted
from Smrchek and Zeeman, 1997).
Discussion and Summary
Sediment issues for both new and existing indus-
trial chemicals are becoming more and more important to
OPPT (see figure on page 7-48 [OPPT Sediment Issues]).
OPPT has asked for, received, and evaluated the results
of sediment toxicity testing for both new and existing
industrial chemicals (Smrchek et al., 1995; Smrchek and
Zeeman, 1997). It has also been interested in the sedi-
ment toxicity test methods being developed nationally
through the American Society for Testing and Materials
(ASTM) and the U.S. EPA, and internationally through
the Organization for Economic Cooperation and Devel-
opment — the OECD (Ingersoll, 1995; OECD, 1997;
Smrchek and Zeeman, 1997). OPPT also continues to
have an interest in and support the ongoing refinements
in true chronic toxicity testing of sediment organisms,
i.e., longer duration chronic testing, such as the 65-day
life-cycle test recently developed for Chironomus tentans
(Benoit et al., 1997).
In summary, sediment issues have been a concern
for both OPPT's new and existing industrial chemicals
for almost a decade. OPPT receives notices iromindustry
for about 2,300 new chemicals per year. Most of the time
there does not appear to be a problem related to sedi-
ments. But in those few cases where we are concerned
that there could be such problems, OPPT has been able to
either get results from sediment toxicity testing, or iden-
tify ways to mitigate the concerns for those chemicals.
Sediment toxicity testing has also been requested and
received for existing chemicals. However, the current
focus with existing chemicals is likely to continue the use
of screening methods to identify those high production
volume chemicals that might have characteristics that
result hi concerns for partitioning into the sediments and
having the potential to adversely affect organisms in the
envkonment.
Disclaimer
This document has been reviewed by the U.S.
EPA's Office of Pollution Prevention and Toxics, and
approved for publication. Approval neither signifies that
the contents necessarily reflect the official views and
policies of the Agency, nor does mention of trade names
or commercial products, constitute endorsement or rec-
ommendation of these products for use.
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Clements, R.G., R.S. Boethling, M. Zeeman and C.M.
Auer. 1994. Persistent bioaccumulative chemicals:
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July 24-29, 1994. 13pp.
Ingersoll, C.G. 1995. Sediment tests. Pp. 231-255, Chap-
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Effects, environmental fate, and risk assessment,
2ndEd., G. Rand, Ed., Taylor & Francis, Washing-
ton, DC.
Nabholz, J.V., R.G. Clements, M. Zeeman, K.C. Osborn
and R. Wedge. 1993. Validation of structure activ- ,
ity relationships used by the USEPA's Office of
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ecological risks of a new chemical under the Toxic
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USEPA/OPPT: Current activities and future needs.
Pp. 127-158 In: Making environment science. J.R.
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Zeeman,M. 1993. Assessing the ecological risks of anew
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Control Act (TSCA). Invited presentation at the
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Zeeman, M. 1997. Aquatic toxicology and ecological
risk assessment: US-EPA/OPPT perspective and
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Zelikoff, J. Lynch and J. Schepers, Eds.,
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Pp. 7-21 In: Environmental toxicology and risk
• assessment, 1st Vol. ASTM STP 1179. W. Landis,
. J. Hughes and M. Lewis, Eds., American Society
for Testing and'Materials, Philadelphia, PA.
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development of SAR/QSAR for use under EPA's
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Testing and Materials, Philadelphia, PA.
Zeeman, M., C.M. Auer, R.G. Clements, JiV. Nabholz
.and R.S. Boethling. 1995. U.S. EPA regulatory
perspectives on the use of QSAR for new and
existing chemical evaluations. SAR & QSAR in
Environ. Res. 3: 179-201.
Zeeman, M., D. Rodier, J.V. Nabholz, D:G. Lynch, G.J.
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Graphic References
Clements, R.G., R.S. Boethling, M. Zeeman and C.M.
Auer. 1994. Persistent bioaccumulative chemi-
cals: Screening the TSCA Inventory. Handout for
presentation at the SETAC Foundation Workshop
on the Environmental Risk Assessment for Orga-
riochlorine Chemicals, Alliston, Ontario, Canada.
July 24-29,1994. 13 pp. ,
Nabholz, J.V., M. Zeeman and D. Rodier. The use of
assessment (uncertainty) factors in estimating the ,
ecological risks of a new chemical under the Toxic
Substances Control Act. Invited submission for the
Proceedings of the SETAC Foundation Workshop
on Uncertainty Analysis in Ecological Risk As-
sessment, Pellston, MI. August 23-28,1995.28pp.
+ figures/tables (Submitted).
U.S. EPA. 1994. Assessing the ecological,risks of anew
. chemical under the Toxic Substance Control Act.
Pp. 1-1 to 1-35 In: A review of ecological assess-
ment case studies from a risk assessment perspec-
tive, Vol. II. EPA/630/R-94/003. U.S. Environ-
mental Protection Agency, Office of Research and
Development, Washington, DC.
Zeeman, M. 1993. Assessing the ecological risks of anew
chemical under .the Toxic Substance Control Act
(TSCA). Invited presentation at the SETAC Sym-
posium on the EPA Framework .For Ecological
Risk Assessment, SETAC 14th Annual Meeting,
Houston, TX. November 14-18, 1993.
Zeeman, M., C.M. Auer, R.G. Clements, J.V. Nabholz
and R.S. Boethling. 1995. U.S. EPA regulatory
perspectives on the use of QSAR for new and
existing chemical evaluations. SAR & QSAR in
Environ. Res. 3: 179-201.
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7-40
National Sediment Bioaccumulation Conference
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Division
Information
Manage-
ment
Division
Environ-
mental
Assistance
Division
Chemical
Manage-
ment
Division
Pollution
Prevention
Division
Environmental Effects Branch
Health Effects Branch
Senior Science Staff
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Proceedings
7-41
TSCA: The Gap Filling Law
Toxic Substances Control Act
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National Sediment Bioaccumulation Conference
TSCA (Passed 1976)
Existing Chemicals Inventory (1979)
~ 60,000 Chemicals (Grandfathered)
~ 10,000 Chemicals Added (by 1991)
New Chemicals (PMN'sJi
Chemical PMN's ~ 2,500/yr (currently)
Genetically Engineered Microbe PMN's
Submit Extant Data Only
90-Day Clock (after submit PMN)
[§8, etc.]
[§5]
PMNs Received/Fiscal Year
and FY90-FY95 Budget
$6.6M (FY90)
FTE:168
3000
2500
2000
1000
0
r
D Number of
Submissions
$2.6M (FY95)
FTE: 114
79 81 83 85 87 89 91 93 95
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Proceedings
7-43
Required Submission in
New Chemical Notice
Chemical Name
Chemical Structure
Production Volume
Uses and Disposal Methods
Human Exposure Estimates
Any Extant Test Data
(Testing Not Required)
P
B
LU
o
t
a
Flow Chart and Decision Criteria for
the Ecological Risk Assessment '
of a PMN Substance
STEP 1. FOCUS MEETING
Worst Case Analysis
Does the PEC exceed the CC?
No
Yes
STEP 2. STANDARD REVIEW
Obtain More Information/Data
A More In-Depth Analysis
Is the CC exceeded 20 or more
days out of one year?
No
Yes
STEP 3. RISK MANAGEMENT OPTIONS
Allow Manufacture
• Controls Pending Testing
Significant New Use Rule (SNUR)
Ban
DROP or Issue
a Significant New
Use Rule (SNUR).
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National Sediment Bioaccumulation Conference
PHYSICAL/CHEMICAL PROPERTIES
OF PMN SUBSTANCE
Chemical Class: Neutral Organic
Chemical Name & Structure: CBI
Physical State: Liquid
Molecular Weight: 232
Log Kow: 6.7 [Via CLOGP program (Leo and Weininger, 1985)]
Log Koc: 6.56 [Via regression equation (Karickhoff et al., 1979)]
Water Solubility: 0.30 mg/L [Measured]
Vapor Pressure: < 0.001 Torr @ 20° C.
PMN SUBSTANCE
STRESSOR-RESPONSE PROFILE
QSAR ESTIMATED TOXICITY
(Clements, 1988)
Fish 96 hr. LC: No effects at saturation
50
Daphnid 48 hr. LC50: No effects at saturation
Green Algae 96 hr. EC50: No effects at saturation
Fish Chronic Value: 0.002 mg/L
Daphnid Chronic Value: 0.004 mg/L
Algal NOEC: No effects at saturation
ACTUAL MEASURED TQXICITY
Fish Acute Test (FHM; 96 hr): No effects at saturation
Fish Early Life Stage Test (FHM; 31 -day):
Chronic Value (growth, mean wet weight): 0.013 mg/L
Chronic Value (survival, growth (length)): 0.061 mg/L
Daphnid Reproduction Test (D. magna; 21 -day):
Chronic Value (survival, growth, reprod.): 0.007 mg/L
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Proceed\ngs
7-4-5
Summary of Five Risk
Characterization Iterations
ITERATION
1
2
3
4
5
ESTIMATES / ASSUMPTIONS
Fish are the most sensitive species. CC = 1 ug/L. PMN
substance mixes instantaneously in water. No losses.
Actual test data for Daphnids still yield a CC of 1 ug/L.
Determine how often this concentration is exceeded
using PDM3.
Estimate risk to benthic organisms using Daphnid
chronic value and mitigation by organic matter.
EXAMS II used to estimate concentrations.
Site specific data obtained on use and disposal.
EXAMS II rerun with new data.
Actual test data for benthic organisms obtained.
UNCERTAINTY
Worst case. Actual test
data not available.
Worst case. Other species
may be more sensitive.
Generic production sites.
Actual data for benthic
invertebrates not available.
Estimated toxicity for
benthic invertebrates.
Best estimates for identified
sites. May not hold for
other sites or uses.
Screening for Persistent Bioaccumulators
TSCA INVENTORY
Estimate Log P
Using CLOGP 3.3
LogP Not Calculated
Missing Fragment(s)
Potential Candidates for
Persistent Bioaccumulators
Duluth Database
6668 Chemicals
Initial screening process performed by ERL, Duluth to
identify potential bioconcentrators.
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National Sediment Bioaccumulation Conference
DULUTH DATABASE
6668 CHEMICALS
CUS DATABASE
8592 CHEMICALS
LOG P GREATER THAN 4.3
744 CHEMICALS
LOG P LESS THAN 4.3
290 CHEMICALS
LOG P 4.3 TO 8.0
495 CHEMICALS
LOG P GREATER THAN 8.0
249 CHEMICALS
M.W. LESS THAN 600
473 CHEMICALS
M.W. GREATER THAN 600
22 CHEMICALS
HALOGENS (48)
EVALUATE PERSISTENCE
EVALUATION COMPLETED
48 CHEMICALS
EVALUATION COMPLETED
32 CHEMICALS
EST. HALF-LIFE >30 DAYS
80 CHEMICALS
Application of criteria to screen the Duluth database for
potential bioaccumulators
POTENTIAL TESTING OF
PERSISTENT BIOACCUMULATORS
Sediment/Water Biodegradation
• Fish Bioconcentration
• Chronic Aquatic Toxicity
• Chronic Sediment Toxicity
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Proceedings
7-47
Preliminary Testing Scheme For
Determining Sediment Effects
TIERI
TOXICITY TESTS
Fish Acute
Toxicity
I •
Daphnid Acute Algal
(Pore waters/ (Pore waters/
elutriates) elutriates)
Toxicity . Toxicity
Amphipod
Sediment
Acute
Toxicity
I
TIER II
TOXICITY TESTS
Chironomid
Sediment
Subchronic
Toxicity
; I
Fish
Chronic
Toxicity
• I
Invertebrate/
Fish Full Life
Cycle Chronic
Toxicity
I
Daphnid Higher Amphipod Chironomid
Chronic Plant Chronic Chronic
Toxicity Toxicity Toxicity (emergence)
TIER III
TOXICITY TESTS
Fish
Bioconcentration
Higher
Plant
Uptake
Invertebrate
Sediment
Chronic
Toxicity
Invertebrate
Lumbriculus.
Macoma. Nereis
Sediment
Bioaccumulation
I
TIER IV
FIELD TESTS
(Adapted from Smrchek & Zeeman, 1997)
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National Sediment Bioaccumulatlon Conference
OPPT SEDIMENT ISSUES
NEW CHEMICALS
• 90 % Minimum Risks
• 5-10 % Further Review
• PMN Case Study — Sediments
[EPA/630/R-94/003]
EXISTING CHEMICALS
• ITC Recommendations [e.g. OMCTS]
• Screening Methods [e.g., PB's see
SAR/QSAR Env. Res. 3:179-201; 1995]
'The work will teach
you how to do it."
(Estonian Proverb)
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National Sediment Bioaccumulation Conference
Dredged Material
Management Program
Craig Vogt
U.S. Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds,
Washington, DC
The Dredged Material Management Program is
jointly managed by EPA and the U.S. Army Corps
of Engineers. Today, I want to give you a brief
overview of the pertinent statutes, regulations, and guide-
lines and how we implement the program, including a
discussion about testing, particularly what tests we do
and how we make decisions based on the results.
In dredged material management, there are two
statutes that we must follow: the Marine Protection,
Research, and Sanctuaries Act (MPRSA) and the Clean
Water Act (CWA). There is some overlap between the
statutes, but generally speaking, the MPRSA applies to
ocean waters and the. CWA applies to inland waters,
including estuaries and fresh waters. Related to this
activity is the London Convention of 1972 which is the
international.treaty on ocean dumping. We implement
the terms of the London Convention through the MPRSA,
which is commonly referred to as the Ocean Dumping
Act. The London Convention essentially sets forth a
permitting regime that includes a black list and a gray list.
The black list specifies chemicals that cannot be dumped
into the ocean unless they are present only as trace
contaminants or they are rapidly rendered harmless;
examples include mercury, cadmium, crude oil, organo-
halogens, and chemical or biological warfare agents.
The gray list includes a group of chemical contaminants
that require a permit if they are present in dredged
material (or any other material) that is proposed to be
dumped into the ocean.
For dredged material management, there are spe-
cific regulations and guidelines on how to make deci-
sions regarding issuance of a permit for disposal of
dredged material in ocean or fresh/estuarine waters, and
they include consideration of acute and chronic toxicity,
including bioaccumulation; Under the two statutes, EPA
is charged with developing the environmental criteria
that form the basis for judgements on the acceptability of
dredged material disposal in the aquatic environment.
The Corps of Engineers is the permitting authority and
the Corps determines whether or not the dredged material
meets the environmental criteria. EPA has a review and
concurrence role in the permit issuance process. For
ocean waters, EPA has site designation responsibility
which means that we designate an actual site in the ocean
where dredged material can be disposed.
The statutes and regulations require that dumping
of dredged material will not unreasonably degrade or
endanger human health or the environment. Results of
biological effects-based testing (i.e., bioassays) are the
basis for decision-making in the Dredged Material
Program. We consider both acute and chronic toxicity.
EPA and the Corps jointly develop the testing procedures
to assess the potential risks to human health and the
environment of disposal of dredged material in aquatic
environments. Testing manuals have been developed by
the Corps and EPA; the manual for ocean disposal is
commonly referred to as the Green Book. The Inland
Testing Manual is a companion document currently in
draft form; the final document should be available soon.
Methods are included in the testing manuals for acute
• toxicity and bioaccumulation.
The overall framework that is used in the Dredged
Material Management Program to make determinations
on acceptability for aquatic disposal is provided below.
We use a reference site approach. This approach has
already been described by Norm Rubinstein in an earlier
session at this conference; briefly, we compare the results
of testing of the dredged material to those of a reference
site. For acute toxicity, we use a criterion for decision-
making of an increase of 20 percent acute toxicity due to
the dredged material compared to the reference material.
For bioaccumulation, we proceed through a logical
progression of evaluations to determine the acceptability
of dredged material for aquatic disposal. One tool that is
available are U.S. Food and Drug Administration (FDA)
action levels. If contaminant levels in the dredged
material exceed the FDA action level, then the material
would fail the criteria for open water disposal. If con-
taminant levels in the dredged material do not exceed the
FDA action level, then further evaluation is required.
The dredged material is then evaluated for additional
factors, including such factors as how many contami-
nants have bioaccumulated, the magnitude of that
bioaccumulation, the lexicological importance of the
contaminants, and the potential for biomagnification.
Evaluations.of potential impacts upon both human and
ecological health are carried out.
Progress is being made in regard to assessing the
results of bioaccumulation tests to determine the accept-
ability for dredged material aquatic disposal. However,
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National Sediment Bioaccumulation Conference
there is a need for better information and data, such as
has been presented in this conference. The Corps of
Engineers and EPA sponsored a joint workshop a year
ago on interpreting the consequences of bioaccumulation.
Those proceedings should be out soon. The Corps of
Engineers is also developing a bioaccumulation database
that should be on the Internet in the next few months.
EPA is contributing to that database. And finally, EPA
has worked jointly with the Corps of Engineers to
develop a manual for making better decisions on
bioaccumulation. This manual will define a framework
for decision-making focusing on a much more formal-
ized risk assessment and risk management approach
for dredged material containing bioaccumulative
contaminants. EPA and the Corps of Engineers are also
collaborating on development of a chronic test using an
amphipod with survival, growth, and reproduction
as endpoints.
In summary, we do need more information. I think
this conference will help in pulling together important
information.
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National Sediment Bioaccumulation Conference
Dredged Material Management:
A Regional Perspective
Mario Del Vicario
U.S. Environmental Protection Agency Region 2, New York, New York
I would like to focus my talk on problems we are having
with the dredged material program in the New York/
New Jersey area, particularly for the marine environ-
ment. I will be describing issues related to dredged
material disposal at the ocean disposal site (known as the
Mud Dump Site) located about 6 miles east of Sandy
Hook, NJ. We are devoting considerable attention to this
site because of its close proximity to a densely populated
coastal area. -The annual volume of dredged materials
deposited at this site typically ranges from four to six
million cubic yards.
Dredged material in our program is classified into
three categories for ocean disposal. This regional classi-
fication scheme is based on requirements in the testing
manual for Section 103 of the Marine Protection, Re-
search, and Sanctuaries Act (MPRSA). This testing
manual, which was developed jointly by the U.S. Envi-
ronmental Protection Agency (EPA) and the U.S. Army
Corps of Engineers (USAGE) in 1977, is commonly
referred to as the Green Book. We designate dredged
material that is suitable for unrestricted ocean disposal as
category 1 material. This material does not show acute
toxicity or potential bioaccumulation. Category 2 mate-
rial does not show acute toxicity, but does show some '
potential for bioaccumulation. This material requires
capping with either category 1 material or sand for ocean
disposal. Category 3 material shows both acute toxicity
and bioaccumulation potential. There can be no disposal
of category 3 material in the ocean environment.
In addition to testing for toxicity and bio-
accumulation, we analyze bulk sediments to. help us
determine which chemicals we need to test for bioaccu-
mulation. Based on the 1977 Green Book testing require-
ments, dredged material in our program was generally
classified as about 95 percent category 1 material, 5 per-
cent category 2 material, and less than 1 percent category
3 material! Before 1991, we also had matrix values for
mercury, cadmium, PCBs, and DDTs that delineated
category,! and category 2 materials^ Material that ex-
ceeded the matrix values was classified as category 2
rather than category 1. During this same period, toxicity
test results and U.S. Food and Drug Administration (FDA)
action levels delineated category 3 material.
The, Green Book was revised in 1991. These
revisions contained changes in testing, including more
specificity for bioaccumulation testing and identification
of more sensitive test species for toxicity testing. The new.
Green Book requirements had a dramatic impact on the
dredged material program hi our region. Based on the
revised testing requirements, the distribution of material
in each category changed from 95 percent to 40 percentin
category 1, from 5 percent to 30 percent in category 2, and
from less than 1 percent to 30 percent in category 3. We
are still trying to address difficulties related to these
changes, including the substantial increase in the cost of
disposing of much larger quantities of category 2 and
3 material and the lack of availability of disposal sites for
category 3 material. Today an annual volume of
1.7 million cubic yards of material is not being dredged
because disposal sites are hot available.
One cost concern is. the cost of testing. We have
seen the cost go up dramatically in recent years. It is fairly
typical for someone that needs to dredge in the New York
area to spend $80,000 to $150,000 to determine whether
the material would be classified as category 1,2, or 3. That
price range covers the cost of sediment chemistry and
conducting bioassays to generate toxicity information.
We have tried to minimize the need to do extensive
testing, but we still must meet the requirements in the
Green Book and the program regulations. As more
information becomes available linking sediment chemis-
try to biological impacts, We hope that application of this
information will reduce the cost of testing.
Another cost concern is the cost of disposal. Before
1991, the cost of disposing unrestricted dredged material
"at the ocean disposal site was $5.00 per cubic yard. The
current cost of disposing category 2 dredged material at
this site, including capping, ranges from $30.00 to $50.00
per cubic yard. The cost differences span an order of
magnitude. Disposal costs are even greater for dredged
material at sites that serve as alternatives to ocean dis-
posal. The cost of disposing at these:alternative'sites
currently ranges between $60.00 and $120.00 per cubic
yard.
