&F.PA
United States
Environmental Protection
Agency
Office of Emergency and
Remedial Response
Washington DC 20460
EPA 540-1-86'060
(OSWER Directive 9285 4-
October 1986
Superfund
Superfund Public Health
Evaluation Manual
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OSVER Directive 9285.4-1
SUPERFUND PUBLIC HEALTH EVALUATION MANUAL
Office of Emergency and Remedial Response
Office of Solid Waste and Emergency Response
U.S. Environmental Protection Agency
Washington, D.C. 20460
October 1986
U.S. Environrrcr-^i Pr: lection Agency
Region V, !j;-;
230 South Cu-;;,:::•:• Corset rs* •
Chicago, Illinois 60504 ....,*«
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OSVER Directive 9285.4-1
NOTICE
This manual provides guidance on methods for public health evaluations
that are conducted as part of EPA's feasibility study process at Superfund
remedial sites. The manual specifically supports Chapter 5 of the Guidance
for Feasibility Studies (U.S. EPA, Office of Emergency and Remedial Response,
April, 1985), which briefly describes public health evaluation procedures.
This manual does not contain procedures for health assessments, which are
separate analyses conducted by the Agency for Toxic Substances and Disease
Registry (ATSDR). The procedures and data given in this manual supersede
information previously released by the Office of Emergency and Remedial
Response on public health evaluation at Superfund sites.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
ACKNOWLEDGMENTS
This document was developed by EPA's Office of Emergency and Remedial
Response (OERR). Dr. Craig Zamuda and Mr. Bruce Clemens of OERR's Policy
Analysis Staff (PAS) were the EPA Project Officers, under the direction of Mr.
James Lounsbury, Director of PAS. Additional guidance was provided by Ms.
Stacey Katz of the Office of Policy, Planning, and Evaluation (OPPE).
Assistance also was provided by the EPA Work Group, whose members included:
Harry Allen
Doug Ammon
James Baker
Judy Be11in
Paul Bitter
Brint Bixler
Bonnie Casper
Margaret Chu
Chris DeRosa
Terry Eby
Sally Edwards
Dick Hill
Josephine Huang
Phil Jalbert
Meg Kelly
Jack Kooyoomj ian
Arnie Kuzraack
John Mateo
Abe Mittelman
Esther Rinde
John Schaum
Anita Schmidt
Paul Schumann
Ed Schoener
Ellen Siegler
Jim Spatarella
George Sugiyama
OERR/Hazardous Response Support Division
ORD (Office of Research and Development)
Region 8
Office of Solid Waste
Region 5
OERR/Hazardous Site Control Division
ORD
.ORD
ORD
OERR/Emergency Response Division
Region 1
Office of Pesticides and Toxic Substances (OPTS)
ORD
OERR/Policy Analysis Staff
Office of Solid Waste and Emergency Response
OERR/Emergency Response Division
Office of Drinking Water
Region 2
Office of Waste Programs Enforcement
OPTS
ORD
OPTS
OERR/Hazardous Site Control Division
Region 3
Office of General Counsel
OERR/Hazardous Site Control Division
Office of Air and Radiation
ICF Incorporated assisted OERR in development of this document, in partial
fulfillment of Contract No. 68-01-7090. The ICF project team included Baxter
Jones, Jeff Goodman, David Cooper, Janice Longstreth, and Hugh Huizenga.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
ACKNOWLEDGMENTS
This document was developed by EPA's Office of Emergency and Remedial
Response (OERR). Dr. Craig Zamuda and Mr. Bruce Clemens of OERR's Policy
Analysis Staff (PAS) were the EPA Project Officers, under the direction of Mr.
James Lounsbury, Director of PAS. Additional guidance was provided by Ms.
Stacey Katz of the Office of Policy, Planning, and Evaluation (OPPE).
Assistance also was provided by the EPA Work Group, whose members included:
Harry Allen
Doug Ammon
James Baker
Judy Bellin
Paul Bitter
Brint Bixler
Bonnie Casper
Margaret Chu
Chris DeRosa
Terry Eby
Sally Edwards
Dick Hill
Josephine Huang
Phil Jalbert
Meg Kelly
Jack Kooyoomjian
Arnie Kuzmack
John Mateo
Abe Mittelman
Esther Rinde
John Schaum
Anita Schmidt
Paul Schumann
Ed Schoener
Ellen Siegler
Jim Spatarella
George Sugiyama
OERR/Hazardous Response Support Division
ORD (Office of Research and Development)
Region 8
Office of Solid Waste
Region 5
OERR/Hazardous Site Control Division
ORD
ORD
ORD
OERR/Emergency Response Division
Region 1
Office of Pesticides and Toxic Substances (OPTS)
ORD
OERR/Policy Analysis Staff
Office of Solid Waste and Emergency Response
OERR/Emergency Response Division
Office of Drinking Water
Region 2
Office of Waste Programs Enforcement
OPTS
ORD-
OPTS
OERR/Hazardous Site Control Division
Region 3
Office of General Counsel
OERR/Hazardous Site Control Division
Office of Air and Radiation
ICF Incorporated assisted OERR in development of this document, in partial
fulfillment of Contract No. 68-01-7090. The ICF project team included Baxter
Jones, Jeff Goodman, David Cooper, Janice Longstreth, and Hugh Huizenga.
* * * October 1986 * * *
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OSVER Directive 9285.4-1
TABLE OF CONTENTS
Page
PREFACE AND EXECUTIVE SUMMARY 1
1. OVERVIEW OF THE SUPERFUND PUBLIC HEALTH EVALUATION PROCESS ' 4
1.1 Description of Process Components 6
1.1.1 Baseline Public Health Evaluation 6
1.1.2 Analysis of Remedial Alternatives and
Development of Performance Goals 7
1.2 Applicability of Process Components to Various Sites 9
2. BACKGROUND: AGENCY RULES, POLICIES, AND GUIDELINES 12
2.1 The National Oil and Hazardous Substances Pollution
Contingency Plan (NCP) 12
2.2 Guidance for Remedial Investigations and Feasibility
Studies 13
2.3 CERCLA Compliance with Other Environmental Statutes 15
2.4 Agency Policy for Planning and Implementing Off-Site
Response Actions 16
2.5 Agency Guidelines on Risk Assessment 17
2.6 Memorandum of Understanding Between EPA and the
Agency for Toxic Substances and Disease Registry 17
3. STEP 1: SELECTION OF INDICATOR CHEMICALS • 19
3.1 Develop Initial List of Indicator Chemicals 21
3.2 Select Final Indicator Chemicals 27
4. STEP 2: ESTIMATION OF EXPOSURE POINT CONCENTRATIONS OF
INDICATOR CHEMICALS ' 35
4.1 Identify Exposure Pathways 39
4.1.1 Determine Possible Chemical Release Sources
and Release Media 41
4.1.2 Identify and Characterize Possible Human.
Exposure Points 41
4.1.3 Integrate Release Sources, Environmental Transport
Media, Exposure Points, and Exposure Routes into
Exposure Pathways 47
4.1.4 Determine Presence of Sensitive Human Populations 47
* * * October 1986 * * *
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OSWER Directive 9285.4-1
TABLE OF CONTENTS (continued)
4.2 Estimate Exposure Point Concentrations - 47
4.2.1 Quantify Chemical Releases 50
4.2.2 Predict Environmental Fate and Transport 52
4.3 Compare to Requirements, Standards, and Criteria 56
4.3.1 Compare to Applicable or Relevant and
Appropriate Requirements 56
4.3.1.1 Maximum Contaminant Levels (MCLs) and
Maximum Contaminant Level Goals (MCLGs) 58
4.3.1.2 National Ambient Air Quality Standards
(NAAQS) 66
4.3.1.3 Federal Ambient Water Quality Criteria 66
4.3.1.4 State Environmental Standards 67
4.3.2 Compare to Other Criteria, Advisories, and Guidance.... 68
4.3.2.1 Proposed MCLs and MCLGs .' 74
4.3.2.2 Drinking Water Health Advisories 74
5. STEP 3: ESTIMATION OF CHEMICAL INTAKES 77
5 .1 Calculate Air Intakes 80
5 .2 Calculate Ground-Water Intakes 80
5.3 Calculate Surface Water Intakes 82
5.4 Calculate Intakes From Other Exposure Pathways 86
5.5 Combine Pathway-Specific Intakes to Yield Total Oral
and Total Inhalation Intakes 87
6. STEP 4: TOXICITY ASSESSMENT 92
7. STEP 5: RISK CHARACTERIZATION 96
7 .1 Noncarcinogenic Effects 96
7 .2 Potential Carcinogenic Effects 98
7 . 3 Uncertainties 103
8. DEVELOPMENT OF PERFORMANCE GOALS AND ANALYSIS OF RISKS FOR
REMEDIAL ALTERNATIVES 106
8.1 Reevaluate Indicator Chemicals 108
8.2 Identify Potential Exposure Pathways 108
8.2.1 Determine Possible Sources of Chemical Release 110
8.2.2 Determine Human Exposure Points 110
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OSWER Directive 9285.4-1
TABLE OF CONTENTS (continued)
Page
8.2.3 Integrate Release Sources, Transport Media, Exposure
Points, and Exposure Routes into Exposure Pathways ..... 113
8.2.4 Identify All Exposure Pathways for Each Exposure
Point ............................................ ......
8.3 Determine Target Concentrations at Human Exposure Points ...... 113
8.3.1 Target Concentrations for Chemicals With Applicable
or Relevant and Appropriate Requirements ............... 113
8.3.2 Target Concentrations for Chemicals Without Applicable
or Relevant and Appropriate Requirements ............... 118
8.3.2.1 Apportion Total Potential Carcinogenic Risk
Among Multiple Carcinogens .................... 118
8.3.2.2 Calculate Target Air Concentrations ........... 122
8.3.2.3 Calculate Target Drinking Water
Concentrations ................................ 122
8.3.3 Summarize Data ......................................... 125
8 . 4 Estimate Target Release Rates ................................ 125
8.4.1 Predict Environmental Fate and Transport ............... 125
8.4.2 Summarize Data ......................................... 130
8.5 Assess Chronic Risk For Noncarcinogens ........................ 130
8.6 Assess Potential Short-Term Health Effects of Remedial
Alternatives .................................................. 133
9 . SUMMARIZING THE PUBLIC HEALTH EVALUATION ........................... 139
9 . 1 Summarize the Baseline Public Health Evaluation ............... 143
9 . 2 Summarize Analysis of Remedial Alternatives ................... 144
APPENDICES
Appendix A - References
Appendix B - Glossary
Appendix C - Summary Tables for Chemical -Specific Data
Appendix D - Detailed Procedures for Determining Toxicity
Constants for Indicator Chemical Selection
Appendix E - Memorandum of Understanding Between the Agency
for Toxic Substances and Disease Registry and
the United States Environmental Protection Agency
* * * October 1986 * * *
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OSWER Directive 9285.4-1
LIST OF EXHIBITS
Page
1-1 Flowchart of the Superfund Public Health
Evaluation Process 8
1-2 Continuum of Analytical Complexity for Superfund Public
Health Evaluations 10
3-1 Overview of Step 1: Selecting Indicator Chemicals r.... 20
3-2 Concentration and Toxicity Constant -Units 23
4-1 Overview of Step 2: Estimating Exposure Point
Concentrations ". 38
4-2 Illustration of Exposure Pathways 40
4-3 Common Chemical Release Sources At Sites in the
Absence of Remedial Action 42
4-4 Typical Exposure Points for Chemical Releases from
Hazardous Waste Sites 46
4-5 Selected Applicable or Relevant and Appropriate Ambient
Requirements 59
4-6 EPA Ambient Water Quality Criteria (WQC) for
Protection of Human Health 61
4-7 EPA Proposed MCLs and MCLGs 69
4-8 EPA Drinking Water Health Advisories 71
5-1 Overview of Step 3: Estimating Human Intakes 78
5-2 Standard Values Used in Daily Intake Calculations 79
6-1 Overview of Step 4: Assessing Toxicity 93
7-1 Overview of Step 5: Characterizing Risks 97
8-1 Flowchart of Performance Goals Process 109
8-2 Possible Chemical Release Sources Following Remedial
Actions Ill
8-3 Common Temporary Chemical Release Sources During
Implementation of a Remedial Alternative 135
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OSVER Directive 9285.4-1
LIST OF EXHIBITS (continued)
Page
9-1 Worksheets that Should be Included in a Public Health
Evaluation Summary 140
9-2 Summary of the Baseline Public Health Evaluation 141
9-3 Summary of the Public Health Evaluation of Remedial
Alternatives 142
B-l List of Acronyms B-l
B-2 Definitions of Terms Developed Specifically for the
Superfund Public Health Evaluation Process B-3
C-l Physical, Chemical, and Fate Data C-8
C-2 Half-Lives in Various Media C-14
C-3 Toxicity Data for Potential Carcinogenic Effects --
Selection of Indicator Chemicals Only C-20
C-4 Toxicity Data for Potential Carcinogenic Effects --
Risk Characterization „ C-24
C-5 Toxicity Data for Noncarcinogenic Effects -- "
Selection of Indicator Chemicals Only C-28
C-6 Toxicity Data for Noncarcinogenic Effects --
Risk Characterization C-36
C-7 Chemicals and Chemical Groups Having EPA Health Effects
Assessment (HEA) Documents C-44
D-l Rating Constants (RVe) for Noncarcinogens D-3
D-2 EPA Weight-of-Evidence Categories for Potential Carcinogens.. D-5
* * * October 1986 * * *
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OSWER Directive 9285.4-1
LIST OF WORKSHEETS
3-1* Scoring for Indicator Chemical Selection: Concentrations
and Koc Values in Various Environmental Media 25
3-2 Scoring for Indicator Chemical Selection: Toxicity
Information 26
3-3 Scoring for Indicator Chemical Selection: Calculation of
CT and IS Values for Carcinogenic Effects 28
3-4 Scoring for Indicator Chemical Selection: Calculation of
CT and IS Values for Noncarcinogenic Effects 29
3-5* Scoring for Indicator Chemical Selection: Evaluation of
Exposure Factors and Final Chemical Selection 30
4-1 Preliminary Release Source Analysis for Baseline Site
Conditions ^. 43
4-2* Matrix of Potential Exposure Pathways 48
4-3 Results of Release Quantification 53
4-4* Contaminant Concentrations at Exposure Points 57
4-5* Comparison of Applicable or Relevant and Appropriate
Requirements to Estimated Exposure Point Concentrations 65
4-6* Comparison of Other Federal and State Criteria
to Estimated Exposure Point Concentrations 75
5-1 Calculate Air Intakes 81
5-2 Calculate Ground-Water Intakes . . . . 83
5-3 Calculate Surface Water Intakes 84
5-4 Calculate Intakes from Ingestion of Contaminated Fish. 85
5-5* Pathways Contributing to Total Exposure 88
5-6* Total Subchronic Daily Intake (SDI) Calculation 89
5-7* Total Chronic Daily Intake (GDI) Calculation 90
6-1 Critical Toxicity Values 95
7-1* Calculation of Subchronic Hazard Index 99
7-2* Calculation of Chronic Hazard Index 100
7-3* Calculation of Risk from Potential Carcinogens 102
7-4 Site-Specific Factors Increasing Uncertainty 104
8-1 Release Source Analysis 112
8-2* Matrix of Potential Exposure Pathways for Remedial
Alternatives 114
8-3 Identify All Pathways for Exposure Points 115
8-4 Target Concentrations for Chemicals with Ambient
Requirements 117
8-5 Apportioning Total Target Risk Among Multiple Potential
Carcinogens 120
8-6 Calculation of Target Air Concentrations 123
8-7 Calculation of Target Drinking Water Concentrations 124
8-8 Apportionment of Target Oral Intake via Drinking Water
and Fish Consumption 126
8-9 Calculation of Target Surface Water Concentrations Based
on Fish Consumption 127
8-10 Final Target Concentrations of Potential Carcinogens 128
* * * October 1986 * * *
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OSWER Directive 9285.4-1
LIST OF WORKSHEETS (continued)
8-11* Summary of Exposure Pathways, Exposure Points, and
Target Concentrations 129
8-12 Long-Term Target Releases .- 131
8-13 Summary Table: Exposure to Noncarcinogens 132
8-14* Summary Table: Chronic Intakes and Risks from
Noncarcinogens 134
8-15 Matrix of Potential Short-Term Exposure Pathways 136
8-16* Summary Table: Subchronic Intakes and Risks 138
* Designated for inclusion with public health evaluation summary.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
PREFACE AND EXECUTIVE SUMMARY
This manual establishes a framework for public health evaluation at
Superfund sites and for development of health-based performance goals for
remedial alternatives that are based on applicable or relevant and appropriate
requirements of other laws, where available, or risk analysis techniques where
those requirements are not available. These procedures were developed by
EPA's Office of Emergency and Remedial Response (OERR) in conjunction with an
Agency-wide Task Force, which included representatives from the program
offices, the Office of Waste Programs Enforcement, the Office of Research and
Development, the Office of Policy, Planning and Evaluation, and several
Regional offices. The procedures provided in the manual are designed to
conform to EPA's risk assessment guidelines (51 Federal Register 33992-34054,
September 24, 1986). In addition, guidance developed by EPA's Office of Waste
Programs Enforcement for endangerment assessments at enforcement-lead sites
incorporates the procedures in this manual.
Public health evaluation is an important component of the remedial investi-
gation (RI) and feasibility study (FS) phase of cleanup at Superfund sites.
This procedures manual was developed to supplement Chapter 5 of the Guidance on
Feasibility Studies Under CERCLA. That guidance describes what the public
health evaluation process is, but not how to conduct it. In contrast, this
manual provides detailed guidance on how to conduct the evaluation.
The Superfund Public Health Evaluation Manual has been developed for use
by a diverse audience, including EPA regional staff, state Superfund program
staff, federal and state remedial contractors, and potentially responsible
parties. Individuals having different levels of scientific training and
experience are likely to use the manual in designing, conducting, and reviewing
public health evaluations. Because assumptions and judgments are required in
many parts of the analysis, the individuals conducting the evaluation are key
elements in the process. The manual is not intended for use by non-technical
personnel to perform technical evaluations, nor to allow professionals trained
in one discipline to perform the work of another. Rather, it is the
.responsibility 'of remedial project managers, using the manual as a guide, to
match the scientific support they deem necessary with the appropriate
resources at their disposal.
Public health evaluation cannot be reduced to simple, "cookbook"
procedures. If all judgment could be removed from the process, undoubtedly
the results from various sites would be far more consistent. In addition,
state-of-the-art public health evaluation techniques have not been fully
accepted by all scientists, and important chemical data are frequently
unavailable. For instance, toxicity testing has not kept pace with the need
for information on many chemicals, and procedures used in exposure assessment
often require many assumptions. The universe of uncontrolled hazardous waste
sites is both variable and complex, with each site posing a unique set of
circumstances. It would be unrealistic to expect that all data necessary to
determine precisely the health risks associated with every site will be
available. Where data gaps necessitate making assumptions to conduct the
public health evaluation for a site, the manual instructs that all such
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OSVER Directive 9285.4-1
-2-
assumptions be clearly documented. The manual is designed to be flexible,
allowing the use of professional judgment. It is not a "cookbook". Instead,
it provides a systematic process for evaluating potential public health
impacts at a site and for documenting and supporting the assessment, its
assumptions, and its conclusions.
The manual provides a range of analytical procedures that may be needed at
a particular site. It is up to the remedial project manager to determine the
level of analysis required by using criteria discussed in this manual. In
addition, the manual contains a series of worksheets to assist in performing
the public health evaluation. The worksheets are not intended to drive the
evaluation, but to provide a consistent format for reporting results. The
results of the public health evaluation should be presented within the
appropriate section of the Rl/FS report.
Information gathered for the public health evaluation can be organized in
the appropriate worksheets provided in the manual or in a comparable format.
The information for the evaluation is important and the worksheets are only a
suggested format. Not all worksheets will be applicable to all sites;
site-specific characteristics will determine which worksheets are relevant.
Worksheets in this manual are filled in with illustrative examples to help
explain the various procedures given in the text. These sample worksheets are
for instructional purposes only; indicated values should not be construed as
representing actual conditions.
The Superfund Public Health Evaluation Manual is divided into nine
chapters. Some of the chapters are applicable to all sites, while some are
applicable to a subset of sites. Chapter 1 is an overview of the entire
Superfund public health evaluation framework. The second chapter provides
background on Agency rules, policies, and guidance relevant to the public
health evaluation process. Chapters 3 through 7 give procedures for the
baseline public health evaluation, and Chapter 8 presents methods to formulate
health-based performance goals for remedial alternatives. The final chapter
provides guidance on how to summarize and present the results of the
evaluation. Additional information related to the public health evaluation
process is included in several appendices to the manual.
Two necessary supplements to this manual are: (1) a set of Health Effects
Assessments (HEAs) for toxic chemicals typically found at uncontrolled
hazardous waste sites, and (2) the Superfund Exposure Assessment Manual, which
provides detailed methods for analyzing chemical releases from waste sites and
assessing fate and transport in environmental media. The 58 available HEAs
provide a rapid index of up-to-date toxicological information and should be
used by EPA personnel and contractors to avoid inconsistency and duplication
of effort. Other parties may also find the assessments useful and time-saving.
The Agency is planning to develop additional HEAs for many commonly occurring
chemicals found at Superfund sites. Copies of HEAs for specific chemicals are
available through the National Technical Information Service (NTIS). Appendix
C of this manual provides a list of chemicals with HEAs along with their NTIS
publication numbers (Exhibit C-7) and also summarizes data from the HEAs
necessary for the public health evaluation process (Exhibits C-4 and C-6).
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-3-
Because toxicity data will change as new information becomes available,
OERR will distribute updated summary tables on a regular basis. OERR has
compiled the toxicity data from Appendix C along with values for key standards
and criteria into a personal computer data base, PHRED--Public Health Risk
Evaluation Database. PHRED has been designed to allow the user to both store
and print selected fields of chemical data. The software-package can be used
on an IBM PC/XT/AT or compatible PC/XT/AT. The software consists of two
disks: a program disk and a data disk. OERR plans to periodically update the
data disk as new information becomes available. OERR also is developing a
comprehensive document, the Superfund Risk Assessment Information Directory,
to supplement the Superfund Public Health Evaluation Manual and other risk
assessment guidance prepared by EPA. The directory will assist in
decision-making by providing EPA officials with ready access to the most
current risk assessment information. Such a compilation of sources, models,
data bases, and individuals will make it possible to rapidly evaluate
state-of-the-art risk assessment information, allow quick response to
inquiries, reduce possible duplications of effort, and maximize consistency
among sources of information.
At the time this manual was prepared for final publication, Congress had
just passed a CERCLA reauthorization bill. Throughout this manual, where
reauthorization is likely to affect the procedures for conducting public
health evaluations, footnotes to the text have been included to describe the
changes likely to result. Users should also be aware that citations in this
manual to specific sections of CERCLA refer to CERCLA of 1980 (P.L. 96-510)
and may not be valid for the reauthorization statute.
For further information concerning the Superfund Public Health Evaluation
Manual and process contact the Director, Policy Analysis Staff, Office of
Emergency and Remedial Response, U.S. EPA, 401 M Street, S.W., Washington,
D.C. 20460.
* * * October 1986 * * *
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OSVER Directive 9285.4-1
-4-
CHAPTER 1
OVERVIEW OF THE SUPERFUND PUBLIC HEALTH EVALUATION PROCESS
The Comprehensive Environmental Response, Compensation and Liability Act
of 1980 (CERCLA) establishes a national program for responding to releases of
hazardous substances into the environment. In addition, the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP) establishes the process
for determining appropriate remedial actions at Superfund sites.1-1 Together,
CERCLA and the NCP require that a remedial action selected for a Superfund
site be cost-effective and that it be adequate to protect public health. The
NCP, Guidance on Remedial Investigations under CERCLA (EPA, 1985b), and
Guidance on Feasibility Studies under CERCLA (EPA, 1985a) require that
selection of a cost-effective remedy be based on a comparison of alternatives
that examines public health impacts, environmental impacts, technological and
engineering feasibility, cost, and institutional factors. As a general rule,
EPA will pursue remedies that attain or exceed2-1 the requirements of
applicable or relevant and appropriate federal public health or environmental
laws. However, because of unique circumstances at particular sites, there may
be alternatives that do not meet the standards of other laws, but that still
provide protection of public health, welfare, and the environment. The
Agency's most current toxicity data, documented in Health Effects Assessments
(HEAs), along with other criteria, advisories and guidance will also be
considered and may be used in fashioning remedies.
This manual supplements Chapter 5 of the feasibility study guidance, which
provides interim guidance on conducting an evaluation of potential public
health impacts at Superfund sites. The manual provides an approach that may
be followed for analyzing public health impacts of.remedial alternatives. EPA
recognizes that other approaches may be equally valid. This manual covers the
two key elements of a public health evaluation that should be addressed in any
feasibility study, regardless of the approach that is used: (1) the baseline
public health evaluation, and (2) the public health analysis of remedial
alternatives.
Section 104 of CERCLA authorizes taking a removal or remedial action to
protect public health, welfare, or the environment when there is a release or
substantial threat of release of any hazardous substance or when there is a
1J CERCLA was reauthorized just before this manual was prepared for
final publication. Several provisions of the reauthorization measure will
affect the procedures described in this manual. In addition, the NCP will be
revised as a result of reauthorization.
2J For instance, the Agency might choose incineration as an alternative
that exceeds what would be required by applicable standards because it is a
more permanent and reliable solution than RCRA closure standards for land
disposal facilities.
* * * October 1986 * * *
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OSVER Directive 9285.4-1
-3-
release or substantial threat of release of any pollutant or contaminant that
may present an imminent and substantial danger to the public health or welfare.
A baseline public health evaluation is an analysis of site conditions in the
absence of remedial action. It provides the remedial project manager with an
understanding of the nature of chemical releases from the site, the pathways
of human exposure, the degree to which such releases violate applicable or
relevant and appropriate requirements and, in the absence of these require-
ments, a measure of the threat to public health as a result of releases. The
information developed in the baseline evaluation provides input for developing
and evaluating remedial alternatives. In addition, the baseline evaluation
satisfies the NCP requirement to complete a detailed analysis of the no-action
alternative, including an evaluation of public health impacts.
The baseline evaluation may also be applied in enforcement situations.
Although the level of effort may be more rigorous in an enforcement-lead
situation, the basic process is the same. For administrative and judicial
enforcement actions under Section 106 of CERCLA, an endangerment assessment
must be performed to justify the enforcement action. The endangerment
assessment is the risk assessment process the Office of Waste Programs
Enforcement (OWPE) uses to determine the magnitude and probability of actual
or potential harm to public health, welfare, or the environment by the
threatened or actual release of a hazardous substance. The endangerment
assessment process is described in the Endangerment Assessment Guidance
document signed by the Assistant Administrator of OSWER in the fall of 1985
and explained in the Endangerment Assessment Handbook released by OWPE in
October, 1985. The Superfund Public Health Evaluation Manual provides methods
employed in the endangerment assessment process and therefore has been made
compatible with the requirement for conducting endangerment assessments for
Superfund enforcement sites.
Development of performance goals for remedial alternatives is the second
key phase of the public health evaluation. The manual describes specific
procedures for comparing health risks and developing performance goals for
remedial measures. The process builds on information collected and evaluated
in the baseline evaluation and closely follows the guidelines in the NCP and
EPA's policy.on CERCLA compliance with the requirements of other environmental
statutes.3J
The analytical framework provided in the manual is a flexible one.
While the manual provides a logical series of analytical procedures, these
procedures are not intended to substitute for a well-reasoned thought process
or scie.itific judgment. The manual recognizes that there is a minimum level
of analysis and documentation that is necessary in any feasibility study,
regardless of the particular approach used. The manual also recognizes that,
depending on the number and type of substances present, the amount and
adequacy of chemical, physical, and toxicological information known about the
substances, the proximity of receptors, the effectiveness of available
JJ EPA's CERCLA compliance with other environmental statutes policy is
published as an appendix to the preamble of the NCP (50 Federal Register
47946-47950, November 20, 1985). The CERCLA reauthorization bill elevates the
CERCLA compliance policy requirements to a statutory requirement.
* * * October 1986 * * *
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OSVER Directive 9285.4-1
-6-
technology, and the characteristics of the exposure pathways, the remedial
project manager will need to carefully consider the level of effort and amount
of quantification needed to conduct an evaluation. The remainder of Chapter 1
explains these factors in more detail; however, judgment by the remedial
project manager ultimately will determine the appropriate level of analysis.
It is also important to realize that not all of the components of the
manual are appropriate to use at all sites. For example, an evaluation of the
baseline situation must be conducted at all sites. However, the approach
presented in Chapter 3 for selecting indicator chemicals is useful only at
sites with a wide array of chemicals. Similarly, part of the performance goal
development approach in Chapter 8 is useful only at sites where applicable or
relevant and appropriate ambient concentration requirements are not available
for all chemicals of interest.
1.1 DESCRIPTION OF PROCESS COMPONENTS
The public health evaluation framework presented in this manual has two
major components:
• baseline public health evaluation, and
• development of performance goals for remedial
alternatives.
As previously mentioned, an analysis of the baseline is a requirement for all
remedial sites. Baseline public health evaluations can range from
straightforward and uncomplicated to very detailed and complex. In addition
to a baseline analysis, the remedial project manager should develop
health-based performance goals, which will assist in development and
refinement of appropriate remedial alternatives.
1.1.1 Baseline Public Health Evaluation
The baseline public health evaluation covers a wide range of complexity,
quantification, and level of effort, depending on numerous site factors. The
evaluation can be viewed as spanning a continuum of complexity and resource
requirements. The appropriate level of detail for a public health
evaluation is a site-specific decision.