Increasing costs, coupled with the shift in classifica-
tion of dredged material to categories with more disposal
restrictions, could pose a difficult dilemma for maintain-
ing the viability of the ports in the New York/ New Jersey
Harbor area and the regional economy tied to those port
activities. We are working on a regional level to develop
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National Sediment Bioaccumulation Conference
contaminant guidance levels that we can use to make
decisions on a case-by-case basis. Alex Lechich de-
scribed our regional process in bis earlier presentation at
this conference. However rigorous our process is for
defining values to categorize dredged material, we can
expect to be challenged. There is too much at stake in this
area. All the individual aspects of our work will likely be
questioned and we need to be prepared to meet mat
challenge. The work we are doing, including derivation
of biota-sediment accumulation factors (BSAFs) and an
impact analysis on ecological and human health, must be
sound and scientifically defensible.
You can help us meet that challenge. We need
sound science to support our process in developing re-
gional guidance levels and the decision-making that will
follow from that process. We were very fortunate to have
Bob Huggett and several of his senior scientists meet with
us about our dredging issues and discuss how to address
them. We hope to see national guidance levels developed,
but will continue with our regional work in the interim. I
have been hearing timelines mentioned like 5 years,
10 years, or even longer. But I appeal to you to make the
progress we need in this area sooner, because the chal-
lenge is already there for us. ,
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National Sediment Bioaccumulation Conference
•Day Three: September 13; 1996
Session Seven:
Questions and Answers
A
fter each session, there was an opportunity for
questions and answers and group discussions per-
.taining to the speakers' presentations.
Q (Susan Svirsky, U.S. EPA Region 1): I would just
like to make a couple of clarifying points, and perhaps
the last one is a question for Larry Zaragoza to see if
you have experienced what we have. First, in some
parts of the country, we are doing ecorisk assessments
with more frequency than human health risk assess-
ments at this point because of the tailing off of issues
' related to human health. Now we are dealing with the
tougher issues, and that leads into my second point
concerning your slide. The number of sediment clean-
ups (14) is extremely misleading in that we have
practiced avoidance behavior and put off the sediment
cleanups to subsequent operable units for the sites.
We are just now getting into the really tough problems,
and we are going to be having a hug-e number of
sediment-driven operable units to work with. I was
wondering if that is your understanding as well?
Larry Zaragoza:
Our analysis included over 200 sites from all over the
country. I would need to go back and see how many of
those sites had final records of decision (RODs) at the
time this analysis was done. I agree with you that
basically we have found sediments to be very difficult
to deal with.- I have reviewed a lot of RODs and there
are a number of them that have not yet dealt with the
sediment issues because they were waiting for techno-
logical or other reasons. I am also encouraged by the
comments you made that we are having more ecorisk
assessments done. I think that is something probably
everyone in this room is glad to hear.
Betsy Southerland:
Senator Levin is planning some amendments to the
Superfund bill directed at encouraging more contami-
nated sediment cleanups. We do not know what the
bill is going to look like, because they have not re-
leased the language yet. I know that was one of his
prime concerns since he is from the Great Lakes area.
Q (Nelson Thomas, U.S. EPA, Office of Research and
Development): Jim, 5 to 8 years ago your office was a
leader in trying to deal with the whole subject of
bioaccumulation. Now you say it is going to be 5 or 10
years before you can factor this information into the
permitting process. Why do we need this 10- to 15-
year delay to account for bioaccumulation in NPDES
permits? ,
Jim Pendergast:
About six winters ago, I visited Nelson in Duluth to work
with him to develop guidance on how to bring bioaccu-
mulation into NPDES decisions. We can do things today
if we are talking about bioaccumulation in the aqueous
phase. When I was talking about 5 to 10 years in the
future, I was referring to sediment bioaccumulation.
What we have learned since that day in Duluth is that the
fate and transport of sediments is a lot more difficult to
grapple with than we originally thought. Back then we
thought that it would work to add sediment into the model
using a steady-state approach. When we did field studies
in Lake Charles (LA) and the Blackstone River (MA and
RI), the steady-state approach worked fine in the water
column, but it did not work well in the sediment. Since
then, we have learned from the modelers that the steady-
state models do not deal well with sediments. Models for
sediments must account for flooding events and other
dynamic processes. That is the technology we need to
develop. I think it is going to take 5 to 10 years to work
that out in a way that is simple enough to put into a mass
production process like NPDES permitting.
Q (Nelson Thomas): So, you do not see anything in the
interim that will be able to handle bioaccumulation in
the NPDES permits?
Jim Pendergast:
Not for the sediments.
Q (Phillip Rury, Arthur D. Little, Inc.): Tom, has EPA
considered shifting this 90-day risk assessment burden
to industry, which would put EPA in more of a review
capacity? This might be a little more manageable.
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National Sediment Bioaccumulation Conference
Tom Murray:
Yes, we are actually involved in that right now. One
of the things we have been trying to do over the last few
years, with some degree of success, is to make the various
tools that we use available to industry. We recently did
a pilot project with Kodak where we provided them with
about six different modeling packages. They applied
them within their own business to make decisions about
what the environmental Impacts might be for the chemi-
cals they use in their photographic processes. They felt
that the pilot was a great success since the models allowed
them to make their own decisions. They do not have to
come into our complex program and wait for a decision.
We are going through a process this year and next year to
build on that experience and distribute information to
other chemical manufacturers. We will probably work
with the Chemical Manufacturers Association and other
trade associations to see about getting more people in-
volved with this. We are also going through a data
integration process within OPPT to bring together the
arsenal of tools that we use and create acontext to educate
a broader audience on how we use them. We are planning
to make this information available on the Internet so
people can access it, learn how to use it, and begin
applying the models themselves.
Maurice Zeeman:
The 90-day time frame is statutory. It is not something
that we chose. Nevertheless, we have been very creative
in doing things to meet that deadline. For example,
because our group relies so heavily on structure-activity
relationships (SARs), we have developed a PC program
called ECOS AR that is available from the National Cen-
ter for Environmental Publication and Information
(NCEPI) in Cincinnati (OH). If you know the chemical
class of a compound, it will predict the toxicity of that
compound and produce a hazard profile. The program is
a tool for making predictions, not a data base. We have
made this program available to industry and they use it to
determine whether or not they should submit a chemical.
If they find out that a substance is going to be really toxic
on a chronic basis, then they might decide not to submit
it We have already started to see safer chemicals being
submitted to us from that application.
Q (MickDeGraeve, Great Lakes Environmental Center):
Craig, how do you determine what types of bioaccum-
ulative chemicals might potentially be present in dredged
material? What process do you use?
Craig Vogt:
We go out and take a sample of dredged material, run a
bulk chemistry analysis on it, determine what kind of
chemical contaminants are there, and then take the next
step of looking at the bioaccumulation.
Q (G. Fred Lee, G. Fred Lee & Associates): The Mud
Dump Site has been studied a number of times. The last
I heard, they have not found a problem after dumping
from 5 to 10 million cubic yards a year for how many
years?
Mario Del Vicario:
The Mud Dump Site has been an area for historical use
since the 1930s. We have measured background levels
for sediment chemistry and tissue analysis, both in the
site and in areas outside the site mat are not influenced by
disposal in the site. What we have found is certain levels
of contamination out there. Do we find terrible things
going on? As far as bioaccumulation measurements go,
a lot of the sediment and the tissue data are not at levels
that you would say are startling, considering that a lot of
material went out years ago without our having the
knowledge that contaminants were even in the material.
Dioxin is the classic; example. Millions of cubic yards of
dioxin-contaminated material went out to that disposal
site in the past. We do not see tremendous accumulations
out there in worm, lobster, or fish tissue. We do see
accumulations, but not what you would expect based on
what you would see if you went to our Superfund site.
What we have seen when we go out to areas surrounding
the Mud Dump Site are places where toxicity test results,
particularly for amphipods, indicate that Category III
material is sitting on the bottom. Weplan to do remediation
using Category I material to improve the areas where we
see high levels of toxicity or accumulation. The Category
I material will consist of clean dredged material from the
harbor, and maybe some sand, depending on benthic
community structure. I believe that much of the problem
here is a perceived problem. Newspapers in the Northeast
have described the terrible dilemma with sediment con-
taminants in the New York area. I think a lot of the news
coverage was exaggerated, but unfortunately, we now
have to prove that each regulatory decision made by EPA
, and the Corps of Engineers results in safe disposal of
dredged material. That is why we need the science.
Q (G. Fred Lee): The science should be based on what you
find at the site and not extrapolated from some other
place.
Mario Del Vkario:
Well, we do look at the site conditions to make decisions,
but part of what we have done in the last 10 years is use
capping as a tool to minimize bioaccumulation at the site.
I feel it has been a very effective tool.
Q (Betsy Southerland): I am going to have the panelists
tell us their biggest problem with using bioaccumulation
data today in their regulatory programs and what high
priority needs they have to improve their use of bioaccu-
mulation data. Then I am going to open it up to the
audience to address what the future needs are. It is
important to document this discussion because ORD is
currently preparing its next big grant proposal for con-
taminated sediments. Any high priority needs that you
identify at this conference -will be included in the request
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Proceedings
7-55
for application (RFA) for the grant. They will also be
incorporated into the ORD Research Strategy to direct
the use of their own in-house resources. If the panel does
not mention a high priority need that you have perceived
after listening to the discussion in the past two days,
please speak up and let us add this issue to the priorities.
I will ask Mario Del Vicario to begin.
Mario Del Vicario:
A critical need for the Dredged Material Program is to
ensure that the information we have available to help us
make decisions is truly supportable and defensible.; We
have been able to apply work completed on food chain
multipliers, and trophic models to generate information
for decision-making In our program. We need to con-
tinue to use information like that and work to make the
information better. We also need to continue to improve
how we are looking at chronic values, aquatic effects
data, dose-response relationships, and concentration ef-
fects data. A concern I have is being able to make good
regulatory decisions without someone having to pay for
elaborate and expensive tests when we can perhaps de-
velop simpler ways to get abetter, quicker answer. Tothe
extent possible, we should attempt to provide easier ways
for people to get decisions.
Tom Murray:
I think, programmatically speaking, we have very few
barriers. If I had to describe some of the problems that we
might have with the use of bioaccumulation information,
one wouldbeobtaininginformationthathas good QA/QC.
We are dealing directly with industry and with their
. economy in terms of producing and manufacturing chemi-
cals. We want to try to provide as reasonable an assess-
ment as we can. When you move into problematic areas
such as bioaccumulation and sediment toxicity, it be--
comes more questionable. We. are looking both for the
availability of data and for good quality information. I
know there is probably a lot of information in the EPA
Regions and states that we do not have access to. It would
be nice to figure out how to get'those data. Another
problem we have is that, unlike programs in the Regions,
states, and the Office of Water to some extent, we do not
do site-specific analyses. In some instances, we go into
a particular area and do an analysis. If bioaccumulation
data are available there, we might be able to use them.
Much of the work we do on a chemical is really more of
a generic population-type estimate, where we are looking
at manufacturing/processing user sites all across the coun-
try. The sediment situations may differ at these sites and
we are trying to come up with a generic answer. That
would cause a problem for us with the bioaccumulation
data.
Q (Betsy Southerland): Tom, when you say you need
more data, do you want tissue residue effects levels in
aquatic life, wildlife, and humans, or bioaccumulation
factors-and fate and transport information? , -
Tom Murray: >
All of the above. We basically are; scavengers looking for
a way to get good information in our hands. Any and all,
of that data would be helpful.; , ,',
Jim Pendergast:
Like Tom Murray's program, the NPDES Program does
not have any legal regulatory barriers, but there are three
data gaps that I see. First, we need to find a better way of.
being able to identify existing and future potential
bioaccumulative problems. When Craig Vogtwas asked
how.they determine the pollutants for the dredged mate-
rial program, he responded that they use chemistry. That
approach would not be practical for the NPDES Program
where we must work with hundreds of thousands of
chemicals. Instead, we are working :with the Office, of
Research and Development to develop a screening meth- ,
odology. We currently have a draft guidance that needs
some refinements, but it is about 95 percent complete.
We need to finish.the guidance and get it distributed.
Second, we need to have a better handle on the fate and
transport of sediments. For programs involving
remediation or dredging, you can identify where the .
pollutants are and determine appropriate ways to remove
and dispose of the contaminated material. For TSCA
programs, you work with a facility to keep pollutants
from being released into the environment. But in the
NPDES Program, we are working with mixtures ,and
multiple sources in attempting to regulate close to 3 00,000
sources. We.must be able to use fate and transport to link
the sources with the problems, and we need, a tool to do
that. If possible, we need to develop something, more
simplistic than the WASP model that.is.a little bit easier
to run and a little less data intensive. We began to develop
this tool 3 or 4 years ago, but we need more time to
complete the effort The last problem is trying to look at
things holistically. It is much easier to get data on point
sources. Getting data on nonpoint sources can be more
difficult. You have to put all that information together to
try to get the picture of what we need to do. We really
have to start using geographic information systems (GIS)
more widely to determine what goes into the watershed
and what sources are contributing to the predominant
problems. A lot of work has already been done in this
area, but much more still needs to be done. It will take
some tune not only to fit together the existing pieces of
the puzzle, but also to fill in the missing puzzle pieces.
Latry Zaragoza:
I see a couple different needs for the Superfund Program.
One is.the kind of work Mike Kravitz is undertaking to
understand the meaning of different testing. This will be
very useful. It is difficult when you have several tests
available, but you are not really sure how to interpret the
results and determine what is significant. Traditionally,
we have tended to look to other offices for guidance on
that issue. Another issue for our program, is determining
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National Sediment Bioaccumulation Conference
how the significant risks in the water column or sedi-
ments compare with risks in other media. We would like
to be consistent in the way that we are addressing risks for
a particular site. If we find that we are much more
sensitive in one medium than another, we need to balance
how we are addressing all the factors we consider. Better
science could help us balance those factors, even with the
added complication of having to incorporate cost/benefit
analyses into our evaluations. Finally, there is the issue
of what to do with contaminated sediment once it has
been identified at a site. If it is dredged, the material may
be difficult to dispose of. This is an issue because there
are a lot of sites in our program with contaminated
sediments.
Q (Betsy Southerland): Are you talking about develop-
ing new remedial technologies or improving existing
technologies for remedial alternatives like capping or
disposal in confined disposal facilities (CDFs)?
Larry Zaragoza:
I am talking about all those things. There are problems
with existing technologies to deal With contaminated
materials. Not only are there limitations in terms of
places that can hold the sediments, but there are also
debates about what would be an appropriate disposal site.
And the question has been raised about whether CDFs
are an appropriate place for disposal of certain types of
sediments. We have been involved in intensive discus-
sions on all of these issues. It is really important to have
an open dialogue on this subject now, because Superfund
legislation is being considered for reauthorization and it
is likely that the reauthorization package will include
amendments to address anumber of different issues. One
set of amendments will target facilitating the process for
addressing contaminated sediments. It will probably
include a research component that can help us resolve
outstanding issues. But the cost/benefit question will
come up again if we focus more on sediments or the water
column than on soil.
Maurice Zeeman:
I will begin and end with the same question, "What
sediment and bioaccumulation data?" I say that because
a lot of monitoring is being done today for the same
chemicals we have been looking at for over thirty years.
These typically include organochlorine insecticides,
PAHs, PCBs, dioxins, furans, and heavy metals. The
Toxics Release Inventory, which was established as a
result of Superfund, required industry to report on their
emissions for only 300 chemicals. The reporting re-
quirement focused on chemicals that were highly toxic,
but not necessarily persistent and bioaccumulative. In
the late 1980's, industry reported several billion pounds
of emissions for just 300 of the 75,000 existing chemi-
cals. These reports indicate that a lot of chemicals are
being released into the air or water. Not all of them will
necessarily be a problem, but a fair portion could end up
in the sediment. We need to move beyond looking at the
usual suspects. My group is responsible for conducting
ecotoxicity assessments, but we rarely have bioaccumu-
lation data to use in these assessments. We have a tiered
testing approach in our program for both new and
existing chemicals. We require testing for acute toxicity
and if we think a chemical is likely to bioaccumulate, we
move to chronic toxicity testing. There are cases,
especially for high log P chemicals, where acute toxicity
testing may not always be appropriate. In these cases,
we need to consider moving right to chronic toxicity
testing. So, I go back to my original question, "What
sediment and bioaccumulation data?"
Craig Vogt:
There are a lot of needs for the Dredged Material
Management Program. Mario Del Vicario summarized
some of those needs very well, but I am going to expand
on them in terms of tissue residue effects levels, chronic
tests, and fate and transport models. We basically need
more information to be able to get better answers for
several important program questions. For example, we
have a site designated in the ocean for disposal of
dredged material. When dredged material is dumped
there, where does it go? Does it stay on the site or does
it move to another location? Better fate and transport
models would help us answer these questions. The
Dredged Material Management Progam is moving into
a more formalized process for risk assessment that will
involve looking at exposure, characterizing risk and
managing based on the risk assessment results. We have
the Green Book and the Inland Testing Manual, but we
need help on exposure and exposure analyses. We also
need to determine what tissue residue effects levels
mean on an ecological scale. Without that type of
information, decision-making gets difficult. As we
continue to develop the science, we can rely more fully
on science as the basis for decision-making, rather than
politics and misinformation that has influenced public
perception. The public currently considers the oceans to
be a sacred place where nothing should be dumped. But
disposal of dredged material at ocean sites is a very
minor source of contaminants that enter the ocean com-
pared to other sources such as surface water runoff and
some point source discharges. It is a matter of balance
and how you achieve that balance. I would like to see
better risk assessments conducted for the various media.
We can use this additional information to involve stake-
holders and together make more scientifically sound
decisions for managing dredged material.
Betsy Southerland:
I would like to open the panel discussion up to the
audience. Please state your name and affiliation before
you begin to address the panel.
Q (Susan Svirsky, U.S. EPA Region 1, Superfund Pro-
gram): Maurice Zeeman, do you have analytical
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7-57
methods available for some of these chemicals that are
outside the normal sweep of what we look for? If so, can
you make them available to us so we can further our
analytical capability and look for some, of them?
Maurice Zeeman:
I am a biologist, so I am not a good source of information
about analytical chemistry. Let me refer you to Bob
Boethling of my office for that information. But I do
know, for example, that chlorinated paraffins are com-
pounds like PCBs that are'a messy mixture of chemicals.
The analytical chemistry for these mixtures can be very
complex. I am convinced that these chemicals are ex-
tremely hazardous to organisms in the environment, but
manufacturers are producing hundreds of millions of
pounds of them each year worldwide. Some limited
monitoring data from a few places around the world
indicate that they are causing problems. However, there
are a fair number of more simple compounds where the
analytical methodology should not be so complex to
develop and apply.
Betsy Southerland:
Susan, *there are two studies I am aware of that might
provide some useful information for you. One was a
study that Bob Huggett conducted with the Virginia
Water Control Board when he was still at the Virginia
Institute of Marine Science. It was a big study where they
collected sediments downstream of some urban indus-
trial areas and analyzed the chemicals in the sediments
using some kind of library scan. They were able to
identify over 300 compounds that were persisting in the
sediments. You can locate literature on the study to see what
method they used. There is also the screening procedure
for wastewater being developed by our Duluth laboratory
that Jim Pendergast mentioned earlier. For this proce-
dure, wastewater is fractionated based on octanol-water
partition coefficients and the fractions are run across a
library scan to identify any potential bioaccumulatives
that could be in a waste stream. They are doing some
additional testing before they release the protocol.
Steve Cibik, ENSR:
We have come a long way in taking the "pseudo" out of
pseudo science and replacing it with good science, espe-
cially with recent developments for BCFs, bioaccumula-
tion, trophic modeling, and food chain modeling. We
made a big advance when EPA issued the Wildlife
Exposure Handbook to help standardize risk assess-
ments. What we need now is better information on tissue
residue values, because I heard that we are
approaching a factor of 2 or 3 in accuracy for many of
these things, but adding one safety factor to a risk assess-
ment will give you a factor of 5 or 10. Decisions in risk
. assessment have to be based on good tissue residue
values. We already have a Ipt of aquatic toxicity numbers
available. I hope EPA will be able to help develop more
information for wildlife. We need tissue residue values
for both terrestrial and avian wildlife.
Q(Catherine Fox^U.S. EPA, Office of Enforcement and
Compliance Assurance): The 1992 mandate of the Water
Resources Development Act (WRDA) called for the de-
velopment of the Rational Sediment Inventory, a national
data base which is now available. Many of you have
evaluated it to identify hot spots based on a number of
factors, including fish tissue data. What we can do right
now is to look at these hot spots based on fish tissue data,
and for the various programs, to address the current
sources of contaminants to prevent the discharge of these
contaminants from point sources, nonpoint sources, and
sediments. I have looked at this using a GIS and found
some really interesting things that are happening right
now with discharges. I would like to go_ upstream and
look at the sediments. I am asking the panel to consider
this as a need that we could, address now. We have the
people and we have a lot of the tools. Jim Pendergast
lookedat this 5 years ago. He probably knows a lot that could •
help us now. This is an area of interest for enforcement
and I am requesting assistance from other offices.
Tom Murray:
As Maurice has mentioned, there are many chemicals on
the inventory that OPPT has not had a chance to look at.
OPPT is setting up a priority system to look at these
chemicals. A couple of things are happening in OPPT
right now to advance that process. One is that we are
moving away from a single chemical approach to life and
trying to look at chemicals as use clusters or clusters of
chemicals that might be found in a product. We have
developed some systems within our organization to help
us set those priorities. For example, we are looking at
indoor air sources as one system. We are ranking various
chemicals in this system to figure' out which indoor air
chemical products or chemical products that might lead
to indoor air problems are the most important to look at.