The baseline evaluation, as described in this manual, involves five
steps. They are not a required set of procedures to be followed at all sites
because some of the steps (or parts of steps) do "not necessarily apply to some
sites. As a first step in the process, indicator chemicals are selected, if
needed, from among the list of contaminants known to "be at the site. The
procedure for selecting indicator chemicals, discussed in Chapter 3,
incorporates chemical toxicity information, physical/chemical factors, and
measured concentrations at the site. The second step in the evaluation, an
assessment of exposure concentrations of the indicator chemicals is described
in Chapter 4. Chemical releases are estimated and environmental fate and
transport may be modeled to project exposure levels via air, ground water,
surface water, or other pathways. Following the estimation of exposure
concentrations, comparison to applicable or relevant and appropriate
requirements (e.g., Federal drinking water standards) is made.
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The next step involves estimating human intakes. Standard assumptions for
daily water and air intake, fish consumption, and other relevant factors are
provided in Chapter 5 for use if site-specific information is unavailable.
The fourth step of the process, presented in Chapter 6, involves an in-depth
review of the toxicity of the indicator chemicals. Appendix C, which contains
a listing of critical toxicity values for chemicals commonly occurring at
uncontrolled hazardous waste sites, and EPA's Health Effects Assessment
documents are important companions to Chapter 6. Finally, in Step 5 (Chapter
7), human health risks are characterized for potential carcinogens and for
noncarcinogenic effects by combining the exposure and toxicity information
developed in Steps 1 through 4.
1.1.2 Analysis of Remedial Alternatives and Development of Performance
Goals
The second component of the Superfund public health evaluation process is
analysis and development of health-based performance goals for proposed
remedial alternatives. This component is described in Chapter 8. Performance
goals for source control4-1 remedies will be based on applicable or relevant
and appropriate design and operating requirements and best engineering
judgment. Where soil removal is part of the remedial action, a risk-based
approach can be used to determine the extent of removal. Performance goals
for management of migration5-1 alternatives will be based on applicable or
relevant and appropriate ambient chemical concentration requirements, if
available. Otherwise, a target carcinogenic risk range will be used to
develop numerical performance goals. The emphasis of the performance goal
procedure is to use techniques of risk analysis to assist in setting target
levels of contaminant concentrations at exposure points (and for some remedial
technologies, such as a waste treatment plant, to set target levels of
contaminant discharge or emission). The pub-lic health evaluation for remedial
alternatives is closely linked with other components of the feasibility study,
especially the detailed technical evaluation.
EPA is developing additional guidance to aid in the development of
remedial alternatives for certain specific situations (including guidance
documents for cleanup of surface tank and drum sites and surface impoundments
and for provision of alternate water supplies). These manuals will assist in
the development of performance goals in many circumstances.
Exhibit 1-1 is a flowchart illustrating the major components of the
Superfund public health evaluation process. The flowchart shows a possible
sequence of activities but does not indicate which activities are applicable
to which sites, an important topic that is discussed in the next section.
*J Source control remedies are those that remove or control the source
of contamination at a site.
5J Management of migration remedies are those that address substances
that have already migrated away from the source.
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EXHIBIT 1-1
FLOWCHART OF THE SUPERFUND PUBLIC HEALTH EVALUATION PROCESS
ARARs
for all \No
Indicators?
Step 3
Estimate
Human
Intakes
Step 4
Assess
Toxlclly
Step 5
Characterize
Risks
^^
Baseline
Evaluation
Complete
^
Analyze
Remedial
Alternatives
and Develop
Performance
Goals llased
on Target
Risk Range
and/or ARAKs
^^
Document
Analysis
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1.2 APPLICABILITY OF PROCESS COMPONENTS TO VARIOUS SITES
It should be apparent that not all of the components of the Superfund
public health evaluation process described in Section 1.1 apply to all
remedial sites. This manual establishes a generic framework that is broadly
applicable across sites. As a consequence of attempting to cover a wide
variety of sites, many of the process components, steps, and techniques
described in the manual do not apply to some sites. In addition most of the
components can vary greatly in level of detail. Obviously, determining which
elements of the process are necessary, which are desirable, and which are
extraneous is a key decision for each site. All components should not be
forced into the assessment-of a site, and the evaluation should be limited to
the complexity and level of detail necessary to adequately assess risks. It
cannot be overemphasized that the manual is not a "cookbook" of procedures
that must be followed without exception for each and every site. Rather, the
manual establishes a public health evaluation framework that must be adapted
to individual sites. Although professional judgment and common sense are
the ultimate inputs to deciding applicability and level of detail, the
following paragraphs provide some guidance in this area.
Public health evaluation can be thought of as spanning a continuum of
complexity, detail, and level of effort, just as sites vary in conditions and
complexity. Exhibit 1-2 illustrates the concept of an analytical continuum
and identifies some of the site-specific factors affecting level of effort
that the remedial project manager must consider. These factors include:
• number and identity of chemicals present;
• availability of appropriate standards and/or toxicity
data;
• number and complexity of exposure pathways (including
complexity of release sources and transport media);
• necessity for precision of the results, which in turn
depends on site conditions such as the extent of
contaminant migration, proximity, characteristics and
size of potentially exposed populations, and enforcement
considerations (additional quantification may be
warranted for some enforcement sites); and
• quality and quantity of available monitoring data.SJ
Sites best represented by the descriptions toward the left of the
continuum on Exhibit 1-2 correspond to a relatively low level of effort and
analytical complexity, while sites corresponding to the descriptions toward
SJ All site monitoring data must be subjected to appropriate quality
control-quality assurance programs. Lack of acceptable data may by necessity
limit the amount of data available for the public health evaluation, and
therefore may limit the scope of the evaluation.
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EXHIBIT 1-2
CONTINUUM OF ANALYTICAL COMPLEXITY FOR SUPERFUND
PUBLIC HEALTH EVALUATIONS
Increasing Complexity I Lev el of Effort
1 or 2 chemicals
Slandarcls/toxicity
data available
1 significant
exposure pathway
No ground water
problem, or simple
hydrogeology
1 simple
source
Limited need
for precision
Substantial
monitoring data
available
10-15 chemicals
Standards/toxicity
data mostly available
< 3 significant
exposure pathways
Complex
hydrogeology
Complex sources
Precision needed
Some monitoring
data available; limited
extrapolation required
Many chemicals
Standards/toxicity
data missing for
key chemicals
> 3 significant
exposure pathways
Highly complex
hydrogeology
Multiple complex
sources
Considerable
precision needed
Inadequate monitoring
data; modeling
required
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OSWER Directive 9285.4-1
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the right are more complex and generally will require a greater level of
effort. It is important to understand that the factors given on the continuum
are largely independent. Thus, one factor may correspond to the need for a
complex analysis while others correspond to a simple analysis (e.g., a site
may have two chemicals with available standards and only one exposure pathway,
via ground water, but may have a complex subsurface and need considerable
precision). Although it is clearly a simplification, Exhibit 1-2 should
assist in defining the appropriate level of quantitative analysis for a site.
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CHAPTER 2
BACKGROUND: AGENCY RULES, POLICIES, AND GUIDELINES
To understand the context of the public health evaluation process, it is
important to be familiar with EPA rules, policies, and guidelines relevant to
remedial actions at Superfund sites. In this chapter, the most important
related rules, policies, and guidelines are summarized and references for
further information are provided.
2.1 THE NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION
CONTINGENCY PLAN (NCP)
The NCP7J is a regulation that provides a framework for implementing the
response powers and responsibilities established under CERCLA. Subpart F of
the NCP outlines the hazardous substance response process and includes
provisions for both removal and remedial actions. Federal and state agencies
and private parties responsible for preparing feasibility studies for Superfund
remedial sites should be familiar with the NCP. The most recent version of
the NCP was published on November 20, 1985 (EPA, 1985c).'J A copy can be
obtained from EPA's Office of Emergency and Remedial Response (OERR), U.S. EPA
CERCLA Docket Clerk, 401 M Street, SW, Washington, DC 20460.
The NCP sets forth a five-step remedial response process:
• Site discovery or notification: Releases of
hazardous substances, pollutants, or contaminants
identified by federal, state, local government agencies,
or private parties are reported to the National Response
Center. Upon discovery, such potential sites are
screened to identify release situations warranting
further remedial response consideration. These sites
are entered into the Emergency and Remedial Response
Inventory System (ERRIS). This computerized system
serves as a data base of site information and tracks the
change in status of a site through the response process.
• Preliminary assessment and site inspection (PA/SI):
The preliminary assessment involves collection and
review of all available information and may include
off-site reconnaissance to evaluate the source and
nature of hazardous substances present and to identify
the responsible party(s). Depending on the results of
the preliminary assessment, a site may be referred for
further action. Site inspections routinely include the
collection of samples and are conducted to determine the
7J Part 300, Chapter 40 of the Code of Federal Regulations (40 CFR 300)
IJ Reauthorization of CERCLA will result in revision of the NCP.
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extent of the problem and to obtain information needed
to 'determine whether a removal action is needed at the
site or whether the site should be considered for
inclusion on the National Priorities List (NPL).
• Establishing priorities for remedial action: Sites
are scored using the Hazard Ranking System and data from
the PA/SI. This scoring process is the primary mechanism
for determining the sites to be included on the NPL,
which identifies sites eligible for Superfund-financed
remedial action.
• Remedial investigation/feasibility study (RI/FS):
The RI/FS process is the framework for determining
appropriate remedial actions at sites on the NPL.
Remedial investigations are conducted to obtain
information needed to identify, evaluate, and select
cleanup alternatives. The feasibility study is the
actual analysis of alternatives based on technological,
public health, institutional, cost, and environmental
factors. The RI/FS process was developed to identify
the most appropriate, cost-effective remedy for a site.
• Remedial action design and construction: The
detailed design of the selected remedial action is
developed and then implemented.
The Superfund Public Health Evaluation Manual provides detailed guidance for
the public health analysis that is part of the RI/FS process.
2.2 GUIDANCE FOR REMEDIAL INVESTIGATIONS AND FEASIBILITY
STUDIES
As noted in Section 2.1, the NCP requires that a remedial investigation
and feasibility study be conducted for sites listed on the National Priorities
List. EPA has developed and published guidance for both the remedial
investigation (EPA, 1985b) and feasibility study (EPA, 1985a). The RI/FS
guidance provides the context into which the public health evaluation fits.
The remedial investigation and feasibility study are described briefly below.
For more details, refer to the guidance documents referenced above.
The Guidance for Remedial Investigations Under CERCLA is intended to
provide a detailed structure for field studies to support remedial decisions
under CERCLA. The remedial investigation emphasizes data collection and site
characterization and is conducted concurrently with the feasibility study.
The remedial investigation also supports remedial alternative evaluation and
design through bench and pilot studies.
The initial activity in the remedial investigation is scoping. The
scoping effort includes the collection and evaluation of existing-data,
identification of remedial investigation objectives, and identification of
general response actions for the feasibility study. A preliminary
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determination of which federal environmental and public health requirements
are applicable or relevant and appropriate to the site is also made as a part
of the scoping effort.
Several activities supporting the remedial investigation may require
preparation of specific plans or implementation of specific procedures. These
include preparing a sampling plan; identifying data management procedures;
planning for worker health and safety needs; and identifying and reviewing
institutional issues arising from federal, state, and local regulations,
policies, and guidelines.
Site characterization is the focal point of the remedial investigation and
involves collection and analysis of data needed for various types of
assessments in the feasibility study. Because site data and complexity vary,
a multilevel approach to data collection is recommended, including problem
identification and scoping, followed by problem quantification, followed if
necessary by further problem quantification and detailed investigation. The
focus, data needs, and data evaluations conducted at each level of the
investigation are described in the guidance document.
The Guidance for Feasibility Studies Under CERCLA is intended to provide a
detailed structure for identifying, evaluating, and selecting remedial action
alternatives under CERCLA. The feasibility study process begins with
development of specific alternatives, based on the general response actions
identified in the remedial investigation. Remedial technologies are screened
for their applicability to the site. Technologies considered appropriate are
then combined to form alternatives, which are screened on the basis of public
health and environmental concerns and order-of-magnitude costs.
Alternatives that pass the screening process undergo detailed analyses to
provide site decision-makers with information for selecting an alternative
that is cost-effective. The guidance document describes methods for
engineering, institutional, public health, environmental, and cost analyses.
The engineering analysis evaluates constructability and reliability to ensure
the technical feasibility of alternatives. The institutional analysis
examines alternatives in terms of the federal, state, or local requirements,
advisories, or guidance. The public health evaluation, for which this manual
provides more detailed guidance, assesses potential health risks if no action
is taken and for remedial alternatives that are developed. The environmental
analysis includes assessment of adverse environmental impacts if no action is
taken and the short- and long-term effects of the alternatives. The cost
analysis examines capital and operating costs of each alternative.
Once the de-tailed analyses are conducted, the information is organized to
compare findings of the evaluations for each alternative. The objective of
this summary is to ensure that important information is presented in a concise
format so that the decision-maker can choose the remedy that provides the best
balance of human health and environmental protection, engineering reliability,
and cost.
Although there are separate guidance documents, the remedial investigation
and the feasibility study are interdependent. The activities comprising the
remedial investigation and feasibility study are generally performed
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concurrently rather than sequentially. The remedial investigation emphasizes
data collection and site characterization, whereas the feasibility study
emphasizes data analysis and evaluation of alternatives.
2.3 CERCLA COMPLIANCE WITH OTHER ENVIRONMENTAL STATUTES
Section 104 of CERCLA requires that wastes taken off-site during a
remedial action be disposed in a facility approved under Subtitle C of the
Resource Conservation and Recovery Act (RCRA). CERCLA, however, does not
address the requirements of other federal environmental and public health laws
(e.g., Clean Water Act, Toxic Substances Control Act) in conducting on-site
response actions.9-1
The NCP requires that remedies selected for on-site CERCLA response
actions attain or exceed applicable or relevant and appropriate environmental
and public health requirements unless one of five specific situations
exists.10-' Other federal criteria, advisories, guidances, and state
standards should also be considered in fashioning CERCLA remedies and, if
pertinent, should be used. For on-site actions (i.e., where wastes are
treated, stored, or disposed on-site), permits (e.g., federal/state RCRA or
NPDES) are not required for CERCLA response actions; however, all appropriate
permits are required for off-sit-e action.
The CERCLA compliance with other environmental statutes policy is critical
to an evaluation of remedial alternatives and therefore must be reviewed
before remedial options are developed. A copy of the policy is published as
an appendix to the preamble of the N'CP (50 Federal Register 47946-47950,
November 20, 1985). To the extent that it is both possible and appropriate,
at least one remedial alternative should be developed as part of the
feasibility study in each of the following categories:
• alternatives for off-site treatment or disposal;
• alternatives that attain applicable or relevant and
appropriate Federal public health or environmental
requirements;
• alternatives that exceed applicable or relevant and
appropriate Federal public health or environmental
requirements;
8J The CERCLA reauthorization bill specifically requires compliance with
other federal and state environmental laws; some details of EPA's current
compliance policy will likely be changed as a result of reauthorization.
IOJ The five exceptions are fund balancing, technical impracticality,
unacceptable environmental impacts, interim measures, and enforcement actions
when strong public interest calls for expedited cleanup and litigation
probably would not result in a desired response (see 40 CFR 300.68(i)(5)).
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• alternatives that do not attain applicable or
relevant and appropriate Federal public health or
environmental requirements, but that will reduce the
likelihood of present or future threat from the
hazardous substances and that provide significant
protection to public health, welfare, and the
environment; and
• the no-action alternative.
The CERCLA compliance policy provides a list of requirements that are
potentially applicable or relevant and appropriate'(i.e., must be used in the
development of alternatives) and other federal criteria, advisories,
guidances, and state standards that are to be considered and may be used if
pertinent. In cases where requirements are deemed applicable or relevant and
appropriate to remedial actions developed and considered during the
feasibility study process, they should-be applied carefully in the public
health evaluation, with consideration given to the economic and technical
factors used to establish the requirement that may be significantly different
from circumstances at a specific Superfund site. For instance, drinking water
maximum contaminant levels (MCLs) are developed using certain economic
considerations that may not be appropriate to some Superfund sites. In
addition, various requirements may be applicable at different points in the
exposure pathway.
This manual provides guidance for incorporating applicable or relevant and
appropriate requirements into the public health evaluation process.. Although
RCRA design and operating standards are clearly important requirements to
consider in remedial design at Superfund sites, they are not discussed at
length in this manual because they do not provide ambient concentration levels
for chemicals. This manual focuses on ambient chemical concentration
standards and criteria that can be used for comparison to baseline conditions
and to set quantitative performance goals. The Office of Emergency and
Remedial Response is also preparing further guidance for implementing the
compliance policy. That guidance, the Manual on CERCLA Compliance with Other
Environmental Statutes, will explain specifically how applicable or relevant
and appropriate requirements under other laws should be identified and used in
the design of remedial alternatives and will also include case studies to
illustrate different situations. The manual is currently in draft form. For
further information contact the U.S. EPA CERCLA Docket Clerk, 401 M Street,
SW, Washington, DC 20460.
2.4 AGENCY POLICY FOR PLANNING AND IMPLEMENTING
OFF-SITE RESPONSE ACTIONS
In 1985 EPA adopted a policy for Superfund response actions involving
off-site storage, treatment, or disposal of CERCLA hazardous substances.11-1
11J "Procedures for Planning and Implementing Off-Site Response
Actions," Memorandum from Jack W. McGraw, Acting Assistant Administrator for
Solid Waste and Emergency Response to EPA Regional Administrators, May 6, 1985.
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Th e policy requires that certain criteria must be met in selecting a hazardous
waste management facility to receive CERCLA hazardous substances. The
facility must have either a. permit or interim status under RCRA. A RCRA
compliance inspection must have been performed within six months prior to
receiving the hazardous substances. No Superfund hazardous substances may be
taken off-site to a RCRA facility if the facility has significant RCRA
violations or other environmental conditions that affect the satisfactory
operation of the facility 'in_l_rss the ovner or creator cor"nits to correct the
problem and disposal occurs within the facility only at a new or existing unit
in compliance with RCRA requirements.12-1 In addition, that new or existing.
unit must not contribute in any significant way to adverse conditions at the
facility. The policy also establishes a preference for response actions that
use treatment, reuse, or recycling rather than land disposal.
Copies of the procedures and further information are available from the
U.S. EPA CERCLA Docket Clerk, 401 M Street, SW, Washington, DC 20460.
2.5 AGENCY GUIDELINES ON RISK ASSESSMENT
EPA has adopted guidelines to improve consistency in Agency risk
assessments. The guidelines address five areas: carcinogenicity,
mutagenicity, reproductive effects, exposure assessments, and assessment of
chemical mixtures (EPA, 1986a,b,c,d, and e). Guidelines for assessment of
other systemic effects are currently in preparation. The risk assessment
guidelines were used in development of the procedures described in this manual
and of the supporting toxicity data provided in the Health Effects Assessment
Documents. For further background scientific information, users should obtain
and review these guidelines and their support documents. Copies are available
from EPA's Office of Health and Environmental Assessment, Technical
Information Staff, 410 M Street, SW, Washington, DC 20460.
2.6 MEMORANDUM OF UNDERSTANDING BETWEEN EPA AND THE
AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY
EPA and the Agency for Toxic Substances and Disease Registry (ATSDR) have
developed a Memorandum of-Understanding (MOU).to define and coordinate joint
and respective responsibilities under CERCLA, Executive Order 12316,13J and '
12J Under the reauthorization bill, CERCLA wastes transported off-site
may only be disposed in a non-leaking waste disposal unit of a permitted RCRA
facility. In addition the facility must be in compliance with RCRA corrective
action requirements for any other units that are found to be releasing wastes
into the environment.
13J E.O. 12316 delegates to EPA the primary response authority under
CERCLA section 104 relating to release of hazardous substances, pollutants, or
contaminants. E.O. 12316 delegates to the Department of Health and Human
Services authorities for conducting activities relating to illness, disease,
and complaints thereof.
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OSWER Directive 9285.4-1
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the NCP. The MOU establishes policies for conducting response and non-response
health activities related to releases of hazardous substances. A copy of the
MOU is provided in Appendix E.1UJ
Under the current MOU, ATSDR's major responsibilities include assessment
of populations with current or potential exposure to waste sites, development
of health advisories, and follow-up investigation of populations to evaluate
future health effects. As defined by the MOU, EPA's major health-related
responsibilities are risk assessment and risk management. Risk assessment is
defined as a qualitative/quantitative process conducted to characterize the
nature and magnitude of potential risks to public health from exposure to
hazardous substances, pollutants, or contaminants released from specific
Superfund sites. The framework for such EPA public health evaluations is
given in this procedures manual.
Where ATSDR is involved, EPA and ATSDR are to coordinate any
health-related activities during the remedial process. Health assessments,
health advisories, and other information developed by ATSDR should be
considered by the public health evaluation team at Superfund sites, and
appropriate data and conclusions should be incorporated into the public health
evaluation process and reports. Likewise, EPA public health evaluations
should be made available to ATSDR for consideration during their analyses. It
is EPA's responsibility to incorporate both the results of risk assessments
developed as part of the public health evaluation process and any ATSDR
analyses into risk management determinations of extent of remedy.
At sites where ATSDR is involved, its staff should be consulted for
assistance in interpretation of human health data, such as clinical or
epidemiologic survey information. The MOU clearly states that if human
subjects testing is necessary, ATSDR will be responsible for such testing and
will coordinate it with EPA.
Under reauthorization ATSDR "will be required to conduct health assessments
for all sites on or proposed for addition to the MPL, according to a
statutorily mandated schedule. The purpose of these ATSDR health assessments
is to assist in determining whether actions should be taken to reduce human
exposure to hazardous substances and whether additional information (e.g.,
epidemiologic studies, disease registries, health surveillance programs) on
human exposure and associated health risk is needed. Although both EPA and
ATSDR are responsible for developing independent analyses related to public
health, EPA is solely responsible for making risk management decisions based
on these analyses. Currently, EPA and ATSDR are working together to define
the roles and responsibilities of the two agencies under reauthorization and
the relationship between EPA public health evaluations and ATSDR health
assessments. In addition, a procedures document to better integrate ATSDR
health assessments in the RI/FS process is being developed.
lfcj Under reauthorization, ATSDR's health-related responsibilities will
be expanded significantly. As a result, a new agreement between EPA and ATSDR
will be developed.
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CHAPTER 3
STEP 1: SELECTION OF
INDICATOR CHEMICALS
The baseline public health evaluation process consists of five steps,
which are shown in the flowchart given earlier in Exhibit 1-1. These steps
are discussed individually in Chapters 3 through 7. As emphasized in Chapter
1, not all steps will be needed at all sites because of variability in site •
conditions.
Prior to initiating these five steps, available site data relevant to
detailed public health evaluation should be gathered, organized, and
reviewed. Among the types of information to be collected are site background
data, disposal history (and records, if available), types of remedial actions
being considered, on-site and off-site chemical analysis data, site
characterization data necessary for exposure assessment (e.g., topography,
hydrogeology), information on local human populations, and any human body
burden and health effects data (unlikely to be available at many sites). Data
sources will include preliminary assessments and reports, site inspection
reports, Field Investigation Team (FIT) reports, remedial investigation
scoping documentation, analytical data and reports available from ongoing site
characterization (RI) and alternatives screening (FS) activities, and ATSDR
health assessments.
The next task of the public health evaluation is to determine whether
indicator chemicals need to be selected for the site. The indicator chemical
selection procedure described here is designed to identify the "highest risk"
chemicals at a site so that the public health evaluation is focused on the
chemicals of greatest concern. In general, if less than 10 to 15 chemicals
are actually identified at a site, this indicator selection step is not
necessary. In such cases, proceed to Chapter 4 and evaluate all of the
chemicals at the site. This "shortcut" will be especially useful when only a
very few chemicals are present at a site and a simple quantitative analysis is
appropriate. However, remedial investigation sampling at hazardous waste
sites often demonstrates the presence of a large number of chemical
substances. In such instances, conducting a public health evaluation that
includes all the identified chemicals may be unnecessarily time-consuming. To
avoid unnecessary effort, the Superfund process is based on selected indicator
chemicals that pose the greatest potential public health risk at a site. Such
indicator chemicals must be chosen carefully so that they represent the most
toxic, mobile, and persistent chemicals at the site, as well as those present
in the largest amounts (i.e., the "highest risk" chemicals).
Step 1 of the baseline analysis (i.e., analysis of a site under an
assumption of no remedial action) is selection, if necessary, of a subset of
the chemicals present at a site as indicator chemicals. An outline of this
step is presented in Exhibit 3-1, and procedures for the selection are given
in the remainder of this chapter. The toxicity data required to complete the
selection procedure for many commonly found chemicals are listed in Exhibits
C-3 and C-5 in Appendix C. Appendix D documents the methods used to derive
the toxicity data given in Exhibits C-3 and C-5.
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EXHIBIT 3-1
OVERVIEW OF STEP 1: SELECTING INDICATOR CHEMICALS
Identify Chemicals Present at a Site
Determine Representative Concentrations from Site Monitoring Data
Calculate Indicator Scores Based on Maximum and Representative
Concentrations and Route-Specific Toxicity Data
Select Indicator Chemicals Based on Indicator
Scores and Physical/Chemical Property Data
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Two important factors for ranking chemicals in the indicator chemical
selection process are their measured concentrations at the site and their
toxicity. Additional factors to be considered include physical and chemical
parameters related to environmental mobility and persistence. The indicator
chemicals selected for the baseline public health evaluation by following the
procedures in this chapter will be reviewed later for applicability to the
remedial alternatives. Because of concerns related to treatability and
additional exposure pathways, more chemicals may need to be assessed in the
analysis of remedial alternatives (see Section 8.1).
It is emphasized that the indicator chemical selection process presented
here is not supposed to contravene professional judgment. If, after
completing the procedures given in this chapter, certain chemicals considered
to be potentially significant are not selected, do not hesitate to include
them. Simply amend Worksheet 3-5 with an explanation of the reasoning and why
this process did not identify them. It is not intended that the indicator
chemical selection process exclude any chemical that may cause significant
human or environmental harm. Rather, the intent of the process is to ensure
that all chemicals posing a significant risk to human health are addressed and
to focus the public health evaluation on the primary chemicals of concern.
3.1 DEVELOP INITIAL LIST OF INDICATOR CHEMICALS
The first task in the indicator chemical selection process is development
of an initial indicator chemical list, which is based principally on chemical
toxicity information, site concentration data, and environmental mobility as
reflected in K 15J (the organic carbon partition coefficient) values.' K is
oc oc
considered to account for the possibility of substances leaching out of the
soil and being introduced into surface and ground water. The initial list
will eventually be pared down using additional factors to develop a final
indicator list. The indicator chemical selection process is designed for
sites with large numbers of chemicals where consideration of all physical,
chemical, and concentration information at one time is too cumbersome. If
only a moderate number of chemicals are present at a site, all toxicity,
chemical, and physical factors may be considered simultaneously.
Each chemical detected at the site above local background levels is
scored. If, based on recent monitoring data in the site vicinity, it is clear
that levels of certain chemicals do not exceed local background
concentrations, and there is no known source (e.g., intact drums, waste pile)
at the site, these chemicals may be excluded from the evaluation. However,
determining background may be difficult. If there is a question about what
background is or the relation of a chemical concentration to background,
report these doubts but do not exclude the chemical from the evaluation.
15J A chemical's K is being used as an estimator of environmental
mobility. In general, chemicals with high values have correspondingly high
bioconcentration factors, whereas chemicals with low values will tend to be
leachable from soil and mobile in..ground water. A more detailed discussion of
K is presented later in the text, of this chapter.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-22-
The following algorithm is used to score each chemical measured at the
site:
3
IS = Z (C • T )
i j=l ij ij
where
IS. = indicator score for chemical i (unitless)
C.. = concentration of chemical i in medium j at the site based on
monitoring data (units must be mg/1 in water, mg/kg in soil, or
mg/m3 in air)
T.. = a toxicity constant for chemical i in medium j (units are
the inverse of above concentration units).
Concentration values used in this equation for a given chemical should be
representative of all available site monitoring data that have been QA/QC •
validated. Toxicity constants (T values) are derived for each environmental
medium and two types of toxic effects (carcinogenicity and other chronic
effects). Exhibit 3-2 lists for each medium of concern the units of
concentration that should be used to express exposure levels, the exposure
route (e.g., ingestion or inhalation), and the corresponding toxicity
constants and their units. In all cases, toxicity constant units are the
inverse of their respective concentration units so that indicator scores
(C»T) will always be unitless. Essentially, the indicator score is a ratio
between measured concentration and a toxicity-based concentration benchmark
that is used to rank the site chemicals.
Toxicity constants for noncarcinogens (Tn) are derived from the minimum
effective dose (MED) for chronic effects, a severity of effect factor, and
standard factors for body weight and oral or inhalation intake (e.g., 70 kg
body weight, 2 liters/day of drinking water, 20 cubic meters/day of air).
Toxicity constants for potential carcinogens (Tc) are based on the dose at
which a 10 percent incremental carcinogenic response is observed (EDin) and
the same standard intake and body'weight factors. The intake factor for soil
toxicity constants is based on an assumption of 100 milligrams of soil consumed
per day for 2- to 6-year-olds (EPA, 1984).
Toxicity constants, T, are medium-specific. The toxicity constant for use
with drinking water concentrations is referred to as T, whereas one for
concentrations in air is T, and one for concentrations in soil is T.
Values for toxicity constants ( T, r, and T) for a number of compounds
are given in Appendix C. Appendix D describes in detail the methods used for
calculating the toxicity constants in Appendix C. The data base for this
procedure is adopted from the supporting documentation for the Superfund
Reportable Quantities rulemaking. Its use for selection of indicator chemicals
at Superfund sites will be reconsidered if another more appropriate data base
becomes available for ranking the toxicity of a large number of chemicals.
Because of probable differences in dose-response mechanisms (non-threshold
vs. threshold), potential carcinogens (PCs) and noncarcinogens (NCs) are
scored and selected independently. Indicator scores for carcinogens and
noncarcinogens are not on comparable scales and should never be compared.
* * * October 1986 * * *
\
-------
OSWER Directive 9285.4-1
-23-
EXHIBIT 3-2
CONCENTRATION AND TOXICITY CONSTANT UNITS
Environmenta 1
Medium
Water
Soil
Air
Environmental
Concentration
Units
mg/1 a/
mg/kg b/
mg/m c/
Exposure
Route
ingest ion
ingest ion
inhalation
Toxicity
Constant
WT
ST
•r
Toxicity
Constant Units
(mg/l)~L
(mg/kg)
(mg/m )
a/ Milligrams per liter of drinking water.
b/ Milligrams per kilogram of soil.
c/. Milligrams per cubic meter of air.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-24-
To begin the indicator selection process, use Worksheet 3-1 to list all
compounds found at the site. For each compound record its Chemical Abstract
Service (CAS) number and K value from Appendix C. Record the maximum and
minimum observed concentrations as well as a "representative" concentration
for each compound. Determination of the representative concentration should
be based on an analysis of all the site monitoring data, with the goal being
to represent long range trends at potential human exposure points. It may be
appropriate to use a geometric or arithmetic mean of some or all of the samples
as the most representative concentration, or it may be more appropriate to
choose a concentration that reflects a time trend occurring at the site. Use
the monitoring data most relevant to a public health evaluation at the site.
For example, simply averaging upgradient and downgradient well results would
usually be inappropriate. To get a concentration that represents the concen-
tration of chemicals in a ground-water plume, the mean should generally be
calculated based on samples where the chemical has been detected, not including
samples below detection limits. Focus on data from locations nearest to expo-
sure points. Also, consider detection frequency in determining a representa-
tive concentration, giving relatively less weight to chemicals detected
infrequently. Be sure to be consistent for all chemicals within each medium
so that the selection process is not biased (i.e., do not choose a geometric
mean concentration for one chemical and an arithmetic mean for a second).
Indicate on the worksheet the basis for the representative concentration
chosen and note any assumptions or additional information required to use this
information. If there are concerns about use of these concentrations, note
them. For example, even if the concentrations adequately represent the
quantitative monitoring information available, they may not seem to reflect
the reality of a 450,000-gallon lined lagoon whose liner may fail at any
time. Another concern related to representativeness of monitoring data is
detectability. If there is reason to believe that a chemical is present but
is not being detected by the sampling and analytical protocols used, be sure
to note this also. If a chemical is considered sufficiently important, it may
be chosen as an indicator chemical regardless of its concentration. Also note
any chemicals that were identified analytically but for which no quantitative
data are available.
After completing Worksheet 3-1, refer to Appendix C to determine each
compound's toxicologic class (potential carcinogen (PC) and/or noncarcinogen
(NC)), severity rating value (noncarcinogens) or weight-of-evidence rating
W S jj
(carcinogens), and appropriate toxicity constants ( T, T, and T) .
Enter this information on Worksheet 3-2. If a chemical is designated as both
a PC and NC, complete the indicator scoring procedure for it in both
toxicologic classes. Generally, compounds not listed in Appendix C or with
insufficient data for indicator scoring should be classified as unknown under
toxicologic class.1*-1 These substances should be listed in the final report
1SJ Users should be aware that a few chemicals (e.g., dichloromethane)
have the necessary toxicity values for risk characterization (Exhibits C-4 and
C-6) but not for indicator selection (Exhibits C-3 and C-5). This results
from the use of different toxicity data bases for deriving indicator selection
parameters and risk characterization parameters. Therefore, be sure not to
exclude chemicals simply because they lack the toxicity constants necessary
for indicator selection.
* * * October 1986 * * *
\
-------
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 3-1
SCORING FOR INDICATOR CHEMICAL SELECTION: CONCENTRATIONS AND Hoc VALUES
IN VARIOUS ENVIRONMENTAL MEDIA
Ground Water Surface Water Soil
Chemical Koc (mq/M (mq/l) (mg/kg)
(CAS No,) Value Range Repres a/ Ref b/ Range Repres a/ Ref b/ Range c/ Repres c/
Arsenic -- <.010-.M6 .075 B.112 <.010 - B.112 1.7-36 7
(7HMO-38-2)
Tetrachlor- 361 BDL e/-67 3.2 A. 18 BDL-.012 .003 AJ8 BDL-13.000 2
oethylene
(127-18-«4)
Beryl 1 lum -- <.005-.05 .006 B.112 <.005 - B.112 <.25-2.6 0.6
(7110-141-71
Air
(mq/m3)
Ref b/ Range Repres Ref b/
A. 22 - d/
A. 23 -
A. 22 -
A.18 BDL-.026 .002
A.16
BDL-210 13.8
A,23
1.2.1- 9200 BDL-1.2 . 11
Trichloro-
_benzene
(120-82-11
a/ Mean of reported values used as representative concentration for surface and ground water; zero used for all values
reported as below detection limit.
b/ A = Feasibility Study document, B = Remedial Investigation document. Page numbers follow document designation.
c/ Soil concentration range is across surface, subsurface soils, and sediments; mean of the surface soil values used as
representntIve concentration; zero used for all values reported as below detection limit.
d/ No data reported for this medium.
e/ BDL = below detection limits.
INSTRUCTIONS
1. Write down each chemical found at the site with Its CAS Number and Koc value (see Appendix C).
2. If more than 20 chemicals are listed. Identify those with the ten highest Koc values with an II and those with the ten
lowest Koc values with an L.
3. Indicate the range of concentrations for each chemical in each medium and the source of the information (e.g., Rl report).
l|. Determine a "representative" concentration and enter it; indicate In footnotes the basis of the representative value.
ASSUMPTIONS
List all the major assumptions made in developing the data for this worksheet; also indicate any concerns about the
monitoring data:
O
O
H-
H
(B
O
rt
»-••
R>
CD
Ui
-------
Chemlca 1
Arsenic
Tetrachloroethy lene
Be r.v 1 1 i urn
1 ,2,/i-Trichlorobenzene
Name or Site:
Date:
Analyst:
QC:
WORKSHEET 3-2
SCORING FOR INDICATOR CHEMICAL SELECTION:
TOXICITY INFORMATION
Toxicologic Rating Value/EPA w b/ s b/
Class Category a/ T T
PC A /I.I 2.0E-4
NC 9 18 9.0E-U
PC B2 8.9E-3 c/ /I./IE-7
NC 7 (oral) 9.6E-3 4.8E-7
10 ( inha (at ion)
PC B1 ( inhalation)
NC 8
NC l| (oral ) 0.21 1. 1E-5
1 ( inhalation)
a b/
T
0.089
0.028
a/ Rating value is Tor severity or effect for noncarcinogens, range in 1(low) to 10(high); EPA
category is a qualitative weight-of-evldence designation Tor potential carcinogens; explanation or
the categories is presented in Exhibit 0-2, Appendix D. Information taken from Appendix C.
b/ Data taken from Appendix C.
c/ 5E-3 is the same as 5.0 x 10-3.
INSTRUCTIONS
1. Record compounds from Worksheet 3-1, then refer to Appendix C and note whether they are classed as PC
or NC or both.
2. Record the rating value or EPA category for each compound In each class (see Appendix C). If there
are route-specific differences, record both values.
3. Record the T values from Appendix C.
ASSUMPTIONS
List all the major assumptions made in developing' the data for this worksheet:
O
c/i
CJ
M-
H
(D
o
rt
H-
VO
00
Ln
-------
OSWER Directive 9285.4-1
-27-
to provide an indication of the uncertainty associated with omitted chemicals
and to assist headquarters personnel in identifying data gaps. If you have
reason to believe that these compounds may be significant at your site,
contact the Environmental Criteria and Assessment Office (ECAO), U.S. EPA, 26
W. St. Clair Street, Cincinnati, Ohio 45268, for guidance in estimating the
necessary toxicity constants.'
The next task is to calculate IS values for each chemical. List all
potential carcinogens on Worksheet 3-3 and all noncarcinogens on Worksheet
3-4. Calculate C times T (C"T) for each medium for each chemical, using
both the peak and the representative concentrations. To develop an indicator
score (IS), sum the C»T values across media. If a compound is present in
both ground and surface water use only the higher C*T value for these two
media (i.e., do not include both in the IS score). This approach for water
makes the conservative assumption that all drinking water is obtained from the
source giving the higher C*T value. Rank the compounds on these two
worksheets separately on the basis of the indicator scores.
Record on Worksheet 3-5, in rank order based on IS values, the top-scoring
10 to 15 compounds from both Worksheet 3-3 (potential carcinogenic effects)
and Worksheet 3-4 (noncarcinogenic effects). Compare the list of chemicals on
Worksheet 3-5 to the chemicals identified with either an H or an L on
Worksheet 3-1 (H indicates one of 10 chemicals with highest K values, L
indicates one of 10 with lowest). If an important exposure scenario at the
site involves consumption of contaminated fish and none of the 10 chemicals
designated with an H made it onto the initial list, consider placing one or
more of them onto that list. Also, if exposure via ground-water contamination
is a concern and none of the 10 chemicals 'designated with an L made it onto
the initial indicator list, consider enlarging the list to include one or more
of these chemicals.
The list of 20 to 30 compounds on Worksheet 3-5 is the initial list of
indicator chemicals from which the final set of indicators is selected for the
site. In most cases the initial list and final selection should be based on
representative concentrations, although indicator scores based on maximum or
peak concentrations may be used to 'modify the selection. There is no
predetermined number of indicator chemicals appropriate for all sites; between
5 and 10 chemicals would be a manageable number and may be sufficient for most
sites. However, if a very large number of chemicals has been detected at a
site, it may be wise to select more indicators. The number and identity of
indicator chemicals selected is a site-specific decision that must be made and
documented for the site. Guidance for making the final selection is given in
the following section.
3.2 SELECT FINAL INDICATOR CHEMICALS
Final selection of indicator chemicals is not based on a numerical ranking
algorithm or set of precise decision rules. Instead, there are several
chemical-specific factors to consider, plus a few general selection rules.
The initial factor to consider is the relative indicator scores (IS) of the
chemicals. The IS, based in part on concentrations at the site, has already
been used to rank chemicals for the initial indicator chemical list (Worksheet
3-5). In general, higher ranking chemicals based on representative IS values
* October 1986 * * *
-------
OSWER Directive 9285.4-1
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-------
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 3-»»
SCORING FOR INDICATOR CHEMICAL SELECTION:
CALCULATION OF CT AND IS VALUES FOR NONCARCINOGEN1C EFFECTS
Chemica 1
Arsenic
Tetrachlo roe thy lene
Be r.v 1 1 1 urn
Trlchl orobenzene
Ground
CT
Max
8^3_
0.60
0.25
Water
Repres
0.11
0.028
0.023
Surface Water So i
CT CT
Max Repres Max
3.2E-2
1.1E-1 2.7E-5 6.2E-3
5.5E-3 'I.2E-H 2.2E-3
1 Ai r
CT
Repres Max Repres
6.3E-3
9.6E-7
— — —
1.7E-U
IS
Max
8.3
0.60
_
0.25
Va 1 uc
Repres
0. Hi
0.028
0.023
Tentative
Rank
Max Repres
1 1
2 2
_ _
3 3
INSTRUCTIONS
1. List all of the chemicals to be considered for noncareinogenic effects.
2. Calculate concentration times toxlcity (CT) values using the information from Worksheets 3-1 and 3-2. Calculate CT
values based on both maximum and representative concentrations for all media in which the chemical was detected.
3. Sum the CT values across media, keeping the two types of concentration separate. Use only the highest CT value of
ground water and surface water If both were contaminated. Record the sums In the IS column.
i|. Rank the compounds based on both their maximum and representative IS values.
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
D
H-
t-l
O
rt
H-
(0
oo
tn
-------
Name of Site:
Date:
Ana lyst:
QC:
WORKSHEET 3-5
SCORING FOR INDICATOR CHEMICAL SELECTION:
EVALUATION OF EXPOSURE FACTORS AND FINAL CHEMICAL SELECTION
a/
IS Va lues Ranking
Chemical PC NC PC NC
Arsenic 0.31 O.l'i 1 1
Tetrachlo roe thy lone 0.026 0.026 _2 _2
Be r.v 1 1 i urn
Trichlorobenzene NA 0.023 MA _J
a/ Based on representative concentrations.
1. List the top 10 to 15 PC and NC based on IS
2. Refer to Appendix C and record each chemical
Water Vapor Henry's Law
Solubility Pressure Constant Half-Life (Days)
(mg/l) (mm Hg ) ( a tm-m3/mole ) Koc GW SW Soil Air 1C
1.5E+6 00 - >10.000 >10.000 >10.000 5 +
150 16 0,026 Z6ij 26M 1-30 NA «LZ +
0.2 00 - >10.000 >10.000 >10.000 NA +
10 0.29 0^0023 9.200 >10.000 1,2 NA 50 +
INSTRUCTIONS
scores, giving their IS values and their ranking.
's solubility, vapor pressure, Henry's law constant, Koc, and half-lives in
,
air, water, and soil.
3. Select the final indicator chemicals. Use your judgement -- if a compound,has a high water solubility and a long
ha I f-1 i f e yet is ranked lower than a compound with minimal water solubility and a short half-life, you may wish to move
it up, in the ranking (refer to Section 3.2 for additional guidance on the final selection).
l|. Document any changes in ranking made because of exposure factors.
5. In the last column indicate with a + those chemicals which have been selected as indicator chemicals (in this example all
were selected because there are only four chemicals).
ASSUMPTIONS
List all major assumptions made in the development of data for this worksheet:
O
H-
N
ID
n
rt
H-
ff
oo
In
-------
OSWER Directive 9285.4-1
-31-
should be selected in preference to lower ranking chemicals within the same
toxicologic class (PC or NC) . This rule can be modified, however, on the
basis of the additional selection factors discussed below. Consideration
should also be given to the quantity of chemicals found at the site. Some
pollutants may not appear in very high concentration but may be distributed
throughout the entire site, adding up to a substantial total quantity.
Because values of IS for PC and NC are not directly comparable, the IS
value .is not relevant to a determination of the relative number of PC and NC
to select. In fact, this determination is subjective. Always include at
least some of both classes, and consider the relative number of•PC and NC
present at the site (e.g., if 90 percent of the chemicals at a site are
noncarcinogens, probably more noncarcinogens than carcinogens should be
selected). In any case, include several top-ranked (by IS) PC and NC as
indicator chemicals unless there are extremely strong site-specific reasons
for doing otherwise.
Although IS is the initial selection factor, several additional factors
are also important. These factors include five important chemical properties
related to exposure potential: water solubility, vapor pressure, Henry's Law
constant, organic carbon partition coefficient (K ), and persistence in
various media. High or low values of any of these factors for a chemical
found at a site may produce a high future exposure potential and may warrant
inclusion of a particular chemical in the list of indicator chemicals despite
a low IS score. Values for these factors are given in Appendix C for many
chemicals. Record appropriate values for the preliminary indicator chemicals
listed on Worksheet 3-5. For chemicals not listed in Appendix C, determine
values using sources listed in Appendix C or other standard references. Also,
estimation techniques are available for many physical/chemical parameters and
have been summarized in Lyman et al. (1982) and Mabey et al. (1982). Use of
estimation techniques in the absence of experimental data is encouraged, as
long as the procedures are documented.
Clearly, other chemical properties could affect exposures and risks at a
specific site. However, to limit the amount of data to be collected and
considered, the indicator selection procedure focuses on the five properties
listed above. These properties are important, but not exclusive, determinants
of environmental transport and fate. Some of the properties have different
implications for different exposure pathways. As a result, consideration of
the potentially important exposure pathways at a site is important when
applying physical/chemical factors in the selection process. A brief
description of the relevance of each property to potential chemical release,
transport, and fate is given below. Additional discussion of these parameters
is available in numerous references, including Kenaga and Goring (1978), Lyman
et al. (1982), Nelson et al. (1983), and Maki et al. (1980).
Water solubility is the maximum concentration of a chemical that .
dissolves in pure water at a specific temperature and pH. Solubility of an •
inorganic species can vary widely, depending on temperature, pH, Eh (redox
potential), and the types and concentrations of complexing species present.
Solubilities range from less than 1 ppb to greater than 100,000 ppm, with most
•common organics falling between 1 and 100,000 ppm (Lyman, 1982a). Water
solubility is a critical property affecting environmental fate (Menzer and
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
•32-
Nelson, 1980)/. Highly soluble chemicals can be rapidly leached from wastes
and contaminated soil and are generally mobile in ground water. Solubility is
one of the controlling factors affecting leachate strength and migration of
chemicals from waste sites (along with sorption potential, soil type, and
water infiltration). Soluble chemicals also tend to be more readily
biodegradable than those with low solubility (Lyman, 19S2a). Water solubility
is especially important in the evaluation of aquatic exposure" pathways.
Solubility affects "leachability" into both ground water and surface water,
and highly soluble compounds are usually less strongly adsorbed (thus more
mobile) in both ground and surface water. Solubility, along with several
other factors, also affects volatilization from water -- in general, high
solubility is associated with lower volatilization rates (Menzer and Nelson,
1980).
Some chemicals may be measured at a site at concentrations higher than
their water solubilities. This situation can arise in the case of non-aqueous
phase liquids (i.e., liquids that are not dissolved in water and that form a
second liquid layer, often floating on top of an aqueous phase or perched on
top of an aquifer). In these cases almost pure contaminant may be found.
Also, contaminants may be dissolved in the non-aqeous phase at concentrations
higher than their water solubilities. Chemicals detected at concentrations
higher than their water solubilities may warrant special consideration in
selection of indicator chemicals.
Vapor pressure and Henry's Law constant are two measures of chemical
volatility and thus are important in evaluating air exposure pathways. Vapor
pressure is a relative measure of the volatility of a chemical in its pure
state (Jaber et al., 1984). Vapor pressures of liquids range from 0.001 to
760 torr (mm Hg), with solids ranging down to 10* (Grain, 1982). Vapor
pressure is an important determinant of the rate of vaporization from waste
sites, but other factors, including temperature and wind speed, degree of
adsorption, water solubility, and soil conditions, are also important. Vapor
pressure is most directly relevant to exposure pathways involving chemical
releases to air from spills or contaminated surface soils. Henry's Law
constant, which combines vapor pressure with solubility and molecular weight,
is more appropriate for estimating releases to air from contaminated water
(e.g., ponds, lagoons) and should be used to evaluate chemicals for which this
type of pathway is expected. At sites where air exposure pathways are not
important, these two factors should not be used in the selection of final
indicator chemicals.
The organic carbon partition coefficient (K ) is a measure of
oc
relative sorption potential for organics and is a significant environmental
fate determinant for all exposure pathways, especially aqueous pathways. The
K indicates the tendency of an organic chemical to be adsorbed, and it is
largely independent of soil properties (Lyman, 1982b). K is expressed as
the ratio of amount of chemical adsorbed per unit weight of organic carbon to
the chemical concentration in solution at equilibrium. Therefore:
K = mg adsorbed/kg organic carbon
oc — '—a a
mg dissolved/liter solution
* * * October 1986 * * *
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OSVER Directive 9285.4-1
-33-
The normal range of K values is from 1 to 107, with higher values
indicating greater sorption potential (Lyman, 1982b). Many other partition
coefficients exist (e.g., K , K,, K ), but K was selected for this
om a ow oc
purpose because it is chemical-specific (essentially independent of soil
conditions) and for organics is directly related to soil and sediment
sorption, both of which are significant chemical fate processes at many
Superfund sites. For inorganics, some other parameter such as the
distribution coefficient for a specific soil type (K.) or the maximum
exchangeable mass may be a better measure of relative adsorption potential.
The significance and interpretation of K varies with different exposure
pathways. For ground water, low K -values indicate faster leaching from the
waste source into an aquifer and relatively rapid transport through the aquifer
(i.e., limited retardation of the chemical). K is directly proportional to
the retardation factor, which is used in many ground-water transport models.
Therefore, among chemicals with similar IS values due to ground-water pathways,
high mobility (low K ) chemicals generally would be of more concern. If a
chemical with a low K is present at a high concentration in soil but is
oc r
not chosen because of a low IS value, consider adding it to the final
indicator list.
For surface water pathways, K also has several significant
implications. A high K indicates tight bonding of a chemical to soil,
which means that less of the chemical will be dissolved in site runoff, but
also implies that runoff of contaminated soil particles may occur over a
longer time period. At some Superfund sites, direct recharge of surface water
by ground water is important; in these situations, because of ground-water
mobility considerations, chemicals with high K are of relatively lower
concern. Once a chemical gets into surface water, however, a high K may
be of great concern because it indicates a tendency to bioaccumulate (K is
related to bioaccumulation potential). If aquatic food chain pathways are
possibly significant, this implication of K should be considered. The
K value also indicates the relative amount of sediment adsorption in
oc
surface waters.
An example of the consideration of K in indicator chemical selection
oc
follows. For a site with:. (1) potential ground-water exposure pathways, (2)
high soil concentrations of a chemical with low K , and (3) low
0 oc
concentrations of the same chemical in available ground-water monitoring data,
consideration should be given to selecting that chemical despite its probable
low indicator score. The combination of low K and high soil concentration
oc
indicates that significant releases of the chemical to ground water are
possible in the future.
* * * October 1986 * * *
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OSWER Directive'9285.4-1
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Th e final chemical property to be considered in the indicator selection
process is persistence in various environmental media. This property is a
measure of how long a chemical will exist in a given medium, obviously a
critical factor in assessing exposure potential. Important removal processes
are phase transfer (e.g., water to air, soil to water), chemical
transformation (hydrolysis, photolysis), and biological transformation.
Available persistence data are given in Appendix C as ranges of overall
half-lives (i.e., due to all removal processes) in air, soil, ground water,
and surface water. If half-life values from other sources are used, be sure
to determine whether they represent overall disappearance rates or whether
they correspond to a specific removal mechanism.
Half-lives of chemicals vary from seconds to thousands of years. Small
half-lives generally indicate a lower level of concern, although degradation
products may have a higher toxicity or environmental mobility than the
original chemical. In considering persistence as a secondary factor for
selecting indicator chemicals, you must consider the exposure pathways
contributing to the IS score (Worksheets 3-3 and 3-4). Do not use relative
persistence in one medium to approximate it in another because the important
removal processes may be very different.
One additional factor, to be considered for potential carcinogens only, is
the qualitative weight-of-evidence rating. This rating is an indication of the
quality and quantity of data underlying a chemical's designation as a potential
human carcinogen. The categories of evidence for human carcinogenicity include
sufficient, limited, and inadequate. Chemicals on the preliminary indicators
list with sufficient evidence of human carcinogenicity (EPA Group A) and
chemicals with'limited human evidence and sufficient animal evidence (EPA
Group Bl) should generally be selected as final indicators unless there are
convincing reasons to do otherwise. For chemicals with similar IS values,
ones with stronger weight-of-evidence should usually be selected.
Using the preceding discussion as guidance, make the final selection of
indicator chemicals. Starting with the initial chemical list given in
Worksheet 3-5, consider IS scores and relevant additional factors in the final
selection process. Indicate on Worksheet 3-5 the final selections and the
rationale for each. If toxic organics and inorganics are both present at the
site, be sure to include at least one of each on the final list of indicator
chemicals.
By following the procedures described in this chapter, a subset of the
chemicals present at the site has been selected to serve as indicator
chemicals. The procedure has been structured to favor the selection of those
chemicals that pose the greatest potential risks and therefore should serve as
indicator chemicals. There are many components of the selection procedure
that require individual judgment. Care must be taken to apply the general
principles set forth in each step in a consistent manner so that the final
scores are comparable. The scores developed here are used only for relative
ranking and have no meaning outside the context of this procedure. They
should not be considered as a quantitative measure of a chemical's toxicity or
exposure. As a next step in the quantitative analysis process, exposure
pathways will be identified for these indicator chemicals and exposure point
concentrations estimated.
* * * October 1986
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OStfER Directive 9285.4-1
-35-
CHAPTER 4
STEP 2: ESTIMATION OF EXPOSURE POINT
CONCENTRATIONS OF INDICATOR CHEMICALS
This chapter describes methods for estimating baseline environmental
concentrations of indicator chemicals so that the extent and duration'of human
exposure in the absence of any remedial action can be determined. During the
remedial investigation, it is essential to collect sufficient environmental
sampling data so that if contamination has reached a human exposure point,
some actual data may be used in the evaluation of potential effects. However,
at many Superfund sites, contamination has not yet reached the point of human
exposure. As a result, it is necessary to. estimate how and when such exposure
will take place. Chemical fate and transport equations and models may be
useful for predicting exposures. Many models, ranging widely in
sophistication, data input requirements, cost, and reliability, are
available. Ultimately, the remedial project manager must decide what model to
use in exposure assessment. Consideration should be given $.0 the complexity
of the site and the environment, the precision needed, and the time available
for analysis. The Superfund Exposure Assessment Manual, a companion to
this manual, describes the various models available and provides guidance in
selecting appropriate modeling techniques for each site. It should be
recognized, however, that the uncertainty associated with modeling results can
be significant.
At most sites, a combination of site monitoring data and environmental
modeling results will be required to estimate chemical concentrations at
exposure points. Alone, both types of information have considerable
drawbacks. Taken together, site monitoring data and environmental modeling
offer the best approach to estimating exposure levels.
Site monitoring data have the advantage of being actual measurements of
chemical concentrations on and in the vicinity of the site. Within the
accuracy and precision of the sampling and analysis procedures, these
measurements are real chemical levels representative of the sampling time,
location, and medium.17J Consideration of site monitoring data alone,
however, has several disadvantages for public health evaluation, particularly
for assessment of long-term effects. Potential drawbacks include:
• Temporal representativeness -- Monitoring data may be
representative of current and/or past conditions, but do
not give a clear indication of future conditions. Often
at Superfund sites the sampling history is too short to
detect time trends, especially in ground water. Be'cause
it is necessary to predict future exposures to quantify
long-term risks, especially if contaminants have yet to
reach any exposure points, monitoring data must be
17J Site monitoring data should be QA/QC validated before use in the
risk assessment process.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-36-
supplemented by some kind of environmental fate modeling
(or simple assumptions, such as that concentration will
remain constant or continue to change at the observed
trend for the next 70 years). Over-reliance on
environmental monitoring data can lead to an
underemphasis on chemicals not yet released from a
source and on slow-moving chemicals that have not yet
reached monitoring points. Source monitoring data can
help identify these chemicals.
• Spatial representativeness -- Monitoring data are
representative of their sampling locations, which may or
may not be relevant to a risk assessment. In the past,
monitoring at Superfund sites was often conducted
on-site at or near a contaminant source. Because
chemical concentrations are spatially variable, and
available data may not cover off-site human exposure
points, monitoring data usually must be supplemented by
modeling to allow an adequate assessment of public
health effects.
The extreme time and space variability of environmental concentration data
at Superfund sites and the need for projections of future health risks, often
at off-site exposure points, necessitate the use of chemical fate modeling
along with site monitoring data. Monitoring usually represents a time
"window" that is too small and a spatial distribution that is too limited to
fully represent site conditions. However, at all sites the available
monitoring data must be reviewed thoroughly and used to the extent possible.
For example, monitoring data should always be used to assist in selection,
calibration, and verification of chemical fate models and to help in the
estimation of source terms (i.e., release rates) for these models.
Environmental fate modeling at Superfund sites also has significant
disadvantages. However, models can project chemical concentrations over space
and time and thus overcome the major drawback to site monitoring data. With
all fate models, especially ones dealing with long-term subsurface transport,
there is considerable uncertainty. Ground-water models have not been
validated over the long time periods of concern, and many subsurface
environments (e.g., anisotropic, heterogeneous) are not well suited to
available models. More sophisticated computer models are expensive to use,
often require extensive data inputs, and still may not be very accurate
because of limitations in the characterization of the source term or other
input data. Thus, simple environmental fate models using conservative (i.e.,
reasonable worst case) assumptions are usually most appropriate for Superfund
sites.
In the event that data from human monitoring in the site vicinity (e.g.,
blood or tissue analyses, genetic testing data) are available or such
monitoring is planned, the Agency for Toxic Substances and Disease Registry
(ATSDR) should be consulted. ATSDR should take the lead in conducting any
human monitoring and in assessing the current health status of people near the
site based on human monitoring data.
October 1986 * * *
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• OSWER Directive 9285.4-1
-37-
At some Superfund sites, background chemical contamination is
significant and should be accounted for in the public health evaluation.
Background is defined here as chemical contamination due to a source other
than the site under evaluation. Background can be either "natural," as in the
case of certain inorganics such as arsenic, or from various anthropogenic
sources (e.g., industrial point sources, other uncontrolled waste sites,
agricultural pesticide applications). Try to define local background
conditions for chemicals of concern based on recent monitoring data, such as
RI site characterization results, at locations clearly unaffected by the site
(e.g., upgradient, upwind). Three or four upgradient samples taken on one day
are insufficient to establish background. However, if background conditions
can be assessed with confidence based on available monitoring data, this
information should be incorporated into the evaluation. Information resources
such as the U.S. Geological Survey, the Soil Conservation Service, the Army
Corps of Engineers, and state land use agencies may be helpful in determining
background concentrations.
The recommended option for including background is to estimate all
chemical concentrations, intakes, and risks -for two scenarios: (1) actual
conditions at the site, reflecting both background and site-specific
contamination, and (2) background alone, as if the site did not exist. The
first scenario allows an estimate of overall health risk at exposure points
affected by the site, without attribution of the source of the risk. The
second scenario indicates the probable risk due to sources other than the
site, and comparison of the two scenarios gives information on the relative
importance of the site to overall risk. For example, if background arsenic
was 5 ppm in drinking water and projected exposure from all sources was 15
ppm, both values could be carried through the entire process, completing
parallel worksheets for background and overall risk scenarios.