We have also developed the use cluster scoring system to
look at a variety of information and help identify what
areas or what chemicals we should focus on. Catherine,
maybe we can help generate more information about the
sediment contaminants you are concerned about We
could perhaps consider a cluster of chemicals that may
find its way into sediments or tissue and factor that
additional area into our priority-setting process.
Betsy Southerland:
Enforcement actions based on data in the National Sediment
Inventory or fish advisory data base must be based on the
fate and transport modeling which Jim Pendergast men-
tioned earlier. There is a lot of concern that it would be
difficult to take the ambient data and trace it back to 'a
source. None of the data that we have either in the
sediment inventory or in our fish advisory data base, will
prove cause and effect. We need additional studies to be
able to take the presence of a contamination problem and
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National Sediment Bioaccumulation Conference
work it back to a responsible source. If that responsible
source is a point source in violation of permit limits on
those toxicants, then it certainly would be appropriate to
take an enforcement action. But again, the ambient
information in our data bases will not allow you to link to
sources. You will have to demonstrate cause* and effect
from additional studies.
Jim Pendergast:
I would like to add one other thing to that. Catherine, you
may want to talk with Louise Wise in the Office of
Wetlands, Oceans, and Watersheds. She helps chair a
Division Director group on watersheds. All of the Office
of Water divisions are working to fry to figure out how to
do things on a watershed basis, so we avoid the sector-by-
scctor approach and try to look at things holistically. A
Minnesota example can illustrate one of the reasons why
this is important when you are dealing with fish adviso-
ries and sediments. There are a number of lakes in
Minnesota with fish advisories for mercury, but no iden-
tifiable point source for mercury. Mercury may be
transported into the area in the air and deposited in the
lakes when it rains. You should start to address these
Issues with the watershed group.
Q (John Haggard, General Electric Company): Robert
Paulson brought up a new term that I think is particularly
appropriate for sites where companies with liability and
regulatory agencies are dealing with difficult sediment
problems. That term is potentially reasonable parties or
PRPs. We are one of the PRPs at a number of these sites
and we clearly have concerns with the liability manage-
ment. How do we manage these problems in a cost-
effective way? These sites are presenting unique prob-
lems to regulatory agencies, because there are no simple
solutions to sediment problems. Where are you going to
put this vast volume of contaminated material? What is
science telling us about what we can really achieve?
What damage might we cause by removing the material?
There is a lot of positive research going on to help reduce
the uncertainty. This is very important to industry since
we would like to see some actual benefits from the money
expended. I would like to make a recommendation
related to a chart Larry Zaragoza presented that showed
the basis for decisions at sediment sites. 1 was surprised
to see that 9 of the 14 sites involved risk-based decisions.
We have looked at 80 or 90 contaminated sediment sites
and found that only about a dozen have gone through a
record of decision process and some remediation. When
we look at sites, we can rarely figure out the basis for the
decision. Documentation on these sites is a serious
problem. In addition, when we look at how well the
technology performed, we see clear problems with dredg-
ing. I would recommend strongly to this group that you
look at the capabilities of the technology within d com-
parative riskframework at these contaminated sediment
sites. It is an important issue that I hope somebody will
take a shot at.
Betsy Southerland:
A group from our Office of Research and Development
laboratory in Cincinnati, Ohio just informed me that they
are organizing the National Conference on Management
and Treatment of Contaminated Sediments to be held
during May 1997 in Cincinnati. They are inviting speak-
ers to present a series of case studies ranging from bench-
scale remediation projects to full-scale remediation ef-
forts. They are also inviting a large variety of vendors to
display and demonstrate new equipment developed for
remediation projects and' equipment that has proven
successful for previous projects. The conference will be
a good opportunity to hear about experiences with sedi-
ment remediation. Since a number of the case studies will
involve Superfund sites, we can request that the speakers
include details in their presentations about how they
reached the decision for remediation and how they deter-
mined the volume of sediment for removal.
Larry Zaragoza:
1 think that one of the things we need to do is to begin
operating in an environment where people can actually
see the logic and consistency behind a particular pro-
gram. We have been confronted by a whole host of
challenges in the area of contaminated Sediments. Susan
Svirsky raised some of the issues in her earlier comments
about people avoiding dealing with sediment problems to
date because of these challenges. But for sediment sites
that have been addressed, these efforts might be consid-
ered successful if all the parties involved in the site agree
to. clean it up and the community is pleased about the
actions being taken at the site. That is very different from
having a national profile that shows you benefits infor-
mation and consistency in cleanup levels across the
country. As a result of looking at how we have operated
as a program and hearing comments like yours, we are
seeking to collect that information in a more systematic
and consistent manner. We have already collected some
information, but we are trying to do a better job of
obtaining more information. I think you can expect that
in the future more comprehensive information about our
sites will be readily available.
Maurice Zeeman:
We also have to realize that there has been a bias in many
cases for "we have to do something" action. Certainly in
the past, there have been cases where actions other than
removal were appropriate. An example that comes to
mind is the case in Triana, Alabama where people were
being exposed to high levels of DDT. The highest levels
were found on an Army base that produced a lot of DDT.
The Army Corps of Engineers solution was to reroute
part of the river and cover the most contaminated areas
with topsoil. That may not have been the best solution,
but it was the most cost-effective approach under the
circumstances. I have been teaching a course in
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environmental toxicology at the National Institutes of
Health (NIH) since 1982. One of the things I have found
really remarkable with that experience is how ignorant
we can become over time. I have asked my classes
recently about what happened with the Kepone spill in
the James River, and virtually nobody is aware of the
incident any more. Many people think the problem has
gone away. It was going to cost many millions of dollars
to dredge after the spill, so the lower river was closed to
a number of activities and allowed to recover naturally
with deposition of clean sediments'. It is a solution that
has worked over time. But, Bob Huggett has presented
results of studies that show Kepone-contaminated sedi-
ments have been moving out into Chesapeake Bay. All
we need is the right kind of hurricane to redistribute these
sediments for the problem to occur all over again.
Q (Helder .Costa, Inchcape Testing Services, Aquatec
Laboratory): Several EPA-sponsoredstudies have shown
close associations between alkylated PAHs in petroleum-
influenced systems and adverse effects to benthic organ-
isms and habitat. In the Delaware Estuary, for instance,
the alkylated PAHs accounted for typically 50 to 70
percent, or even 80 percent, of the total PAH loading. I
want to comment that we can only begin to understand the
importance of PAHs as a chemical compound class when
we begin to consider the alkylated PAHs in petroleum-
influenced systems.
Betsy Southerland:
I know that Rick Swartz from our laboratory in Newport,
Oregon will soon be publishing a total PAH analysis
based on narcosis effects. He is trying to help us analyze
PAHs as a whole chemical group instead of having to
'consider each PAH with its individual toxicity.
Q (Helder Costa): I particularly applaud the work Rick
Swartz has done in developing the sum PAH model and
publishing the results in the SETAC journal (Environ-
mental Toxicolpgy and Chemistry, Vol. 14, No. 11, pp.
1977-1987, 1995). In his paper, he acknowledged the
importance of alkylated PAHs in petroleum-influenced
regimes as a temporary limitation to the model.
Betsy Southerland:
An individual from the Metropolitan Washington Coun-
cil of Governments has conducted some studies that show
PAHs are coming not only from products of combustion,
but also from ground water contaminated by leakage
from automobiles and other sources. That is new infor-
mation to me in terms of sources.
Q (John Zambrano, New York State Department of Envi-
ronmental Conservation): If we agree that contaminated
sediments are a problem that we want to do something
about, we are going to have to know the relative amounts
of various sources of contamination. We also need to
know Whether past contaminants that'we may not be able
to do much about are circulating within the system, or
whether new contaminants are being introduced by cur-
rent sources. Could these sources be point sources that
we are hot regulating sufficiently such as stormwater or
combined sewer overflows? Could land runoff or atmo-
spheric deposition be contributing to the problem? It
seems to me that unless you know the amounts from
various sources, you will not be able to make intelligent
decisions within the Superfund Program, the NPDES
Program, or the Dredged Material Program. I think we
need to do more sampling and modeling to get that
information.
Larry Zaragoza:
Your commends very well taken. I agree that it is worthwhile
, to have thatkind of information. For a Superfund site, we
would specifically look for that kind of information to see
what is going on at the site level. But that only speaks to
a particular site. It does not tell you about what is going
• on in the rest of the country. Sediment assessment
generally needs to be site-specific, but that complicates
comparing a site to other sites across the country.
Betsy Southerland:
The best mass balance study done to date that I know of
was the work conducted for PCBs on the Fox River in
Wisconsin. I think they had a budget of about $}5 million
for monitoring. I know that EPA programs are trying to
look at mass balances, particularly in the Office of Air
and Radiation. The air program has worked with us in
preparing their second report to Congress on deposition
of air pollutants to the Great Waters. They are trying to
do large-scale mass balances for substances like mercury
and PCBs to determine how much mercury and PCB
• contamination can be attributed to air emissions.
Q (Don Porcella, Electric Power Research Institute): I
have enjoyedthis conference very much. Therehavebeen
some new approaches developed and presented here,
particularly the food chain modeling. Will these ap-
proaches be incorporated into future analyses? All the
approaches we have heard about include the concept of
models. For example, a bioassay is a physical model as
opposed to a mathematical model. I think it is really >
important to do groundtruthingfor these models, as well
as to address the "So what?" question Gil Veith raisedat
the beginning of the conference. This question particu-
larly relates to Fred Lee's comment about whether there
has in fact been any damage in the New,York Harbor area
from dredged material disposal.
Mick DeGraeve:
I just want to reinforce the importance of what Betsy
Southerland and Jim Pendergast .mentioned about
finalizing-the screening procedure for bioconcentratable
contaminants. Larry Burkhard, who is in the audience, is
the principal author of the method. One thing'that Betsy
and Jim did not mention is that the method works not only
for effluents in water, -but also for tissues and sediments.
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National Sediment Bioaccumulation Conference
In terms of some of the dredging-related issues, it can be,
applied to address the likelihood of bioconcentratable
contaminants being present in sediments and certainly in
tissues. We have used the procedure commercially to
address some very interesting questions and it has worked
quite well.
Q (Betsy Southerland): Have you used it on sediments or
just wastewater?
Mick DeGraeve:
We have used it on sediments. I am glad that efforts are
going forward to finalize it.
Jim Pendergast:
My focus at EPA has been primarily on wastewater. But
for one year in the 1980s, I worked with the Superfund
Program. While I was there, it would have really helped
to have had that methodology available to assess sedi-
ments at Superfund sites. The guidance also includes
information about integrating fish tissue data in the
decision-making process to determine whether or not
there is a problem. We tried to make it a one-stop
document to deal with multimedia.
Q (Lynn McCarty, LS. McCarty Scientific Research &
Consulting): My opinions are entirely my own since I do
not represent an agency. There are two areas I would like
to comment on. The first one is technical. If you continue
to go down the toxicological route, you are eventually
going to have to deal with molar units. Since toxicology
is a function of the number of molecules of a compound,
not its weight, you will find that many relationships that
would be obscured by using weight-based measures will
become much clearer when you use molar weight. The
second issue is a philosophical one at the very end of the
scale of what we are talking about today. I was pleased
to hear Dr. Patton indicate in her discussion that both
science and policy are included in the EPA risk assess-
ment process. That is an explicit recognition of some-
thing that I think a number of people have realized for a
long time, but it is an important distinction. We must keep
the science and the policy separate or at least identify
themassuch. In this whole process of becoming open and
transparent, making this distinction is particularly im-
portant. What we are trying to do in this whole exercise
is risk management. We are trying to achieve some sort
of environmental protection. As scientists, we need
technical decision criteria to do that and to fit into the
decision-making process. In other words, we need to be
able to define what a significant adverse effect is. It is
great to say that we have to protect the environment, but
when it comes down to scientific measurements, what
does that mean? We have some difficulties because we
are trying to define future problems from an existing
problem perspective and from a modeling perspective.
The objective of risk assessments providing information
to make choices among alternatives. So, what is the
framework? What are the effects that we are concerned
about and what are the alternatives that we are choosing
among? Developing information for risk assessments
involves specific goals that change from the research
emphasis being presented here to regulatory utility. If we
do not have risk management directions that are framed
in technical terms, we cannot make decisions. That is
what this is all about. This is a policy issue, and the
science is guiding the decisions. I found the list of
questions Dr. Southerland provided for the speakers to
be very useful because it addressed many of the important
technical issues. Unfortunately, I do not think we have
coalesced those into a useful decision-making frame-
work. I would like to encourage the panel and EPA to
consider that, because I think that many of the people at
this meeting are looking for very specific directions.
What is it that we want to do, and how can the science that
we have available help us in making the decisions and
choosing among those alternatives?
Alex Lechich:
As a scientist regulator, I sometimes feel that research
scientists do not carry the same burden as we do, so I do
not have any qualms about trying to lay a little more
weight on their shoulders. In terms of the data bases that
are being developed for the' specific effects, I think it
would be helpful to go beyond just assembling, compil-
ing, and presenting this information. Have the people
who are most familiar with the studies and the data itself
become involved where there are conflicts. In some
cases, we can look at the data and make fairly clear
decisions. In other cases where the results conflict with
each other, it would be nice to have the people closest to
those studies review them and provide a recommendation
as to where to go from there.
Phillip Rury, Arthur D. Little, Inc.:
I would like to thank and commend all of the people who
contributed to this excellent conference. It is probably
one of the better conferences I have been to in many years.
I would also like to say that I feel it is long overdue and
I hope that we can see a sequel to this very soon. In terms
of some of the gaps that I see and the future research needs
that some of the speakers have identified, those same gaps
were reflected in the presentations here. I would hope
that we could address them in future conferences. I would
implore everyone to look in these directions. In a kind of
evolutionary-speak sense, perhaps our research needs to
crawl up onto the land again. The aquatic focus of this
conference was obvious, but I am concerned mat issues
such as amphibian bioaccumulation are not being ad-
dressed. The questions concerning wetland species also
need to be addressed more vigorously. For example, the
data base presentations at this conference specifically
excluded amphibians with the exception of tadpoles. We
have found this lack of information on amphibians to be
a major constraint in several risk assessments. Mink food
chain exposure models, for example, are highly sensitive
to the frog elements in the diet. We also have a dearth of
bioaccumulation factors. Several that do exist are quite
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high and they are driving the cleanup goals. I would also
like to get on my soapbox about the lack of integration of
ecological and human health risk assessment. I would
hope that maybe in another 10 or 20 years, as the pace of
regulatory change proceeds, that we might see a shift to
an ecosystem-level approach to risk assessment that
includes consideration of both human health and eco-
logical risks. This approach should allow us to realize
some efficiencies of costs and some enhancements of
understanding by integrating humans into an ecosystem
risk assessment as a mandatory indicator species in
every case.
Burt Shephard, URS Greiner, Inc.:
There are two areas I would like to comment on. One is
to respond to the remarks about the .data bases. I think
those of us who are putting the data bases together are
very much aware of the conflicting data. You might not
see it at the first level of building thedata bases, butl think
that shortly thereafter you will see some attempt by those
of us putting the databases together to resolve conflicts.
Some of the data quality issues are very important to us.
Some of the data are not very good, but some are excel-
lent. Initially, we will be putting out summaries of the
data with a lot of data qualifiers saying how things were
done and let the end users make their own judgments
about whether the data is good or bad for their own
purposes. I certainly concur with the comments and think
we will be making some efforts to resolve some of the
conflicts within the data at some point down the road.
Second, before we can really define a contaminated
sediment, we need to know something about what ah
uncontaminated sediment is. There were some talks here
about defining background reference area sediment con-
centrations. Within the risk assessment area, that is a very
large need right now. The guidance today within the
various EPA Regions for defining background or refer-
ence area concentrations is, inconsistent. I think it is very
important to have a defined statistical guidance that
describes 'how to compile reference area data and com-
pare site data to it to see if the site data are exceeding the
reference or background data to a degree that indicates
contamination problems. The RCRA guidance docu- .
ments on statistical comparisons are the best ones that I
have seen within EPA. They look at sample mean
comparisons between sites and background areas. They
also have, for lack of a better term, a hot spot out on the
tail of the distribution to see if very high concentrations
fall within a distribution or within a confidence limit of
a distribution. I" think some consistency with
comparing backgrounds or calculating backgrounds
would be very useful to everyone who has to do risk
assessments.
Q:(MalcolmWatts,Zeneca,inc.): I want to support the
comments that have been made by Fred Lee, Lynn
McCarty, and John Haggard. Lynn McCarty asked;
"What do we want to do and how does science help us? "
What we want to do is to maintain or clean up the
environment. That is pretty obvious. We are all breathing
out carbon dioxide and contributing to global warming.
Shall we all remove ourselves from the planet? Clearly
not. I suggest that it is a matter of cost-effectiveness.
How much does it cost and what are the benefits? Fred
Lee said this morning that there seemed to be very little
damage from the New York Harbor dredging. So, I
question the costs. /; also question the effectiveness,
versus the benefits. I would like your comments on cost-
effectiveness and the extent to which we have tried to look
at the costs of doing nothing and the benefits of doing
something.
Betsy Southerland:
We did do a few case studies where we looked at the costs
and benefits of remediation. I am sure everyone here is
aware that the science of analyzing benefits is an area
where we lack monetization methods. We have three
tiers of benefits analysis that we do for environmental ,
projects. The first tier, which is a qualitative discussion
of benefits, is the one we generally have to use. If you
have more data you can move up to tier two, which is a
quantitative description of benefits. Only at the third tier
do you have monetization of benefits. No matter which
of our programs is doing a regulation of other action, we
always have a tough time at EPA doing monetization of
benefits, whereas monetization of costs is a very well-
defined area. We have disagreements with the regulated
community about our cost estimates, but we have plenty
of procedures to provide us with costs. At any rate, when
we have done cost/benefit* analyses on some remediation
projects, we have been able to demonstrate that the
benefits have met or exceeded the cost of the remediation.
There were studies at three Supermnd sites where the
costs were in the area of $25 million to $50 million for the
sediment remediation and the benefits were at or above
$50 million. Those are the only cases that I know of
where the focus has been on calculating the costs and
benefits of sediment cleanup. Since they have state water
quality sediment standards, Washington State is doing
similar work.
Larry Zaragoza:
I did not want to give any site-specific information, but I
did want to say that Superfund is not a cost/benefit
statute. In making the request that decisions be put into
a cost/benefit framework, I think you need to look at what
the legislative direction is for the program. Basically,
each of our programs has a different framework and a
different legislative history. We are supposed to admin-
ister each program based on what the law says. We
should also coordinate among programs to be efficient
and to learn from each other. The last Congress had a lot
of discussion about costs and benefits, and I expect that
we are going to see that reflected in the next set of
legislation. I would also like to reinforce what Betsy
Southerland said about the monetization of benefits.
Quantifying benefits in monetary terms is not something
we have done a lot of. It is controversial, so that will make
it challenging in many cases to develop a number that
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National Sediment Bioaccumulation Conference
may be accepted. There are anumber of issues in this area
that will continue to be debated.
Maurice Zeeman:
As Mother Nature says, "Pay me now or pay me later, but
a lot more later." If the Great Lakes area is any example,
the time frame for many ecological concerns is decades.
If you are talking about the need to know this week how
much it is going to cost and what the benefits are, you are
going to end up with nearly intractable problems. The
Chesapeake Bay is another example. We are seeing
examples around us of problems where their scope and
scale is virtually beyond all the small management and
cost/benefit decisions we are making. I concur with what
the prior two people said. We are getting better at it, but
so far the environment has been virtually free: That is the
reason that it is so contaminated.
Betsy Southerland:
If there is no further discussion, I will close this session
with a few summary remarks. I want to reiterate that the
future needs raised by speakers and other participants in
this conference will be factored into ORD research plan-
ning and included in our bioaccumulation report. If you
are not already on the mailing list, I also want to remind
you to sign up for the Contaminated Sediments News, a
newletter that we produce and distribute from our office.
We will provide follow up information for several things
mentioned during this conference in future issues of our
newsletter.
It has been tremendously informative and enjoyable for
all of us that have worked for more than a year to organize
this conference. We especially appreciate the commit-
ment of all the speakers and moderators to continue
working with us when we had to reschedule the confer-
ence due to the Federal furlough in the fall of 1995. It was
a challenge we were finally able to overcome. We thank
you for your interest and participation in this conference.
My staff will be available after the conference to listen to
any additional comments and suggestions you may have
before you leave. Again, thank you for coming. We will
be keeping in touch with you through the Contaminated
Sediments News.
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National Sediment Bioaccumulation Conference
Speakers9 Biographies
James K. Andreasen, Ph.D.
Dr. Andreasen is. the leader of the pcological
'Assessment Team at the National Center for Environ-
mental Assessment within the Office of Research and
Development of the U.S. Environmental Protection
Agency (EPA). He works in Washington, D.C.
Dr. Andreasen'received his Ph.D. from the Department
of Fisheries and Wildlife at Oregon State University in.
1975. Following a short teaching career at the University
of Alaska, he secured a position with the Federal Govern-
ment and has been conducting research on the effects of ,
contaminants and other environmental stressors on eco-
systems for the past 20 years. He came to the Office of
Research and Development 3 years ago from the Fish and
Wildlife Service, where he worked in the environmental
contaminants program. Dr. Andreasen is active in the
Society of Environmental Toxicology and Chemistry
and currently serves as the president of the Chesapeake-
Potomac Regional Chapter. During his free time he
enjoys genealogy, family history research, and wood-
working. His 17 grandchildren enjoy the toys and other
creations he makes in his shop. One of his goals in life is
to someday return to the wide open spaces of the West.
Lawrence P. Burkhard, Ph.D.
Dr. Burkhard is a research chemist hi the Ecologi-
, cal Toxicology Research Branch of EPA's National
Health and Environmental Effects Research Laboratory,
Mid-Continent Ecology Division, in Duluth, Minnesota,
He received his B.S. in Civil Engineering from Pennsyl-
vania State University and his M.S. and Ph.D. in Water
Chemistry from the University of Wisconsin-Madison.
His research interests include the behavior and effects of
bioaccumulative organic contaminants in aquatic eco-
systems, analytical methodologies for the detection and
quantification of known and unknown organic contami-
nants in environmental samples, and lexicologically
based analytical methodologies for the detection and
identification of unknown toxicants in environmental
samples.
Peter M. Chapman, Ph.D.
Dr. Chapman is a senior principal atEVS Environ-
ment Consultants, North Vancouver, British Columbia.
He received his B.Sc. in Marine Biology, his M.Sc. in
Biological Oceanography, and his Ph.D. in Benthic
Ecology from the University of Victoria (1979), His
experience and expertise since graduation have centered
on ecotoxicology and aquatic ecology, which he has
combined into integrative assessments such as the Sedi-
ment Quality Triad. He has published over 90 peer-
reviewed journal publications and book chapters and
over 200 technical reports on a wide variety of subjects,
including sediment bioaccumulation.
David W. Charters, Ph.D.
Dr. Charters is an environmental' scientist with
EPA's Environmental Response Team located in Edison,
.New Jersey. He attended undergraduate school at Syra-
cuse University and continued his education at the State
University of'New York at Binghamton, where he re-
ceived a Doctorate in Biology specializing in Environ-
mental Pathology. Dr. Charters' dissertation study was
conducted at Love Canal, Niagara Falls, New York, and
he investigated the demographic structure of the small
mammal populations in the area and the histopathologi-
cal responses of these indigenous mammals. .Dr. Char-
ters joined EPA's Environmental Response Team in.
1985 and has worked on ecological risk assessment since
then hi the Superftmd program. He has conducted
investigations on many of the National Superfund sites
and has conducted studies and investigations internation-
ally. He is presently completing Superfund guidance on
conducting, ecological risk assessments ,and is involved
in the reauthorization of the Superfund law.
John P. Connolly, Ph.D., P.E.
Dr. Connolly is "a principal engineer with
HydroQual, Inc., in Mahwah, New Jersey. He received
his B.E. in Civil Engineering and his M.E. in Environ-
mental Engineering from Manhattan College. His Ph.D.
hi Environmental Health engineering is from the Univer-
sity of Texas at Austin. Prior to his Ph.D. studies,
Dr. Connolly worked for more th,an 2 years at Manhattan
College on the development and application of a model
of eutrophication in Lake Erie. His thesis research on the
fate of sediment-associated hydrophobic organics was
conducted at the U.S. EPA Environmental Research Lab
in Gulf Breeze, Florida, where he also was involved in
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National Sediment Bioaccumulatlon Conference
microcosm studies of the transport and degradation of
toxic organics in sediment. Upon completion of his
Ph.D., he accepted a faculty position in the Environmen-
tal Engineering and Science Program at Manhattan Col-
lege. During his 14 years at Manhattan, Dr. Connolly
conducted research in several areas, including the devel-
opment of models of toxic chemical fate and
bioaccumulation, eutrophication modeling, and model-
ing the fate and effects of genetically engineered micro-
organisms introduced to surface waters. While at Man-
hattan he consulted with HydroQual, Inc., on a wide
range of problems. In June 1994 he left Manhattan to join
HydroQual full-time. His recent work has included
several bioaccumulation projects. Among these are
detailed analysis of bioaccumulation field data for EPA
and modeling assessments of DDE bioaccumulation
from sediments on the Palos Verdes Shelf and PCB
bioaccumulation from sediments in Green Bay.
Philip M. Cook, Ph.D.
Dr. Cook is the Acting Chief of the Ecological
Toxicology Branch at the Mid-Continent Ecology Divi-
sion of EPA's National Health and Environmental Ef-
fects Laboratory in Duluth, Minnesota. Dr. Cook re-
ceived a B.S. in Chemistry from Tufts University, an
M.S. in Geochemistry from Colorado School of Mines,
and a Ph.D. in Physical Inorganic Chemistry from the
University of Wisconsin. Following graduate school in
1972, he accepted a position as a research chemist at the
U.S. EPA National Water Quality Laboratory at Duluth,
where his initial work involved evaluation of risks asso-
ciated with mining wastes in Lake Superior. His manage-
ment positions since then have included Chief of the
Hazardous Waste Research Branch and Associate Direc-
tor for Research Operations. Dr. Cook has diverse
research experience that includes effects of fine particles
such as asbestos; sediment contaminant bioavailability;
ecological risks of organochlorine chemicals, especially
PCDDs, PCDFs and PCBs; and methods for ecological
risk assessment in the Great Lakes.
Judy L. Crane, Ph.D.
Dr. Crane is the Team Leader of the Toxics Unit hi
the Division of Water Quality at the Minnesota Pollution
Control Agency (MPCA) in St. Paul, Minnesota. She
received a B.S. in Animal Ecology from Iowa State
University, an M.S. in Ecology and Behavioral Biology
from the University of Minnesota-Minneapolis, and a
Ph.D. in Water Chemistry from the University of Wis-
consin-Madison. Her professional work experience in-
cludes contractual work with the U.S. EPA Environmen-
tal Research Laboratories in Duluth, Minnesota
(1983-1985) and Athens, Georgia (1990-1992), as well
as consulting work with EVS Consultants (1992-1995) in
Vancouver, British Columbia. Dr. Crane was actively
involved in the Great Lakes National Program Office's
Assessment and Remediation of Contaminated Sediments
(ARCS) Program from 1990 to 1995, where she was
responsible for conducting baseline and comparative
human health risk assessments for selected Areas of
Concern. She has also been involved in developing
ecological risk assessment guidance for contaminated
sites in Canada and developing interim sediment quality
criteria for the Province of British Columbia. Dr. Crane
is currently working as a research scientist for the MPCA,
where she is leading several federally funded contami-
nated sediment investigations in the Duluth/Superior
Harbor.
Tudor T. Davies, Ph.D.
Dr. Davies joined EPA in 1972, in the Office of
Research and Development (ORD). From 1975 to 1979
he was the Deputy Laboratory Dkector of the ORD Gulf
Breeze Environmental Research Laboratory in Gulf
Breeze, Florida. He then became the Director of the
Narragansett Environmental Research Laboratory from
1979 to 1983; during that time he also served as the
director of the EPA Chesapeake Bay Program. Prior to
his current position as Dkector of the Office of Science
and Technology, he was the Director for the Office of
Water's Office of Marine and Estuarine Protection for 7
years. Dr. Davies attended the University of Wales in
Swansea, and he holds a Bachelor of Science and a
Doctorate in Geology. He was an Associate Professor of
Geology at the University of South Carolina.
Mario P. Del Vicario, M.S.
Mr. Del Vicario serves as the Chief of the Place-
Based Protection Branch (PBPB) for Region 2 of the U.S.
Environmental Protection Agency. He began his em-
ployment at EPA in 1985 as the Assistant Chief of the
Marine and Wetlands Protection Branch and was Chief
of that branch from 1987 to 1996. Prior to his service with
EPA, Mr. Del Vicario was employed by the U.S. Army
Corp of Engineers in the New York District from 1975 to
1985, where he served as the Assistant Chief of the
Environmental Analysis Branch. He was a microbiolo-
gist with the NYC Health Department from 1973 to 1975.
Mr. Del Vicario received a B.A. in biology from
Adelphi University in 1971 and an M.S. in Marine
Science in 1973. From 1980 to 1986, he was enrolled in
a Ph.D. program in Ecology in the City University
system.
Dominic M. Di Toro, Ph.D.
Dr. Di Toro is aprincipal consultant for HydroQual,
Inc., in Mahwah, New Jersey. He received his B.E.E. in
Electrical Engineering from Manhattan College, and his
M.A. and Ph.D. in Electrical Engineering and Civil and
Geological Engineering from Princeton University.
Dr. Di Toro has specialized in the development and
application of mathematical and statistical models to
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Proceedings
8-3
stream, lake, estuarine, and coastal water quality and
sediment problems. He has published over sixty techni-
cal papers and has participated as Expert Consultant,
Principal Investigator, and Project Manager on numer-
ous water quality studies for industry and governmental
agencies. Recently,-his work has focused on the devel-
opment of sediment quality criteria and the development
of eutrophication and sediment flux models for nutrients
and metals.
L. fay Field, M.S.
Mr. Field received a bachelor's degree1 from the
University of Michigan and an M.S. in Fisheries from the
University of Washington. Since 1986, he has worked as
a marine biologist for the National Oceanic and Atmo-
spheric Administration (NOAA), Office of Ocean Re-.
sources Conservation and Assessment, Hazardous Mate-
rials Response and Assessment Division, Coastal
Resources Coordination Branch in Seattle, Washington.
His responsibilities include providing technical support
to NOAA Coastal Resource Coordinators and EPA in the
evaluation of ecological risk to coastal marine resources
from hazardous waste sites. .
Christopher G. Ingersoll, Ph.D.
Dr. Ingersoll is a fisheries biologist with the U.S.
Geological Survey at the Environmental Contaminants
Research Center in Columbia, Missouri. He received his
bachelor's (1978) and master's (1982) from Miami Uni-
versity in Oxford, Ohio, and his doctorate (1986) from
the University of Wyoming in Laramie, Wyoming. His
current research is focused on investigating the toxicity
and bioavailability of contaminates in sediment. He has
coordinated the development of chronic toxicity meth-
ods for the ampbipodHyalella azteca that.have been used
to evaluate contaminated sediments in ..several areas,
including the Great Lakes, the upper Mississippi River,
and the Clark Fork River in Montana. A second area of
research that he has been working on with EPA is
developing a sediment bioaccumulation test with the
oligochaete Lumbriculus variegatus. Dr. Ingersoll also
chairs the ASTM Subcommittee E47.03 on Sediment
Toxicology. This subcommittee, in coordination with
EPA and Environment Canada, has developed a variety
of standard methods for evaluating sediment toxicity and
bioaccumulation.
Michael J. Kravitz, MJV.
Mr. Kravitz is a biologist in the Standards and
Applied Science Division of the Office of Science and
Technology at U.S. EPA Headquarters. In this capacity
he consults with, coordinates, and provides technical
support to EPA personnel and programs related to con-
taminated sediment issues. As co-chair of EPA's
Bioaccumulation Analysis Workgroup, Mr. Kravitz is
helping to lead the development of an EPA report on the
current status of bioaccumulation testing and interpreta-
tion for the purpose of sediment quality assessment. He
has been responsible for the development of a number of
EPA and EPA/Army Corps of Engineers guidance docu-
ments, including the Draft Inland Testing Manual and:
QA/QC Guidance for Sampling and Analysis of Sedi-
ments, Water, and Tissues for Dredged Material Evalu-
ations. Prior to joining EPA, Mr. Kravitz worked in the
field of marine/estuarine benthic ecology at laboratories
in New York, Oregon, Florida, Virginia, and Massachu-
setts. Mr. Kravitz received a B.S. in Biology from the
State University of New York at Stony Brook, and an
M.A. in Marine Science (major in Biological Oceanog-
raphy) from the College of William and Mary School of
Marine Science in Gloucester Point, Virginia.
Peter F. Landrum, Ph.D.
Dr. Landrum is the head of the Biogeochemical
Sciences Division of NOAA's Great Lakes Environmen-
tal Research Laboratory in Ann Arbor, Michigan, where
he oversees research on aquatic contaminants, bio-
geochemistry, and ecosystems studies directed to exam-
ine the effects of anthropogenic impacts on the Great
Lakes as well as the day-to-day administration for the
division. He received his B.S. in Chemistry from Cali-
fornia State College, San Bernadino, and Ph.D. in Phar-
macology and Toxicology from the University of Cali-
fornia, Davis. He spent the next 2 years working as a
research associate for the University "of Georgia at the
Savannah River Ecology Laboratory, Aiken, South Caro-
lina. His research focused on the fate, transport, and
bioaccumulation of polycyclic aromatic hydrocarbons in
freshwater stream systems. He then moved to the Great
Lakes Environmental Research Laboratory as a research
chemist to conduct research in the bioavailability and
bioaccumulation of organic contaminants by aquatic
invertebrates with an emphasis on the benthos. Over the
last 15 years, his research has examined the role of
dissolved organic matter on the bioavailability of water-
borne contaminants and the influence of sediment char-
acteristics on sediment-associated contaminants. More
recent work has examined the utility of whole-body
residue levels to determine the dose required to produce
contaminant toxicity. In addition to his research,
Dr. Landrum served as a part-time instructor in environ-
mental toxicology at Eastern Michigan University.
Alex Lechich, M.S.
Mr. Lechich has been an environmental scientist
with EPA Region 2 since 1988, principally working on
ocean disposal, contaminated sediment, and dredging
issues. Prior to that, he worked for 3 years with the New
York District Corps of Engineers in its regulatory pro-
gram. Mr. Lechich received a B.S. in Biology from the
State University of New York at Stony Brook in 1983 and
an M.S. in Marine Environmental Science from Stony
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8-4
National Sediment Bioaccumulation Conference
Brook's Marine Sciences Research Center in 1984. He
served in the U.S. Army for 3 years hi the late 1970s,
where he collected and analyzed ambient air samples
from nerve gas de-commissioning areas on a base near
Denver. Prior to completing his undergraduate and
graduate work, Mr. Lechich worked for several industrial
chemical companies, mainly doing organic chemistry
product development and quality control. Following his
graduate work, he worked for the New York Power
Authority.
Henry Lee II, Ph.D.
Dr. Lee is with the Pacific Northwest Estuarine
Ecosystem Study of the Western Ecology Division of
EPA, located at the Newport, Oregon, laboratory. He
received his B.S. in Biology from Rollins College and his
Ph.D. in Marine Sciences from the University of North
Carolina. After a postdoctoral position at the University
of Maryland and an NRC postdoctoral position with
EPA, Dr. Lee joined the EPA staff at Newport, Oregon.
He spent the next decade working on bioaccumulation
and contaminated sediments, including investigations on
the application of equilibrium partitioning and
toxicokinetic models to benthic invertebrates, and the
development of bioassay methods. His work on contami-
nated sediments culminated when Dr. Lee directed an
ecological risk assessment of sediment-associated DDT.
During this period, Dr. Lee also was the Program Man-
ager for EPA's Marine Stratospheric Ozone Depletion
Program. He is presently directing a research program to
assess the cumulativeeffects of chemical andnonchemical
(e.g., sedimentation, introduced species) stressors on an
ecosystem scale.
Lynn Scott McCarty, Ph.D.
Dr. McCarty operates L.S. McCarty Scien-
tific Research & Consulting, an ecotoxicological con-
sulting business based in Oakville, Ontario, Canada. He
received B.S. and M.S. degrees from Brock University
and a Ph.D. from the University of Waterloo. He has
spent over 18 years examining various aspects of envi-
ronmental contamination, ecotoxicology, and environ-
mental risk assessment. This included a number of years
as an environmental scientist and ecological studies
group manager at MacLaren-Plansearch (Lavalin), sci-
entific consultant for the Health Studies Service of the
Ontario Ministry of Labour, and senior scientist with
CanTox, Inc. He has been involved in a wide variety of
projects examining environmental impacts and/or hu-
man health effects for an assortment of situations and
contaminants/stresses. This included the production or
critical review of a number of air and water quality
guidelines, as well as risk assessments hi Canada and the
USA.
Dr. McCarty's scientific interests include Quanti-
tative Structure-Activity Relationships (QSAR),
toxicokinetics, mixture toxiciiy, residue-based potency
estimation, and risk assessment. He has been an invited
expert dealing with human and environmental health at
a number of workshops sponsored by CNTC, SETAC,
U.S. EPA, and U.S. Army Corps of Engineers: In
addition to reports for clients, he continues to publish in
the primary scientific literature, contribute to book chap-
ters, and make presentations at professional scientific
meetings, as well as hi courts, regulatory hearings, and
public meetings.
David R. Mount, Ph.D.
Dr. Mount is a research fishery biologist with
EPA's Office of Research and Development, Mid-Con-
tinent Ecology Division, Duluth, Minnesota. He re-
ceived his B.A. hi Biology with a statistics concentration
from St. Olaf College in Northfield,,Minnespta, and his
Ph.D. in Zoology and Physiology (emphasis in aquatic
toxicology) from the University of Wyoming. After a
year of postdoctoral research at the Fish Physiology and
Toxicology Laboratory at the University of Wyoming,
Dr. Mount worked for 5 years at ENSR Consulting and
Engineering as a senior aquatic toxicologist, and as the
manager of the Environmental Toxicology Department.
Dr. Mount joined the federal government in 1993 as the
Deputy Chief Biologist at the National Biological
Service's National Fisheries Contaminant Research Cen-
ter, before transferring to his current position with EPA.
Dr. Mount's research interests include-effluent and sedi-
ment toxicology, and the effects of major ions on fresh-
water organisms. His current research centers on sedi-
ments, including the development of Toxicity
Identification Evaluation (TIE) procedures and evalua-
tion of the bioavailability of sediment contaminants.
Wayne R. Munns, Jr., Ph.D.
Since 1995, Dr. Munns has been a Research Ecolo-
gist (Ecological Risk Assessor) and Leader of the Eco-
logical Significance Team in EPA's National Health and
Environmental Effects Research Laboratory,
Narragansett, Rhode Island, which is responsible for
conducting ecological effects research to reduce the
uncertainties associated with risk assessment. He re-
ceived his B.A. in Biology from the University of Wash-
ington and his Ph.D. in Biological Sciences from the
University of Rhode Island. In 1983, he joined Science
Applications International Corporation, ultimately ac-
cepting positions as senior scientist, division manager,
and assistant vice president. Over the past 13 years,
Dr. Munns has served as principal investigator in a
number of marine and estuarine ecological risk assess-
ment case studies involving contaminated sediments,
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Proceedings
8-5
and has conducted research evaluating the effects of
chemical stressors on the population dynamics of aquatic
organisms.
Thomas M. Murray, M.S.
Mr. Murray is Chief of the Exposure Assessment
Branch in the Office of Pollution Prevention and Toxics
at EPA Headquarters. In this capacity, he is responsible
for integrating the assessment of total chemical exposure
to humans and the environment in support of OPPT's
regulatory ,and nonregulatory program activities; sup-
porting OPPT's testing and existing chemical programs
by providing integrated assessments of chemical expo-
sure to humans and the environment; providing scientific
assessment of total chemical exposure, including chemi-
cal and biological fate; and providing exposure assess-
ment and project management support to various OPPT
Design for the Environment and Pollution Prevention
Program activities. Mr. Murray has been with the Office
of Pollution Prevention and Toxics since 1985. Prior to
that he spent 14 years with EPA's Office of Water.
He received his B.S. in Biology from Mt. St. Marys'
College and an M.S. in Biology from the
American University.
Dorothy E. Patton, Ph.D.
Dr. Patton holds several positions at the U.S.
Environmental Protection Agency. She is the Executive
Director of EPA's Science Policy Council, a new Agency
organization established to address significant science
policy issues that go beyond program and regional bound-
, aries. She also directs the Office of Science Policy and the
Office of Regulatory and Science Integration. From
1985 through July 1994, Dr. Patton was the Executive
Director of EPA's Risk Assessment Forum, a standing
committee of senior EPA scientists charged with devel-
oping Agency-wide guidance on selected risk science
issues. She also chaired that group from 1989 to 1995.
Dr. Patton began her EPA career in 1976 as an attorney
in the Office of General Counsel, where she worked on
legal and scientific issues arising under the laws relating
to pesticides, toxic substances, and the air program.
Before joining EPA, Dr. Patton was an Assistant Profes-
sor of Biology in the City University of New York (York
College), and she did postdoctoral research in cellular
and developmental biology at the Albert Einstein Col-
lege of Medicine in New York. She has a J.D. from
Columbia University School of Law, aPh.D in develop-
mental biology from the University of Chicago, and a
bachelor's degree in chemistry from the University of
Wisconsin.
Robert L. Paulson, M.S.
Mr. Paulson is an environmental toxicologist in the
Water Quality Modeling Section of the Wisconsin De-
partment of Natural Resources' Bureau of Watershed
Management. He received his B.S. in Water Resources
from the University of Wisconsin-Stevens Point and his
M.S. in Fisheries from the University of Missouri.
Mr. Paulson's thesis research focused on field validation
and predictability of laboratory methods of assessing the
effects of contaminants. "Prior to joining WDNR,
Mr. Paulson was a staff toxicologist with The Johns
Hopkins University, Applied Physics Laboratory, where
his work centered on effluent and single-chemical estua-
rine and freshwater toxieity testing. Mr. Paulson also
spent a brief period of time in private consulting;
Mr. Paulson joined WDNR as the coordinator of .the
whole effluent toxieity testing for the point source dis-
charge permit program. His current assignment is to
coordinate WDNR's technical staff in conjunction with
the efforts of the Fox River Coalition to develop a whole-
river sediment strategy.
Amy E. Pelka, M.S.