The methods for estimating environmental concentrations described in this
chapter and the Superfund Exposure Assessment Manual should be applied to the
selected indicator chemicals. Exhibit .4-1 diagrams the activities involved in
estimating exposure point concentrations. The first task is a detailed
exposure pathway analysis, which is described in Section 4.1. The second
task, estimation of short-term and long-term concentrations for each indicator
chemical at each human exposure point, is discussed in Section 4.2. These
concentrations will generally be derived from a combination of site monitoring
and modeling information. Short-term concentrations (STC) are averaged over a
relatively short time period (10 to 90 days) and are used to evaluate
potential effects of subchronic exposure; long-term concentrations (LTC) are
averaged over longer time periods, up to a human lifetime (70 years), and are
used in the assessment of effects of chronic exposure.
For assessment of potential carcinogenic risk, the LTC should usually be
averaged over a lifetime. However, for assessment of other chronic health
risks, the LTC should not necessarily be averaged over a 70-year period and
for some chemicals it would clearly be incorrect to do so. The recommended
approach is to average LTCs over the time period of highest exposure for
assessment of noncarcinogenic effects and not to substantially reduce an LTC
value by averaging over a full lifetime. However, if significant
noncarcinogenic risk is projected using this approach, it may be necessary to
refer to the specific toxicologic studies on which the toxicity values {i.e.,
reference dose) are based to determine the most appropriate averaging period.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
EXHIBIT 4-1
OVERVIEW OF STEP 2: ESTIMATING EXPOSURE POINT CONCENTRATIONS
Identify Potential Human Exposure Pathways
Estimate Exposure Point Concentrations of Indicator Chemicals
Using Environmental Monitoring and Appropriate Models
\7
Compare Projected Concentrations to Applicable
or Relevant and Appropriate Requirements
-------
OSWER Directive 9285.4-1
-39-
For example, volatilization from a site may be rapid for a few months and
then decrease substantially. The peak STC would be obtained by averaging
concentrations over the 10- to 90-day period of greatest volatilization. The
LTC for assessing cancer risk would be averaged over the entire 70-year
period, beginning with the date of the site assessment. The LTC will always
be less than or equal to the peak STC.
The concentrations derived in Step 2 of the public health evaluation
process will be the inputs to Step 3 -- estimation of chemical intakes. The
exposure point concentrations will .also be compared to applicable or relevant
and appropriate ambient concentration requirements, a task described in
Section 4.3.
Worksheets are provided as a means for organizing and documenting the data
collected for estimating exposure point concentrations. Filling in these
worksheets will not be sufficient to complete the quantitative analyses
required. Rather, they serve to direct and focus the analysis so that the
results can be used directly in later steps of the public health evaluation.
All procedures, assumptions, and calculations used to develop concentration
estimates must be clearly documented in a format that will facilitate review.
4.1 IDENTIFY EXPOSURE PATHWAYS
This section describes an approach for identifying potential human
exposure pathways at a Superfund site. An exposure pathway consists of four
necessary elements: (1) a source and mechanism of chemical release to the
environment, (2) an environmental transport medium (e.g., air, ground water)
for the released chemical, (3) a point of potential human contact with the
contaminated medium (referred to as the exposure point), and (4) a human
exposure route (e.g., drinking water ingestion) at the contact point. Exhibit
4-2 illustrates the elements of an exposure pathway. Each pathway therefore
describes a unique mechanism by which a population or an individual is exposed
to contaminants originating from a site. The overall risks posed by a site
are a composite of the set of individual pathway risks. Risks for individual
pathways, however, may not be additive because they may represent risks to
different populations.
The Superfund risk assessment process is based on concern for both
individual risk and risk to exposed populations. One exposure point that
should be evaluated for a pathway is the geographic point of highest individual
exposure for a given release source/transport medium combination (i.e., the
geographic location where human inhabitants are exposed to the highest
predicted chemical concentrations). Exposure points with lower predicted
chemical concentrations and large potentially exposed populations should also
be evaluated. For example, a potentially vulnerable public water supply
serving a large population should be included in the evaluation even if higher
exposures are projected at a few private wells closer to the site.
To identify possible exposure pathways, human activity patterns near the
site should be defined and combined with chemical release source and transport
media information. This task is accomplished using a qualitative, yet
systematic procedure that relies on professional judgment and experience.
Because chemical release and transport are more rigorously analyzed in the
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
H
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-------
OSVER Directive 9285.4-1
-41-
next phase of the exposure assessment (Section 4.2), the initial list of
exposure pathways can be modified as the analysis proceeds. If there are
questions or uncertainties about a possible exposure pathway, it should not be
eliminated from the analysis until the next phase is completed.
The analysis described here is a first-cut organization of the relevant
site information so that major exposure pathways can be defined. It is not
intended as a time-consuming task in the overall public health evaluation
process. Iterations of this procedure following the results of additional
site sampling and/or modeling will confirm the important exposure pathways. A
four-step framework for the exposure pathway analysis is described below.
4.1.1 Determine Possible Chemical Release Sources and Release Media
To determine possible release sources for a site in the absence of
remedial action, use all available site descriptions and data from preliminary
assessment, site inspection, and remedial investigation. Also obtain and use
any appropriate information being developed as part of the feasibility study.
Monitoring data showing off-site contamination in excess of background levels
are especially valuable because they demonstrate chemical release and
transport from the site. Exhibit 4-3 lists some typical release sources at
Superfund remedial sites, organized by release medium. In many cases the
release, transport, and exposure media will be the same (i.e., release to air
will result in transport and exposure via air). However, intermedia transfers
can occur and may be critical at some sites (e.g., fish ingestion exposures,
which result from releases to surface water).
Use Worksheet 4-1 to summarize the results of the initial release source
analysis. Supplement Worksheet 4-1 with a site map that indicates locations
of the release sources. At this point, combinations of release
source/transport medium for a site (i.e., the first two components of exposure
pathways) have been identified and the -exposure points for each must now be
determined.
4.1.2 Identify and Characterize Possible Human Exposure Points
First, identify for each combination of release source and transport medium
(Worksheet 4-1) the location of highest individual exposure to the general
public (defined here as the "significant" exposure point). Next, determine
the number of people potentially affected at each of the significant exposure
points and record the basis for the estimate. Both short-term and long-term
exposures must be considered. In addition, include any locations with the
potential for exposure of large numbers of people" (e.g., public drinking water
supplies, shopping centers, industrial parks) or sensitive populations that
may be at special risk "(e.g., schools, hospitals). Some of these locations
should be included as supplementary exposure points in the.exposure and risk
analysis to follow. In addition to identifying locations of exposure points,
determine the probable routes of exposure at each. Guidance for identifying
significant exposure points is given below for each transport medium.
Consider including the site itself as an exposure point, based on a reason-
able future use scenario. Clearly, this consideration would be inappropriate
at sites where future development is improbable, but some sites may have
* * * October 1986 * * *
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-42-
EXHIBIT 4-3
COMMON CHEMICAL RELEASE SOURCES AT
SITES IN THE ABSENCE OF REMEDIAL ACTION
Release
Medium
Release
Mechanism
Release Source
Air
Volatilization
Surface water
Ground water
Soil
Fugitive dust
generation
Surface runoff
Episodic overland
flows
Ground-water seepage
Site leaching
Site leaching
Surface runoff
Episodic overland
flows
Fugitive dust
generation/
deposition
Tracking
Surface wastes -- lagoons, ponds,
pits, 'spills
Contaminated surface soil
Contaminated wetlands
Leaking drums
Contaminated surface soil
Waste piles
Contaminated surface soil
Lagoon overflow
Spills, leaking containers
Contaminated ground water
Surface or buried wastes
Contaminated soil
Surface or buried wastes
Contaminated surface soil
Lagoon overflow
Spills
Contaminated surface soil
Waste piles
Contaminated surface soil
* * * October 1986 * * *
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OSVER Directive 9285.4-1
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Name of Site:
Date:
Analvst:
QC:
.WORKSHEET 4-1
PRELIMINARY'-RELEASE SOURCE ANALYSIS
FOR BASELINE SITE CONDITIONS
Release
Medium
Potential
Release Source
Release
Mechanism
Release
Time Frame
Release
Probability/
Amount
Air Contaminated
surface soil
Volatilization
100% probability;
amounts may be high
Surface On-site lagoon
water
Overflow
Low probability;
relatively high
amounts
Ground
water
Soil
INSTRUCTIONS
For each medium, list potential release sources and mechanisms.
Estimate release time frame: chronic (C) or episodic (E).
1.
2.
3.
Record any information, qualitative or quantitative, on release
probabilities and amounts. If quantitative data from observations made
during the remedial investigation on frequency, duration, probability, and
quantity of releases are available, report those values here.
4. Attach a site map indicating locations of release sources.
ASSUMPTIONS
List all'major assumptions in developing the data for this worksheet:
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-44-
future human'contact uses. Consult with local planning and zoning officials
to determine a reasonable future use scenario. If the scenario includes human
contact, include these on-site exposure pathways in the analysis.
Air Exposure. For air exposures, the individuals exposed to highest
concentrations will generally be the people located downwind of and nearest to
the source. This may not always be true; for example, the point of highest
ambient ground-level concentration may be some distance from the source if the
source is elevated. In these cases, the appropriate exposure point must be
determined later, in conjunction with sampling or air modeling efforts (as
described in Section 4.2). At the majority of Superfund sites, however, it
can probably be assumed that the nearest population is the pertinent exposure
point. Once the release sources into air are determined in the first task, it
is relatively straightforward to locate the closest population. These
populations can be located in residential, industrial, or commercial areas or
at other points of human activity. Potential sources of this information
include:
• site vicinity surveys;
• topographic maps;
• aerial photos of the site;
• county or city land-use maps; and
• census data.
On a map, indicate precisely for each air release source the direction and
distance to the significant exposure point.
The point of highest short-term individual exposure by air may well be
different from the point of highest -long-term exposure. The highest short-
term exposure point will generally be the closest population in any direction
from the site, whereas the highest long-term exposure point will, in most
cases, be downwind. Therefore, select the exposure point for determining
long-term concentration within the downwind 90° arc from the emission source
(45° on each side of the average downwind centerline as determined from
historical wind data for locations near the site), unless it can be
demonstrated that long-term concentrations will be higher elsewhere.
Historical wind data are usually available for airports and some other
locations through the National Oceanic and Atmospheric Administration (NOAA).
Surface Water Exposure. The significant exposure points for surface
water pathways depend on downstream uses of the water. Both withdrawal points
ar.d areas of in-stream use must be considered. Withdrawal uses to be
considered include domestic water supply (drinking-, cooking, bathing),
agricultural use (livestock watering, irrigation), and industrial use.
Relevant in-stream uses include swimming and other water contact sports and
private and commercial fishing (resulting in ingestion of contaminated fish).
Sources for identifying withdrawal points and uses include:
• site vicinity surveys;
• state water agency records;
• local water utility records;
• withdrawal permits; and
• EPA Office of Drinking Water data bases (Federal Reporting Data
System, or FRDS).
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-45-
Locate on a map the exact points of withdrawal in relation to the source from
topographic maps. Indicate points of in-stream use from site vicinity surveys
and possibly from local or state planning and recreation agencies.
At some sites, an important potential route of exposure via surface water
is through the ingestion of contaminated fish or shellfish. Fish living in
contaminated water concentrate contaminants from the water in-their tissue.
Due to the solubility of some contaminants in fats, many chemicals are
bioconcentrated and appear in the tissue at concentrations higher than in the
surrounding water. Consumption of fish from surface water near sites should
be considered as a possible exposure route.
Ground-Water Exposure. Determining points of highest exposure to
ground-water contaminants will often be difficult unless subsurface flow
modeling is done. In general, nearby wells will have higher concentrations
than distant wells, and wells in the direction of ground-water flow (often
approximated by surface slope) will be higher. If comprehensive ground-water
modeling is planned, do not determine the significant exposure point until it
is completed. Determine instead the locations, depths, pumping rates, and
uses of all wells in the immediate site vicinity and in the likely direction
of flow. Specify the ground-water formations from which various wells are
pumping, and determine the general extent of hydraulic connection among the
multiple formations. Identify well information through state or local agency
well logs or site vicinity surveys. This information can then be used in
conjunction with monitoring and/or modeling results developed to determine the
significant exposure points.
If subsurface modeling is not planned, determine the likely flow direction
from geohydrologic data and assume that the closest domestic well in that
direction is the highest individual exposure point. Locations and depths of
public water supply wells should also be determined. In addition to domestic
wells, locations of agricultural and industrial wells and any other relevant
ground-water uses must be determined.
Hydraulic connections between ground water and the surface water exposure
points identified above should also be determined.
Soil Exposure. Areas of highest direct exposure to contaminated surface
soil will generally be on or directly adjacent to the waste site. If access
to the site is not restricted or otherwise limited (e.g., by distance), the
site itself usually can be assumed to be the point of highest individual
exposure to surface soil. If site access is limited, the significant exposure
point for soil often will be the nearest residence or other human use area
(e.g., playground). If there is no evidence of surface soil contamination in
the site vicinity, there may be no important direct exposure pathways
resulting from soil contamination. A possible indirect route of exposure from
soil contamination to be considered is chemical uptake by plants, with
subsequent ingestion by humans.
Typical exposure points for the four environmental exposure media are
summarized in Exhibit 4-4. This exhibit can be used as guidance for
determining exposure points, but this determination is a site-by-site analysis
and the possibility of other exposure points must be considered for each site.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-46-
EXHIBIT 4-4
TYPICAL EXPOSURE POINTS FOR CHEMICAL
RELEASES FROM HAZARDOUS WASTE SITES
Transport/Exposure
Medium -
Typical
Exposure Point
Major
Exposure Route
Air
Nearest residence to
source
Nearest population magnet
(e.g., shopping center,
school, industrial park)
Other residence/population
at point of highest
concentration
Inhalation
Inhalation
Inhalation
Surface water
Withdrawal point for
potable use
Withdrawal point for
agricultural use
Withdrawal point for other
uses (e.g., industrial)
Nearest point for
swimming/contact sports
Nearest point for fishing
Ingestion, dermal,
inhalation
Inhalation, inges-
tion (food),
dermal
Inhalation, dermal
Ingestion, dermal
Ingestion (food)
Ground water
Nearest potable well
(private or public)
Nearest agricultural well
Nearest well for other
uses (e.g., industrial)
Ingestion, dermal,
inhalation
Inhalation, inges-
tion (food),
dermal
Inhalation, dermal
Soil
On-site
Immediately adjacent to
site (if site is
restricted)
Nearest cropland
Dermal, ingestion
Dermal, ingestion
Ingestion (food)
* * * October 1986 * * *
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OSVER Directive 9285.4-1
4.1.3 Integrate Release Sources, Environmental Transport Media,
Exposure Points, and Exposure Routes into Exposure Pathways
Assemble the information developed in the previous two steps and determine
the complete exposure pathways that-exist for the site. Use Worksheet 4-2 to
record the exposure pathway information. A complete exposure pathway is one
that has all the necessary components: a source and mechanism of chemical
release, an environmental transport medium, a potential human exposure point,
and a likely route of exposure. For example, if a release to ground water is
projected but there is no ground-water use (or projected use) from the
affected aquifer, then the exposure pathway is incomplete. The exposure
points for the complete exposure pathways define the spatial locations at
which chemical concentrations must be projected. The health risk estimates
developed later in this process are based on exposures at these locations.
The total number of people that may be exposed does not enter into the public
health evaluation quantitatively; however, it may be important on a
qualitative basis.
In some cases, exposures via identified pathways may be non-quantifiable.
There are a number of possible reasons for this, including the absence of data
on which to base estimates of chemical releases, environmental concentrations,
or human intakes. If an exposure pathway is determined to be non-quantifiable
during the exposure assessment procedure to follow, continue to include it as
a potential pathway on all subsequent worksheets, designating it as
non-quantified. This information can be taken into account in assessments of
the uncertainty of the results.
4.1.4 Determine Presence of Sensitive Human Populations
Review the information on the site area and determine if any population
groups with high sensitivity to chemical exposure are present. Sensitive
subpopulations that may be at higher risk include infants and children,
elderly people, pregnant women, and people with chronic illnesses. Sites may
be located in areas without readily identifiable sensitive subpopulations, but
if such subpopulations are present, the number of people involved and their
location should be determined.
To identify sensitive subpopulations in the site area, determine locations
of schools, day care centers, hospitals, nursing homes, and retirement
communities that are within three miles of the site or that use drinking water
potentially affected by the site. Use local census data and information from
local public health officials for this determination. Record this information
on Worksheet 6-2 (see Chapter 6).
4.2 ESTIMATE EXPOSURE POINT CONCENTRATIONS
To the extent available, measured chemical concentration data should be
reviewed for each chemical, exposure medium, and exposure point. Such
monitoring data can be used to estimate peak short-term concentrations at
exposure points. However, in addition to short-term indications of
concentration, long-term concentrations (averaged over periods up to a human
lifetime, 70 years) need to be estimated. Long-term concentrations are more
difficult to estimate and usually require environmental fate modeling (see
* * * October 1986 * * *
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Name or Site:
WORKSHEET 1-2
MATRIX OF POTENTIAL EXPOSURE PATHWAYS
Date:
Analyst:
QC:
Release/
Transport Medium
Air
Ground water
Surface water
Re lease/Source
Mechani sm
Contaminated soil/
volai i 1 i zat ion
Contaminated soil/
volat i 1 i zat ion
Contaminated soil/
leaching
Contaminated soil/.
leaching
Exposure
Point
Nearest residences *
(0.7 mile SW of site)
Trailer park (2
miles south of s i te I
Wei 1 s at nearest
residences*
Wei Is at 2 mi les
serving neighborhood
Exposure
Route
Inha 1 at ion
Inlia la t ion
Inqestion of
drinking water
Ingest ion or
drinking water
Number of
People
50
600
50
900
Pathway
Comp lete
Yes
Yes
Yes
Yes
Soil
* Significant exposure point.
INSTRUCTIONS
1. List all release sources and mechanisms by release medium.
2. Describe the nature of the exposure point and its location with respect to release source (e.g., nearest
residence to volatilization release site, 300 feet NW). Denote significant exposure points with an asterisk.
3. List exposure route (e.g., inhalation, ingestion).
'I. Report the number of people potentially exposed at the exposure point.
5. Mark where exposure pathways are complete (i.e., where release source, transport medium, exposure point, and
exposure route all exist).
ASSUMPTIONS
List all major assumptions in developing the data Tor this worksheet:
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OSVER Directive 9285.4-1
-49-
Sections 4.2.1 and 4.2.2). The short-term and long-term concentration
estimates will be used in the next phase of the public health evaluation --
calculating human intake. By understanding the potential long-term exposures
from a site, one will better' understand the consequences of not taking any
action. Short-term concentrations will be important in the evaluation of
chemicals to which even short-term exposure is a concern and which can be
contained by certain management practices. Note that the only chemicals being
evaluated here are those that have been selected as indicator chemicals.
Relevant monitoring results from points of human exposure should be
recorded on Worksheet 4-4 (near the end of Chapter 4) to provide short-term
concentration values. Because several samples are generally taken, some
measure of the variability of the estimate (confidence interval, range) should
be recorded. Long-term concentrations on which to base lifetime exposures may
be estimated on the basis of both monitoring data and the chemical release and
fate models described in the Superfund Exposure Assessment Manual.
After potential exposure pathways are determined, environmental
concentrations for each indicator chemical must be estimated at each of the
significant and supplementary exposure point locations identified in Worksheet
4-2. Concentrations of substances need to be estimated as a function of time
(i.e., short-term and long-term) in each environmental medium -- air, surface
water, ground water, or soil -- through which potential exposures could
occur. For example, if in completing Worksheet 4-2, it is determined that
potential exposure routes for a nearby residential area are inhalation of
contaminated air and ingestion of contaminated ground water, chemical
concentrations over time must be predicted for both air and ground water at
this location.
Estimating environmental concentrations at an exposure point is
essentially a two-step process. First, quantify the amounts of chemicals that
will be released to the environment by the various sources identified in the
exposure pathway analysis. Given these release quantities, then predict the
environmental transport and fate of each indicator substance in the identified
medium of the exposure pathway. An example would be the movement of a
contaminant released to ground water from contaminated soil and then
transported to a drinking water well.
Numerous analytical techniques are available to perform the calculations
required in these two steps. These techniques are described in detail in the
Superfund Exposure Assessment Manual. The techniques vary in sophistication
from simple, desk-top methods that provide rapid, order-of-magnitude
projections, to more rigorous approaches involving computer modeling that may
give more accurate results, but require more time and resources to undertake.
All techniques require certain chemical- and site-specific data, although the
data requirements vary with the degree of sophistication of the method used.
Regardless of the technique used, it is likely that numerous assumptions will
be required because of gaps in available data. The appropriate level of
sophistication will be influenced by data availability, and by the demands and
bounds of the remedial investigation/feasibility study effort at a specific
site. Relatively simple chemical release and transport models are usually
appropriate for Superfund public health evaluation exposure assessments.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-50-
There are two recommended approaches for addressing the unavoidable
estimation uncertainties likely to be encountered in the exposure assessment.
One is to use a conservative (not necessarily "worst-case") approach in making
the assumptions necessary for a particular estimation method. The consequence
of making conservative assumptions is that risks may be substantially
overstated but will not be understated in the final analysis. All assumptions
and the basis for each should be recorded.
A second, and generally preferred, approach is to calculate and present
both best estimates and conservative upper bound estimates for all exposure
point chemical concentrations. If this approach is followed and both sets
of concentration estimates are carried through the entire public health
evaluation (ultimately resulting in two sets of risk estimates), the results
will provide not only an estimate of the risk magnitude but also a good
indication of the overall uncertainty of the analysis. Of course, this
approach requires more calculation effort, but it is a straightforward way to
account for analytical.and data uncertainties. This approach, which yields an
upper bound and best estimate of each risk projection, emphasizes the
uncertainty involved by displaying it quantitatively. A large disparity
between the upper bound and best estimates of risk would indicate relatively
high uncertainty, and vice-versa. This approach requires that two sets of
most subsequent worksheets be completed, one for the best estimate and one for
the upper bound.
A third possible approach, generally beyond the scope of the Superfund
public health evaluation process, is to model the important variables
determining chemical concentration and risk stochastically. This allows
estimation of a risk distribution, from which median and 90th percentile (or
other upper bound) values can be determined. This approach is more complex
and time-consuming than a deterministic approach, and it still only accounts
for uncertainty due to the variables modeled stochastically. It does not
address other sources of uncertainty, such as applicability of the release or
transport models to the real site situation.
The following subsections explain how chemical release and transport
models should be used and the types of outputs that are needed to continue the
risk assessments process. Detailed guidance on chemical release, transport,
and fate assessment at Superfund sites is contained in the Superfund Exposure
Assessment Manual, which accompanies this manual. In addition, a set of
background documents for EPA's proposed guidelines for exposure assessment
(EPA, 1984b) is being prepared and will be a convenient source of this
information when released.
4.2.1 Quantify Chemical Releases
Chemical releases are quantified in terms of release rates. These rates
are then used along with other factors to predict environmental fate and
transport. Various methods are available for estimating release rates. They
are fairly straightforward and can be verified with the use of site sampling
data. Evidence of chemical release into an environmental medium such as ground
water, air or surface water must have been observed to warrant a quantitative
analysis. When release rates calculated from a model result in concentrations
that do r.ot make sense in light of the site sampling data, reexamine the
selection of the model or the reliability of the sampling results.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-51-
To quantify releases, consider separately each release medium and the
associated sources and mechanisms of release that have been identified in the
exposure pathway analysis (Section 4.1) for a specific chemical. Calculate
the mass loading of the chemical contaminant from each release source to the
environmental medium. In some cases, it will be sufficient to calculate a
constant, or steady-state loading rate, based on the assumption that
insignificant reductions in contaminants occur at the source during the
evaluation time period. In other instances, reductions in release rates over
time may need to be accounted. Ultimately, professional judgment must be used
to decide which course to take for each specific release source.
Brief descriptions of methods available to calculate releases are
presented below for each of the four primary environmental media of interest
-- air, surface water, ground water, and soil. References are also made to
more detailed descriptions of the methods contained in other documents. A
substantial amount of data is required to complete the analyses described.
Recognizing that all of the necessary data will rarely be available, the
analyses can be conducted with proper application of professional judgment in
making assumptions. Again, all assumptions and their basises should be
recorded.
Air Release Modeling. Releases of hazardous constituents to air from a
remedial action site generally occur as a result of volatilization or fugitive
dust generation. The calculation of the site volatilization rate depends on
the situation in which the waste constituent exists in the environment. The
rate differs according to whether the wastes are covered with soil, are
concentrated on the surface, or are dissolved in water. Volatilization rate
is determined primarily by the chemical properties of a given substance, the
'concentration of that substance, and environmental conditions such as wind
speed and temperature.
There are a number of mathematical models available that describe
volatilization rates for various types of physical situations. For a review
and discussion of mathematical models describing volatile releases from
hazardous waste sites and the selection of appropriate k-values, refer to the
Superfund Exposure Assessment Manual.
Contaminated fugitive dusts from a waste site can result from many
activities, including:
• wind erosion of wastes and soils
• vehicular traffic movement over contaminated roads
• heavy equipment activity at the site.
One or any combination of these activities can create emissions of toxic
materials associated with the fugitive dust. In addition to the Superfund
Exposure Assessment Manual, a manual recently prepared for EPA1s Exposure
Assessment Group, "Rapid Assessment of Exposure to Particulate Emissions from
Surface Contamination Sites" (Cowherd et al., 1984) is a valuable reference
for fugitive dust calculations.
Surface Water Release Modeling. Releases of hazardous constituents to
surface water can occur due to the point discharge of treated runoff,
leachate, or ground water (this mechanism is not usually relevant to
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-52-
assessment of the no-action-alternative); contaminated surface runoff;
recharge by contaminated ground water; or episodic'overland flow from leaks,
spills, or lagoon or pond overtopping. Refer to the Superfund Exposure
Assessment Manual for additional guidance.
Ground-Water Release Modeling. Calculating releases to ground water
involves the estimation of leachate migration from the site. For an
uncontrolled site, one approach is to use site sampling data to determine the
extent of soil contamination directly beneath the source of chemical release
at the site, and convert these to release rates of constituents. For detailed
guidance, refer to the Superfund Exposure Assessment Manual.
Soil Releases. Surface soils may become contaminated with toxic
materials as a result of intentional placement of the wastes on the ground, or
from spills, lagoons or pond failures, contaminated site runoff, or downwind
deposition of contaminated airborne particulates. The substances of concern
are generally those that adsorb to or are otherwise associated with the soil
particles. Determine the extent of contamination of soils using the results
of the sampling and analysis conducted during the remedial investigation
phase. Monitoring is really the only practical method to provide direct
quantification of soil contamination. The Superfund Exposure Assessment
Manual gives more detailed guidance on estimating soil releases.
Worksheet 4-3 is provided as a convenient mechanism for compiling the
results of the quantification of contaminant releases calculated for each
exposure point. List the results of release calculations in the appropriate
columns of the worksheet and attach all documentation for the release
calculations.
4.2.2 Predict Environmental Fate and Transport
In the second step of the process for estimating environmental
concentrations, use the estimates of mass loadings of chemicals released to
predict the environmental fate and transport of chemicals from the release
source to identified exposure points. For each chemical and each exposure
pathway, the outcome of this exercise will be short-term and long-term
environmental concentrations at the significant exposure point. To arrive at
these concentrations, the entire concentration profile of a substance over
time at the exposure point may have to be modeled; appropriate short-term and
long-term values can then be determined from the profile.
To account for the behavior of all released chemicals, it is necessary to
consider systematically the extent of chemical fate and transport in each
environmental medium. In this way, the remedial project manager can consider
the predominant mechanisms of chemical transport, transfer, and
transformation, and disregard less significant processes. In the following
sections, brief descriptions of the mechanisms for each of the major
environmental release media are presented. More detailed descriptions of
available techniques and computer models and their limitations are given in
the Superfund Exposure Assessment Manual.
Air Transport Modeling. The predominant mechanisms that affect the
atmospheric fate and transport of substances released to the air are
advection, dispersion and, in some cases, natural decay. Ambient
* * * October 1986 * * *
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OSVER Directive 9285.4-1
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OSWER Directive 9285.4-1
-54-
concentrations of a chemical at a specified downwind distance from the site
can be determined as a direct function of chemical release rate when these key
processes are considered. Refer to the Superfund Exposure Assessment Manual
for guidance on appropriate modeling techniques.
At some sites, relatively precise estimates of chemical fate and transport
in air may be required. Sophisticated computer models are available for -
predicting the behavior of chemicals released to the atmosphere. The models
have varying capabilities, data requirements, computer resource requirements
and sophistication of output. The Superfund Exposure Assessment Manual lists
some computer models that are applicable to the analysis of remedial action
sites. Exercise care in selecting the model most appropriate to the specific
site and the hazardous substance characteristics. The reasons for selecting a
particular model should be documented. Generally, for risk assessments in the
feasibility study, the simplest model that reasonably represents the system
should be used.
Surface Water Transport Modeling. The environmental fate of hazardous
materials entering surface water bodies is highly dependent on the type of
water body and the specific chemicals involved. Relatively simple,
straightforward approaches are available for estimating environmental
concentrations -in rivers and streams. However, more complex methods are
necessary for predicting concentrations resulting from releases to lakes,
reservoirs, and estuaries. Applicable methods are described or referenced in
the Superfund Exposure Assessment Manual. In addition, EPA's Water Quality
Assessment documents (Mills e_t al. , 1982) may be helpful in selecting water
models.
Sophisticated computer models are also available for the analysis of
environmental fate of hazardous substances in surface water bodies. As with
the sophisticated air models, these vary in complexity, input data
requirements, computer resource requirements, and model capabilities. Again,
simple models are generally preferable. If a computer modeling approach is
desired for a site, select the modeling procedure most appropriate to the
circumstances under study. Again, document the rationale for selecting a
particular model.