Ms, Pelka is an environmental health scientist in
the Office of Strategic Environmental Analysis in EPA
Region 5, Chicago, Illinois. She received her B.S. in
Zoology (specialization in cellular biology) from the
University of Wisconsin-Madison and her M.S. in Mi-
crobiology/Immunology from Northwestern University.
After graduate school she began working with Region 5,
in the Water Division, on sedirnents and water quality
standards. She has worked for the Water Division and
now the Strategic Analysis office for the past 5 years,
primarily as a human health risk assessor. She has
worked on several Superfund and other enforcement
cases, as well as various technical and risk policy issues.
Her primary areas of focus have been sediment sites,
bioaccumulation, risk assessment policy, and commu-
nity-rbased environmental protection.
James F. Pendergast, M.S.
Mr. Pendergast is currently Acting Director
of the NPDES Permits Division at U.S. EPA Headquar-
ters. In this capacity, he directs national activities and
initiatives for the NPDES permits, pretreatment, and
sludge programs. He has worked on reauthorization of
the Clean Water Act as a special assistant to EPA's
Assistant Administrator for Water and as Chief of the
Wafer Quality and Industrial Permits Branch in the
NPDES Permits Division. He has also worked in EPA
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8-6
National Sediment Bioaccumulation Conference
Region 6 in the NPDES permit and Superfund programs.
Prior to joining EPA, Mr. Pendergast was a project
manager at Limno-Tech, Inc., in Michigan, where he
developed models of water quality impacts from nonpoint
and point sources. He received a B.S. in Environmental
Engineering and an M.S. in Water Resources
Engineering from the University of Michigan and is a
registered engineer.
Richard J. Pruell, Ph.D.
Dr. Pruell is a research chemist at the Atlantic
Ecology Division (Narragansett, Rhode Island) of EPA's
National Health and Ecological Effects Laboratory. He
received a B.A. hi Biology from Merrimack College, an
M.S. in Marine Biology from Southeastern Massachu-
setts University, and a Ph.D. in Chemical Oceanography
from the Graduate School of Oceanography of the Uni-
versity of Rhode Island. Since receiving his degree in
1984, Dr. Pruell has worked at the Narragansett EPA
laboratory on issues related to the biogeochemistry of
organic contaminants in marine ecosystems.
Mary C. Reiley, M.S.
Ms. Reiley is the Team Coordinator for the Eco-
logical Criteria Team within the Health and Ecological
Criteria Division. She received her B.S. in Biology from
the College of William and Mary and her M.S. in
Environmental Biology from George Mason University.
Ms. Reiley joined the Office of Science and Technology
in 1991 to coordinate the sediment quality criteria pro-
gram. Prior to that she spent 7 years in the Office of Water
Enforcement Program, where she was the Team Leader
for the Toxics Team and involved in a variety of issues
including permitting limits set below detection, whole
effluent toxicity, and compliance negotiations. Her
current role as Ecological Criteria Team Coordinator
maintains her involvement in methodology and criteria
development and technical support for aquatic life as-
sessments, sediment quality assessment, and whole ef-
fluent toxicity testing. The team works closely with the
Surface Water Assessment Team, on which Ms. Reiley
serves as the program lead for integrated pathways
analysis for criteria development.
Norman I. Rubinstein, M.S.
Mr. Rubinstein is the Acting Division Director for
the National Health and Environmental Effects Research
Laboratory, Atlantic Ecology Division, in Narragansett,
Rhode Island. He received his B.S. in Biology from the
City College of New ,York and his M.S. in Marine
Science from the University of West Florida. He joined
EPA in 1976 as a research aquatic biologist at the
Environmental Research Laboratory, Gulf Breeze,
Florida. In 1983 Mr. Rubinstein joined the research staff
at the Environmental Research Laboratory, Narragansett,
Rhode Island where he focused his studies on the
bioavailability of contaminants in sediments. He became
Chief of the Research Exposure Branch at the Narragansett
Laboratory in 1989 and was appointed Deputy Director for
Research in 1994. He has been the apting Division
Director at Narragansett since the ORD laboratory reorga-
nization in 1995. Mr. Rubinstein has been associated with
EPA's research efforts in support of the Ocean Disposal
Program since the development of the original dredged
material testing manual (the "Green Book") in 1976.
Burt K. Shephard, M.S.
Mr. Shephard is a senior ecotoxicologist with URS
Greiner, Inc., in Seattle, Washington. He received his
B.S. in Chemistry and M.S. in Environmental Health
from Purdue University. He also has completed course
work toward a Ph.D. in Fisheries Biology from Iowa State
University, where he is a past recipient of the Society of
Environmental Toxicology and Chemistry Pre-Doctoral
Fellowship Award. Mr. Shephard has nearly 20 years of
experience working to evaluate the environmental im-
pacts or ecological risks of metals, nutrients, PCBs,
chlorinated insecticides, and PAHs for both environmen-
tal consulting firms and EPA. This work has taken him
throughout the United States, as well as to several foreign
countries. Mr. Shephard's current work involves defin-
ing ecological risks to aquatic biota from bioaccumulated
chemicals.
Elizabeth Southerland, Ph.D.
Dr. Southerland is Acting Director of the Standards
and Applied Science Division in EPA's Office of Water
in Washington, D.C. Dr. Southerland received her Ph.D.
in Environmental Science and Engineering from Virginia
Polytechnic Institute and State University. Over the past
25 years, she has held a variety of positions in state and
local government, consulting engineering, and EPA. Dr.
Southerland is currently the Acting Director of EPA's
Standards and Applied Science Division, which is re-
sponsible for the national water quality standards pro-
gram and environmental assessments in support of water
quality- and sediment quality-based controls.
Robert V. Thomann, Ph.D.
Dr. Thomann is Professor of Environmental Engi-
neering at Manhattan College. He received a bachelor's
degree in Civil Engineering from Manhattan College hi
1956, a master's degree in Civil Engineering from New
York University in 1960, and a Ph.D. in Physical Ocean-
ography from New York University in 1963. He spent 10
years with the U.S. Public Health Service from 1956 to
1966, during which time he was Technical Director for
the Delaware Estuary Study. Dr. Thomann joined the
faculty of Manhattan College in 1966. His work has been
in mathematical modeling of water quality and ecosystem
-------
, Proceedings
fate, transport, and transformation processes. He has
published about 50 papers and two books, has lectured at
a variety of institutions, and has received several honors
for his research work. Dr. Thomann has worked on many
major water bodies in the United States and abroad and
is currently doing research on modeling bioaccumulation
processes including the transfers of PCBs in the Hudson
estuary aquatic food web.
8-7
Ecology in Olympia, Washington, for the past 3 years.
She received a B.S. in Human Ecology/Public Policy
from Rutgers University and an M.P.H. in Environmental
Health from the University of California, Berkeley. Prior
to working for the Department of Ecology, Ms. Weiss
worked as a pesticide policy specialist and organizer for
the environmental and consumer group Public Citizen in
Washington, D.C,
Nelson A. Thomas, B.S.
Mr. Thomas received bis B.S. in Natural Resources
(fisheries) from the University of Michigan. He was the
limnologist for the State of Ohio when Lake Erie was
discovered to be greatly affected by eutrophication. He then
joined the U.S. EPA and served as chief biologist for the
Office of Enforcement and Standards. After 10 years, he
assumed a research position to conceive, supervise, and
conduct large lakes research. Currently, as senior advisor
for national programs with EPA, he develops and coordinates
freshwater research for the control of toxic chemicals. His
areas of responsibility include water quality criteria,
complex effluent toxicity testing, sediment quality criteria;
and integrated watershed assessment for ecosystem
protection.
Marc L. Tuchman, Ph.D.
Dr. Tuchman received his B.S. in Biology from
Colgate University and his Ph.D. in Natural Resources
from the University of Michigan. He has been with EPA
for the past 12 years, working in the Waste Division and
Water Division prior to his current position in the Great
Lakes National Program Office (GLNPO). Over the past
10 years, Dr. Tuchman has been involved in a variety of
contaminated sediment and dredging issues. For 6 years
he was actively involved in EPA's Assessment and
Remediation of Contaminated Sediments (ARCS) Pro-
gram, having served as Program Manager for the latter 2
years of the program. Dr. Tuchman currently serves as
team leader of GLNPO's Sediment Assessment and
Remediation Team, where he is responsible for coordi-
nating GLNPO's sediment assessment and remediation
activities in the Great Lakes basin.
Laura B. Weiss, M.P.H.
Ms: Weiss is a toxicologist who has been the
project manager for the development of health-based
sediment criteria for the Washington State Department of
Lawrence J. Zaragoza, Ph.D.
Dr. Zaragoza received his doctorate in Environ-
mental Science and Engineering from the University of
California at Los Angeles in 1982. He started with EPA
in 1979 in the Office of Air Quality Planning and
Standards. Today, Dr. Zaragoza works for EPA's
Office of Emergency and Remedial Response, which
administers the Headquarters • component of the
Superfund Program. His responsibilities at EPA have
included representing the OERR on issues related to
contaminated sediments, the identification of research
needs for- the air and hazardous waste programs, and
Project Officer responsibilities for the Interagency
Agreements with the Agency for Toxic.Substances and
Disease Registry (ATSDR) and the National Institute
for Environmental Health Statistics .(NIEHS).
Dr. Zaragoza has experience in drafting of EPA regula-
tions (e.g., National Ambient Air Quality Standards, air
toxics, revisions to the Hazard Ranking System) and
guidances (e.g., Risk Assessment Guidance for
Superfund and Capacity Assurance Guidance).
Maurice Zeeman, Ph.D.
Dr. Zeeman is Chief of the Environmental Effects
Branch in the Health and Environmental Review Divi-
sion of OPPT at EPA Headquarters. He directs 16
professional experts in their assessment of the potential
ecological hazards and risks of thousands of new and
existing industrial chemicals evaluated under the Toxic
Substances Control Act (JSCA). He also teaches a
course in environmental toxicology in the Department
of Pharmacology and Toxicology for the Graduate
School at the National Institutes of Health. Prior to
joining EPA, he was an expert toxicologist for the U.S.
Food and Drug Administration, where he evaluated the
effects of chemicals on humans (under the FD&C Act)
and on the environment (under NEPA). Dr. Zeeman
received a Master's in Zoology/Ecology from
UCLA and a Ph.D. in Biology from Utah State
University.
-------
-------
National Sediment tSioaeeumulation
September 11-13,1996
Hyatt Regency
Bethesda, Maryland
FINAL AGENDA
Sponsored by:
Office of Water/Office of Science and Technology
Office of Research and Development
Wednesday, September 1 1
7:30-8:30 Registration
8:30-8:45 Welcome and Introduction
Dr. Elizabeth Southerland and
Dr. Thomas Armitage
Office of Science and Technology
U.S. Environmental Protection Agency
BIOACCUMULATION OVERVIEW AND APPROACHES
8:45-9:15 Contaminated Sediments: State of the
Science and Future Research Directions
Dr. Oilman D. Veith, Associate Director for
Ecology
National Health and Environmental Effects
Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Field and Laboratory Methods for Measuring
Bioaccumulation
Moderator: Dr. Peter Chapman
EVS Environmental Consultants, Ltd.
9:15-9:40 Methods for Assessing Sediment
Bioaccumulation in Marine/Estuarine
Benthic Organisms
Dr. Henry Lee
Office of Research and Development
U.S. Environmental Protection Agency
9:40-10:05 Methods for Assessing Bioaccumulation
of Sediment-Associated Contaminants
with Freshwater Invertebrates
Dr. Christopher Ingersoll
Environmental Contaminants Research Center
U.S. Geological Survey
10:05-10:20 Break
10:20-10:45 Kinetic Models for Assessing
Bioaccumulation
Dr. Peter Landrum
Great Lakes Environmental Research
Laboratory
National Oceanic and Atmospheric
Administration
10:45-11:15 Discussion/Question and Answer
Session
11:15-12:30 Lunch
Interpretation and Applications of
Bioaccumulation Results '
Moderator: Dr. Richard Pruell
Office of Research and Development
U.S. Environmental Protection Agency
12:30-12:55 Reference Sediment Approach for
Determining Sediment Contamination
' ' - Mr. Norman Rubinstein
Office of Research and Development
U.S. Environmental Protection Agency
12:55-1:20 Development of Tissue Residue
Threshold Values
Dr. David Mount
Office of Research and Development
U.S. Environmental Protection Agency
1:20-1:45 Use of Tissue Residue Data in Exposure
and Effects Assessments for Aquatic
Organisms
Mr. L. Jay Field
National Ocean Service
National Oceanic and Atmospheric
Administration
-------
Final Agenda
1:45-2:10 Comments on the Significance and Use
of Tissue Residues in Sediment
Toxicology and Risk Assessment
Dr. Lynn McCarfy
LS McCarty Scientific Research & Consulting
2:10-2:35 Quantification of Ecological Risks to
Aquatic Biota from Bioaccumulated
Chemicals
Mr. Burt Shephard
URS Greiner, Inc.
2:35-3:05 Discussion/Question and Answer
Session
3:05-3:25 Break
Modeling Bioavailability of Sediment
Contaminants
Moderator: Mr. Nelson Thomas
Office of Research and Development
U.S. Environmental Protection Agency
3:25-3:50 Equilibrium Partitioning and Organic
Carbon Normalization
Dr. Dominic Di Toro
HydroQual, Inc.
3:50-4:15 Estimating Bioaccumulation Potential in
Dredged Sediment Regulation
Dr. Victor McFarland
Waterways Experiment Station
U.S. Army Corps of Engineers
4:15-4:40 Development of Bioaccumulation Factors
for Protection of Fish and Wildlife in the
Great Lakes
Dr. Philip Cook
Office of Research and Development
U.S. Environmental Protection Agency
4:40-5:00 From Modeling to Criteria: Integrated
Approach to Criteria Development
Ms. Mary Reiley
Office of Science and Technology
U.S. Environmental Protection Agency
5:00-5:30 Discussion/Question and Answer
Session
6:00-7:00 Welcome Reception
Thursday, September 12
Food Chain Models and Bioenergetics
Moderator: Dr. Lawrence Burkhard
Office of Research and Development .
U.S. Environmental Protection Agency
8:30-9:00 Food Chain Models for Predicting
Bioaccumulation
Dr. Frank Gobas
Simon Fraser University
9:00-9:30 Use of Food Web Models to Evaluate
Bioaccumulation Data
Dr. John Connolly
HydroQual, Inc.
9:30-10:00 Bioaccumulation Modeling of PCBs in
the Hudson Estuary: A Review and
Update
Dr. Robert Thomann
Manhattan College
10:00-10:30 Discussion/Question and Answer
Session
10:30-10:45 Break
BIOACCUMULATION AND RISK ASSESSMENT
10:45-11:15 Risk Assessment Overview
Dr. Dorothy Patton
Office of Research and Development
U.S. Environmental Protection Agency
Human Health-Based Risk Assessment
Moderator: Dr. Marc Tuchman
Great Lakes National Program Office
U.S. Environmental Protection Agency
11:15-11:45 Methodology for Assessing Human
Health-Based Risks
Dr. Judy Crane
Minnesota Pollution Control Agency
11:45-1:00 Lunch
-------
Final Agenda
Case Studies:
1:00-1:45 Bioaccumulation Models and
Applications: Setting Sediment Cleanup
Goals in the Great Lakes
Ms.AmyPelka
Region 5
U.S. Environmental Protection Agency
1:45-2:15 Use of Human Health- and Ecological-
Based Goals in Developing a Whole
River Sediment Strategy: Fox River, Wl
Mr. Robert Paulson
Wisconsin Department of Natural
. Resources
2:15-2:45 Development of Health-Based Sediment
Criteria for Puget Sound
Ms. Laura Weiss
Washington Department of Ecology
2:45-3:15 Development of Bioaccumulation
Guidance for Dredged Material
Evaluations in EPA Region 2
Mr. Alex Lechich
Region 2
U.S. Environmental Protection Agency
3:15-3:45 Discussion/Question and Answer
Session
3:45-4:00 Break
Ecological-Based Risk Assessment
Moderator: Dr. James Andreasen
Office of Research and Development
U.S. Environmental Protection Agency
4:00-4:30 Use of Bioaccumulation Data in Aquatic
Life Risk Assessment
Dr. Wayne Munns
Office of Research and Development
U.S. Environmental Protection Agency
4:30-5:00 Wildlife Risk Assessment
Dr. David Charters
• Office of Solid Waste and Emergency
Response
U.S. Environmental Protection Agency
5:00-5:30 Discussion/Question and Answer
Session
Friday, September 13
BIOACCUMULATION RESULTS AND DECISION-
MAKING
Integrating Bioaccumulation Results into EPA's
Decision-Making Process
Moderator: Dr. Elizabeth Southerland
Office of Science and Technology
U.S. Environmental Protection Agency
8:30-8:40 Opening Remarks
Dr. Elizabeth Southerland
Office of Science and Technology
U.S.^Environmental Protection Agency
8:40-9:00 Bioaccumulation Testing and
Interpretation for the Purpose of
Sediment Quality Assessment: Status
and Needs
Mr. Michael Kravitz
Office of Science.and Technology
U.S. Environmental Protection Agency
9:00-10:30 Panel Presentations
• Superfund Program
Dr. Lawrence Zaragoza
• NPDES Program
Mr. James Pendergast
• Office of Pollution Prevention and Toxics
Mr. Thomas Murray
Dr. Maurice Zeeman
• Dredged Material Program
Mr. Craig Vogt
Mr. Mario Del Vicario
10:30-10:45 Break
10:45-12:00 Panel Discussion
• Common Elements Among Programs
• Barriers to Decision-Making
• Recommendations
12:00-12:30 Future Needs/Conference Wrap Up
-------
-------
National Sediment Bioaccumulation Conference
September 11-13,1996
Bethesda, Maryland
LIST OF ATTENDEES
ToddAbel
McLaren/Hart - ChemRisk
1685 Congress Street
Portland, ME 04102
PH 207/774-0012
FX 207/774-8263
JimAhl _/;.. ' -'. •
Maryland D^R/Tawes State Office Building
580 Taylor Ave (Building E-2)
Annapolis, MD 21401
PH 410/974-2985,..:'
FX 410/974-2833
Robert Allen
Delaware DNREC
715 Grantham Lane.
Newcastle, DE 19720
PH 302/323-4540
FX 302/3234561
David Altfater •
Ohio EPA
1685 Westbelt Drive
Columbus, OH 43228
PH 614/728-3400
FX 614/728-3380
James Andreasen (8623)
U.S. EPA/ORD/NCEA
401 M Street, SW
Washington, DC 20460
PH 202/260-5259
FX 202/260-8719
Alan Anthony
VA Department of Environmental Quality
P.O. Box 10009
Richmond, VA 23240-0009
PH 804/698-4114
FX 804/698-4522
Thomas Ardito
NOAA/NMFS
1315 East-West Highway, SSMC3, F/HP5
Silver Spring, MD 20910-3282
PH 301/713-0174x106
FX 301/713-0184'
Thomas Armitage (4305)
U.S.EPA/OST
401 M Street, SW
Washington, DC 20460
PH 202/260-5388
FX 202/260-9830
Ray Arnold
Exxon Biomedical Sciences
Mettlers Road, CN 2350
East Millstone, NJ 08875
PH 908/873-6305
FX 908/873-6009 '
ArtAsaki •
U.S. Army Ctr for Health Prom. & Prev. Medicine
ATTN: MCHB-DC-ES, 5158 Blackhawk Road
Aberdeen Proving Ground, MD 21020-5422
PH 410/671-3816 .
FX 410/671-8104 , •
Denise Baker
U.S. Fish and Wildlife Service
3704 Griffin Land, SE, Suite 102
Olympia, WA 98501
PH 360/753-5821
FX 360/753-9008 . • ,
Michael Barbachem
URS Consultants, Inc.
5606 Virginia Beach Blvd.
Virginia Beach, VA 23462-5631
PH 757/499-4224
FX 757/473-8214
Robert Barrick ,
PTI Environmental Services
15375 SE 30th Place, #250
Believue, WA 98007
PH 206/643-9803-'
FX 206/643-9827 •
Justine Barton (ECO-083)
U.S. EPA Region 10
1200 6th Ave.