Ground-Water Transport Modeling. In describing the behavior of contami-
nants released to ground water from a hazardous waste site, two major sub-
surface zones must be considered: the unsaturated soil zone above the ground
water (vadose zone), and the saturated zone, commonly called the aquifer. In
general, after a substance is released, it first moves vertically down through
the unsaturated soil zone to the ground water. Then, after initial mixing in
the ground water, the substance travels horizontally because of the advective -
flow of the ground water underlying the site. The primary processes that
affect the fate and transport of contaminants in' these two zones are advection
(including infiltration and leaching from the surface), dispersion, sorption
(including reversible adsorption, ion exchange, complexation, and
precipitation), and degradation. As a released substance flows away from the
source area, these processes act to reduce its concentration.
Time plays a key role in the movement of contaminants in the subsurface
environment. Unlike the air and surface water media where releases of
chemicals generally result in downwind or downstream ambient concentrations
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
within relatively short times after release (i.e., minutes, hours, or days),
ground water moves slowly and takes much longer (years) to transport
contaminants. Consequently, the estimation of ground-water concentrations at
a given exposure point must be bounded by a specified time frame for which the
public health evaluation will be conducted.
For purposes of evaluating individual risks for the no-action alternative
at Superfund sites, ground-water concentrations should be estimated for at
least 70 years. This period is selected because it approximates an average
human life span, and it is the basis for establishment of the acceptable
chronic chemical intakes contained in the health effects assessments (HEAs).
Use the highest concentration value predicted at an exposure point during the
70-year period to represent the short-term concentration. For long-term
concentrations, use a 70-year time-weighted average.
Numerous mathematical models are available that describe pollutant fate
and transport in the subsurface environment. These models are described or
referenced in the Superfund Exposure Assessment Manual. These models attempt
to define waste migration over time and distance using the physical and
chemical processes involved. The physical and chemical characteristics
considered by these models include:
• Boundary conditions (hydraulic head distributions,
recharge and discharge points, locations and types of
boundaries);
• Material constants (hydraulic conductivity, porosity,
transmissivity, extent of hydrogeologic units);
• Attenuation mechanisms (adsorption-desorption, ion
exchange, complexing, nuclear decay, ion filtration, gas
generation, precipitation-dissolution, biodegradation,
chemical degradation);
• Molecular diffusion and hydrodynamic dispersion
(transverse, longitudinal, and vertical); and
• Waste constituent concentrations (initial and
background concentrations, boundary conditions).
These characteristics are incorporated into models by combining two sets of
transport expressions: a ground-water flow equation and a chemical mass
transport equation. The result is a prediction of solute transport in the
ground-water system, with chemical reactions considered.
Separate models exist for predicting transport through both the
unsaturated and saturated zones. Models are often linked into a comprehensive
package to effectively simulate movement through both unsaturated and
saturated soil zones. In addition, some ground-water models have the
capability of predicting hazardous substance fate throughout both zones. Most
of these models are designed to be used with a computer. The Superfund
Exposure Assessment Manual lists some computer models applicable for site
analysis.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-56-
Models for ground-water transport generally have not been fully verified,
and their reliability is difficult to assess. Site-specific conditions and
the analyst's ability to account for site-specific characteristics with
quantitative input data influence the reliability of model results. Carefully
applied professional judgment is therefore necessary both in using the models
and in interpreting the results. Ground-water monitoring data collected in
the vicinity of the site should be used whenever possible to test the
reasonableness of model results. Models can sometimes be calibrated with the
measurements taken during the RI. When no monitoring data are available,
important sources of uncertainty should be noted and their impact on model
results should be anticipated and recorded.
Worksheet 4-4 is provided as a format for recording the estimated chemical
concentrations for each exposure point.
4.3 COMPARE TO REQUIREMENTS, STANDARDS, AND CRITERIA
At this point in the process, the projected baseline concentrations of
indicator chemicals at exposure points should be compared to "applicable or
relevant and appropriate requirements" (as defined by the NCP and originally
identified in the CERCLA compliance with other environmental statutes policy
memorandum that is an appendix to the NCP; additional requirements are identi-
fied in the CERCLA reauthorization statute). "Other criteria, advisories, and
guidance" may also be compared to exposure point concentrations, if pertinent
to site exposure conditions. The following subsections describe the procedure
for comparing both to requirements and to other criteria. The user should be
aware that EPA continues to update toxicological information and, based on
these updated data, may issue revised standards and criteria.
This entire section of the manual focuses on numerical criteria that are
in the form of ambient environmental concentration levels. In the case of
applicable or relevant and appropriate requirements or other criteria expressed
in intake or dose units (e.g., in mg/kg-day), the comparison should be deferred
until the intake estimation step of this process is complete (see Chapter 5).
4.3.1 Compare to Applicable or Relevant and Appropriate Requirements
If all indicator chemicals at a site have applicable or relevant and
appropriate requirements (ARARs), then the remainder of the baseline process
described in Chapters 5 through 7 is not necessary. In these cases, the
comparison of predicted exposure point concentrations of indicator chemicals
to ARARs will suffice as a baseline public health evaluation. At sites where
some indicator chemicals do not have ARARs, make the comparison to
requirements for those chemicals that have them and then proceed with the
complete risk characterization process for all indicator chemicals.
Therefore, in cases where ARARs are not available for all indicator chemicals,
the baseline public health evaluation will include both a comparison to ARARs
and a risk assessment as described in Chapters 5 through 7.
At the present time, EPA considers drinking water maximum contaminant
levels (MCLs) and maximum contaminant level goals (MCLGs), federal ambient
water quality criteria, national ambient air quality standards (NAAQS), and
state environmental standards to be potentially applicable or relevant and
* * * October 1986 * * *
-------
Name of Site:
Date:
Analyst:
QC:
WORKSHEET l|-'l
CONTAMINANT CONCENTRATIONS AT EXPOSURE POINTS
1 .
2.
3.
«
1.
2.
3.
14.
Release
Chemica 1 Med turn
Benzene Air
Ground
water
Lead Ground
water
Exposure
Point
Nearest 0
!?*?§ Ldence*
Ho a rest
Residence" 0
Nca rest
Residence" 0
Significant exposure point.
INSTRUCT
List all Indicator chemicals.
List all release media for each chemical: air, ground
List all exposure points Tor each release medium. Ind
List projected short-term and long-term concentrations
Short-Term Concentration Lotui-Term Concentration
Best Upper Bound Best Upper Bound
Estimate Estimate Estimate Estimate
3
.026 mq/m 0.50 O.OO'IO m
-------
OSWER Directive 9285.4-1
-58-
appropriate requirements for ambient.concentrations. Exhibits 4-5 and 4-6
list federal ARARs for ambient environmental concentrations of contaminants.
RCRA design and operating requirements are also applicable or relevant and
appropriate for design of remedial alternatives but, because they are not-
pertinent to the baseline public health analysis, they are not discussed
further here (see Chapter 8).
The determination of exactly which requirements are applicable or relevant
and appropriate to a particular Superfund site should be made on a
site-specific basis. Potential ARARs will not necessarily be appropriate for
every site. For potential ground-water and surface water exposure via
drinking water, the most appropriate comparison values are Safe Drinking Water
Act MCLs and MCLGs; for air exposure, national ambient air quality standards
may be appropriate comparison values; for surface water contamination with
possible exposure via ingestion of aquatic organisms, federal ambient water
quality criteria may be appropriate. ARARs should correspond to the medium
(e.g., air, water) for which they were developed and must be applicable or
relevant and appropriate to site conditions. If requirements are available
for all indicator chemicals, but are not appropriate to site exposure
conditions, a full risk characterization should be completed.
Use Worksheet 4-5 to compare ARARs to environmental concentrations
projected for exposure points. Calculate ratios between predicted
concentrations and requirements, and designate whether concentrations exceed
or fall below the requirements. Also, when risk levels associated with these
requirements are known, they should be recorded. This information will be
carried through to the'end of the process and included in summary tables for
the baseline public health evaluation. Factors in the development of the
requirements listed in Exhibits 4-5 and 4-6 are discussed briefly in the
following sections.
4.3.1.1 Maximum Contaminant Levels (MCLs) and Maximum Contaminant Level
Goals (MCLGs)
Drinking water standards under the Safe Drinking Water Act are promulgated
as maximum contaminant levels (MCLs). MCLs are currently available for 16
specific chemicals (10 inorganics and 6 organic pesticides), total
trihalomethanes (covers four chemicals), certain radionuclides, and
microorganisms (40 CFR 141). Under the Safe Drinking Water Act amendments of
1986 (P.L. 99-339), EPA is required to promulgate MCLs for 83 contaminants
within three years. Generally, an MCL for a toxic chemical represents the
allowable lifetime exposure to the contaminant for a 70 kg adult who is
assumed to ingest two liters of water per day. Total environmental exposure
of a particular contaminant from various sources was considered in calculating
specific MCLs. EPA estimated the amount of the substance to which the average
person is likely to be exposed from all sources (e.g., air, food, water) and
then determined the fraction of the total intake resulting from drinking water
ingestion. Lifetime exposure limits were set at the lowest practical level to
minimize the amount of contamination ingested from water, especially when
exposure from other sources is large. The MCL calculation is adjusted by an
exposure factor to reflect gastrointestinal absorption associated with water
consumption.
In addition to health factors, an MCL is required by law to reflect the
technological and economic feasibility of removing the contaminant from the
water supply. The limit set must be feasible given the best available
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-59-
EXHIBIT 4-5
SELECTED APPLICABLE OR RELEVANT AND
APPROPRIATE AMBIENT REQUIREMENTS a/
-
CHEMICAL
Arsenic
Barium
SAFE DRINKING
WATER ACT
MCLs b/
lmg/1)
0.05
1.0
SAFE DRINKING
WATER ACT
MCLGs c/
(mg/n
CLEAN
AIR ACT
NAAQS
(ug/m3)
Benzene
Cadmium
Carbon monoxide
Carbon tetrachloride
Chlorophenoxys
2 ,4-Dichlorophenoxyacetic
acid (2,4-D)
0.01
0.1
2,4,5-Trichlorophenoxy-propionic 0.01
acid (2,4,5-TP)
Chromium VI (hexavalent)
p-Dichlorobenzene
1,2-Dichloroethane
1,1-Dichloroethylene
Endrin
Fluoride
Lindane (99°0 gamma-HCCH)
Hydrocarbons (non-methane)
Lead
Mercury
Methoxychlor
Nitrate (as N)
Nitrogen dioxide
Ozone
Particulate Matter
Radionuclides
Radium-226 and 228
Gross alpha activity
Tritium
Strontium-90
Other man-made radionuclides
Selenium
Silver
Sulfur oxides
0.05
0.0002
1.4-2.4
0.004
0.05
0.002
0.1
10.0
0.75
0
0.007
5 pCi/1
15 pCi/1 -
20,000 pCi/1
8 pCi/1
h/
0.01
0.05
40,000 (1-hour) d/
10,000 (8-hour) d/
160 (3-hour) d/
1.5 (90-day) e/
100 (1-year) f/
235 (1-hour) d/
260 (24-hour)~d/
75 (1-year) &/
365 (24-hour) d/
80 (1-year) f/
* October 1986 * * *
-------
OSVER Directive 9285.4-1
-60-
EXHIBIT 4-5
(Continued)
SELECTED APPLICABLE OR RELEVANT AND
APPROPRIATE AMBIENT REQUIREMENTS a/
SAFE DRINKING
WATER ACT
MCLs b/
CHEMICAL (mg/1)
Toxaphene 0 . 005
1,1, 1-Trichloroethane
Trichloroethylene
Trihalomethanes (total) i/ 0.1
Vinyl chloride
SAFE DRINKING
WATER ACT
MCLGs c/
(mg/1)
0.2
0
0
CLEAN
AIR ACT
NAAQS
(ug/m3)
a/ Federal ambient water quality criteria (see Exhibit 4-6) and state
environmental standards are also ARARs.
b/ EPA has also proposed MCLs for eight volatile organic chemicals:
trichloroethylene, carbon tetrachloride, 1,1,1-trichloroethane, vinyl
chloride, 1,2-dichloroethane, benzene, 1,1-dichloroethylene , and
p-dichlorobenzene (50 Federal Register 46902-46933, November 13, 1985).
Refer to Exhibit 4-7 for the proposed MCL values.
c/ EPA has also proposed MCLGs for 40 additional chemicals. Refer to
Exhibit 4-7 for the proposed MCLG values.
d/ Maximum concentration not to be exceeded more than once per year.
e/ Three-month arithmetic mean concentration.
f/ Annual arithmetic mean concentration.
g/ Annual geometric mean concentration.
h/ Radionuclides in drinking water are limited to activity levels
corresponding to a total body or any internal organ dose of 4 millirem/year,
summed over all radionuclides present.
i/ Total trihalomethanes refers to the sum concentration of chloroform,
bromodichloromethane, dibromochloromethane, and bromoform.
* * * October 1986 * * *
-------
OSVER Directive 9285.4-1
-61-
EXHIBIT 4-6
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
WQC (Concentrations in Parentheses
Correspond to Midpoint of Risk Range
for Potential Carcinogens Only) a/
Aquatic Organisms .
and Drinking Water
Adjusted for Drinking
Water Only b/
Acenaphthene
Acrolein
Acrylonitrile*
Aldrin*
Ant imony-''
Arsenic--
Asbestos
Benzene-
Benzidine*
Beryllium-
Cadmium"'
Carbon tetrachloride*
Chlordane*
Chlorinated benzenes
Hexachlorobenzene*
1,2,4 , 5-Tetrachlorobenzene-'
Pentachlorobenzene*
Trichlorobenzene-'
Monochlorobenzene-
Chlorinated ethanes
1,2-Dichloroethane-
1,1, 1-Trichloroethane-
1,1,2-Trichloroethanev"
1,1,2 ,2-Tetrachloroethane-
Hexachloroethane*
Monochloroethane
1,1-Dichloroethane*
1,1,1,2-Tetrachloroethane
Pentachloroethane
Chlorinated naphthalenes
Chlorinated phenols
3-Monochloropheno1
4-Monochlorophenol
2,3-Dichlorophenol
2,5-Dichlorophenol
2,6-Dichlorophenol
3,4-Dichlorophenol
2 ,3,4,6-Tetrachloropheno1*
2,4,5-Trichlorophenol-
20 ug/1 (Organoleptic)'
320 ug/1
0 (58 ng/1)
0 (0.074 ng/1)
146 ug/1
0 (2.2 ng/1)
0 (30,000 fibers/1)
0 (0.66 ug/1)
0 (0.12 ng/1)
0 (3.7 ng/1)
10 ug/1
c/
(0.4 ug/1)
(0.46 ng/1)
0 (0.72 ng/1)
38 ug/1
74 ug/1
Insufficient data
488 ug/1
0 (0.94 ug/1)
18.4 mg/1
0 (0.6 ug/1)
0 (0.17 ug/1)
0 (1.9 ug/1)
Insufficient data
Insufficient data
Insufficient data
Insufficient data
Insufficient data
0-. 1 ug/1 (Organoleptic)
'0.1 ug/1 (Organoleptic)
0.04 ug/1 (Organoleptic)
0.5 ug/1 (Organoleptic)
0.2 ug/1 (Organoleptic)
0.3 ug/1 (Organoleptic)
1.0 ug/1 (Organoleptic)
2600 ug/1
20 ug/1 (Organoleptic)
540 ug/1
0 (63 ng/1)
0 (1.2 ng/1)
146 ug/1
(25 ng/1)
(30,000 fibers/1)
0 (0.67 ug/1)
0 (0.15 ng/1)
0 (3.9. ng/1)
10 ug/1
0 (0.42 ug/1)
0 (22 ng/1)
0 (21 ng/1)
180 ug/1
570 ug/1
Insufficient data
488 ug/1
0 (0.94 ug/1)
19 mg/1
0 (0.6 ug/1)
0 (0.17 ug/1)
0 (2.4 ug/1)
Insufficient data
Insufficient data
Insufficient data
Insufficient data
Insufficient data
0.1 ug/1 (Organoleptic)
0.1 ug/1 (Organoleptic)
0.04 ug/1 (Organoleptic)
0.5 ug/1 (Organoleptic)
0.2. ug/1 (Organoleptic)
0.3 ug/1 (Organoleptic)
1.0 ug/1 (Organoleptic)
2600 ug/1
* * * October 1986 * * *
-------
-62-
OSVER Directive 9285.4-1
EXHIBIT 4-6
.(Continued)
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
WQC (Concentrations in Parentheses
Correspond to Midpoint of Risk Range
for Potential Carcinogens Only) a/
Aquatic Organisms
and Drinking Water
Adjusted for Drinking
Water Only b/
2,4,6-Trichlorophenol*
2-Methyl-4-chlorophenol
3-Methyl-4-chlorophenol
3-Methyl-6-chlorophenol
Chloroalkyl ethers
bis-(Chloromethyl) ether*
bis-(2-Chloroethyl) ether*
bis-(2-Chloroisopropyl) ether
Chloroform*
2-Chlorophenol
Chromium Cr+6*
Cr+3*
Copper*
Cyanide*
DDT*
Dichlorobenzenes* (all isomers)
Dichlorobenzidines
Dichloroethylenes
1, 1-Dichloroethylene*
1,2-Dichloroethylene
Dichloromethane*
2,4-Dichlorophenol*
Dichloropropanes/Dichloropropenes
Dichloropropanes
Dichloropropenes
Dieldrin*
2,4-Dimethylphenol
2,4-Dinitrotoluene*
1,2-DiphenyIhydrazine*
Endosulfan*
Endrin
Ethylbenzene*
Fluoranthene
Haloethers
Halomethanes
Heptachlor*
Hexachlorobutadiene*
Hexachlorocyclohexanes (HCCH)
alpha-HCCH*
0 (1.2 ug/1)
1800 ug/1 (Organoleptic)
3000 ug/1 (Organoleptic)
20 ug/1 (Organoleptic)
0 (0.0038 ng/1)
0 (30 ng/1)
34.7 ug/1
0 (0.19 ug/1)
0.1 ug/1 (Organoleptic)
50 ug/1
170 mg/1
1 mg/1 (Organoleptic)
200 ug/1
0 (0.024 ng/1)
400 ug/1
0 (10.3 ng/1)
0 (33 ng/1)
Insufficient data
See Halomethanes
3.09 mg/1
Insufficient data
87 ug/1
0 (0.071 ng/1)
400 ug/1 (Organoleptic)
0 (0.11 ug/1)
0 "(42 ng/1)
74 ug/1
1 ug/1
1.4 mg/1
42 ug/1
Insufficient data
0 (0.19 ug/1)
0 (0.28 ng/1)
0 (0.45 ug/1)
0 (9.2 ng/1)
0 (1.8 ug/1)
1800 ug/1 (Organoleptic)
3000 ug/1 (Organoleptic)
20 ug/1 (Organoleptic)
0 (0.0039 ng/1)
0 (30 ng/1)
34.7 ug/1
0 (0.19 ug/1)
0.1 ug/1 (Organoleptic)
50 ug/1
179 mg/1
1 mg/1 (Organoleptic)
200 ug/1
0 (> 1.2 ng/1)
470 ug/1
0 (20.7 ng/1)
0 (33 rig/1)
Insufficient data
See Halomethanes
3.09 mg/1
Insufficient data
87 ug/1
0 (1.1 ng/1)
400 ug/1 (Organoleptic)
0 (0.11 ug/1)
0 (46 ng/1)
138 ug/1
1 ug/1
2.4 mg/1
188 ug/1
Insufficient data
0 (0.19 ug/1)
0 (11 ng/1)
0 (0.45 ug/1)
0 (13 ng/1)
October 1986 * *
-------
OSVER Directive 9285.4-1
-63-
EXHIBIT 4-6
(Continued)
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
WQC (Concentrations in Parentheses
Correspond to Midpoint of Risk Range
for Potential Carcinogens Only) &/
Aquatic Organisms
and Drinking Water
Adjusted for Drinking
Water Only b/
beta-HCCH*
gamma-HCCH*
delta-HCCH
epsilon-HCCH
Technical-HCCH
Hexachlorocyclopentadiene*
Isophorone*
Lead*
Mercury*
Naphthalene
Nickel*
Nitrobenzene*
Nitrophenols
2,4-Dinitro-o-cresol
Dinitrophenol*
Mononit ropheno1
Trihitrophenol
Nitrosamines
n-Nitrosodimethylamine*
n-Nitrosodiethylamine*
n-Nitrosodi-n-butylamine*
n-Nitrosodiphenylamine
n-Nitrosopyrrolidine*
Pentachlorophenol*
Phenol*
Phthalate esters
Dimethylphthalate
Diethylphthalate*
Dibutylphthalate*
Di-2-ethylhexylphthalate*
Polychlorinated biphenyls- (PCBs)*
Polynuclear aromatic hydrocarbons
(PAHs)*
Selenium*
Silver*
2,3,7,8-TCDD*
Tetrachloroethylene*
Thallium*
0 (16.3 ng/1)
0 (12.3 ng/1)
Insufficient data
Insufficient data
0 (5.2 ng/1)
206 ug/1
5.2 mg/1
50 ug/1
144 ng/1
Insufficent data
13.4 ug/1
19.8 mg/1
13.4 ug/1
70 ug/1
Insufficient data
Insufficient data
(1.4 ng/1)
(0.8 ng/1)
(6.4 ng/1)
(4.9 ug/1)
(16 ng/1)
01 mg/1
3.5 mg/1
313 mg/1
350 mg/1
34 mg/1
15 mg/1
0 (0.079
ng/1)
0 (2.8 ng/1)
10 ug/1
50 ug/1
0 (0.000013 ng/1)
0 (0.8 ug/1)
13 ug/1
0 (23.2 ng/1)
0 (17.4 ng/1)
Insufficient data
Insufficient data
0 (7.4 ng/1)
206 ug/1
5.2 mg/1
50 ug/1
10 ug/1
Insufficient data
15.4 ug/1
19.8 mg/1
13.6 ug/1
70 ug/1
Insufficient data
Insufficient data
0 (1.4 ng/1)
0 (0.6 ng/1)
0 (6.4 ng/1)
0 (7.0 ug/1)
0 (16 ng/1)
1.01 mg/1
3.5 mg/1
350 mg/1
434 mg/1
44 mg/1
21 mg/1
0 (> 12.6 ng/1)
0 (3.1 ng/1)
10 ug/1
50 ug/1
0 (0.00018 ng/1)
0 (0.88 ug/1)
17.8 ug/1
* * *
October 1986
* * *
-------
OSVER Directive 9285.4-1
-64-
EXHIBIT 4-6
(Continued)
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
WQC (Concentrations in Parentheses
Correspond to Midpoint of Risk Range
for Potential Carcinogens Only) a/
Aquatic Organisms Adjusted for Drinking
CHEMICAL and Drinking Water Water Only b/
Toluene- 14.3 mg/1 15 mg/1
Toxaphene* 0 (0.71 ng/1) 0 (26 ng/1)
Trichloroethylene* 0 (2.7 ug/1) 0 (2.8 ug/1)
Vinyl chloride- 0 (2.0 ug/1) 0 (2.0 ug/1)
Zinc-' 5 mg/1 (Organoleptic) 5 mg/1 (Organoleptic)
* Toxicity values necessary for risk characterization are given in Appendix C.
a/ The criterion value, which is zero for all potential carcinogens, is listed
for all chemicals in the table. The concentration value given in parentheses for
potential carcinogens corresponds to a risk of 10 , which is the midpoint of the
range of 10 to 10 given in water quality criteria documents. To obtain
_ C _£
concentrations corresponding to risks of 10 , the 10 concentrations should
be multiplied by 10. To obtain concentrations corresponding to risks of 10 ,
the 10 concentrations should be divided by 10.
b/ These adjusted criteria, for drinking water ingestion only, were derived
from published EPA ambient water quality criteria (45 Federal Register 79318-79379,
November 28, 1980) for combined fish and drinking water ingestion and for fish
ingestion alone. The adjusted values are not official EPA ambient water quality
criteria, but may be appropriate for Superfund sites with contaminated ground
water. In the derivation of these values, intake was assumed to be 2 liters/day
for drinking water and" 6.5 grams/day for fish, and human body weight was assumed to
be -70 kilograms. Values for bioconcentration factor, carcinogenic potency, and
acceptable daily intake were those used for water quality criteria development.
c/ Criteria designated as Organoleptic are based on taste and odor effects,
not human health effects. Health-based water quality criteria are not available
for these chemicals.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
03
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OSWER Directive 9285.4-1
-66-
technology and treatment techniques. A safety factor is included in each of
the standards to provide adequate protection for sensitive populations that
may be at special risk such as infants and children. Safety factors vary from
chemical to chemical because of the different risks associated with each.
As part of the process for developing final drinking water standards
(i.e., MCLs), EPA develops maximum contaminant level goals (MCLGs).llJ
MCLGs are entirely health-based; thus, they are always less than or equal to
MCLs. EPA recently promulgated MCLGs for eight volatile organic chemicals (40
CFR 141.50; 50 Federal Register 46880-46901, November 13, 1985). Exhibit
4-5 lists the MCLs and MCLGs promulgated as of publication of this manual.
4.3.1.2 National Ambient Air Quality Standards (NAAQS)
NAAQS are available for six chemicals or chemical groups and for airborne
particulates; of these, the NAAQS for lead, hydrocarbons, and airborne
particulates appear to be most useful for Superfund public health
evaluations. In the development of primary NAAQSl'J , sources of the
contaminant that contribute to air pollution and all sources" of exposure to
the contaminant (e.g, food, water, air) are considered in determining the
health risk. In addition, the statute states that primary NAAQS must be based
exclusively on air quality criteria issued by EPA for each air pollutant. The
Act does not require EPA to consider the costs (economics) of achieving the
standards or the technological feasibility of implementing the standards.
Standards can be promulgated as annual maximums, annual geometric means,
annual arithmetic means, or for other time periods thet vary from one hour to
one year depending on the pollutant.
Primary standards must allow for an adequate margin of safety to account
for unidentified hazards and effects. There is no rule used in setting the
margin of safety for the standards. The law requires EPA to direct its efforts
at groups of particularly sensitive citizens, such as bronchial asthmatics and
emphysematics. In developing primary NAAQS, EPA must specify the nature and
severity of the health effects of each contaminant, characterize the sensitive
population involved, determine probable adverse health effect levels in sensi-
tive persons, and estimate the level below which an adequate margin of safety
reduces or eliminates risks. Primary NAAQS are based for the most part on the
direct health effects of chemicals to sensitive groups.
4.3.1.3 Federal Ambient Water Quality Criteria
Federal-ambient water quality criteria for the protection of human health
have been developed for 62 out of 65 classes of toxic pollutants (a total of
95 individual chemicals have numerical health criteria). The health-based
water quality criterion is an estimate of the ambient surface water
concentration that will not result in adverse health effects in humans. In
the case of suspect or proven carcinogens, concentrations associated with a
ltj MCLGs were formerly known as recommended maximum contaminant levels
(RMCLs).
19J EPA also develops secondary NAAQS under the Clean Air Act to protect
the public welfare from known or anticipated effects.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-67-
range of incremental cancer risks are provided to supplement a criterion of
zero. The federal criteria are non-enforceable guidelines, which many states
have used in the development of enforceable ambient water quality standards
(see Section 4.3.1.4). Exhibit 4-6 lists federal ambient water quality
criteria for specific chemicals.
For most chemicals, federal water quality criteria to protect human health
are available for two different exposure pathways. One criterion is based on
lifetime ingestion of both drinking water and aquatic organisms, and the other
is based on lifetime ingestion of aquatic organisms alone. The calculations
incorporate the assumption that a 70-kilogram adult consumes 2 liters of water
and/or 6.5 grams of aquatic organisms daily for a 70-year lifetime. Of
course, calculations can be made to derive an adjusted criterion for drinking
water ingestion only, based on the two published criteria and the same intake
assumptions (as was done for Exhibit 4-6). These adjusted criteria are more
appropriate than non-adjusted criteria for Superfund sites with contamination
of potential ground-water sources of drinking water because they are based on
more realistic exposure assumptions (i.e., exclusion of aquatic organism
ingestion as an exposure pathway).
Derivation of Criteria for N'oncarcinogens. On the basis of a survey of
the toxicology. literature, EPA established a "no observed advers-e effect
level" (NOAEL) for each chemical. The NOAELs were usually based on animal
studies, although human data were used whenever available. By applying a
safety factor to account for the uncertainty in using available data to
estimate human effects, an acceptable daily intake (ADI) was determined.
Criteria (i.e., water concentrations) were then derived from the ADIs and the
standard intake assumptions given above.
Derivation of Criteria for Carcinogens. The same exposure and intake
assumptions were used for potential carcinogens. A literature search for
human and animal carcinogenic effects formed the basis for EPA's estimate of
the risk posed by potential human carcinogens. Because methods are not
currently available to establish the presence of a threshold for carcinogenic
effects, the criteria for all carcinogens state that the recommended
concentration for maximum protection of human health is zero. EPA also
estimated water concentrations corresponding to incremental risk levels, using
a linear, non-threshold extrapolation model. Extrapolation models provide
only an estimate of risk, but they represent the best available tool for
describing the potential threat of a substance, given certain assumptions. In
its published criteria, EPA provides water concentrations corresponding to
incremental lifetime cancer risks of 10-7, 10-', and 10-5.
4.3.1.4 State Environmental Standards
State environmental standards are ARARs for Superfund remedial actions in
that state. The availability of and numerical values for these standards vary
widely from state to state. The remedial project manager is responsible for
determining the availability of applicable or relevant and appropriate state
standards for a site.
Water quality standards developed under the Clean Water Act are a commonly
available type of state standard. These standards serve the dual purposes of
establishing the ;water quality goals for a specific water body and as the
regulatory basis for establishing water quality-based controls beyond the
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-68-
technology-based levels of treatment required by Sections 301(b) and 306 of
the Clean Water Act. Water quality standards are adopted by states (or, where
necessary, promulgated by EPA) to protect the public health or welfare,
enhance the quality of the water, and serve the purposes of the Act. A water
quality standard consists of basically two parts: (1) a "designated use" (or
uses), which considers the water body's use and value for public water
supplies, for propagation of fish, shellfish, and wildlife, and for
recreational, navigation, agricultural, industrial, and other purposes; and
(2) "criteria", which are numerical limits or narrative statements necessary
to protect the designated use.