Seattle, WA 98101
PH 206/553-4974
FX 206/553-1775
Steven Bay
So. California Coastal Water Research
7171 Fenwick Lane
Westminster, CA 92683
PH 714/894-2222
FX 714/894-9699
Chris Beaverson
U.S. EPA Region 10/NOAA
1200 Sixth Avenue
Seattle, WA 98101
PH 206/553-2101
FX 206/553-0124
Russell Bellmer
NOAA/NMFS • -
1315 East-West Highway
Silver Spring, MD 20910-3226
PH 301/713-0174
FX 301/713-0184
Joanne Benante
U.S. EPA Region 4
345 Courtland Street, NE
Atlanta, GA 30365
PH'404/347-3555
FX 404/347-3058
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LIST OF ATTENDEES (continued)
Channing Bennett
US. EPA Region 4
345 Courtland Street
Atlanla, GA 30365
PH 404/347-3555, X6317
FX 404/347-1918
Walter Berry
'U.S. EPA
27 Tarzwell Drive
Narragansett, Rl 02882
PH 401/782-3101
FX 401/782-3030
Jeff Bigler (4305)
U.S. EPA/SASD
401 M Street, S.W.
Washington, DC 20460
PH 202/260-1305
FX 202/260-9830
David Bleil
Maryland Department of Natural Resources
580 Taylor Ave (Tawes State Office Bldg)
Annapolis, MD 21401
PH 410/974-2988
FX 410V974-2833
Robert Boethling (7406)
U.S. EPA/EETD/EAB
401 M Street, S.W.
Washington, DC 20460
PH 202/260-3912
FX 202/260-0981
Callie Bolattino (G-9J)
U.S. EPA Region 5/Great Lakes Nat'l Prog. Ofc
77 W. Jackson Blvd
Chicago, IL 60604
PH 312/353-3490
FX 312/353-2018
Suzanne Bollon
NOAAMMFS/ST2
2421 S.Dinwiddie Street
Arlington, VA 22206
PH 301/713-2367
FX 301/713-2813
Weldon Bosworth
Dames and Moore
5 Industrial Way
Salem, NH 03079
PH 603/893-0616
FX 603/893-6240
Dumont Bouchard
U.S. EPA/ORD
460 College Station Road
Athens, GA 30605
PH 706/546-2248
FX 706/546-2459
Lisa Bradford
U.S. EPA Region 3
841 Chestnut Street
Philadelphia, PA 19107
PH 215/566-3363
FX 215/566-3001
Todd Bridges
U.S. Army Corps of Engineers
USAE WES ES-F, 3909 Halls Ferry Road
Vicksburg, MS 39180
PH 601/634-3626
FX 601/634-3713
Tom Brosnan
New York City Department of Env. Protection
RM 213, New Administration Bldg
Wards Island, NY 10035-6096
PH 212/860-9378
FX 212/860-9570
Dail Brown
National Marine Fisheries Service
1315 East-West Highway
Silver Spring, MD 20910-3226
PH 301/713-2325
FX 301/713-1043
Kurt Buchholz
Battelle Ocean Sciences
2101 Wilson Blvd., Suite 800
Arlington, VA 22201-3008
PH 703/875-2947
FX 703/527-5640
Al Buoni
Labat-Anderson Incorported
8000 Westpark Drive, Suite 400
McLean, VA 22102
PH 703/506-9600
FX 703/5064646
Kelly Burch
PA Dept. of Environmental Protection
230 Chestnut Street
Meadville, PA 16335
PH 814/332-6816
FX 814/332-6125
Lawrence Burkhard
U.S. EPA/ORD/NHEERL
6201 Congdon Blvd
Duluth, MN 55804
PH 218/720-5554
FX 218/720-5539
John Burleson
Marine Corps Base Quantico/Nat. Res. Env. Affr Br
3040 McCawley Ave., Suite 2 ,
Quantico.VA 22134
PH 703/784-4030
FX 703/784-4953
Janet Burn's
ChemRlsk
109 Jefferson, Suite D
Oak Ridge, TN 37830
PH 423/483-5081
FX 423/482-9473
Dennis Burton
University of Maryland
P.O. Box 169
Queenstown, MD 21658
PH 410/827-8056
FX 410/827-9039 ,
Scott Burton
Maxus Energy Corporation
1015 Belleville Turnpike
Kearny.NJ 07032
PH 201/955-0855
FX 201/955-1063
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LJST:QF ATTENDEES (continued)
Jonathan Butcher
The Cadmus Group
1920 Highway 54, Suite 100
Durham, NC 27713
PH 919/544-6639
FX 919/544-9453
Richard Cahill
Illinois State Geological Survey
615 East Peabody Drive
Champaign, IL 61820 '••
PH 217/244-2532
FX 217/244-2785
Teresa Caputi
Malcolm Pirnie, Inc.
One International Blvd.
Mahwah, NJ 07495
PH 201/529-0858 ext 303
FX 201/529-0855
Norman Carlin
Sidley and Austin
875 Third Avenue
New York, NY 10022
PH 212/908-2325
FX 212/908-2021'
•Thomas Carpenter
ICF Kaiser
9300 Lee Highway
Fairfax, VA 22031
PH 703/218-2757
•FX 703/934-3178
JodiCassell. ' ' . .
UC Sea Grant Extension
300 Piedmont Avenue, Room 305A
San Bruno, CA '94066
PH 415/871-7559
FX 415/871-7399 '.'"'..
Peter Chapman .,-...
EVS Environmental Consultants -
195PembertonAve ,
North Vancouver, Brit.Cq., V7P 2Ri
PH 604/986-4331
FX 604/662-8548
Dave Charters
U.S. EPA, Environmental Resp. Branch
2890 Woodbridge Avenue, Bldg 18, MS:101
Edison, NJ 08837-3679
PH 908/906-6825 "•' ' ' , ,•
FX 908/321-6724 , '
Eugenia Chow
U.S. EPA Region.5
77 West Jackson Blvd
Chicago, IL 60604
PH 312/353:3156 '
FX 312/886-4071'
Karen Chytalo
NYS Department of- Eny. Conseryation ,
205 S. Belle Meade Road
EastSetauket, NY 11733 •-, .
PH 516/444-0468.' --'•../ ' ,
FX 516/444-0474 -'• '
Stephen Cibik
ENSR . • - _ ,
35'NagpgPark ' ,
Acton, MA 01720
PH 508/635-9200x3072
FX 508/635-9180
David Clarke . " .. '. '
Inside Washington Publishers, Risk Policy Rpt
1225 Jefferson Davis Highway, Suite 1400
Arlington, VA 22207
PH 703/416-8564
FX 703/416-8543 '. ••'.-'
Rosita Clarke-Moreno
U.S. EPA/SFD
77 W.Jackson Blvd.
Chicago, IL 60604
PH 312/886-7251
FX 312/353-5541
John Clayton
Ogden Environmental and Energy Services
5510 Morehouse Drive.
SanDeigo.CA 92121'".-""'"
PH 619/458-9044x338 ' ,
FX 619/458-0943 '
James Collier
District of Columbia
2100 Martin Luther King, Jr.. Drive, SE
Washington, DC 20020 •' ••.
PH 202/645-6601 ".
FX 202/645-6622 ' . •
JoanColson • -
,y,S.,EPA/ORD, Natl Risk Mgmt Res. Lab.
26 M L King Drive ."...'...
Cinncinati,OH 45268 ',.' ' ..''.
PH 513/569-7501 '-.-. ; . .'•'
FX 513/569-7585 '.;-'
John Connolly
HydroQual, Inc.
1 Lethbridge Plaza
Mahwah, NJ 07430
PH 201/529-5151
FX 201/529-5728
Phil Cook
Mid-Continent Ecology, Division/U.S. EPA/ORD
6201 Congdon Blvd • , '
Duluth, MN 55804
PH 218/720-5553
FX 218/720-5539
Marjorie Coombs (4305)
U.S. EPA/OST/SASD
401 M Street, SW ' ''. ,
Washington, DC 20460
PH 202/260-9821
FX 202/260-9830
Jack Cooper
NYS DEC, Bureau of Eny. Protection
50 Wolf Road-
Albany, NY 12233-4756 -
PH 518/457-1769 .
FX 518/485-8424 , .
Helder Costa
ITS Environmental Labs
375 Paramount Drive, Suite B
Raynham, MA 02767-5154
PH 508/990-1424
FX 508/990-1424'-
-------
LIST OF ATTENDEES (continued)
Bcmie Counts
Ohio EPA
1685 Weslbelt Drive
Columbus, OH 43228
PH 614/728-3399
FX 614/728-3380
Martin Coyne
Inside Washington Publisher
1225 Jefferson Davis Highway, Suite 1400
Arlington, VA 22207
PH 702/416-8564 '
FX 702/416-8543
David Cozzie (5307W)
U.S. EPA/OSW .
401 M Street, SW
Washington, DC 20460
PH 703/308-0479 '
FX 703/308-0511
Greg Cramer
U.S. Food and Drug Administration. HFS-416
2SOC Street, SW
Washington, DC 20204
PH 202/418-3160
FX 202/418-3196
Judy Crane
MN Pollution Control Agency, Water Quality Div.
520 Lafayette Road
St. Paul, MN 55155-4194
PH 612/2974068
FX 612/297-8683
Philip Crocker.
U.S. EPA Region 6
1445 Ross Avenue
Dallas, TX 75202-2753
PH 214/665-6644
FX 214/665-6689
Rico Cruz
Nez Perce Tribe
P.O. Box 365
Lapwal, ID 83540
PH 208/843-7375
FX 208/843-7378
John Cubit
NOAA - Damage Assessment Center
501 West Ocean Blvd., Suite 4470
Long Beach, CA 90802
PH 310/9804081
FX 310/9804084
Linda Cummings .
Terra Consulting Group
8900 Anselmo Lane
Baton Rouge, LA 70810
PH 504/769-1141
FX 504/769-1724
Jerome Cura
Menzle-Cura and Assoc., Inc.
One Courthouse Lane, Suite 2
Cheimsford, MA 01824
PH 508/4534300
FX 508/453-7260
Bradford Gushing
Applied Environmental Management, Inc.
16 Chester County Commons
Malvern, PA 19355
PH 610/251-0450
FX 610.251-0711
Visty Dalai
Maryland Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
PH 410/631-3689
FX 410/631-7034
Bernard Daniel
U.S.EPA/NERL
26 West Martin Luther King Drive
Cincinnati, OH 45268
PH 513/569-7401
FX 513/569-7609
Paul Danielson
Nez Perce Tribe
P.O. Box 365
Lapwai, ID 83540
PH 208/843-7375
FX 208/843-7378
Patrick Dargan
ALCOA
ALCOA Massena OPNS, Park Ave.
Massena, NY 13662
PH 315/7644287
FX 315/7644444
Jim Davenport (MC-150)
Texas Natural Resource Conservation Comm.
P.O. Box 13087
Austin, TX 78711-3087
PH 512/2394585
FX 512/2394420
Tudor Davies (4301)
U.S. EPA/OST
401 M Street, SW
Washington, DC 20460
PH 202/260-5400
FX 202/260-5400
Helen Davies
NSW EPA
799 Pacific Highway
Chatswood, NSW Australia,
PH 61.29325.5715
FX 61.29325.5788
2057
Mick DeGraeve
GlEC
739 Hastings
Traverse City, Ml 49686
PH 616/941-2230
FX 616/941-2240
Tod DeLong
Roy F. Weston, Inc.
OneWestonWay
West Chester, PA 19380-1499
PH 610/701-7304
FX 610/701-7401
Ted DeWitt
Battelle Marine Sciences Laboratory
1529 W.Sequim Bay Road
Sequim, WA 98382
PH 360/681-3656
FX 360/681-3681
-------
LIST OF ATTENDEES (continued)
Cynthia Decker
New York State Department of Env. Conserv.
205 N. Belle Mead Road
East Setauker, NY 11733
PH 516/444-0462 ' .
FX 516/444-0474 ' •'
Mario Del Vicario •
U.S. EPA Region II
250 Broadway
New York, NY 10007
PH 212/637-3781
FX 212/637-3889
Edward Demarest
NJ Department of Enviornmental Protection
4th floor, west, CN413
Trenton, NJ 08625-0413
PH 609/633-1348
FX 609/292-0848
TedDewitt
Battelle Marine Sciences, Marine Eco. Proc. Group
• 1529 W.Sequim Bay Road
Sequim, WA 98382
PH 360/681-3656
FX 360/681-3681
DomDiToro
HydrbQual, Inc.
Onelethbridge Plaza
Mahwah, NJ 07430
PH 201/529-5928
FX 201/529-5728
Lisa DiPinto
NOAA - Damage Assessement Center
1305 East-West Highway, Rn\ 10218
Silver Spring, MD 20910
PH 301/713-3038x187
FX 301/7134387
Rebecca Dickhut
College of William and Mary '_ '
Virginia Institute of Marine Science
Gloucester Point, VA 23062
PH 804/642-7247
FX 804/642-7186
Tom Dillon
EA Engineering, Science and Technology
11019McCormickRoad
Hunt Valley, MD 210'3f
PH 410/584-7000
FX 410/785-2309
L.K. Dixon
Mote Marine Laboratory
1600 Thompson Parkway
Sarasota, FL 34210
PH 941/388-4441 .
FX 941/3884312
Charles Dobbs
ALCOA Tech Center
100 Technical Drive
Alcoa Center, PA 15069
PH 412/337-2164
FX 412/337-1860
Chuck Dobroski
Roy F. Weston, Inc.
OneWestonWay •
West Chester, PA 19380-1499
PH 610/701-7216
FX 610/701-7401
Philip Dorn
Shell Development Company
P.O. Box 1380
Houston, TX 77251-1380
PH 713/544-7855
FX 713/544-8727
Barbara Douglas
Navy Facilities Engineering Command
10 Industrial Highway, MSC #82
Lester, PA 19113 '
PH 610/595-0567x188
FX 610/595-0555
Philip Downey, Ph.D.
Inchcape Testing Services
55 South Park Drive
Colchester, VT 05446
PH 802/655-1203x11
FX 802/658-3189
Kelly Eisenman
U.S. EPA Chesapeake Bay Program
'410 Severn Ave., Suite 109 '
Annapolis, MD 21403
PH 410/267-5728
FX 410/267-5777
Jim Eldridge
SAIC
18706 North Creek. Parkway, Suite 110
Bothell, WA 98011
PH 206/485-5800
FX 206/485-5566
Bonnie ElederT-17J
U.S. EPA Region 5
77 W. Jackson Blvd.
Chicago, IL 60102
PH 312/8864885
FX 312/886-2737
Michael Elias
ICF Kaiser
9300 Lee Highway
Fairfax, VA 22031
PH 703/934-3838
FX 703/934-3315
Steve Ells (5204G)
U.S. EPA/Superfund
401 M Street, SW •
Washington, DC 20460
PH 703/603-8822
FX 703/603-9100
Alex Ellwood
Penn State University, Applied Research Lab
331 W. College Avenue
State College, PA 16801 ••'''.'
PH 814/237-8120
FX 814/863-7304
Mohamed Elnabarawy .. . '
3M Environmental Technology and Services
879 East 7th St., Bldg. 41-01-05 P.O. Box 33331-
St. Paul, MN 55133-3331 ' - •
PH 612/778-5151
FX 612/778-7203 . .
-------
LIST OF ATTENDEES (continued)
Vaiten Emery, Jr. ((ES-)F)
USAGE
3909 Halls Ferry Road
VJcksburg, MS 39180-6199
PH 601/634-4302
FX 601/634-3713
David Engel
NOAA/NMFS/Beaufort Lab.
101 Rivers Island Road
Beaufort, NC 28516
PH 919/728-8741"
FX 919/728-8784
David Evans
NOAA/NMFS/Beaufort Lab.
101 Piversjsland Road
Beaufort, NC 28516,
PH 919/728-8752
FX 919/728-8784
Jane Marshall Farris (4305)
U.S. EPA/OST
401M Street, SW
Washington, DC 20460
PH 202/260^8897
FX 202/260-9830
James Felkel( 7507C)
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 703/305-5828
FX 703/305-6309 '
Jay Field
NOAA/HMRAD N/ORCA 32
BINC15700
Seattle, WA 98115
PH 206/526-6404
FX 206/526-6941
John Fifkins
U.S. EPA/ORD/MED, Large Lakes Res. Station
9311 Groh Road
Grosselle.MI 48138
PH 313/692-7614
FX 313/692-7603
Ken Finkelstein
NOAA
c/o EPA, JFK Federal Building (HIO)
' Boston, MA 02203
PH 617/223-5537
FX 617/573-9662
Dan Fisher
University of Maryland
P.O. Box 169
Queenstown, MD 21,601
PH 410/827-8056
FX 410/827-9039
Bob Fotey
U.S. Fish and Wildlife Service
177 Admiral Cochrane Drive
Annapolis, MD 21401
PH 410/573-4519
FX 410/269-0832
Catherine Fox (2222A)
U.S. EPA/OECA
401 M Street, SW
Washington, DC 20460
PH 202/5644299
FX 214/564-0031
Rick Fox
H^rt Crowser
One O'Hare Centre, 6250 River Road, Suite 3000
Rosemont, IL 60018
PH 847/292-4426
FX 847/292-0507 .
LeoFrancendese
U.S. EPA Region 4
345 Courttand Street, NE
Atlanta, GA 30365
PH 404/3474931 x6104
FX 404/347-7817
Ronald French
Camp Dresser and McKee, Inc.
One Woodward Ave., Suite 1500
Detroit, Ml 48226
PH 313/963-1313
FX 313/963-3130
Alyce Fritz (N/ORCA 32}
DOC/NOAA/HAZMAT
7600 Sand Point Way, NE'
Seattle, WA 98115
PH 206/526-6305
FX 206/526-6865
Awilda Fuentes 5202G
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 703/603-8748
FX 703/603-9133
Taku Fuji
Hart Crowser
1910 Fairview Ave., East
Seattle, WA 98102
PH 206/324-9530
FX 206/328-5581
Cris Gaines (4305)
U.S. EPA/OST/SASD
. 401 M Street, SW
Washington, DC 20460
PH 202/260-6284
FX 202/260-9830
William Gala
Chevron Res. and Technol. Co.
100 Chevron Way
Richmond, CA 94802
PH 510/242-4361
FX 510/242-5577
Gayle Carman
NOAA; Hazmat, Coastal Res. Coord. Branch
7600 Sand Point Way, NE
Seattle, WA 98115
PH 206/5264542
FX 206/526-6865
Mary Jo Garreis
MD Department of the Environment
2500 Braening Highway ,
Baltimore, MD 21224
PH 410/631-3906
FX 410/633-0456
-------
LIST OF ATTENDEES (continued)
Tony Giedt
NOAA.
One Blackburn Drive
Gloucester, MA 01930
PH 508/281-9289 '
FX 508/281-9389
JohnGiga
Baltec Associates
130 Business Park Drive
Armonk, NY 10504
PH 914/273-2626
' FX 914/273-7350
Frank Gpbas
Simon Fraser University
School of Res. & Envir. Mgmt
Burnaby, BC Canada, V7K1S6
PH 604/291-5928
FX 604/291-4968 .
Todd Goeks
NOAA Hazm'at
77 West Jackson Blvd,SRT-4J
Chicago, IL 60604
PH 312/886-7527
FX 312/353-9281
Ibrah'ima Goodwin
U.S. EPA/OW
401 M Street, SW
Washington, DC 20460
PH 202/260-1308
FX 202/260-9830
Joseph Gorsuch
Eastman Kodak Company, Kodak Env. Services
1100 Ridgeway Avenue
Rochester, NY 14652-6255 '
PH 716/588-2124
FX 716/722-3173 . •
Barry Graham
Beta Gamma Services
841 Vale View Drive
Vista, CA 92083 •
PH 619/941-8093
FX 619/941-3252
Emily Green
Sierra Club
214 N Henry Street, Suite 203
Madison, Wl 53703
PH 608/257-4994
FX 608/257-3513
Andrew Green
Waterways Experiment Station, USAGE (NRG)
3909 Halls Ferry Road
Vicksburg, MS 39180-6149
PH 601/634-3889 .
FX 601/634-3120 ' • ' .
Joseph Greenblott (8104)
U.S. EPA/ORD/ORSI .
401 M Street, SW
Washington, DC 20460. '
PH 202/260-0467
FX 202/260-6932
Richard Greene
Delaware Dept. Nat. Res. & Env. Control
89 Kings Highway, P.O. Box 1401
Dover, DE 19903
PH 302/739-4590
FX 302/739-6140
Chuck Grimm
Natural Resources and Env. Affairs Branch
3040 McCawley Ave., Suite 2
Quantico.VA 22134
PH 703/784-4030
FX 703/784-4953
Daniel Grpsse
Terr Aq Env.
3754 Jennifer Street, N.W.
Washington, DC 20015
PH 202/244-4300
FX 202/244-4667
Donald Grothe
Monsanto Company - U4E
800 N. Lindbergh Blvd
St. Louis, MO 63167
PH 314/6944940
FX 314/694-1531
Jeff Grovhoug
NCCOSC-NRaD (U.S.. Navy R&D)
53475 -Strother Road
San Diego, CA.92152-6310
PH 619/553-5425
FX 619/553-6305
Barry Gruessner
ICPRB
6110 Executive Blvd, Suite 300
Rockville, MD 20852
PH 301/984-1908
FX 301/984-5841
Samuel Hadeed
AMSA
1000 Connecticut Ave., NW, Suite 410
Washington, DC 20036
PH 202/833-4655
FX 202/8334657
John Haggard
General Electric Company
1 Computer Drive South
Albany/NY 12205
PH 518/458-6619 '
FX 518/458-1014
Simeon Hahn .
Navy , -
10 Industrial Highway, MS 82
Lester, PA 19113-2090
PH 610/595-0567
FX 610/595-0555
Rob Hale
VIMS/College of William and Mary-
Route 1208 '
GloucsterPt.VA 23062
PH 804/642-7228
FX 804/642-7186
Eve Halper
Interstate Sanitation Commission
311 W. 43rd Street, Room 201
New York City, NY 10036
PH 212/582-0380 .'