States must adopt appropriate water quality criteria sufficiently
stringent to protect the designated uses. Numerical criteria may be based on
ambient water quality criteria recommendations published by EPA (see Section
4.3.1.3) or developed by other scientifically defensible methods. States may
also modify EPA's recommended criteria to reflect local environmental
conditions and human exposure patterns before incorporation into water quality
standards. When a criterion for the protection of human health must be
developed for a chemical for which a national criterion has not been
recommended, the state should consult EPA headquarters for assistance.
Guidelines for deriving human health-based water quality criteria were
published on November 28, 1980 (EPA, 1980).
4.3.2 Compare to Other Criteria, Advisories, and Guidance
In the absence of ARARs for all indicator chemicals, the remainder of the
process as outlined in Chapters 5 through 7 should be completed. 'In addition,
information on how exposure point concentrations compare to "other criteria,
advisories, and guidance" (i.e., not ARARs) is useful as a supplement to the
risk assessment and should be noted in the public health evaluation chapter in
the feasibility study report. At sites where neither ARARs or appropriate
toxicity values are available for some indicator chemicals, the comparison of
ambient concentrations to other criteria may provide an important basis on
which to judge the potential health effects of environmental concentrations of
toxic substances.
For the purposes of Superfund public health evaluations, EPA considers
drinking water health advisories and proposed drinking water standards to be
pertinent for comparison with predicted concentrations, provided they are for
the same exposure pathway. Exhibit 4-7 lists proposed MCLs and MCLGs and
Exhibit 4-8 lists health advisories. Other standards may be used for
comparison as well, provided they correspond to the environmental medium for
which they were designed and are appropriate to site conditions. Criteria
inappropriate for public health evaluation of long-term chemical exposures,
such as LDrn values and unadjusted occupational threshold limit values
(TLVs), should not be used in this comparison.20-1
20J LD__ values and TLVs usually reflect short-term exposures. ^c0
("lethal dose-50") is the dose of a chemical that is fatal in 50 percent of
the exposed population. TLVs are time-weighted average concentrations of
chemicals in air that should not be exceeded for a given time period (usually
15 minutes or 8 hours ) .
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-69-
EXHIBIT 4-7
EPA PROPOSED MCLs AND MCLGs
CHEMICAL
PROPOSED
MCL (mg/1) a/
PROPOSED
MCLG (mg/1) b/
Acrylamide
Alachlor
Aldicarb
Aldicarb sulfoxide
Aldicarb sulfone
Arsenic
Asbestos
Barium
Benzene
Cadmium
Carbofuran
Carbon tetrachloride
Chlordane
Chromium
Copper
Dibromochloropropane
o-Dichlorobenzene
p-Dichlorobenzene
1,2-Dichloroethane
1,1-Dichloroethylene
1,2-cis-Dichloroethylene
1,2-trans-Dichloroethylene
1,2-Dichloropropane
2,4-D
Epichlorohydrin
Ethylbenzene
Ethylene dibromide (EDB)
Heptachlor
Heptachlor epoxide
Lead
Lindane
Mercury
Methoxychlor
Monochlorobenzene
Nitrate
Nitrite
Polychlorinated biphenyls
Pentachlorophenol
Selenium
Styrene
Tetrachloroethylene
1,1,1-Trichloroethane
0.005
0.005
0.75
0.005
0.007
009
009
009
05
1 c/
1.5
0.005
0.036
0
0.12
1.3
0
0.62
0.07
0.07
0.006
0.07
0
0.68
0
0
0
0.02
0.0002
0.003
0.34
0.06
10
1
0
0.22
0.045
0.14
0
0.2
* * *
October 1986
* * *
-------
OSWER Directive 9285.4-1
-70-
EXHIBIT 4-7
(Continued)
EPA PROPOSED MCLs AND MCLGs
PROPOSED PROPOSED
CHEMICAL . MCL (rag/1) a/ MCLG (mg/1) b/
Trichloroethylene 0.005
Toluene 2
Toxaphene 0
2,4,5-TP 0.052
Vinyl chloride 0.001
Xylene 0.44
a/ MCL = maximum contaminant level; proposed values taken from 50 Federal
Register 46902 (November 13, 1985).
b/ MCLG = maximum contaminant level goal; proposed values taken from 50
Federal Register 46936 (November 13, 1985).
c/ Million fibers per liter.
* * * October 1986 * *
-------
OSWER Directive 9285.4-1
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CHEMICAL
Oxamyl
PCBs*
Pent a chlo ropheno 1 *
Styrene*
To tra chlo roe thy lene*
Toluene*
Toxaphene*
2,I|,5-TP»
1,1, 1-Trl chlo roe thane*
Trlchlo roe thy lene*
Vinyl Chloride*
Xy lenes*
* Toxic 1 ty va lues
EXHIBIT '4-8
(Continued)
EPA DRINKING WATER HEALTH ADVISORIES
-
Reference Concentration for
One-day Ten-day Longer-term a/ Lifetime Potential Carcinogens b/
(uq/l) (uq/l) (uq/l) (Uq/l)f ( uq/ 1 )
10 kg 10 kg 10 kg 70kg
350 350
--
1000 300 300 1050
27000 20000 20000 70000
3UOOO 1940 6800
70 kg 70 kg
810 NA
_-
1050 NA
0.011
0.7
18000 6000 -- -- 10800 NA
500 80
200 200
1 '40000 35000 35000 125000
._
2600 2600 13 '46
12000 7800 7800 27300
necessary for risk characterization are given In Appendix C.
a/ Longer term health advisories are for exposures ranging from several months
compared only to estimated short-term concentrations (STC).
b/ The concentration given corresponds to a potential carcinogenic risk of 10-6
risks of 10-M and 10-5, the 10-6 concentrations should be multiplied by 100 and 10,
corresponding to risks of 10-7, the 10-6 concentrations should be divided by 10.
c/ The one- and ten-day health advisories for nitrate and nitrite are given for
0.031
260 NA
1000 22000
2.8
NA 0.015
2200 NA
to several years and should generally be
To obtain concentrations corresponding to
respectively. To obtain concentrations
both a (| kg newborn and a 10 kg Infant.
OSVER Directive
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-------
OSWER Directive 9285.4-1
-74-
Some ambient concentration requirements or criteria will be pertinent to
specific site conditions, while others can be adjusted to make them useful.
For example, if a requirement applies to a different environmental medium or
exposure route than the one threatened by a site, it would probably not be
appropriate to use it without adjustment. As an illustration of this, ambient
water quality criteria, which were developed for surface water, can be
adjusted for ground water by recalculating without the assumption of fish
ingestion (as in Exhibit 4-6). Concentration requirements and criteria may
also be based on a different level, frequency, or duration of exposure than
found at a specific site. Guidance on adjustment of standards for
site-specific applications is currently under development by EPA.
For some chemicals several, "other criteria, advisories, and guidance" may
be available as comparison values. In this case choose the most suitable
value for comparison". Suitability is determined in part by the pertinence of
the criterion to exposure conditions at the site (e.g., exposed population
characteristics, duration and timing of exposure, exposure pathways)
and in part by how recently the value was developed. Some criteria have been
developed recently and may reflect new information compared to older values.
Some standards or criteria may have been scrutinized more closely than others
and may consequently have more scientific credibility. Other standards may be
current and scientifically accepted but not pertinent to exposure routes at
the site and therefore unsuitable. Consequently, the most suitable comparison
value is the most current, credible, and pertinent value available.
Use Worksheet 4-6 to compare "other criteria, advisories, and guidance" to
environmental concentrations projected for exposure points. Calculate the
ratios between predicted concentrations and requirements and be sure to
designate whether concentrations exceed or fall below the requirements. This
information will be carried through to the end of the process and included in
summary tables for the baseline public health evaluation. The criteria and
advisories in Exhibits 4-7 and 4-8 are discussed briefly in the following
sections.
4.3.2.1 Proposed MCLs and MCLGs
EPA has proposed MCLs for the same eight volatile organic chemicals for
which final MCLGs were promulgated (50 Federal Register 46902-46933,
November 13, 1985), and has proposed MCLGs for a larger group of inorganic
chemicals, synthetic organic chemicals, and microorganisms (50 Federal
Register 46936-47022, November 13, 1985). Exhibit 4-7 lists values for both
proposed MCLs and proposed MCLGs. In general, proposed requirements,
including proposed MCLs and MCLGs, should be used in the same manner as "other
criteria, advisories, and guidance" (as defined in the CERCLA compliance with
other environmental statutes policy memorandum; see Section 2.3). It should
be recognized, however, that proposed requirements can be changed before they
are promulgated; thus, final requirements may differ from proposed ones.
After a proposed requirement that falls in the ARAR category becomes final, it
should be added to the active list of ARARs.
4.3.2.2 Drinking Water Health Advisories
In addition to MCLs and MCLGs, EPA provides drinking water suppliers with
guidance on various chemicals that may be encountered in a water system. The
Office of Drinking Water's nonregulatory health advisories are concentrations
* * * October 1986 * * *
-------
Name of Site:
Date:
Aria lyst:
QC:
WORKSHEET '4-6
COMPARISON OF OTHER FEDERAL AND STATE CRITERIA
TO ESTIMATED EXPOSURE POINT CONCENTRATIONS
Exposure Point:
Private Drinking Water Wells at Nearest Residences
Chemica 1
1 . Benzene
2.
App/Rel , Projected
Requirement Criterion Value of Exposure Point Concentration:
Available Being Compared Criterion Concentration Standard Ratio
No Drinking Water Reference 0.00035 mq/ 1 " 0.0085 mq/ 1 (LTC) 24
Concentration for Poten-
tial Care inpgenic Effects
(Jlea 1 th Advisory Summary,
Exhibit 'i-8J
3.
l|.
* Reference concentration Iisted.corresponds to 10-6 potential carcinogenic risk.
INSTRUCTIONS
List all indicator chemicals and designate for each whether it was compared to an applicable or relevant arid
appropriate requirement in Worksheet '1-5.
For each chemical identify the criterion/criteria being compared. In general each chemical should be
compared to the criteria/criterion most appropriate to exposure conditions at the site.
Obtain values for criteria from Exhibit '1-7, 4-8, or other sources.
Obtain the exposure point concentrations to be compared from Worksheet 'l-ll and identify each value as a
short-term concentration (STC) or long-term concentration (LTC).
5. Record the ratios between exposure point concentrations and criteria; ratios greater than 1.0 indicate
exceedance of the criterion.
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
O
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-------
OSWER Directive 928S.4-1
-76-
of contaminants in drinking water at which adverse effects would not be
anticipated to occur. A margin of safety is included to protect sensitive
members of the population. The health advisory numbers are developed from
data describing noncarcinogenic end-points of toxicity. They do not
incorporate quantitatively any potential carcinogenic risk from such exposure.
The Office of Drinking Water has recently developed health advisories for 54
chemicals or chemicals groups, and these values are summarized in Exhibit 4-8.
Under certain circumstances and when the appropriate toxicological data
are available, health advisories may be developed for one-day, ten-day,
longer-term (several months to several years), and lifetime durations of
exposure. One-day and ten-day health advisories are calculated for a 10 kg
child (a one-year old infant) assumed to drink one liter of water per day.
Lifetime health advisories are calculated for a 70 kg adult, assumed to drink
two liters of water per day. Longer-term health advisories are calculated for
both a 10 kg child and a 70 kg adult. For chemicals that are known or
probable human carcinogens according to the proposed Agency classification
scheme, non-zero one-day, ten-day, and longer-term health advisories may be
derived, with attendant caveats. Health advisories for lifetime exposures are
not recommended for this group of substances. For these potential carcinogens,
drinking water concentrations associated with projected upper 95 percent con-
fidence limit excess lifetime cancer risk of 10-s are provided. Comparison
of these values to measured or predicted drinking water concentrations can
give an indication of the magnitude of potential carcinogenic risk.
This chapter, in conjunction with the Superfund Exposure Assessment
Manual, has presented instructions for estimating exposure point
concentrations of the indicator chemicals selected in Chapter 3. Important
exposure pathways have been identified. Ambient concentrations of the
indicator chemicals have been modeled from the point of release to the point
of human exposure for important exposure pathways, and these estimated
concentrations have been compared to applicable or relevant and appropriate
requirements and other federal criteria, advisories, and guidance. If all
indicator chemicals have applicable or relevant and appropriate requirements,
the baseline public health evaluation is now complete. In this case, proceed
to Chapter 8 to begin the analysis of remedial alternatives. Otherwise, the
exposure point concentrations estimated here will be used in Chapter 5 to
calculate chemical intakes, which subsequently will be used to estimate risk.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-77-
CHAPTER 5
STEP 3: ESTIMATION OF CHEMICAL INTAKES
To assess the potential adverse health effects associated with a site, the
amount of human exposure to the selected contaminants must be determined. In
this chapter, methods are presented for estimating human exposures using the
environmental concentrations of substances that were estimated by the methods
described in Chapter 4 and the Superfund Exposure Assessment Manual.
Human exposure is expressed in terms of intake, which is the amount of
substance taken into the body per unit body weight per unit time.21-1 Intakes
are calculated separately for exposures to chemical contaminants in each
environmental medium -- air, ground water, surface water, and soil. Then, for
each exposed population-at-risk, intakes for the same route of exposure are
summed, resulting in a total oral exposure and total inhalation exposure.
Dermal exposure, if determined to be important, should be estimated separately.
Exhibit 5-1 is an overview of the intake estimation step.
Because short-term (subchronic) exposures to relatively high
concentrations of chemical contaminants can cause different toxic effects than
those caused by long-term (chronic) exposures to lower concentrations, two
intake levels are calculated for each chemical -- the subchronic daily intake
(SDI) and the chronic daily intake (GDI). These calculated intakes are based
on short-term and long-term concentrations derived for each chemical using the
procedures in the preceding chapter. All intakes are expressed in mg/kg/day.
In circumstances where contamination already has reached a point of human
exposure, intake calculations may be made based on personal air monitoring and
body burden analysis data for exposed individuals. All human-subject
monitoring and assessment should be coordinated with the Agency for Toxic
Substances and Disease Registry, Department of Health and Human Services.
Results should be reported directly on Worksheets 5-1 through 5-4.
The sections that follow give standard methods to estimate human intakes
through air, ground water, and surface water. If other exposure routes, such
as dermal absorption and soil ingestion are important, contact the Exposure
Assessment Group, Office of Research and Development, U.S. EPA, Washington,
D.C. 20460, for additional guidance. Standard intake assumptions are given
in Exhibit 5-2. If more accurate site-specific information is available, it
can be used to give a better representation of risk at the site. See Exhibit
5-2 for an example of how to use the standard assumptions and how to make
2 1J The term intake is used instead of dose because the information
required to estimate dose is often unavailable. To estimate dose, information
indicating the amount of a chemical that may be absorbed (e.g., across lung or
gastrointestinal tract lining or through the skin) and subsequently distributed
to target organs or tissues would be needed. When absorption data are
available they can be incorporated into the assessment. Because adequate
absorption data for specific chemicals are relatively rare, they cannot be
used consistently and are not included here.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
EXHIBIT 5-1
OVERVIEW OF STEP 3: ESTIMATING HUMAN INTAKES
Adjust Standard Intake Assumptions for Site-Specific Factors, if Appropriate
Combine Adjusted Assumptions with Projected Chemical Concentrations
to Estimate Intakes for Individual Exposure Routes
Sum Intakes Across Exposure Routes, as Appropriate
-------
OSWER Directive 9285.4-1
-79-
EXHIBIT 5-2
STANDARD VALUES USED IN DAILY INTAKE CALCULATIONS a/
Parameter Standard Value Reference
Average body weight, adult 70 kg EPA, 1980
Average body weight, child 10 kg ICRP, 1975
Amount of water ingested
daily, adult 2 liters NAS, 1977
Amount of water ingested
daily, child 1 liter NAS, 1977
Amount of air breathed
daily, adult 20 m3 EPA, 1980
Amount of air breathed 5 mj FDA, 1970
daily, child
Amount of freshwater fish
consumed daily, adult 6.5 g EPA, 1980
a/ Example 1: how to apply the standard assumptions.
If contaminant concentration is 3 mg/liter in drinking water:
(3 mg/liter x 2 liters/day water consumption) * 70 kg body weight
= 0.086 mg/kg/day intake
Example 2: how to apply adjusted assumptions.
If site data indicate that the exposed population has a water consumption
rate of 1.2 liters/day and an average weight of 60 kg, and the contaminant
concentration is 3 mg/liter in drinking water:
(3 mg/liter x 1.2 liters/day water consumption) * 60 kg body weight
= 0.06 mg/kg/day intake
* * * October 1986 * * *
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'OSVER Directive 9285.4-1
-80-
adjustments based on more accurate intake and body weight information for the
exposed population. For example, higher than average fish consumption may be
important for some sites where surface water contamination is a problem. In
addition, the standard intake values do not account for reduced intakes
resulting from human activity patterns that reduce human contact with the
contamination (i.e., it is assumed that exposure occurs 24 hours per day for
the entire period that contamination is present). This conservative approach
can be modified based on site-specific information to the contrary. For
example, if an industrial area is an inhalation exposure point, it may be
appropriate to adjust the standard intake factor by the fraction of a year
spent at the exposure point.
Worksheets are provided as a method of organizing information and keeping
track of intake calculations. However, they will not generally be required as
part of the final report. Only Worksheets 5-5, 5-6, and 5-7, the summary
worksheets, will be required for submission with the final report.
5.1 CALCULATE AIR INTAKES
Human intake of contaminants present in the air is dependent on the
contaminant concentration, the frequency and volume of inhalation, the
duration of exposure, and in the case of particulates, particle size.
The measured or predicted atmospheric concentrations (short-term and
long-term) of each contaminant at specific exposure points are given in
Worksheet 4-4. Insert these values into the appropriate columns of Worksheet
5-1. Note that a separate worksheet must be prepared for each inhalation
exposure point.
A standard human intake coefficient has been calculated for use in
determining air exposures in the absence of more accurate site-specific intake
information. This value takes into account the frequency (breathing rate),
volume, and duration of inhalation intake as well as an average human body
weight. The intake coefficient is calculated by dividing the daily air intake
by the average adult body weight to give a value in m3/kg/day. This
coefficient has been inserted into Worksheet 5-1 and is based on the standard
adult values given in Exhibit 5-2. For short-term exposures, include the
duration of exposure on Worksheet 5-1.
Using Worksheet 5-1, estimate subchronic and chronic air intakes for each
indicator chemical at all relevant exposure points. Note that absorption of
chemicals into the body is not accounted for by the intake estimates (or by
the critical toxicity values described in Chapter 6). However, if.
chemical-specific absorption data are available, they can be used to refine
the assessment as long as the procedures and values are clearly documented.
5.2 CALCULATE GROUND-WATER INTAKES
Human exposure to contaminated ground water can occur when contaminated
wells are used as a drinking water source. The degree of exposure depends on
the concentration of the contaminant in drinking water, the amount of water
consumed per day, and the duration of exposure.
*' * * October 1986 * * *
-------
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 5-1
CALCULATE AIR INTAKES
Exposure Point: Nearest Residence
Chemica 1
1 . Benzene
2. Lead
3.
H.
Human Short- Term
Intake Factor Concentration
(m3/kg/day) (mg/m3)
0.29 0.026
0.29 0
0.29
0.29
Subchron Ic
Da i ly Intake
(mg/kg/day)
0.0075
0
Durat ion
( f ract ion
of year)
0.5
0.5
Long- term
Concentra t Ion
(mg/m3)
O.OO'IO
0
Chronic
D;i i ly 1 ntake
(mg/kg/day)
0.0012
0
INSTRUCTIONS
1. List all indicator chemicals.
2. List the, short-term and long-term concentration or each chemical In air (from Worksheet M-'l) in the
appropriate column.
3. Determine subchronic daily intake (SDI) using the following formula:
SDI
Short-term
= Concentration
Human
x Intake
Factor
Note; Human Intake Factor = standard air Intake per day/standard body weight
Determine chronic dally intake (CDI) using the following formula:
CD I
Long-term
= Concentration
Human
x Intake
Factor
Note: Human Intake Factor = standard air intake per day/standard body weight
5. Include duration of subchronic exposure represented by the intake estimate, in fraction of year.
ASSUMPTIONS
List all major assumptions in developing the data for this' worksheet:
O
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-------
OSWER Directive 9285.4-1
-82-
The measured or predicted concentrations (short-term and long-term) of
each contaminant in ground water at each exposure point are given in Worksheet
4-4. Insert these values into appropriate columns of Worksheet 5-2. Note
that separate worksheets must be prepared for each ground-water exposure point.
A standard human intake coefficient has been calculated for use in
determining drinking water exposures. This value takes into account both
average daily consumption of water and average body weight. The intake
coefficient is calculated by dividing the standard drinking water intake by
the average adult body weight to give a value in I/kg/day. This coefficient
has been inserted into Worksheet 5-2 and is based on the standard adult values
given in Exhibit 5-2. For short-term exposures, also include the duration of
exposure on Worksheet 5-2.
Using Worksheet 5-2, estimate subchronic and chronic drinking water
intakes for each indicator chemical at all relevant ground-water exposure
points.
5.3 CALCULATE SURFACE WATER INTAKES
For potential exposures to contaminated surface water, calculate intakes
from ingestion of drinking water and ingestion of contaminated fish, as
appropriate for the site being assessed.
Drinking Water. Human exposure to contaminated surface water can occur
when the surface water is used as a drinking water source. The degree of
exposure to contaminants present in drinking water derived from surface water
depends on the same factors described for drinking water derived from ground
water.
Obtain the concentrations (short-term and long-term) of each chemical
present in surface water at each exposure point from Worksheet 4-4. Insert
these values into the appropriate columns of Worksheet 5-3. The standard
human intake coefficient for drinking water is the same as that used for
calculating ground-water intakes and has been inserted into Worksheet 5-3.
For short-term exposures, include the duration of exposure on Worksheet 5-3.
Using Worksheet 5-3, estimate subchronic and chronic drinking water
intakes for each indicator chemical at all relevant surface water exposure
points.
Fish Consumption. Another potential route of exposure from contaminated
surface water is through the ingestion of contaminated fish. The factors-that
determine human exposure from contaminated fish are the contaminant
concentration in the fish, the amount of fish consumed, and the duration of
exposure.
The concentration of a contaminant in fish can be estimated by multiplying
the concentration of the contaminant in surface water by the fish bioconcen-
tration factor for that chemical. Obtain surface water concentrations for
each chemical at each exposure point from Worksheet 4-4. Insert the
appropriate values into the appropriate columns of Worksheet 5-4. Standard
* * * October 1986 * * *
-------
1.
2.
3.
'1.
1.
2.
3.
'••
Name oF Site:
Date:
Ana lyst:
QC:
WORKSHEET 5-2
CALCULATE GROUND-WATER INTAKES
Exposure Point: Private Drinking Water Wells
Human Short-Term Subchronic Duration Long-term
Intake Factor Concentration Daily Intake (Fraction Concentration
Chemical (I/kg/day) (mg/1) (mg/kg/day) oF year) (mg/1)
Benzene 0.029 0.20 0.0058 0.5 0.0085
Lead 0.029 O.OH5 0.0013 0.5 0.0050
0.029
0.029
INSTRUCTIONS
List all indicator chemicals.
Chron ic
Da i ly Intake
(mg/kg/day)
0.00025
0 . 000 1 5
List the short-term and long-term concentration oF each chemical in ground water (From Worksheet
l|-'i) In the appropriate column.
Determine subchronic dally intake (SOI) using the Following Formula:
Short-term Human
SOI = Concentration x Intake
Factor
Note: Human Intake Factor = standard drinking water intake per day/standard body weight
Determine chronic daily intake (CDI) using the Following Formula:
Long-term Human
CDI = Concentration x Intake
Factor
Note: Human Intake Factor = standard drinking water intake per day/standard body weight
5. Include duration oF subchronic exposure represented by the intake estimate1, in Fraction oF year.
ASSUMPTIONS
List all major assumptions in developing the data For this worksheet:
O
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C/l
-------
1.
2.
3.
H.
1 .
2.
3.
'I.
Name or Site:
Date:
Ana lyst:
QC: '
WORKSHEET 5-3
CALCWA1E SURFACE WATER INTAKES
Exposure Point: Downstream Drinking Water
Human Short-lerm Subchronic Duration Long-term
Intake Factor Concentration Daily Intake (fraction Concentration
Chemical (I/kg/day) (mg/l) (mg/kg/day) of year) (mg/l)
Benzene 0.029 0.0(168 0.00020 0.5 1.5 x 10-3
Lead 0.029 0.00028 8.1 x 10-6 0.5 1,0 x 10-5
0.029
0.029 '
INSTRUCTIONS
List all indicator chemicals.
List the short-term and long-term concentration of each chemical in surface water (from
>i-'i) in the appropriate column.
Determine subchronic daily intake (SDI) using the following formula:
Short-term Human
SDI = Concentration x Intake
Factor
Note: Human Intake Factor = standard drinking water intake per day/standard body weight
Determine chronic daily intake (Cl)l) using the following formula:
Long-term Human
CDI = Concentration x Intake
Factor
Chronic
Da i ly Intake
(mg/kg/day)
•i.U x 10-5
2.9 x 10-7
Worksheet
Note: Human Intake Factor = standard drinking water intake per day/standard body weight
5. Include duration of subchronic exposure represented by the intake estimate, in fraction of year.
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
H
-------
OSWER Directive 9285.4-1
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-------
OSWER Directive 9285.4-1
-86-
human intake coefficients are calculated by dividing standard freshwater fish
intake per day by the average adult body weight. These coefficients have been
inserted into the worksheet. Obtain the fish bioconcentration factor for each
chemical from Appendix C or other sources. Again, for short-term exposures
include the duration of exposure on Worksheet 5-4. If the concentration of
contaminants in fish has been measured, this concentration can be used for
short-term exposure. It should not necessarily be used for long-term exposure
because surface water concentrations are likely to change over the 70-year
period being considered, causing the concentration of contaminants in the fish
to change over time.
Using Worksheet 5-4, estimate subchronic and chronic daily intakes from
contaminated fish for each indicator chemical at all relevant surface water
exposure points.
5.4 CALCULATE INTAKES FROM OTHER EXPOSURE PATHWAYS
There are a number of other potentially important exposure pathways that
are more difficult to quantify than those just described. Nevertheless, the
human chemical intakes received though such pathways may be extremely
important to certain populations-at-risk. For example, at some sites children
playing outdoors may be exposed to contaminated soil through dermal absorption
or through direct ingestion of soil. If young children have access to a site
or adjacent area with contaminated surface soil, exposure for this
subpopulation via soil ingestion can be estimated based on the following
assumptions:
• Ingestion is primarily of concern for children between
age two and six;
• Ingestion rate varies from 0.1 to 5 grams per day,
with higher values representative of pica behavior; and
• Body weight of children in this age group averages 17
kg, and ranges from 10 to 25 kg.
These assumptions are based on EPA (1984), Kimbrough et al. (1984), and
Anderson et al. (1984). In addition to exposures via soil ingestion, other
soil-related pathways, particularly migration of contaminants to ground and
surface waters, may be very important at a site and therefore should be
considered.
Another potential exposure pathway could be agricultural land being
irrigated with contaminated surface or ground water; human exposure would
occur if produce is contaminated and ingested. Humans may also be exposed via
consumption of game animals that reside in contaminated areas.. Contaminated
surface waters, in addition to providing drinking water, may be used for
recreation and humans may be exposed by swimming in such waters. This may
result in dermal, oral, and inhalation exposures. During bathing or
showering, dermal or inhalation exposure may occur. Volatilization while
cooking with contaminated water may result in inhalation exposure.
Formulas and worksheets for these less common exposure pathways have not
been included in this manual because there has been little experience on which
to base standard formulas. It should be noted, however, that at certain sites
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-87-
and for certain peculations-at-risk, these less common routes of exposure may
be significant. If one of these exposure pathways (e.g., exposure to soil,
dermal exposure or surface water ingestion while swimming) has been identified
as significant, the Exposure Assessment Group at EPA headquarters should be
contacted for guidance on a method for calculating chemical intakes.
5.5 COMBINE PATHWAY-SPECIFIC INTAKES TO YIELD TOTAL ORAL AND
TOTAL INHALATION INTAKES
In this step, total exposure scenarios are developed for each exposure
point, and the relevant route-specific intakes are combined for the affected
population. This exposure summation gives the total daily oral intake and
total daily inhalation intake of each chemical to which the population may be
exposed.
In Chapter 4, chemical concentrations at the significant exposure point
were estimated for each identified exposure pathway (see Worksheets 4-2 and
4-4). Recall that the significant exposure point for a pathway is the point
of highest individual exposure, although locations with large exposed
populations and lower exposure levels should also be included in the analysis
as supplementary exposure points. Now the task is to determine, for each
significant exposure point identified in Chapter 4, which of the other
exposure pathways could contribute to total exposure at that point. Use
Worksheet 5-5 to record this information. Be sure to list any potentially
important non-quantified exposure pathways on Worksheet 5-5. If the
populations-at-risk for different exposure pathways are mutually exclusive, do
not sum intakes from both pathways for the same exposure point. For example,
it is incorrect to sum the intakes associated with ingesting drinking water
from different sources if each person's exposure is exclusively from one of
the sources.
After a total exposure scenario has been developed for each significant
exposure point (e.g., a population living near the site with private drinking
water), combine the individual chemical intakes calculated for each of the
oral exposure pathways identified for that exposure point. Do the same for
inhalation. Referring to Worksheet 5-5, insert the appropriate intakes to be
combined (from Worksheets 5-1 through 5-4) into Worksheet 5-6 (SDIs) and
Worksheet 5-7 (GDIs). Note that some intake values from Worksheets 5-1
through 5-4 may need to be adjusted when applied to exposure points other than
those specified. In situations where the significant exposure points of two
pathways are relatively far apart, the project management team must judge
whether the additional calculation effort is warranted or whether simply
summing the intakes for the significant exposure points is sufficient. For
example, if the significant exposure points for an air and a ground-water
pathway differ, the project manager may choose to adjust the intakes from
Worksheets 5-1 and 5-2 before using them for a total exposure estimate or may
combine the unadjusted intakes for a conservative total exposure estimate.