FX 212/581-5719
-------
LIST OF ATTENDEES (continued)
Ian Hartwell
NOAA/NMFS
1315 East-West Highway
Silver Spring, MD 20910-3282
PH 301/713-2325
FX 301/713-1043
Timothy Hassett
Hercules Incorporated
9282 SW Hercules Plaza
Wilmington/DE 19894
PH 302/594-7656
FX 302/594-7255
Fred Hauchman (MD-51A)
U.S. EPA
Research Triangle Park, NC 27711
PH 919/541-3893
FX 919/541-0642
Melvin Hauptman
Caribbean Superfund Section II
U.S. EPA Region 2
NewYonXNY 10007-1866
PH 212/637-3952
FX 212/637-3966
Steven Hawthorne
Hampton Roads Sanitation District
P.O. Box 5911
Virginia Beach, VA 23471-0911
PH 804/460-2261
FX 804/460-2372
Wendy Hayes
U.S. Army Ctrfor Health Prom. & Prev. Medicine
ATTN: MCHB-DC-ES, 5158 Blackhawk Road
Aberdeen Proving Ground, MD 21010-5422
PH 410/671-3816
FX 410/671-8104
JeffBenning
NOAA
841 Chestnut Building (3HW41)
Philadelphia, PA 19107
PH 215/566-3329
FX 215/566-3001
Lisa Herschberger
4809 W. 99th Street
Bloomington, MN 55437
PH 612/851-8112
Helen Hillman
NOAA c/o U.S. EPA Region 9
75 Hawthorne Street, 9th floor
San Francisco, CA 94105
PH 415/744-2273
FX 415/744-3123
MHock
Alaska DEC
410 WittoughbyAve., Suite 105
Juneau,AK 99801
PH 907/465-5185
FX 907/465-5274
Erika Hoffman (W-3-3)
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
PH 415/744-1986
FX 415/744-1078
Rick Hoffmann (4305)
U.S. EPA/OST
401 M Street, SW
Washington, DC 20460
PH 202/260-0642
FX 202/260-9830
David Hohreiter
Blasland, Bouck & Lee, Inc.
6723 Towpalh Road, Box 66
Syracuse, NY 13214
PH 315/446-9120
FX 315/446-7485
Stewart Holm
Georgia-Pacific
1875 Eye Street NW, Suite 775
Washington, DC 20006
PH 202/659-3600
FX 202/233-1398
William Honachefsky
NJ Department of Environmental Protection
CN422
Trenton, NJ 08625
PH 609/292-0427
FX 609/633-1095
Doug Hotchkiss
Port erf Seattle
P.O. Box 1209
Seattle, WA 98111
PH 206/728-3192
FX 206/728-3188
Timothy lannuzzi
ChemRisk
1685 Congress Street
Portland, ME 04102
PH 207/774-0012
FX 207/744-8263
Chris Ingersoll
U.S. Geological Survey
4200 New Haven Road
Columbia, MO 65201
PH 573/875-5399x1819
FX 573/876-1896
Andrew Jacobson
Rohm and Haas Company
727 Nofristown Road
Spring House, PA 19477
PH 215/841-7361
FX 215/619-1624
Paul Jacobson
Langhei Ecology, LLC
14820 View Way Court
Gleneig, MD 21737
PH 410/489-3675
FX 410/489-4523
Kathryn Jahn
U.S. Fish and Wildlife Service
3817 Luker Road
Cortland, NY 13045
PH 607/753-9334
FX 607/753-9699
-------
LIST OF ATTENDEES (continued)
Paul Jiapizian .„ '
Maryland Department of the Environment
2500 Broening Highway .".. .
Baltimore, MD 21224 ' ' ''.
' PH 410/631-3906 " - '
FX 410/633-0456 " '
Douglas Johnson :
U.S. EPA Region 4...
100 Alabama Street
Atlanta, GA 30303
PH 404/562-9386
Isabel Johnson
KBN Engineering
6241 N.W., 23rd Street, Suite 500
Gainesville,FL 32653 • •'
PH 352/336-5600
FX 352/336-6603
Robert Jones (7405)
U.S.EPA
401 M Street, S.W.
Washington, DC 20460
PH 202/260-8150*
FX 202/260-1906
Krzysztof Jop
SAIC ; ' ."• . .
165 Dean Knauss Drive
Narragansett; Rl 02882
PH 401/782-1900
FX 401/782-2330
Matt Kadlec ' • i-
ETRP -RIPS/Phamiacology
Dept. of Pharmacology
University, MS 38677 •
PH 601/232-5759
FX 601/232-5148
Robert Kaley, II
Monsanto Company -A2NE
800 North Lindbergh Blvd
St. Louis, MO 63167 •
PH 314/694-8558 ,-
FX 314/694-6858
Susan Kane Driscoil
Virginia Institute of Marine Science
P.O. Box 1346 •'.;•' ;
Gloucester Point, VA'23062 ' ;
PH 804/642-7190
FX 804/642-7097
Hamid Karimi '
Environmental Regulation Administration
2100 Martin Luther King, Jr: Ave.; SW > .
Washington, DC 20020-5732 -
PH 202/645-6611
FX 202/645-6622 • '
Maureen Katz - ••• '-'•
U.S. Department of Justice
P.O. Box 7611, Ben Franklin Station-
Washington,DC 20044. • '••'."..
PH 202/514-2468 .
FX 202/616-6584. '" •''.'-
Jim Keating(4305)'
U.S. EPA/OST/SASD
,401 M Street, SW
Washington, DC 20460
PH 202/260-3845
FX 202/260-9830
'Karen Keeley(CL-111)
•U.S. EPA Region-10
1200 Sixth Ave •••••-
Seattle, WA 98119
PH 206/553-2141
FX 206/553-0124
Mark Kennedy : • •• . .
Greeley and Hansen •
8905 Presidential Parkway, Suite 230
Upper Marlboro, MD 20772-2653 .
PH 301/817-3700 •
FX 301/817-3735 . ' -
John Kern ' ".-..-
U.S. Dept. of Commerce/NOAA •, •• ;;
9721 Executive Center Drive N;, Suite 134:
St. Petersburg, FL 33702
PH 813/570-5391 ' ' '
FX 813/570-5390 • •-'-' •-''••'. •'
Charles King
U.S. EPA/RPM Region 4
100 Alabama Street, N.W.
Atlanta, GA 30303
PH 404/562-8931
FX 404/562-8896
Hal Kirk
Dow Chemical
1803Bldg.
Midland, Ml 48674
PH 517/636-2425
FX 517/638-2425
DeniseKlimas • ?
U.S.'EPA Region 4, Waste Mgmt Div.
100 Alabama Street ' : - -• •'•• '
Atlanta, GA 30303 • :'" ••
PH 404/562-8639 . • •
FX 404/562-8662 . ' •
Alfred Korndoerfer, Jr. .'•'••
NJ Department of Environmental Protection
CN 427 - WMM/Bureau of Water-Monitoring
Trenton, NJ 08625-0427'*''
PH 609/292-0427 ' ' '
FX 609/633-1095 ' '• '••'••
Charles.Kovatch •
Univ. of SC, Department of Env. Health Sciences -
.713 South Holly Street ' ' :'
Columbia, SC 29205 ' • :
PH 803/777-6452
Bill Kramer (301)
U.S. EPA/OW/OST •
401'M Street, SW .
Washington, DC 20460
PH 202/260-5824
FX 202/260-5394
Mike Kravitz (4305)
U.S. EPA/OST ••;
401-M Street, SW
Washington, DC 20460
PH 202/260-8085 -
FX 202/260-9830
-------
LIST OF ATTENDEES (continued)
Stephen Kroner (53Q7W)
U.S. EPA
401M Street, SW
Washington, DC 20460
PH 703/308-0468
FX 703/308-0511
Tim Kubiak
U.S. FWS (ARLSQ 330)
4401 N. Fairfax Drive
Arlington, VA 22203
PH 703/358-2148
FX 702/358-1800
Brent Kuenzli
Ohio EPA
347 N. Dunbrigde Road
Bowling Green, OH 43402
PH' 419/352-8461
FX 419/352-8468
AmddKuzmack(4301)
U.S. EPA/OST
401 M Street, SW
Washington, DC 20460
PH 202/260-5821
FX 202/260-5394
Hector Laguette
Brown and Root Environmental
55 Jonspin Road
Wilmington, MA 01887-1062
PH 508/658-7899
FX 508/658-7870
Dan Landeen
Nez Perce Tribe
P.O. Box 365
Lapwai, ID 83540
PH 208/843-7375
FX 208/843-7378
Peter Landnim
NOAA, Great Lakes Environmental Res. Lab.
2205 Commonwealth Blvd.
Ann Arbor, Ml 48105
PH 313/741-2276
FX 313/741-2055
Gunnar Lauenstein
NOAA/NOS/ORCA21
1305 East West Highway
Silver Spring, MD 20910
PH 301/713-3028x152
FX 301/7134388
Drew Lausch( 3HW50) -
U.S. EPA Region 3
841 Chestnut Building
Philadelphia, PA 19107
'PH 215/566-3359
FX 215/566-3001
AlexLechich
P.O. Box 08742
Point Pteasant Beach, NJ 08742
Henry Lee
Coastal Ecology Branch
U.S. EPA/ORD
Newport, OR 97365-5260
PH 503/867-5000
FX 503/867-4049
G. Fred Lee, P.E., D.E.E.
G. Fred Lee & Associates
27298 E. El Macero Drive
El Macero, CA 95618-1005
PH 916/753-9630
FX 916/753-9956
Sandra Lemlich
USAGE
P.O. Box 3755
Seattle, WA 98124-2255
PH 206/764-6930
FX 206/764-6795
Dennis Leonard
Detroit Edison
2000 2nd Avenue
Detroit, Ml 48070
PH 313/235-8714
FX 313/235-5018
Deborah Lester
Parametrix, Inc.
5808 Lake Washington Blvd
Kirkland, WA 98033
PH 206/822-8880
FX 206/889-8808
Ann Levine
Oregon DEQ
2020 SW 4th Avenue
Portland, OR 97201-4987
PH 503/229-6540
FX 503/229-6945
Wilbert Lick
University of California
Dept. of Mech. Engineering
Santa Barbara, CA 93106
PH 805/8934295
FX 805/893-8651
. Tom Lopes
U.S. Geological Survey
1608 Mountain View Road
Rapid City, SD 57702
PH 605/394-1780x240
FX 605/394-5373
Michael Ludwig
NOAA/NMFS
212 Rogers Ave.
Milfford, CT 06460-6499
PH 203/7834228
FX 203/7834295
Warren Lyman
Camp Dresser and McKee, Inc.
10 Cambridge Center
Cambridge, MA 02142
PH 617/252-8829
FX 617/621-2565
Jeffrey Lynn
• International Paper
6400 Poplar Avenue
Memphis, TN 38147
PH 901/763-6721
FX 901/763-6939
-------
LIST OF ATTENDEES (continued)
Wayne Magley
FL Department of Environmental Protection
2600 Blairstone Road .
Tallahassee, FL 32399-2400
PH 904/921-9487
FX 904/487-3618 '
Amal Mahfouz, Ph.D. (4304)
U.S. EPA/OW/OST
401 M Street, Room #1003
Washington, DC 20460
PH 202/260-9568
FX 202/260-1036
John Malinowski
Chester Engineers
600 Clubhouse Drive
Moon Township, PA 15108
PH 412/269-7716
FX 412/269-5865
Carol-Ann Manen
NOAA - Damage Assessment Center
1305 East-West Highway
Silver Spring, MD 20910
PH 301/713-3038 ext 196
FX 301/713-4387
R. Shawn Martin
St. Regis Mohawk Tribe
RRIBoxSA
Hogansburg, NY 13655
PH 518/358-5937
FX 518/358-6252
Robert Martino
Normandeau Associates
3450 Schuylkill Road
Spring City, PA 19475
PH 610/948-4700
FX 610/948-4752
Dave McBride
Washington State Dept. of Health
P.O. Box 47825
Olympia, WA 98504
PH 360/586-8734
FX 360/586-4499
Lynn McCarty
L.S. McCarty Scientific Research & Cons.
280 Glen Oak Drive ' . '
Oakville, Ontario, L6K2J2
PH 905/842-6526
FX 905/842-6526
Victor McFarland
CEWES, USAGE Waterways Experiment Station
3909 Halls Ferry Road
Vicksburg, MS 39180
PH 601/639-3721
FX 601/634-3120
Beth McGee , • " '
University of Maryland, Wye Research Ctr.
P.O. Box 169
Queentown, MD 21658
PH 410/827-8056
FX 410/827-9039 ' -
1 David McHeriry
Weyerhaeuser Co.
P.O. Box 1391
New Bern, NC 28563
PH 919/633-7632 -:
FX 919/633-7634
Douglas Mclaughlin
Fort Howard Corporation
P.O. Box 19130
Green Bay, Wl 54307-9130
PH 414/435-8821
FX 414/435-2325
Pat McMurray
VA Department of Environmental Quality
629 E. Main Street
Richmond, VA 23219
PH 804/698-4186
FX 804/698-4234
James Meador
NMFS/NOAA
2725 Montlake Blvd. E,
Seattle, WA 98112
PH 206/860-3321
FX 206/860-3335
Kelly Mecum
Chesapeake Bay Program/CRC
410 Severn Ave., Suite 109
Annapolis, MD 21403
PH 410/267-5719
FX 410/267-5777
David Melfi
U.S: Army Corps of Engineers
1776 Niagara Street "
Buffalo, NY 14207
PH 716/879-4349
FX 716/8794355
Margaret Metcalf
Louisiana Office of •Public Health
234 Loyola Avenue, Suite 620
New Orleans, LA 70112
PH 504/568-7309
FX 504/568-7035 ;
Ossi Meyn( 7403)
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 202/260-1264
FX 202/260-1236
David Michaud
Wisconsin Electric Power Company
333 W. Everett Street
Milwaukee, Wl 53201
PH 414/221-2187
FX 414/221-2169
Ron Miller (M/222-A)
NASSCO
P.O. Box 85278
San Diego, CA 92186-5278
PH 619/544-7780
FX 619/232-6411
John Miller (4304)
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 202/260-1038
FX 202/260-1,036 .
-------
LIST OF ATTENDEES Continued)
Geoff Mills
NIWA
P.O. Box 11-115
Hamilton, New Zealand,
PH +64-7-8567026
FX +64-7-856-0151
Michael Montgomery
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
PH 415/744-2242
FX 415/7442180
David Moore
USAGE WES
3909 Halls Ferry Road
Vicksburg, MS 39180
PH 601/637-2910
FX 601/634-3713
Raymond P. Morgan, II
University of Maryland (AEL-CEES)
GunterHall
Frostburg, MD 21532
PH 301/689-3115
David Mount (8101)
U.S. EPA/ORD .
6201 Congdon Blvd.
Duluth, MN 55804
PH 218/720-5616
FX 218/720-5539
•Greg Mullen
MT'Department of Justice
NRDLP
Helena, MT 59601
PH, 406/444-0228 •
FX 406/444-0236
Wayne Munns
Allanlic Ecology Division
U.S. EPA/ORD
Narraganselt, Rl 02882
PH 401/782-3017
FX 401/782-3099
Deirdre Murphy
MD Department of Environment
2500 Broening Highway
Baltimore, MD 21224
PH 410/631-3906
FX 410/633-0456
Thomas Murray (7406)
U.-S: EPA/OPPT
401 M Street, SW
Washington, DC 20460
PH 202/260-1873
FX 202/260-0981
Lewis Nagy
NJ Department of Environmental Proteciton
401 East State Street, 74 West Wing
Trenton, NJ 08625
PH 609/984-1817
FX 609/777-0942
Jerry Neff
Battelle Ocean Sciences
397 Washington Street • -
Duxbury, MA 02332
PH 617/934-0571
FX 617/934-2124
Tony Neville
LABAT
5521 N. 23rd Street
Arlington, VA 22205
PH. 703/506-1400x506
Arthur Newell
NYS Department of Env, Conservation
205-S N. Belle Meade Road
EastSelauket.NY 11733
PH 516/444-0430
FX 516/444-0434
Annette Nold( 7406)
U.S. EPA/OPPTS/OPPT
401 M Street, SW
Washington, DC 20460 -
PH 202/260-3920
FX 202/260-0981
Cynthia Nolt( 8104)
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 202/260-1940
FX 202/260-15932 ;'
Ralph NorthrorX 7405)
U.S. EPA
401M Street, SW
Washington, DC 20460
PH 202/260-5023
FX 202/260-1096
Dale Norton
Washington State Dept. of Ecology
300 Desmond Drive, P.O. Box 47710
Olympia, WA 98504-7710
PH 360/407-6765
FX 360/407-6884
Charles Noss
LERF '.• •
601 Wythe Street
Alexandria, VA 22314
PH 703/684-2470
FX 703/684-2492
Thomas O'Connor
MOM N/ORCA21
1305 East West Highway
Silver Spring, MD 20910
PH 301/71^3028x151
FX 301/713-4388
Steve O'Rourke
Environmental Enforcement, Justice Dept.
P.O. Box 7611
Washington, DC 20044
PH 202/514-2779
FX 202/514-2583 •'
Bill Olsen
US Fish and Wildlife Service
1 DON. Park, Suite 320 "
Helena, MT 59601
PH 406/449-5225
FX 406/449-5339 ;
-------
LIST OF ATTENDEES (continued)
AmyOnufrbck
Maryland Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
PH 410/631-3601
FX 410/6334)456
Steven Osborn
City of San Jose, Environmental Services Dept
4245 Zanker Road
San Jose, CA 95134
PH 408/945-3714 '
FX 408/934-0491 ,
Randy Palachek
.Parsons Engineering Science
8000 Centre Park Drive, Suite 200
Austin, TX 78754
PH 512/719-6000
FX 512/719-6099'
Richard Park
Eco Modeling
20302 Butterwick Way
Montgomery Village, MD 20879
PH 301/527-0545
FX 301/527-0545
TomParkerton
Exxon
CN 2350 Mettlers Road
East Millstone, NJ 08875
PH 908/873-6367
FX 908/893-6009
Dorothy Patton( 8101)
U.S. EPA/ORD 8101
401 M Street, SW
Washington, DC 20460
PH 202/260-5900 .
FX 202/260-0744
Robert Paulson
Wisconsin Oept. of Natural Resources
P.O. Box 7921 ,
Madison, Wl 53707-7921
PH 608/266-7790
FX 608/267-2800
Katherine Pease
NOAA
501 W. Ocean Blvd., Suite 4470
Long Beach, CA 90802
PH 310/9804080
FX 310/980-4084
AmyPelka
U.S. EPA Region 5
77 W. Jackson Blvd
Chicago, IL 60604
PH 312/886-9858
FX 312/353-5374
James Pendergast (4203)
US EPA/OWM
401 M Street, SW
Washington, DC 20460
PH 202/260-9545
FX 202/260-1460
Robert Pennington
Uls. Fish & Wildlife/Ches. Bay Prog. Ofc.
177 Admiral Cochrane Road
Annapolis, MD 21401
PH 410/573-4546 " • .
FX 310/269-0832 •
Christopher Penny.
US Navy Atlantic Division, Code 1823
1510 Gilbert Street (BldgN-26)
Norfolk, VA 23511
PH 804/322-4815'
FX 804/322-4805
Esther Peters
Tetra Tech, Inc.
10306 Eaton Place, Suite 340
Fairfax, VA 22030
PH 703/385-6000
FX 703/385-6007
Edward Pfau
Ohio EPA
P.O. Box 1049
Columbus, OH 43216
PH 614/644-2295
FX 614/644-3146
Loren Phillips
U.S. Army Ctr for Health Prom. & Prev. Medicine
ATTN: MCHB-DC-ES, 5158 Blackhawk Road
Aberdeen Proving Ground, MD 21010-5422 •
PH 410/671-3816
FX 410/671-8104 ' ,
Scott Pickard
U.S. Army Corps of Engineers
1776 Niagara Street
Buffalo, NY 14207-3199
PH 716/8794404
FX 716/8794357
Brian Pickard
U.S. Army Ctr for Health Prom. & Prev. Medic.
Building 1675 ' ' .
Aberdeen Proving Ground, MD 21010-5422
PH 410/671-3816 -
FX 410/671-8104
Fred Pinkney
U.S. Fish and Wildlife Service
177 Admiral Gochrane Drive
Annapolis, MD 21401
PH 410/5734521
FX 410/269-0832
D.B. Porcella
EPRI
PO Box 10412
Palo Alto, CA 94304
PH 415/855-2723
FX 415/855-1069
Damian Preziosi
The Weinberg Group, Inc.
122019th Street, NW, Suite 300
Washington, DC 20036-2400
PH 202/833-8077x8090
FX 202/8334257
Riph Pruell
U.S. EPA
. 27 Tarzwell Drive
Najragansett, Rl 02835
PH 401/782-3091 .
FX 401/782-3030
-------
LIST OF ATTENDEES (continued)
Lara Pulton (WA-16J)
U.S. EPA Region 5
77 West Jackson Blvd.
Chicago, IL 60604
PH 312/886-0138
FX 312/886-7804
Thomas Purcell
The Silver Council
5454 Wisconsin Ave, Suite 1510
Chevy Chase, MD 20815
PH 301/664-5150
FX 301/664-5156
Terry Quill
Beveridge and Diamond, P.C.