The next step in the summation procedure is to add the intakes from fish
and drinking water ingestion for each chemical to give the total oral SDI
(Worksheet 5-6) and GDI (Worksheet 5-7) for the population-at-risk at each
significant exposure point. The existence of any non-quantified exposure
pathways should be noted on these summary intake worksheets. In addition, be
sure to note the number of people exposed at each significant exposure point.
October 1986 * * *
-------
-88-
OSWER Directive 9285.4-1
Name of Sice:
Date:
Analyst:
QC:
WORKSHEET 5-5
PATHWAYS CONTRIBUTING TO TOTAL EXPOSURE
Exposure Point
Exposure Pathways
Contributing to
Total Exposure
Comments
1. Nearest downgradient
residences on private wells'-'
Residences 1 mile SW on
vulnerable public wells
Hospital at 2 miles on
public well (sensitive)
Ground-water ingestion
Air inhalation
Soil contact
Ground-water ingestion
Air inhalation
Ground-water ingestion
Non-quantified
Low exposure
•'•' Significant exposure point.
INSTRUCTIONS
1. List the exposure points for all exposure pathways being evaluated (from
Worksheet 4-2).
2. Determine the exposure pathways contributing to total exposure for each
listed exposure point.
3. Note in the comments column which exposure pathways are only short-term,
which are non-quantified, and any other pertinent information.
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-89-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 5-6
TOTAL SUBCHRONIC DAILY INTAKE (SDI) CALCULATION
Total Exposure Point: Nearest Residences on Private Wells
Number of People: 40
Chemical
1 . Benzene
2. Lead
Ground- Surface Fish Total Total
Water Water Ingestion Oral Air
SDI SDI SDI SDI SDI
0.0058 .- 4.7 x 10"6 0.0058 0.0075
0.0013 - 3.8 x 10"6 0.0013 0
3.
4.
INSTRUCTIONS
1. List all indicator chemicals.
2. Refer to Worksheet 5-5 and determine which exposure pathways are relevant
for the total exposure point.
3. Record SDIs (in mg/kg/day) for the total -exposure point from Worksheets,
5-1 through 5-4 in the appropriate columns. Be sure only to include SDIs
estimated for the same time period.
4. For relevant exposure pathways that had intakes calculated for a different
exposure point, adjust the intake estimates for the total exposure point.
Record the rationale and calculations supporting any adjustments and
attach to this worksheet.
•
5. Determine total oral SDI by adding the component SDIs (ground-water,
surface water, fish) for each chemical.
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
* * * ' October 1986 * * *
-------
-90-
OSVER Directive 9285.4-1
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 5-7
TOTAL CHRONIC DAILY INTAKE (CDI) CALCULATION
Total Exposure Point: Nearest Residences on Private Wells
Number of People: 40
Ground- Surface Fish
Water Water Ingestion
Chemical CDI CDI CDI
1. Benzene 0.00025 - 1.3 x 10"6
2. Lead 0.00015 - 1.5 x 10"6
Total
Oral
CDI
0.00025
0.00015
Total
Air
CDI
0.0012'
0
3.
4.
INSTRUCTIONS
1. List all indicator chemicals.
2. Refer to Worksheet 5-5 and determine which exposure pathways are relevant
for the total exposure point.
3. Record GDIs (in mg/kg/day) for the total exposure point from Worksheets
5-1 through 5-4 in the appropriate columns.
4. For relevant exposure pathways that had intakes calculated for a different
exposure point, adjust the intake estimates for the total exposure point.
Record the rationale and calculations supporting any adjustments and
attach to this worksheet.
5. Determine total oral CDI by adding the component GDIs (ground-water,
surface water, fish) for each chemical.
ASSUMPTIONS
List all major assumptions in the development of data for this worksheet:
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-91-
The intake summation procedure described here is-most relevant to the
estimation of total chronic exposure levels. When estimating total subchronic
exposures, be sure not to sum peak intake values estimated for different time
periods. Remember, the time period defined as short term is anywhere from a
10 to a 90 day period. If the SDI for one pathway is estimated to occur
immediately and the SDI for another pathway affecting the same exposure point
is predicted to occur in 5 years, it would be improper to sum these -- they
would affect the same population, but at different times. In this situation,
assessing short-term risks based on the higher of the two values usually will
provide a reasonable assessment of short-term risks. However, exposures
likely to occur immediately should also be assessed.
Human intakes for the indicator chemicals have been calculated from
measured or predicted ambient exposure point concentrations. Intakes received
from air, ground water, surface water, and fish consumption have been
calculated separately for each exposure pathway and combined to give total
oral and total inhalation intakes for each significant exposure point and each
selected indicator chemical. These intake estimates will be combined with
toxicity information gathered for Chapter 6 to perform the risk
characterization for Chapter 7.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-92-
T
CHAPTER 6
STEP 4: TOXICITY ASSESSMENT
r- This chapter describes the critical toxicity values (i.e., numerical values
.'. describing a chemical's toxicity) needed for the risk characterization step of
the Superfund public health evaluation process. An overview of the toxicity
assessment step of the public health evaluation is shown in Exhibit"6-1.
I Toxicity information is used in conjunction with the results of the exposure
i_. assessment to characterize risk. EPA's verified reference doses (RfDs),22J
evaluations by EPA's Carcinogen Assessment Group, and Health Effects
r- Assessment documents (HEAs) developed by EPA's Office of Research and
i Development serve as a consistent source of critical toxicity values for the
Superfund public health evaluation process. Critical toxicity values from
, these sources are summarized in Appendix C to this Manual and also are
r . contained in PHRED (Public Health Risk Evaluation Database). EPA believes
L.; that these are currently the best available sources of toxicity values.
However, this process is intended to accommodate new information and, as new
f~ toxicity data become available, Appendix C and PHRED will be updated to
reflect these changes. Toxicity information for specific chemicals not
covered in Appendix C may be available through the Environmental Criteria and
i Assessment Office (ECAO), U.S. EPA, 26 W. St. Clair Street, Cincinnati, Ohio
; 45268. In situations where Appendix C does not contain the necessary critical
toxicity values for all indicator chemicals at a site, ECAO should be contacted
__ for additional information. In some cases it may be necessary to derive
appropriate values based on available toxicological or epidemiologic data.
Three values that describe the degree of toxicity posed by a chemical are
required in the process:
• the acceptable intake for subchronic exposure (AIS);
r • the acceptable intake for chronic exposure (AIC); and
j • the carcinogenic potency factor (for potential
;— carcinogenic effects only).
: These values are based on empirical data -and have not been adjusted for
u. site-specific conditions. For some chemicals, separate critical toxicity
values are available for ingestion and inhalation routes of exposure.
/-: AIS and AIC values are required for all chemicals being evaluated. These
*"' values are derived from quantitative information available from studies in
animals (or observations made in human epidemiologic studies) on the
i-.7- relationship between intake and noncarcinog-enic toxic effects. They are
L designed to be protective of sensitive populations. The units for the AIS and
AIC are the same as those developed for SDI and CDI in the human exposure phase
i" of the public health evaluation -- mg/kg body weight/day. For teratogenic
• - chemicals, AIS values are generally derived for the teratogenic effects.
22J Reference doses are for noncarcinogenic effects and are similar in
concept to acceptable daily intakes (ADIs).
rrr * * * October 1986 * * *
^i
-------
-------
OSWER Directive 9285.4-1
t '' -94-
; AIS values are determined by a process similar to the procedure used to
develop reference dose values, except that subchronic effects are the basis of
the values instead of chronic effects. Most AIS values are based on
1 • subchronic (-10-90 day) animal studies, although some are derived from human
exposure data. For chemicals without appropriate human data, the highest
subchronic exposure level not causing adverse effects, or no-observed-adverse-
f~ effect-level (NOAEL), is determined for all valid animal studies available in
[• the literature. The NOAEL is then divided by appropriate uncertainty factors
to give the AIS. Uncertainty factors usually include a factor of 10 to
.p. account for extrapolation from animal experiments to human effects and a
j. factor of 10 for intraspecies variability (i.e., to account for the fact that
'-" two individuals of the same species may not react to the same quantity of a
chemical with the same level of response).
I . In general, AIC values are based on long-term animal studies. For a few
chemicals, however, adequate human data are available and are used. The
r-, highest chronic exposure level not causing an adverse effect (NOAEL) is
!-> determined by examining literature values from all appropriate animal
^- studies. The NOAEL value is then divided by uncertainty factors as in AIS
, -. development. Again, a factor of 10 is used for extrapolation from animal
effects to human effects, and a factor of 10 is used to account for
/v- intraspecies variability. If chronic studies are not available, subchronic
NOAELs are used and divided by an additional factor of 10 to account for
' uncertainties in extrapolating from subchronic to chronic exposures.
The carcinogenic potency factor is expressed as the lifetime cancer risk
r— per mg/kg body weight/day. This factor is equivalent to q * when it is
L," based on animal study data evaluated by the multistage model. This factor is
an estimated upper 95 percent confidence limit of the carcinogenic potency of
,•"- the chemical. From it, an upper bound estimate of cancer risk can be
i :• determined.
Although toxicity assessment is an integral part of the overall public
j '. health evaluation, in most cases limited new work will actually be required of
'— the site analyst to complete this step. To prevent duplication of effort and
ensure consistency among public health evaluations, the toxicity assessment
>~" step has already been done for many common toxic substances and is documented
[ -in a HEA or RfD summary. If EPA has completed verification of a reference
dose (RfD) for a specific chemical, then that value should be used as an
OAIC. If critical toxicity values are not available in Appendix C, contact
ECAO for further guidance. Worksheet 6-1 is provided as a format for
summarizing the required toxicity data.
In this chapter, toxicity information was collected to combine with
r-. exposure information from the previous chapter to allow characterization of
J. the health risks of the indicator chemicals. Three kinds of data were
collected: chronic and subchronic acceptable intakes for noncarcinogenic
^ effects and carcinogenic potency factors for potential carcinogenic effects.
'_" Using these data, long-term and short-term health risks can be characterized.
•-. Guidance for risk characterization is presented in Chapter 7.
* * * October 1986 * * -*
-------
-95-
OSWER Directive 9285.4-1
Name of Site:
Date:
Analvst:
QC:
WORKSHEET 6-1
CRITICAL TOXICITY VALUES
Chemical
Inhalation Route
1. " Benzene
2. Lead
3. Methyl ethyl
ketone
Ingestion Route
1 . Benzene
2. Lead
3. Methvl ethvl
ketone
Carcinogenic
AIS AIC Potency Factor
(mg/kg/day) (mg/kg/day) (mg/kg/day)
0.026(A)*
0.00043 N/A
2.2 0.22 N/A
0.052CA)*
0.0014 N/A
0.050 N/A
* EPA weight-of-evidence rating in parentheses for potential carcinogens.
INSTRUCTIONS
1. List all indicator chemicals.
2. List AIS, AIC, and carcinogenic potency factor values and carcinogenicity
weight-of-evidence ratings, obtained from Appendix C (or EPA/ECAO).
3. For teratogenic chemicals, list a separate AIS for that effect only.
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
October 1986 * * *
-------
OSWER Directive 9285.4-1
-96-
CHAPTER 7
STEP 5: RISK CHARACTERIZATION
_
f In this final step of the baseline public health evaluation process, a
'• - comparison is made between projected intakes and reference levels for
noncarcinogens and between calculated risks and target risks for potential •
f~ carcinogens. In the following sections, the methodology for making these
L, comparisons is described. There are separate discussions for noncarcinogenic
and carcinogenic effects because the methodology differs for these two classes
/-- of chemical toxicity. Exhibit 7-1 is an overview of the risk characterization
Remember, comparisons to applicable or relevant and appropriate
-•' requirements and other standards and criteria should already have been made
W> for those chemicals having them (see Section 4.3). This comparison to
requirements, in addition to the risk characterization results, will be
-~ included in the final public health evaluation report in the feasibility study.
7.1 NONCARCINOGENIC EFFECTS
Host sites being assessed will have more than one indicator chemical being
evaluated for noncarcinogenic effects. To assess the overall potential for
noncarcinogenic effects posed by multiple chemicals, a hazard index approach
has been developed based on EPA's Guidelines for Health Risk Assessment of
Chemical Mixtures (EPA, 1986d) . This approach assumes that multiple sub-
threshold exposures could result in an adverse effect and that the magnitude
of the adverse effect will be proportional to the sum of the ratios of the
sub- threshold exposures to acceptable exposures. This can be expressed as:
Hazard Index = E^RL + ^2/^L2 + ' ' ' + E • /RL •
where E. = Exposure level (or intake) for the i toxicant
RL . = Reference level (or intake) for the i toxicant
Any single chemical with an exposure level greater than the reference
level will cause the hazard index to exceed unity, and when the index exceeds
unity, there may be concern for a potential health risk. For multiple chemical
exposures, the hazard index can exceed one even if no single chemical exceeds
its acceptable level. However, the assumption of additivity reflected in the
hazard index equation is most properly applied to compounds that induce the
same effect by the same mechanism. Consequently, application of the equation
to a mixture of compounds that are not expected to induce the same type of
effects could overestimate the potential for effects. If the hazard index
results in a value greater than unity, segregate the compounds in the mixture
by critical effect and derive separate hazard indices for each effect.
Critical effects are described in the Health Effects Assessment documents.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
EXHIBIT 7-1
OVERVIEW OF STEP 5: CHARACTERIZING RISKS
For Noncarcinogens, Compare Estimated Intakes to Reference Levels
For Carcinogens, Combine Estimated Intakes
with Upper-Bound Carcinogenic Potency Factors
to Calculate Risk
-------
_ OSWER Directive 9285.4-1
I- -98-
F~
To make the comparison between estimated subchronic exposure to several
chemicals and acceptable subchronic intakes, determine the subchronic hazard
— index by calculating and then summing the SDI:AIS ratios for all chemicals.
/ : Use Worksheet 7-1 to record this calculation and summation. A separate
subchronic hazard index should be developed for each total exposure point. Be
careful to sum ratios only for chemicals and exposure pathways for which the
1 - short-term concentration time period is the same.
L
If any chemicals with teratogenic effects are being assessed, calculate a
P separate subchronic hazard index for them. The subchronic daily intake (SDI)
^ and the reference level for teratogenic effects should be used for assessment
of teratogenic risk.
r*'-
To make the comparison between estimated chronic exposure to indicator
1 chemicals and acceptable chronic intake, follow a similar procedure,
calculating and then summing the ratios of CDI:AIC for all chemicals to give a
p. chronic hazard index. Calculate a separate index for each total exposure
'^•> point, using Worksheet 7-2 to calculate and record the necessary information.
f,. Throughout this entire public health evaluation process, intakes and risks
j from oral and inhalation exposure pathways have been estimated separately.
This was done so that route-specific toxicity data could be used. However,
the possible effects of multimedia exposure should be evaluated by summing the
hazard indices for inhalation and oral exposures at each total exposure
>— point. This will ensure that acceptable levels are not being exceeded by
combined intakes when multiple exposure pathways exist.
[ It is emphasized that the hazard index is not a mathematical prediction of
incidence or severity of effects. It is simply a numerical index to help
^ identify potential exposure problems. Results for multiple chemicals should
j not be interpreted too strongly.
*s»-
If some of the indicator chemicals do not have adequate toxicity
I information, thus preventing their inclusion in the hazard index, the hazard
L. index may not be reflective of actual hazard at the site. Consideration of
chemicals that do not have toxicity values' could significantly increase the
• hazard index to levels of concern. Professional judgment is required to
determine how to interpret the hazard index for a particular site.
p 7.2 POTENTIAL CARCINOGENIC EFFECTS
b»
For potential carcinogens, risks are estimated as probabilities. The
;J*~, carcinogenic potency factor, which is an upper 95 percent confidence limit on
I; the probability of response per unit intake of a chemical over a lifetime
(i.e., only 5 percent chance that the probability of response could be greater
r- than the estimated value on the basis of the experimental data used), converts
, ; estimated intakes directly to incremental risk. If the exposure assessment is
u* - conservative, the resultant risk predicted is an upper-bound estimate.
Consequently, predicted risk may overestimate the actual risk at a site.
: However, this method is used so that carcinogenic risk will not be
underestimated.
* * *' October 1986 * * *
-------
OSWER Directive 9285.4-1
-99-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 7-1
CALCULATION OF SUBCHRONIC HAZARD INDEX
Total Exposure Point: Nearest Residences on Private Wells
Inhalation Oral
Chemical SDI AIS SDI:AIS SDI AIS SDI:AIS
1. Benzene 0.0075 0.15* 0.05 0.0058 0.15* 0.04
2. Lead 0 0.5* 0 0.0013 0.5* 0.003
3.
4.
* Values for illustration only; not in Appendix C.
Sum of Inhalation SDI:AIS Ratios = 0.05
Sum of Oral SDI:AIS Ratios = 0.04
Sum Total of All Ratios = 0.09
INSTRUCTIONS
1. List all indicator chemicals.
2. List the total inhalation SDI and total oral SDI (in mg/kg/day) from
Worksheet 5-6 in the appropriate columns for each chemical.
3. List route-specific AIS values -(from Worksheet 6-1) and calculate
route-specific SDI:AIS ratios for each chemical.
4. Sum and record route-specific SDI:AIS ratios.
5. Sum and record total (inhalation plus oral) SDI:AIS ratios only if the
SDIs for the two routes refer to the same time period. If total is less
than 1, there is probably no subchronic health hazard. If the sum is
greater than 1, separate the ratios according to health endpoint and do a
separate worksheet for .each endpoint.
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
* * * October 1986 * * *
-------
r.
OSWER Directive 9285.4-1
-100-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 7-2
CALCULATION OF CHRONIC HAZARD INDEX
Total Exposure Point: Nearest Residences on Private Wells
r;
/.
L
r
Inhalation
Chemical
Oral
GDI
AIC
CDI:AIC
GDI
AIC
CDI:AIC
1 . Benzene
2 . Lead
0.0012 0.002* 0.6 0.00025 0.002* 0.1
0 0.00043 0 0.00015 0.0014 0.1
3.
4.
* Values for illustration only; not in Appendix C.
Sum of Inhalation CDI:AIC Ratios =
Sum of Oral CDI:AIC Ratios =
Sum Total of All Ratios =
0.6
0.2
0.8
INSTRUCTIONS
1. List all indicator chemicals.
2. List the total inhalation GDI and total oral GDI (in mg/kg/day) from
Worksheet 5-7 in the appropriate columns for each chemical.
3. List route-specific AIC values (from Worksheet 6-1) and calculate
route-specific CDI:AIC ratios for each chemical.
4. Sum and record route-specific GDI:AIC ratios.
5. Sum and record total (inhalation plus oral) CDI:AIC ratios. If total is
less than 1, there is probably no chronic health hazard. If the sum is
greater than 1, separate the ratios according to health endpoint and do a
separate worksheet for each endpoint.
L:
ASSUMPTIONS
List all major assumptions in developing the data for this worksheet:
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1 ' :'
-101-
i
Because relatively low intakes are most likely from environmental
exposures, it can be assumed that the dose-response relationship will be in .->
the linear portion of the dose-response curve. Under this assumption, the
slope of the dose-response curve is equivalent to the carcinogenic potency
factor, and risk will be directly related to intake at low levels of
exposure. The carcinogenic risk equation is: • \
/*••*
'Risk = GDI x Carcinogenic Potency Factor
f
The carcinogenic risk estimate will generally be an upper-bound estimate. -j
This equation is valid only at low risk levels. For sites where chemical
intakes may be large (e.g., estimated carcinogenic risk above 0.01), an .)
alternate model should be considered. For example, the one-hit equation,
which is consistent with the linear low-dose model given above, may be useful:
I
\
Risk = 1 - exp (- GDI x Carcinogenic Potency Factor) J
In this situation, consult ECAO in Cincinnati for guidance on an appropriate ,
model. ,
For multiple compounds, the risk equation may be generalized to:
Risk = I (GDI. x Carcinogenic Potency Factor.)
This risk summation, also based on EPA's risk assessment guidelines, assumes )
that individual intakes are small. It also assumes independence of action by J
the compounds involved (i.e., that there are no synergistic or antagonistic
chemical interactions and that all chemicals have the same endpoint, cancer). ,
If these assumptions are incorrect, over- or under-estimation of the actual
risk could result.
For Superfund public health evaluations, it also is assumed that cancer
risks from various exposure routes are additive. Expressed mathematically •'
this is:
Carcinogenic Risk [GDI (inhalation) x Potency Factor (inhalation)] + J
for Chemical X =
[GDI (oral) x Potency Factor (oral)]
Therefore, the total carcinogenic risk for a site is estimated by:
Total Risk = (Carcinogenic Risk for Chemical 1 + . . . + Chemical.)
The result of the characterization will be upper-bound estimates of the
potential carcinogenic risk for each total exposure point. Estimates for
individual chemicals and pathways as well as estimates of aggregate risk '
should be developed and reported. Use Worksheet 7-3 to record the risk
calculations for potential carcinogens.
* * * October 1986 * * *
-------
Directive 9285.4-1
-102-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 7-3
CALCULATION OF RISK FROM POTENTIAL CARCINOGENS
Total Exposure Point: Nearest Residences on Private Wells
Exposure
Chemical Route
Carcinogenic Route-
CDI Potency Factor specific
(mg/kg/day) (mg/kg/day)-l Risk
Total
Chemical-
specific
Risk
1. Benzene
Oral
0.00025
Inhalation 0.0012
, 0.052
0.026
1 x 10
3 x 10
-5
-5
4 x 10
-5
2.
TOTAL UPPER BOUND RISK = 4 x 10
-5
r-
L
INSTRUCTIONS
1. List all potentially carcinogenic indicator chemicals.
2. List all exposure routes for each chemical.
3. Record GDIs (Worksheet 5-7) and carcinogenic potency factors (Worksheet
6-1) for each chemical and each exposure route.
4. Multiply the potency factor by the CDI to get the route-specific risk;
then sum the route-specific risks for each chemical.
5. Sum all of the chemical-specific risks to give an upper bound estimate of
total incremental risk due to potential carcinogens.
ASSUMPTIONS
- List all major assumptions in developing the data for this worksheet:
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1 *-,
-103-
l
7.3 UNCERTAINTIES
The public health evaluation process has been designed to rely on a subset
of the chemicals present at a site. These indicator chemicals were identified Jl'
on the basis of certain preliminary data. It is important at this time to
review the original data used to select the indicator chemicals to make sure ~"
that it remains valid and that new indicator chemical candidates have not been ^
uncovered during the evaluation process. It is wise to reevaluate the initial
choice of indicator chemicals at this time to assure yourself that, having —,
been through the entire process, they are still the appropriate chemicals on ' \
which to base the public health evaluation. -J
It is emphasized that all estimates of carcinogenic risk and hazard index •}
are dependent on numerous assumptions, and many uncertainties are inherent in _'.',
the risk assessment process. Probably without exception, information on site
history and site characterization data will be lacking *in some areas. Most ''••
toxicity information is derived from animal studies, and reputable scientists ',
disagree about how to interpret these data. A single toxicity parameter based
on an animal study does not convey the route of administration of test doses
of the suspect chemicals, the organ(s) in which the response occurred, or the
severity of endpoints in the animal experiment used to calculate the
dose-response relationship. Consequently, extrapolation to humans is a source
of uncertainty. Many toxicity studies are done at high doses relative to
exposures associated with waste disposal sites; extrapolation from high to low
doses also increases the uncertainty of risk numbers. Exposure modeling is
based on many simplifying assumptions that add to the uncertainty. Often the •-]
quality or quantity of site-specific chemical monitoring data is inadequate.
The additivity of toxicant risks and the additivity of doses of the same J
toxicant from different exposure routes are additional assumptions and
additional sources of uncertainty. Consequently, the results of the baseline
evaluation should not be taken as a characterization of absolute risk. An
important use of these results is to highlight potential sources of risk at a
site so that they may be dealt with effectively in the remedial process.
The procedures described in this chapter are not expected to supplant
expert judgment nor can they be designed to include all of the information
that may be available. If there are specific data germane to the assumption j
of additivity discussed above (e.g., if two compounds are present at the same -J
site and it is known that the combination is five times more toxic than the
sum of toxicities for the two compounds), then modify the risk estimate
accordingly. If data on chemical interactions are available but are not good
enough to support quantitative assessment, note the information on the
"assumptions" portion of the appropriate worksheet.
A listing should be made of the most significant factors increasing the
uncertainty of the risk assessment results, as illustrated in Worksheet 7-4.
* * * * *
As a result of the procedures described in Chapters 3 through 7, indicator
chemicals at a site have-been identified, releases calculated, exposure routes
identified, and exposure point concentrations calculated. Applicable or
* * * October 1986 * * *
-------
OSVER Directive 9285.4-1
-104-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 7-4
SITE-SPECIFIC FACTORS INCREASING UNCERTAINTY
(1) Sensitive Population(s):
Yes, specifically: Hospital 1/2 mile southwest from site - 300 people
potentially exposed via air and drinking water
(2) Exposure Uncertainties:
A. Non-Quantifiable Exposure Routes
Yes, minor pathways: 1. Ingestion of vegetables and livestock
contaminated by spray irrigation
2. Ingestion/dermal absorption by swimmers
B. Overall Data Adequacy
The site characterization and sampling data is believed to be
sufficiently detailed to allow a reasonable assessment; QA/QC is
acceptable
(3) Percentage of Chemicals Evaluated (number and volume):
Approximately 10 percent of the total number of .chemicals detected
(represents over 70 percent of the total estimated volume)
(4) Chemical or Biological Interactions:
Yes, chemicals: 1. Benzene and PCBs
Extent of Interaction (if known):
Unknown, but PCBs increase metabolism of benzene
(5) Other Factors:
INSTRUCTIONS
1. Complete worksheet, based on results of analysis of the listed factors at
the site.
* * October 1986 * * *
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OSWER Directive 9285.4-1
-105-
relevant and appropriate requirements, when available, were compared to
concentration estimates. Human intakes for each exposure pathway were
calculated"and summed, then combined with toxicity data to get risk estimates
for both potential carcinogens and noncarcinogens. The results of the public
health evaluation of baseline site conditions will now be used as a starting
point for the formulation of numerical performance goals for management of
migration remedial alternatives. These results also can be considered in the
development of source control measures and as a check to make sure all
potential sources of health risk at a site have been considered.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-106-
CHAPTER 8
DEVELOPMENT OF PERFORMANCE GOALS AND ANALYSIS
OF RISKS FOR REMEDIAL ALTERNATIVES
The baseline public health evaluation, using the procedures described in
the preceding chapters, provides considerable information on the baseline
health risks (i.e., in the absence of remedial action) from the site. This
information about chemical releases, routes of exposure, human exposure
points, and the level and timing of risk-will be used as input to further
development of the proposed remedial alternatives. This chapter describes the
procedures for developing target chemical concentrations for remedial
alternatives based on public health considerations and for comparison of
health risks associated with each remedial alternative being considered.
Conceptual alternatives will have already been developed as a concurrent part
of- the feasibility study process. By this time, site engineers should have
defined the options available for remedial actions at a site based on
feasibility and technical considerations. This chapter provides methods to
compare public health risks among the remedial actions developed in other
parts of the RI/FS process.
The NCP defines two different types of remedial alternatives that can be
developed during the feasibility study process: source control
alternatives and management of migration alternatives. This chapter
provides guidance for developing performance goals and for estimating risks
associated with a given level of control for management of migration
alternatives.
Source control alternatives -are those that control or remove the source of
contamination before it has migrated much beyond the source. For example,
site excavation and waste immobilization techniques are considered source
control alternatives. Such remedial alternatives should be assessed and
designed on the basis of applicable or relevant and appropriate requirements
(as defined by the NCP; see Section 2.3) and best engineering judgment.
However, best engineering judgment does not indicate how much to excavate or
help to determine acceptable residual levels of chemicals in soil. The
methods described in this chapter can be used to derive target soil
concentrations associated with a target risk range. Otherwise, the procedures
given in this chapter, with the exception of those described in Section 8.6
for assessing short-term effects, do not apply to source control alternatives.
Management of migration alternatives are those that address contaminants
that have migrated away from the source. For example, pump and treat
techniques for removing ground-water contamination are considered management
of migration alternatives. These alternatives should be analyzed based on
applicable or relevant and appropriate requirements and/or target health risk
levels for population exposure points.
The determination that proposed remedial alternatives attain, exceed, or
fall below RCRA design and operating standards or any other applicable or
relevant and appropriate requirement that is not an ambient concentration
level is made independently of the procedures in this chapter. Thus,
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-107-
although RCRA requirements are a key consideration in the development of
remedial alternatives, they do not provide ambient concentration targets for
specific chemicals and are not discussed further in this chapter. The
procedures of this chapter allow development of ambient concentation goals to
assist in refining remedial alternatives.
Some sites may have both source control and management of migration
alternatives under evaluation. For these sites, follow the procedures
described in this chapter for management of migration alternatives.
The remedial alternative ultimately chosen is a risk management decision
that is made as part of the overall feasibility study. This chapter provides
methods for a health-based comparison among alternatives. After a remedial
action has been chosen, the target concentrations developed for the comparison
can be used as performance goals for the remedial alternative and to calculate
allowable release rates for contaminants at the site. When applicable or
relevant and appropriate ambient requirements are available for all indicator
chemicals at a site, the project manager will have specific environmental
concentration levels for each chemical to use as performance goals.