13501 Street, NW, Suite 700
Washington, DC 20005-3311
PH 202/789-6061
FX 202/789-6190
James Quinn
University of Rhode Island
Narraganselt, Rl 02882
PH 401/874-6219
FX 401/874-6811
Dave Rabbe
Chemical Land Holdings
1015 Belleville Turnpike
Keamy, NJ 07032
PH 201/955-0855
FX 201/955-1063
Tirumuru Reddy
U.S. EPA/NERL
26 West Martin Luther King Drive
Cincinnati, OH 45268
PH 513/569-7295
FX 513/569-7609
Danny Reib!e
Hazardous Substance Research Center
3418 CEBA
Baton Rouge, LA 70816
PH 504/388-6770
FX 504/388-5043
Dianne Reid
NC DEM/Water Quality Planning
P.O. Box 29535
Raleigh, NC 27626-0535
PH 919/733-5083x568
FX 919/715-5637
Mary Reiley (4304)
U.S. EPA
401 M Street, SW
Washington, DC -20460
PH 202/260-9456
FX 202/260-1036 ,
PatrlRe!!!y(G.MRO)
do USCG HQ (Commandant)
2100 2nd Street, SW
Washington, DC 20593
PH 202/267-0568
FX 202/267-4497
Mark Reimer
Fort Howard Corporation
1919 S. Broadway
Green Bay, Wl 54304
PH 414/435-8821
FX 414/498-3225
Eli Reinharz , .
NOAA - Damage Assessment Center
1305 East-West Highway, S SMC #4, Rm 10229
Silver Spring, MD 20910
PH 301/713-3038x193
FX 301/7134387
Mark Relss
U.S. Army Corps of Engineers, NY
26 Federal Plaza, Room 1937
New York, NY 10278
PH 212/264-1852
FX 212/264-4260
Gene Revelas
Striplin Enviornmental Associates
6541 Sexton Drive, N.W., Suite E-1'
Olympia, WA 98502
PH 360/866-2336 '
FX 360/866-4816
Steven Rice
U.S. Fish and'Wildlife Service
728 Grove Street
Hampton, VA 23664
PH 804/693-6694
FX 804/693-9032
Mark Richards
VADEQ
P.O. Box 10009
Richmond, VA 23240
PH 804/698-4207
FX 804/698-4234 ,
Erik Rifkin
Rifkin and Associates •
401 East Pratt Street, Suite 2332
Baltimore, MD 212202
PH 410/962-1401
FX 410/962-1065
Christine Rioux
Camp Dresser and McKee, Inc.
Ten Cambridge Center
Cambridge, MA 02142
PH 617/252-8761
FX 617/252-0998
Blto Rockier
U.S. Department of Justice
P.O.Box 7611
Ben Franklin Station
Washington, DC 20044
Kathryn Rowland
Brown and Root Environmental
661 Andersen Drive
Pittsburgh, PA 15220-2745
PH 412/921-8942
FX 412/921-4040
Norni Rubinstein
Atlantic Ecology Division
U.S. EPA/ORD
Narragansett, Rl 02882
PH 401/782-3001
FX 401/782-3030
-------
LIST OF ATTENDEES (continued)
3ete Rude
.andau Associates, Inc.
'3107 100th Ave., W., P.O. Box 1029
Edmonds, WA 98020-9129
>H 206/778-0907
:X 206/778-6409 ;
Hal Runke .
Barr Engineering Company
8300 Norman Ctr. Drive, Suite 300,
Minneapolis,'WIN 55437-1026
PH 612/832-2804
FX 612/832-2601
Phillip'Rury
Arthur D. Little, Inc. - '
Acorn Park .
Cambridge, MA 02140-2390
PH 617/498-5380
FX 617/498-7040
^arl'Rutz
Myeska Pipeline Service Company
I835 S. Bragaw Street
\nchorage, AK 99512
3H 907/265-8142
:X 907/265-8832 • •
Gary Salmon
Illinois State Geological Survey
615 E. Peabody Drive
Champaign, IL 61820 '
PH 217/244-2752 ' '
FX 217/244-2785
David Sanders
RMTInc.
4351 W. College Ayenue, Suite 210
Appleton.WI 54914
PH 414/830-0209 , " .
FX 414/830-1996
Stephanie Sanzone 1400 •' •
U.S. EPA/Science Advisory Board
401 M Street, SW -• '
Washington, DC 20460 . .
PH 202/260-6557
FX-202/260-7118
Tom Schadt . .. .
Parametrix, Inc.
5808 Lake Wash. Blvd.NE
Kirkland, WA 98033
PH 206/822-8880 ,'
FX 206/822-5245
Dan Schechter
Water Environment Federation
601 Wythe Street ,
Alexandria, VA 22314 .
PH 703/684-2423
FX 703/684-2492
JohnSchell ' . ,
ferra, Inc. . ....'.
Magnolia Centre 1,1203 Gov. Sq. Blvd..
Tallahassee, FL 32301
PH 904/422-0253 ' < -
FX 904/422-0333
Glen Schmiesing
Hercules Incorporated
.1313 N. Market Street
Wilmington, DE 19894-0001
PH 302/594-6581
FX 302/594-7255
Thomas Schultz . • . • -
U.S. Fish and Wildlife Service
c/o TAMU-CC, Campus Bx 338,6380 Ocean P'riv.e
Corpus Christ!, TX 78412 .. .
PH 512/994-9005 . - '
FX 512/994-8262 . " ' ' .
Glen Schuster
ATTN: CESAJ-PD-EE (Schuster)
P.O. Box 4970
Jacksonville, FL 32232
PH 904/232-3691
Dick Schwer
DuPo'nt ,-
1007 MarketStreet
Wilmington, DE 19713
PH 302/774-8024
FX 302/774-8110 ,
Jennifer Scott
EVS Environmental Consultants
290 Broadway, #1831
New York, NY 10007
PH. 212/637-3257 '
FX 212/637-3253
Wary Searing . • . .
Maryland DNR/Tawes State Office Building
580 Taylor Ave •. .
Annapolis, MD 21401, '• - .
PH 410/974-2988
FX 410/974-2833
Burt Shephard
URS Greiner, Inc,
1100 Olive Way, Suite 200
Seattle, WA 98101-1832
Dave Shepp
MWCOG "
777 N. Capitol Street, NE Suite 300
Washington, DC. 20002-4201
PH 202/962-3349 ' . . :
FX 202/962-3201 . .
Cynthia Shoemaker
University, of Maryland, Ches. Biol. Lab.
P.O. Box 38'
Solomons, MD 20688
PH 410/326-7384
FX 410/326-7341
Mohsin Siddique r ....
Environmental Regulation Administration
2100 Martin Luther King Jr. Avenue, SE, Suite 203
Washington, DC 20020'
PH 202/645-6622
FX 202/645-6617 • "' ,
Debbie Siebers (G-9J)
U.S. EPA/GLNPO
77 W.Jackson Street
Chicago, IL 60604
PH 312/353-9299. .
FX 312/353-2018
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LIST OF ATTENDEES (continued)
Gajlndar Singh
Environmental Regulation Administration
2100 Matin Lute King Jr. Ave,, SE, Suite 203
Washington, DC 20020
PH 2021645-6622
FX 202/645-6617
Tim Sinnott
NYS DEC, Bureau of Env. Protection
50 Wolf Road
Albany, NY 12233-4756
PH 518/457-1769 •
FX '518/485-8424
Michael Sivak.
Maryland Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
PH 410/631-3603
FX 410/633-0456
Jim Slzwnor e
Alexandria Sanitation Authority
P.O. Box 1987
Alexandria, VA 22313
PH 703/549-3381
FX 703/519-9023
Chris Skalski
Ohio EPA, Div. of Surface Water
1800 Watermark Drive, P.O. Box 1049
Columbus, OH 43216-1049
PH 614/644-2144
FX 614/644-2329
Ron Sloan
NYS DEC, Bureau of Env. Protection
50 Wolf Road
Albany, NY 12233-4756
PH 518/457-1769
FX 518/485-8424
Paul Slum (C-}3
Maryland DNR, Power Plant Research Prog. (B-3)
Tawes State Office Building
Annapolis, MD 21401-2397
PH 410/974-2261
FX 410/974-3770
Patty Smith (5204G)
U.S. EPA/OERR, Analytical Operations Center
401 M Street, SW
Washington, DC 20460
PH 703/603-9019
FX 703/603-9112
John Smith
Aluminum Company of America, ALCOA Tech. Ctt
100 Technical Drive
ALCOA Center, PA 15221
PH 412/337-5432'.
FX 412/337-5315
Lany Smith
Los Angetes Harbor Department
P.O. Box 151
San Pedro, CA 90733-0151
PH 310/732-3914
FX 310/547-4643
Jerry Smrchek (7403)
U.S. EPA/OPPT
401 M Street, SW
Washington, DC 20460
PH 202/260-1268
FX 202/260-1236
Jean Snider
NOAA/HAZMAT c/o USCG (G-MRO)
2100 20th Street, SW
Washington, DC 20593
PH 202/267-0605
FX 202/267-4497
StanSobczyk
NezPerce Tribe
P.O. Box 365
Lapwai, ID 83540
PH 208/843-7375
FX 2081843-7378
Betsy Southerland (4305)
U.S. EPA/OST
401 M Street, SW
Washington, DC 20460
PH 202/260-3966
FX 202/260-9830
Leanne Stahl (4305)
U.S. EPA/OST/SASD
401 M Street, SW
Washington, DC 20460
•PH 202/260-7055
FX 202/260-9830
John Stansbury
University of Nebraska
W384 Nebraska Hall, UNL
Lincoln, NE 68588
PH 402/554-3896
FX 402/554-3288
Bill Starkel
Brown and Root Environmental
900 Trail Ridge Road
Aiken, SC 29803 • .
PH 803/649-7963
FX 803/642-8454
Jeff Steevens
University of Mississippi
Department of Pharmacology
University, MS 38677
PH 601/232-5720
FX 601/232-5148
Robert Stein
Aware Environmental, Inc.
9305-J Monroe Road
Charlotte, NC 28270
PH 704/845-1697
FX 704/845-1759
Dianne Stephan
Atlantic State Marine Fisheries Comm.
1444 Eye Street, NW, 6th floor
Washington, DC 20005
PH 202/289-6400
FX 202/289-6051
Marty Stevenson
Kinnetic Laboratories, Inc.
55-1 Puapake Place
Lahaina, HI 96761
PH 808/661-1110
FX 808/661-0766
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LIST OF ATTENDEES (continued)
Stephanie Stirling •
U.S. ACE/CENPS-Operations
P.O. Box 3755
Seattle, WA 98124-2255
PH 206/764-6945
FX 206/764-6602
Edwal Stone
MD Dep't. of the Env., Indust. Dis. Perm. Div.
2500 Broening Highway
Baltimore, MD 21224
PH 410/631-3323
FX 410/6314894
Betsy Stripiin
Striplin Environmental Associates
6541 Sexton Drive NW, Suite E-1
Olympia, WA 98502 •
PH 360/866-2336
FX 360/866-4816
Janet Stull
Los Angeles County Sanitation Districts
1955 Workman Mill Road
Whittier, CA 90601-1400
PH 310/699-7411x7411 •
FX 310/692-5103
Anthony Sturtzen
ALCOA
4879 State Street (BldgSOOB)
Riverdale, IA 52722
PH" 319/344-1628
FX 319/344-1967
LoreleiSuit
The Weinberg Group, Inc.' '
122019th Street, NW, Suite 300
Washington, DC 20036
PH 202/833-8077
FX 202/833-4157
Jesse Suit
815 Beverly Avenue
Bethlehem, PA 18018
PH 610/868-8333
Laurie Sullivan
NOAA/U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
PH 415/744-3126
FX 415/744-3123'
Susan Svirsky
US EPA Region 1.0SRR
HBS, JFK Building
Boston, MA 01966
PH 617/573-9649
FX 617/573-9662
James Swart
NYS Department of Env. Conservation
Rm 302,50 Wolf Road
Albany, NY 12233-3503
PH 518/457-0720
FX 518/485-7786 v '
Chris Swenson
U.S. Fish and Wildlife Service '
300 Ala Moana Blvd.; Room 3108
Honolulu, HI 96850
.PH 808/541-3441
FX 808/541-3470
Michael Swindell
DuPont Environmental
231 OOldfield Point Road
Elkton, MD 21921
PH 302/992-6767
FX 302/892-7637
Stephanie Syslo (47507 C)
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 703/305-6355
FX 703/305-6309
Bill Tate( 4305)
U.S. EPA/OST
401 M Street, SW
• Washington, DC 20460
PH 202/260-7052
FX 202/260-9830
Kok-Leng Tay
Environment Canada
45 Alderney Drive
Dartmouth, Novia Scotia, CAN B2Y 2N6
PH 902/426-8304
FX 902/426-3897'
Emmit Taylor
Nez Perce Tribe, Environ. Rest. & Waste Mgmt
P.O. Box 365
Lapwai, ID 83540
PH 208/843-7375
FX 208/843-7378 '
Patti Tenbrook
East Bay Municipal Utility District
P;0. Box24055
'Oakland, CA 94623
PH 510/287-1427
FX 510/465-5462
JeffThielker
Plexus Scientific Corporation
12501 Prosperity Drive, Suite 401
Silver Spring, MD 20904
PH 301/622-9696
FX 301/622-9693
Robert Thomann
Manhatten College
4513 Manhatten College Pkwy
Riverdale, NY 10471
PH 718/862-7947 ' . •
Nelson Thomas
Mid-Continent Ecology Division/US EPA/ORD
6201 Congdon Blvd
Duluth.MN 55804"
PH 218/720-5702
FX 218/720-5539 . " -' • '
Emmy Thomee
NYS DEC, Bureau of Env. Protection
50. Wolf Road
Albany, NY 12233-4756
PH 518/457-8825
FX 518/485-8424
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LIST OF ATTENDEES (continued)
Dennis Tiniberlake
U.S. EPA/ORD/Naltonal Risk Mgmt Res. Lab
26 W.Martin Luther King Drive
Cindnali,OH 45268
PH 513669-7547
FX 513/569-7676
Lial Tischler
Tischler/Kocurek
107 South Mays Street
Round Rock, TX 78664
PH 512/244-9058
FX 512/388-3409
Erick Tokar
Rayonier Inc.
409 E. Harvard Ave."
Shelton, WA 98584
PH 360/427-8245
FX 360/426-7537
AIToimsoff
PPG Industries Inc. - Chemicals
One PPG Race
Pittsburgh, PA 15272
PH 412/434-2084
FX 412/434-2137
Douglas Tomchuk
U.S. EPA Region 2
290 Broadway, 20th floor
New York, NY 10007-1866
PH 212/637-3956
FX 212/637-4284
Dave Tomey
U.S. EPA Region 1
•JFK Federal Building, CWQ
Boston, MA 02203
PH 617/565-3573
FX 617/565-4940
Greg Tracey
SAIC
165 Dean Knauss Drive
Narragansett, RI 02882
PH 401/782-1900
FX 401/782-2330
Wayne Trulli
Battelle Ocean Sciences
397 Washington Street
Duxbury, MA 02360
PH 617/934-0571
FX 617/934-2124
Marc Tuchman
Great Lakes National Program Office
77 W. Jackson Blvd
Chicago, IL 60604
PH 312/353-1369 . ;'
FX 312/353-2018
PaitiLynne Tyler
U.S. EPA New England
60 Westview Street
Lexington, MA 02173
PH 617/860-4342
FX 617/860-4397
Philip Valent 7401
Naval Research Laboratory
Stennis Space Center, MS 39529-5004
PH 601/688-4650
FX 601/688-4093
Pablo Valentin
U.S. EPA Region 5
77 West Jackson Blvd
Chicago, IL 60604
PH 312/353-5592
FX 312/886-4071
Paul Vandermeer
Ohio EPA
1685 Westbelt Drive
Columbus, OH 43228
PH 614/728-3392
FX 614/728-3380
• Oilman Veith(MD-51)
US EPA/ORD
Ecology/Natl Health & Env. Effects'Res. Lab.
Research Triangle Park, NC 27711
PH 919/541-3554
FX 919/5444621
David Velinsky
Academy of Natural Sciences
1900 Ben Franklin Parkway
Philadelphia, PA 19103
PH 215/299-1147
FX 215/299-1079
Carlos Vktoria-Rueda
Parsons Engineering Science
8000 Centre Park Drive, Suite 200
Austin, TX 78754
PH 512/719-6000
FX 512/719-6099
Ching Volpp
NJ Department of Environmental Protection
401 East State Street
Trenton, NJ 08625-0418
PH 609/292-0687 '
FX 609/292-0687
Tony Wagner
Chemical.Manufacturers Association
1300 Wilson Blvd .. ,
Arlington, VA 22209
PH 703/741-5248 ' : :
FX 703/741-6099 '
Sherry Waiker
Environment Canada
351 St. Joseph Blvd., 8lh floor
Hull, Quebec, K1AOH3
PH 819/953-3117
FX 819/953-0461
Claudia Walters 5204G
U.S EPA/OERR/AOC
401 M Street, SW .
Washington, DC 20460
PH 703/603-8847 '
FX 703/603-9112
James Warchall
Sidley and Austin
One First National Pjaza
Ghicago.JL 60603' •
PH 312/853-7692 .
FX 312/853-7036 .
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LIST OF ATTENDEES (continued)
Kimberly Warner
University of Maryland, Ches. Biol. Lab.
P.O. Box 38
Solomons, MD 20688
PH 410/326-7409
FX 410/326-7341
Malcolm Watts
Zeneca, Inc. •
Concord Pike
Wilmington, DE 19897
PH 302/886-3085
FX 302/886-5933
JeffWaugh
Army Environmental Center
Restoration Division, SFI17-AEC-RPO
Aberdeen Proving Ground, MD 21010
PH 410/671-1615
FX 410/671-1635
PeddrickWeis
UMDNJ - New Jersey Medical-School
Department of Anatomy
Newark, NJ 07103 ,
PH 201/982-4409
FX 201/982-7489
Laura Weiss .
Washington Department of Ecology/Central Prog
Olympia, WA 98504-7703
PH 360/407-7446
FX 360/407-6904
Lynn Wellman
U.S. EPA Region 4,4 WD^OTS
100 Alabama Street, S.W.
Atlanta, GA 30303
PH 404/562-8647
FX 404/562-8627
Steve Wharton ,' •
U.S. EPA Region 7 '
726 Minnesota Avenue
Kansas City, KS 66101
PH 913/551-7819
FX 913/551-7063
Ray Whittemore
NCASI-Tufts University
Anderson Hall
Medford, MA 02155
PH 617/627-3254
FX 617/627-3831
Lyman Wible
RMTlnc. ' .
744 Heartland Trail •
Madison, Wl 53717
PH 608/831-4444
FX 608/831-3334
Sheila Wiegman
American Samoa EPA
Executive Office Building
Pago Pago, AS 96799
PH 011/684-633-2304
FX 011/684-6335801
Steve Willey
U.S. Department of Justice
P.O. Box 7611
Ben Franklin Station
Washington, DC 20044
PH 202/514-2807
Les Williams ,
Foster Wheeler Environmental Corp.
. 10900 NE 8th Street, Suite 1300
Bellevue, WA 98004-4405
PH 206/688-3717 -
FX 206/688-3942
Philip Williams
Ohio EPA
347 R.Dunbridge Road
Bowling Green, OH 43402
PH 419/373-3047
FX 419/352-8468
Donald Wilson
D.E. Wilson and Associates
9600N.E.'Timberlane
Bainbridge Is., WA 98110
PH 206/780-2124
FX 206/780-1147
Parley Winger
Dept. Interior National Biological Service •
Univ. of Georgia, School of Forest Resources
Athens, GA 30602 '
PH 706/546-2146,
FX 706/546-2186
Trevor Winton
Sinclair Knight.Merz Pty Lt2
P.O. Box 164 St. Leonards
Sydney,.NSW, Australia, 2065
PH (2)99282100
FX (2)99282504
Stephen Woock
Weyerhaeuser Southern Env. Field Station
Box 1391
New Bern, NC 28563
PH 919/633-7351 '
FX 919/633-7634
Jack Word
Battelle Marine Sciences Laboratory
1529 W. Sequim Bay Road
Sequim, WA 98382
PH 360/681-3668
FX 360/681-3681
David Young
Naval Research Laboratory •
Stennis Space Center, MS 39529
PH .601/688-5507
FX 601/088-5379
Allison Yuhas
Ogden Environmental
' 239 Littleton Road, Suite 7C
Westford, MA 01886
PH 508/692-9090
FX 508/692-6633
Drew Zacherle .
Tetra Tech, Inc.
10306 Eaton Place, Suite 340
Fairfax, VA 22030 .
PH 703/3853000
FX 703/385-6007
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LIST OF ATTENDEES (continued)
John Zambrano
NYS Department of Env. Conservation
50 Wolf Road
Albany, NY 12233-3502
PH 518/457-6997
FX 518/485-7786
Lawrence Zaragoza (5204G)
U.S. EPA/OERR
401 M Street, SW
Washington, DC 20460
PH 703/603-8850
FX 703/603-9103
Chris Zarba (8101)
U.S. EPA/ORD
401 M Street , '
Washington, DC 20460
PH 202/260-1326
FX 202/260-9761
Jennifer Orme Zavaleta
U.S. EPA
401 M Street, SW
Washington, DC 20460
PH 202/260-7586
FX 202/260-1036
Maurice Zeeman (7403)
U.S. EPA/OPPT
401 M Street, SW
Washington, DC 20460
PH 202/260-1240
FX 202/260-1236
Xin Zhang
Alpha-Omega Chemical Company
9311 Groh Road
Grosselle.MI 48138
PH 313/692-7631
FX 313/692-7622
Edward Zillfoux
Florida Risk-Based Priority Council
P.O. Box 088801
N, Palm Beach, FL 33408
PH 561/625-7621
FX 561/625-7665
Roger Zirk
Normandeau Associates
3450 Schuyklll Road
Spring City, PA 19475
PH 610/948-4700
FX 610/948-4752
* U. S. GOVERNMENT PRINTING OFFICE: 1998-618-516/90626
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