When applicable or relevant and appropriate requirements are not available
for all indicator chemicals, remedies considered should reduce ambient
chemical concentrations to levels associated with a carcinogenic risk range of
-4 -7
10 to 10 (e.g., at least one remedial alternative being considered
could be associated with a carcinogenic risk of 10 , one with 10" , and
one with 10 ) where possible. For noncarcinogenic contaminants, exposure
point concentrations should be reduced to correspond to acceptable intake
levels. At sites where both potential carcinogens and noncarcinogens are
involved, the potential carcinogens will generally drive the design process
because concentrations corresponding to the target risk range are usually
lower than acceptable concentrations of noncarcinogens.
When some indicator chemicals have applicable or relevant and appropriate
requirements and others do not, the preferred approach is first to evaluate
remedial alternatives based on the total target carcinogenic risk range, as
when there are no applicable or relevant and appropriate requirements. Then,
for each chemical with a requirement, determine whether at least one
alternative attains, one exceeds, and one falls below its requirement. Given
the broad target range of carcinogenic risk, it is likely that these three
conditions would be met. If not, additional remedial options may have to be
developed to satisfy the proposed policy of considering options that exceed,
attain, and fall below applicable or relevant and appropriate requirements.
A tiered approach for evaluating and comparing alternatives is described
in this chapter. The first step is a reevaluation of the indicator chemicals
to determine whether any additions are necessary due to treatability
concerns. Second, human exposure pathways are determined for each remedial
alternative. The next step is development of preliminary target
concentrations, based either on applicable or relevant and appropriate
requirements or the potential carcinogenic indicator chemicals at the site.
The initial focus on potential carcinogens rather than noncarcinogens greatly
simplifies the process, and it is a logical approach because potential
carcinogens will usually drive the final design (i.e., environmental
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-108-
concentrations of potential carcinogens will generally have to be reduced to
lower levels than concentrations of noncarcinogens). For sites without
applicable or relevant and appropriate requirements, the next step, after
developing preliminary target concentrations, is to estimate corresponding
long-term concentrations of noncarcinogenic indicator chemicals to ensure that
acceptable levels are attained. If necessary, the alternative should be
modified to provide .adequate control of noncarcinogens. The final steps of
the tiered approach are to assess potential short-term health risks associated
with the remedial alternative and to evaluate the potential health effects
that could result from failure of the alternative.
Exhibit 8-1 presents a simple flowchart of the process for formulating
performance goals. The remainder of this chapter describes specific
procedures for comparing health risks and developing performance goals for
management of migration remedial measures. The presentation of" methods in
this chapter assumes an understanding of the previous sections of the manual.
8.1 REEVALUATE INDICATOR CHEMICALS
The first step in determining target concentrations for management of
migration remedial alternatives is a review of indicator chemicals. Indicator
chemicals have already been selected for assessing baseline site risks, but
the list of indicators may need to be modified because of differences among
chemicals in treatability, chemical class, and propensity to be released from
specific remedial alternatives. Some chemicals may be more difficult to treat
than those chosen as indicators for the baseline evaluation. These more
recalcitrant chemicals should be considered in the design of remedial
alternatives. It may be possible to use chemical class as a surrogate for
treatability because chemicals within a class have similar physical and
chemical properties. Consequently, chemical classes that were not important
in the baseline evaluation may become important. In addition, some remedial
alternatives will control or release different chemicals than others (e.g.,
volatiles will be of more concern for an air stripping alternative than a site
capping alternative). Review the list of selected indicator chemicals
(Worksheet 3-5) and the list of all chemicals present at the site (Worksheet
3-1) to determine whether additional chemicals should be included as
indicators, taking into account treatability, chemical class, and new release
sources associated with each specific alternative.
8.2 IDENTIFY POTENTIAL EXPOSURE PATHWAYS
. The next step in determining target concentrations for management of
migration remedial alternatives is identifying potential exposure pathways.
Again, this task has been completed for the no-action alternative, but it
should be reviewed in light of the particular remedial alternatives under
consideration. Some exposure routes identified for the baseline analysis may
not exist for certain remedial alternatives, while some new exposure routes
may result. For example, long-term pumping and air-stripping treatment of
ground water may result in air exposures not occurring under the no-action
alternative. Therefore, for each management of migration remedial alternative
* * * October 1986 * * *
-------
EXHIBIT 8-1
FLOWCHART OF PERFORMANCE GOALS PROCESS
Site with
Complete
Baseline
Public Health
Evaluation
>»
Reevaluate
Indicator
Chemicals and
Exposure
Pathways for
Each Remedial
Alternative
ARARs
for all
Indicators?
Develop Target
Concentration
Range for
Potential
Carcinogens
Based on
Risk
Analyze/Refine
Alternatives to
Ensure that They
Span the
Target
Concentration
Range
Evaluate
Noncarcinogenic
Risk for Each
Alternative
Develop Target
Concentration
Range Based
on ARARs
Analyze/Refine
Alternatives to
Ensure that They
Span the
Target
Concentration
Range
Assess
Potential Short-
Term Health
Risk of
Implementation
and Potential
Effects of
Remedy Failure
o
C/l
a
H-
h
-------
OSVER Directive 9285.4-1
-110-
remaining after initial screening (Chapter 2 of the Guidance for Feasibility
Studies), determine the possible sources of chemical release, transport media,
human exposure points, and exposure routes.
8.2.1 Determine Possible Sources of Chemical Release
Based on available information from preliminary site assessments and the
remedial investigation, identify and evaluate the sources of chemical release
that could result from each remedial alternative being evaluated. Consider
the possibilities of chemical releases to air, surface water, ground water,
and soil from sources on the site itself and also from certain off-site
sources resulting from the remedial action (e.g., a ground-water aeration
tower away from the site). In all situations where contaminated materials are
removed from the site and treated, stored, or disposed at a RCRA-permitted
facility, it is not necessary to include the RCRA facility as a source for
purposes of this assessment. Potential releases during transport of wastes
from the site to the RCRA facility also need not be considered.23-1
Exhibit 8-2 gives some examples of sources of release to each medium
resulting from typical remedial activities. Evaluate the sources given in
Exhibit 8-2 and any others relevant to the site to determine whether each is
important or unimportant, taking into consideration the potential quantity of
waste that may be released, the frequency of releases, and any other important
considerations. Be sure to consider the possibility of other .release sources
not listed in Exhibit 8-2.
Obtain descriptions and details of the remedial alternatives as a basis
for identifying additional potential release sources. Use Worksheet 8-1 to
list and qualitatively evaluate potential release sources for each remedial
alternative. Worksheet 8-1 should be supplemented with a map that indicates
the locations of the release sources for each alternative.
8.2.2 Determine Human Exposure Points
Review Worksheets 4-2 and 4-5 to determine whether the same populations
included in the baseline evaluation will be affected by the specific remedial
alternative under consideration. If so, note the same information previously
collected. Any new significant or supplementary exposure points resulting
from implementation of a remedial action should be noted (see Section 4.1.2,
for definition and discussion of significant exposure points). Populations at
these points will be characterized in a later step.
To assist in your evaluation of specific human exposure points, review
Section 4.1. Exhibit 4-3 in that section lists common exposure points for
chemical releases. Remember, the purpose of this task is to evaluate exposure
23J Releases from waste transport and management in RCRA permitted
facilities are regulated by applicable RCRA regulations (40 CFR 261 to 267)
and are therefore not appropriate considerations for evaluating remedial
alternatives under CERCLA.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-111-
EXHIBIT 8-2
POSSIBLE CHEMICAL RELEASE SOURCES
FOLLOWING REMEDIAL ACTIONS
Release
Medium
Release
Mechanism
Release Source
Air
Volatilization
Stack emission
Aeration treatment processes
Residual contaminated soil or surface
water
Incineration
Surface water
Ground-water seepage Residual contaminated ground water
Effluent discharge Treatment plant
Site runoff Residual contaminated surface soil
Ground water
Site leaching
Effluent discharge
Residual contaminated soil
Treatment plant
Soil
Site leaching
Surface runoff
Residual contaminated soil
Residual contaminated surface soil
* *
October 1986 * *
-------
-n.2-
OSWER Directive 9285.4-1
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 8-1
RELEASE SOURCE ANALYSIS
Remedial Alternative: Pumping and treatment of
ground water using air stripping
Medium
Potential
Release Source/
Mechanism
Release
Time
Frame
Release Probability/
Amount
Air
Aeration treatment
plant emissions
100?; probability for 10
years, then zero; amounts
may be high for some
volatile chemicals
Surface water Aeration treatment
plant discharge
100% probability for 10
years, then zero; amounts
may be high for non-
volatile chemicals
Ground water
Soil
1.
2.
3.
4.
INSTRUCTIONS
For each medium, list potential release sources.
Estimate release time frame: chronic (C) or episodic (E).
Record any information, qualitative or quantitative, on release amounts
and probabilities.
Attach a site map with sources located.
ASSUMPTIONS
List all major assumptions made in, developing data for this worksheet:
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-113-
pathways from a site after the implementation of remedial alternatives. In
subsequent sections, methods are presented for modeling environmental
transport processes from the point of exposure back to the source of
contamination to define allowable releases.
As mentioned above, the affected populations may be identical to those
defined in the baseline evaluation. If a new population might be exposed by
the remedial alternative (e.g., a population that will be exposed to air
emissions from an air stripping tower located at a distance from the site),
this group must be identified and characterized.
8.2.3 Integrate Release Sources, Transport Media, Exposure Points,
and Exposure Routes into Exposure Pathways
Assemble the information developed in the previous tasks and determine the
complete exposure pathways that would exist for each remedial alternative.
Use Worksheet 8-2 to integrate the exposure pathway information. A complete
exposure pathway has four components -- a source of chemical release, an
environmental transport medium, a point where human receptors could be
exposed, and a likely exposure route. For example, if a release to ground
water is projected but ground water from the affected aquifer is not now used
or projected to be used, the exposure pathway is incomplete.
8.2.4 Identify All Exposure Pathways for Each Exposure Point
To determine the total exposure at each exposure point for a remedial
alternative, review the pathways- developed in Worksheet 8-2. Develop
realistic total exposure scenarios (e.g., drinking contaminated ground water
or contacting contaminated surface water) that combine the different pathways
through which the population at an exposure point could conceivably be
exposed. Record these on Worksheet 8-3.
8.3 DETERMINE TARGET CONCENTRATIONS AT HUMAN EXPOSURE
POINTS
This task involves analysis of each indicator chemical relevant to each
significant exposure point (and supplementary exposure points, if necessary)
to determine a target concentration range for each indicator chemical at the
points of human exposure. Target concentrations will be calculated on the
basis of applicable or relevant and appropriate requirements or the target
-4 -7
cancer risk range of 10 to 10 . If applicable or relevant and
appropriate requirements are not available for all indicator chemicals,
proceed to Section 8.3.2.
8.3.1 Target Concentrations for Chemicals With Applicable or Relevant
and Appropriate Requirements
If all indicator chemicals have, applicable or relevant and appropriate
ambient concentration requirements, those requirements will be used as the
basis for the target concentration range. Otherwise, target concentrations
will be based on the target carcinogenic risk range. Some chemicals may have
more than one applicable or relevant and appropriate requirement. In these
* * * October 1986 * * *
-------
-114-
OSWER Directive 9285.4-1
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 8-2
MATRIX OF POTENTIAL EXPOSURE PATHWAYS FOR REMEDIAL ALTERNATIVES
Remedial Alternative: Limited excavation
Release
Medium
Release
Source
Exposure Point
Exposure
Route
Air
Ground water Remaining con-
taminated soil
Surface water
Soil
1.
3.
Private'well, 1/8 mile
away (downgradient)*
Ingestion
••'Significant exposure point.
INSTRUCTIONS
List all potential release sources, by medium (see Worksheet 8-1).
Describe the nature of the exposure point (i.e., point of highest
exposure) and its location with respect to release source (e.g., nearest
residence to volatilization release area, 100 meters NV). Denote
significant exposure points with an asterisk.
List Exposure Route: inhalation, oral, or dermal.
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
* * * October 1986 * * *
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OSVER Directive 9285.4-1
-115-
Name of Site:
Date:
Analvst:
QC:
WORKSHEET 8-3
IDENTIFY ALL PATHWAYS FOR EXPOSURE POINTS
Remedial Alternative: Limited excavation
Exposure Pathways
No. of Exposure Exposure
Exposure Point People Source Route Medium
1. Nearest residence
on private wells 100 Site leachate Ingestion Drinking water
Site volatiles Inhalation Air
2.
3.
INSTRUCTIONS
1. List each exposure point.
2. Note the number of people potentially exposed at each exposure point.
3. Record all exposure pathways relevant to each listed exposure point so
that total exposure can be determined.
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-116-
cases, the requirement most appropriate .for site exposure conditions should be
used. For drinking water exposures, for example, Safe Drinking Water Act MCLs
should generally be used if available.
List on Worksheet 8-4 the numerical value and source of applicable or
relevant and appropriate requirements for all of the indicator chemicals. The
NCP requires consideration of remedies that attain, exceed, and fall below
applicable or relevant and appropriate requirements.2UJ Therefore, on
Worksheet 8-4, list a target concentration that exceeds and one that falls
below the applicable or relevant and appropriate requirements.
Once target concentrations have been determined for each medium affected,
determine which of the concentrations can be achieved by each of the various
remedial alternatives under consideration. Engineering judgment must be used
to initially determine which remedies are likely to reduce chemicals to the
various target concentrations. One approach is to review Worksheet 8-4 and
consider which of the alternatives under consideration will reduce the most
difficult chemical to treat to the most restrictive target concentration, the
"exceeds requirements" category. Next, determine which alternative will
reduce the most difficult chemical to treat to the level of the requirement.
Then determine which remedy meets the "falls below requirement" category by
reducing the concentration of the most difficult chemical to treat to the
least restrictive level. Some of these options may actually be the same
conceptual remedy modified to meet different operating levels, such as a pump
and treat option with different levels of removal; conversely, they may be
completely different remedies. Be sure to verify and document, using chemical
release and transport modeling (see Section 4.2), that the target
concentrations will be met.
Regardless of the "attain, exceed, and fall below requirements" policy,
all remedies that eventually will be considered by the site decision-maker
must be evaluated on public health grounds. This may be done for the
remainder of the alternatives either by matching them with target
concentrations or by using a public health evaluation as described in Chapters
3 through 7.
An example for a hypothetical site is provided in Worksheet 8-4. In this
example, site contamination has polluted the ground water. Only two
contaminants are present, cadmium and arsenic, both of which have applicable
or relevant and appropriate requirements. Values for the standards and for
concentrations exceeding and falling below requirements are included. Assume
that four alternatives are being considered for the site: cap and slurry -
wall; pump, treat, and reinject; pump, treat, and discharge effluent to
surface water; and provide an alternate water supply that meets the drinking
water standards. The most restrictive concentration level is a concentration
of 0.0001 mg/1 for cadmium. Providing an alternate water supply would satisfy
the "exceeds requirement" policy by reducing cadmium below that level. The
2ltJ Reauthorization necessitates revision of the NCP; consequently,
current policies regarding attainment of standards may be changed.
October 1986 * * *
-------
-117-
OSWER Directive 9285.4-1'
Name of Site:
Date:
Analyst:
QC:
• WORKSHEET 8-4
TARGET CONCENTRATIONS FOR CHEMICALS WITH AMBIENT REQUIREMENTS
Chemical
Requirement Used/
Appropriate Medium
Target
Concentration
Exceeding
Requirement
Applicable/ Target
Relevant Concentration
Ambient Falling Below
Requirement Standard
1.
2
3.
4.
Cadmium MCL/drinking water .001 mg/1
Arsenic MCL/drinking water .005 mg/1
0.01 mg/1 0.1 mg/1
0.05 mg/1 0.5 mg/1
INSTRUCTIONS
1. List chemicals with applicable or relevant and appropriate ambient concentration
requirements (see Exhibit 4-5).
2. List the numerical value of the requirement, the source of the requirement, and
the appropriate exposure medium in the appropriate columns.
3. Determine a target concentration exceeding the standard.
4. Determine a concentration falling below the standard.
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
October 1986
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OSVER Directive 9285.4-1
-118-
pump/treat/reinject alternative can be designed to satisfy the arsenic and ,
cadmium standards; by modifying the operating parameters, it can also satisfy
the "falls below requirement" policy. Now the other two options under
consideration must be assessed, either by determining what risks are likely as
a result of their implementation (i.e., forward risk evaluation) or by back-
calculating allowable release rates based on the target concentration range.
8.3.2 Target Concentration for Chemicals Without Applicable or Relevant
and Appropriate Requirements
For situations where all indicator chemicals do not have applicable or
relevant and appropriate requirements, target concentrations for potential
carcinogens are calculated based on toxicity and chemical intake data.
Potential carcinogens are evaluated first because target concentrations for
potential" carcinogens generally will be lower than acceptable concentrations
for noncarcinogens; thus, potential carcinogens will usually drive the design
process. Remedial alternatives under consideration must span the target
carcinogenic risk range. Noncarcinogen exposures will subsequently be
assessed to ensure that they are below acceptable levels.
The remedial alternatives under consideration should have been assessed to
the extent that exposure points and routes have been determined for each
alternative. This section describes how to quantify the target concentrations
for each remedy at.each exposure point. It is necessary to evaluate the risk
of each alternative and to ensure that the proposed alternatives cover a wide
range of risk. According to Agency policy, the target total individual
carcinogenic risk resulting from exposures at a Superfund site may range
-A -7
anywhere between 10 to 10 . Thus, remedial alternatives being
considered should be able to reduce total potential carcinogenic risks to
individuals to levels within this range. The Agency also encourages
development of alternatives that eliminate carcinogenic risk where such a
remedy is feasible. One remedy being considered could correspond to a
carcinogenic risk of 10 , one to 10 , and one to 10 . These may be
the same conceptual alternative with different operating parameters or may be
different alternatives altogether. In addition, the remaining remedial
alternatives under consideration must also be evaluated either by calculating
risks for those alternatives (i.e., forward risk evaluation as described in
Chapters 3 through 7), or by back-calculating allowable release rates based on
the target concentration range. For any remedial alternative which was
developed by back-calculating release rates, a "forward" risk assessment of
the proposed alternative should be performed to verify that it meets the risk
level it was designed to achieve. This can be accomplished by following the
steps described in Chapter 3 through 7.
8.3.2.1 Apportion Total Potential Carcinogenic Risk Among Multiple
Carcinogens
There are a number of ways of translating total risk levels into target
concentrations for individual chemicals. Ultimately, the site assessor must
judge how the carcinogenic exposure should be apportioned among multiple
potential carcinogens and multiple routes of exposure.. Two simple approaches
to this problem are presented below as illustrative examples. The project
* * * October 1986 * * *
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OSVER Directive 9285.4-1
-119-
manager is not restricted to these methods, though they will provide a
reasonable starting point. These approaches assume low-dose additivity of
carcinogenic risk, which is consistent with Agency risk assessment guidelines.
One method is to divide a target carcinogenic risk level by the number of
indicator chemicals that are potential carcinogens. For example, at a target
risk level of 10 where 5 potential carcinogens are of interest, the
resulting target risk level for each individual potential carcinogen would be
2x10 . Once the target risk is determined, the target intake can be
determined using the following formula:
Potential Carcinogenic Risk = (Chronic Daily Intake) x (Potency Factor)
-2 -1
Thus, if the potency factor for benzene is 5.2x10 (mg/kg/day) , the
target benzene intake would be 3.8x10 mg/kg/day:
[2 x 10"7] * [5.2 x 10"2 (mg/kg/day)"1] = 3.8 x 10"6 mg/kg/day
The same calculations would then be repeated for each potential carcinogen and
each level of the carcinogenic risk range. This approach is simple and
conservative, ensuring that the target risk will not be exceeded if the target
intakes are attained, but it may not result in the most efficient design.
Another approach is to let one or two chemicals drive the design process.
One indicator chemical may be so difficult to treat or so potent (e.g.,
dioxin) that exposure levels must be extremely low so that the total risk
falls within the target range. By designing remedies to reduce levels of such
"bad actors" to within the range, concentrations of other indicator chemicals
may become negligible by default, although it should still be demonstrated
that these remaining concentrations of other indicator chemicals would not
violate the risk range.
These approaches, however, may not be optimal with regard to engineering
design or cost-effectiveness considerations. Thus, the specific means by
which the target carcinogenic risk is apportioned must be determined on a
site-by-site basis. Worksheet 8-5 illustrates a method for risk apportionment.
-4 -7
This should be done for target risk levels between 10 and 10
It is understood that this approach assumes additivity, while in fact
there may be chemical interactions taking place. Until guidance is issued in
this area, report any information available on chemical interaction among the
substances of interest. In the unlikely event that quantitative data are
available on the degree to which interactions affect risk, they should be used
to adjust risk estimates.
Remember, the total individual risks from all routes of exposure must fall
within the target range. If exposure to a chemical for a given population
occurs by more than one route, the risk must be apportioned among routes in a
similar manner to the apportionment among multiple chemicals. To determine
where the most efficient reductions in risk can be made, one should first
* * * October 1986
-------
-120-
OSWER Directive 9285.4-1
Name of Site:
Date:
Analvst:
QC:
WORKSHEET 8-5
APPORTIONING TOTAL TARGET RISK
AMONG MULTIPLE POTENTIAL CARCINOGENS
-6*
Target Risk Level: _10
Limited excavation
Remedial Alternative:-
Exposure Point: Nearest residence
Potential Carcinogen
Target
Risk for Each
Chemical
Potency
Factor -1
(mg/kg/day)
Target GDI
(mg/kg/day)
1.
3.
4.
Benzene
5x10
-7
2. Chlordane
5x10
-7
0.052 (oral)
1.61 (oral)
Total Target Risk = 10
-6
1x10
3x10
-7
••'••Risk level used for illustrative purposes only.
INSTRUCTIONS
1. Fill in target carcinogenic risk level under consideration.
2. List all potentially carcinogenic indicator chemicals.
3. Determine apportioned risk level for each chemical. Any method can be
used as long as the total equals the target risk level. One method is
equal apportionment, as follows:
Total Target Risk
Number of Potential Carcinogens
Target Risk
for Each Chemical
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-121-
WORKSHEET 8-5 INSTRUCTIONS (continued)
4. List the potency factor for the appropriate exposure route for each
chemical (obtained from Exhibit C-4 in Appendix C). Be sure to indicate
the exposure route.
5. Calculate target intake (GDI) for each potential carcinogen:
Target Risk * Potency Factor = Target Chronic Daily Intake
ASSUMPTIONS
List all major assumptions in developing the data for this, worksheet:
October 1986 * * *
-------
OSWER Directive 9285.4-1
-122-
determine the target concentrations associated with both air and water routes
of exposure independently. Then, the design engineers may refine the con-
ceptual design iteratively so that the combined exposures from various routes
fall within the stated range. These adjustments should be made based on the
most risky routes of exposure and the most cost-effective way to reduce total
carcinogenic risk from various exposure routes. The following sections present
methods for calculating target concentrations in air and drinking water.
8.3.2.2 Calculate Target Air Concentrations
Using the following formula, calculate the target long-term concentration
in air "for each potential carcinogen:
Target Chronic Daily Intake
Long-term Air Concentration =
Human Intake Factor
Use Worksheet 8-6 to calculate target air concentrations for appropriate
chemicals. This should be done for each remedial alternative. The human
intake factor for air is given in the worksheet, and the target chronic daily
intake is the intake corresponding to the target risk (see Worksheet 8-5).
8.3.2.3 Calculate Target Drinking Water Concentrations
\
A population-at-risk can be exposed to contaminated surface or ground
water (or both) by ingestion of drinking water. Calculate the target
long-term concentration of potential carcinogens in drinking water using the
following formula:
Target Chronic Daily Intake
Long-term Drinking Water Concentration =
Human Intake Factor
Use Worksheet 8-7 to calculate the target concentrations for potential
carcinogens in drinking water. The intake factor is given in the worksheet.
If intakes from water exposure besides drinking water and fish ingestion, such
as dermal exposure or intake of chemicals volatilizing from water, are
important and can be quantified, those intakes should be included and standard
intake assumptions should be adjusted.
The target chronic daily intake level represents total oral exposure.
When drinking water is the only route sf oral exposure, then the above
calculation is appropriate. An added complication arises in cases where there
is exposure to the same population through both drinking water and fish
consumption. .If the contaminated drinking water is from a different water
source than the fish (i.e., ground water or a different surface water body),
apportion the target oral intake between the two routes of ingestion. Use
Worksheet 8-8 for this apportionment arid Worksheet 8-9 to calculate target
surface water concentrations based on intake via fish consumption. The
illustrative apportionment on Worksheet 8-8 assigns equal chronic daily intake
to drinking water and fish consumption. It is important to note that other
apportionments are possible, permitting some tradeoffs between target concen-
trations for a drinking water source and surface water where fish are caught.
* * * October 1986 * * *
-------
-123-
OSWER Directive 9285.4-1
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 8-6
CALCULATION OF TARGET AIR CONCENTRATIONS
Remedial Alternative: Limited excavation
Exposure Point: Nearest residence
Chemical
Target
GDI
(mg/kg/day)
Human
Intake Factor
(m5/kg/day)
Target Long-Term
Concentration
(mg/m3)
1.
Benzene
N/A
0.29
N/A
2.
3.
4.
0.
0.
0.
,29
,29
,29
INSTRUCTIONS
1. List all indicator potential carcinogens with air as an exposure medium.
2. List the target chronic daily intake from Worksheet 8-5.
3. Determine the target long-term air concentration using the following
formula:
Human
Target = Target Chronic * Intake
Concentration Daily Intake Factor
ASSUMPTIONS
List all major assumtions made in developing the data for this worksheet:
October 1986
-------
OSWER Directive 9285.4-1
-124-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 8-7
CALCULATION OF TARGET DRINKING WATER CONCENTRATIONS
Remedial Alternative: Limited excavation
Exposure Point: Nearest residence
Chemical
Target
GDI
(mg/kg/day)
Human
Intake Factor
(1/kg/day)
Target Long-Term
Concentration
(ng/1)
1. Benzene
3.
4.
1x10
-5
0.029
0.029
0.029
0.029
3.4x10
-4
INSTRUCTIONS
1. List all indicator potential carcinogens with drinking water as an
exposure route.
2. List the target chronic daily intake for each chemical from Worksheets 8-5
or 8-8.
3. Determine the target long-term drinking water concentration using the
following formula:
Human
Target = Target Chronic * Intake
Concentration Daily Intake Factor
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
* * * October 1986 * * *
"T
-------
OSVER Directive 9285.4-1
-125-
If exposure through drinking water and fish consumption originate from the
same surface water body, consider both intake routes simultaneously in
calculating target surface water concentrations. No apportionment is required
because a single variable, the surface water concentration, controls the total
intake. If there is simultaneous exposure to the population-at-risk via fish
consumption and drinking water ingestion, calculate the target surface water
concentration using the following equation:
Target Target Chronic Daily Intake
Surface Water = ———•
Concentration KBioconcentration x (Human Intake ~|+ (Human Intake Factor
L Factor) Factor for Fish)J for Drinking Water)
Record the final target concentrations for each potential carcinogen on
Worksheet 8-10. A separate worksheet should be completed for each target risk
-4 -7
level being assessed between 10 and 10 . Usually three risk levels
should be assessed: the primary target (10 ) and the extremes of the
-4 -7
allowable range (10 and 10 ). In Section 8.4, methods are described to
convert the taiget environmental concentrations calculated here to allowable
release rates of chemicals from the source.
8.3.3 Summarize Data
Several data collection and calculation tasks have been completed thus far
and now this information should be integrated to assist in the analysis and
refinement of remedial alternatives. For each alternative, this involves
combining the data from Worksheets 8-3 through 8-10. Worksheet 8-11 provides
a format for this data collection.
8.4 ESTIMATE TARGET RELEASE RATES
Using environmental fate and transport models, target exposure point
concentrations from the previous section can be applied to calculate target
release rates at the identified sources of release for some remedial options.
For options such as capping, slurry walls, and excavation, using models to
calculate these releases is not a straightforward process. For other options
such as pumping and treating, air stripping, and other point source treatment
options with graded effectiveness, this step can be used to calculate
allowable release rates. The estimated target chemical releases can
eventually be incorporated into the remedial design. For example, the target
effluent discharge levels from a contaminated ground-water treatment plant can
be used to specify the treatment and removal efficiency of the facility.
Estimation of release rates requires the use of environmental fate and
transport models. A great deal of uncertainty is inherent in the use of
models, and it should be understood that the values generated by the models
represent "ball park" estimates rather than precise values.
8.4.1 Predict Environmental Fate and Transport
Because the concentration of contaminants changes as substances move from
release sources to exposure points, environmental fate and transport must be
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-126-
Name of Site:
Date:
Analvst:
QC:
WORKSHEET 8-8
APPORTIONMENT OF TARGET ORAL INTAKE VIA
DRINKING WATER AND FISH CONSUMPTION*
Remedial Alternative:
Limited excavation
Exposure Point: Nearest residence
Chemical
Total Target
Oral GDI
(mg/kg/day)
Intake Via
Drinking Water
(mg/kg/day)
Intake Via Fish
Consumption
(mg/kg/day)
1.
Benzene
1x10
-5
5x10
-6
5x10
-6
3.
'•'•'Not required when contaminated fish and drinking water originate from the
same surface water source (see text for methods in this situation).
INSTRUCTIONS
1. List potential carcinogens which have both drinking water and fish
consumption as exposure routes and for which the fish originate from a
different water source than the drinking water.
2. List total target oral intake for each of these (Worksheet 8-5).
3. List apportioned intakes for both drinking water and fish consumption,
remembering that:
Intake via + Intake via = Total target
drinking water fish consumption oral intake
As a first approximation, intake may be apportioned equally between the
two (as in the example). Engineering and economic considerations may
alter the apportionment on subsequent iterations.
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
* * *
October 1986
* * *
-------
-127-
OSVER Directive 9285.4-1
Name of Sice:
Date:
Analyst:
QC:
WORKSHEET 8-9
CALCULATION OF TARGET SURFACE WATER CONCENTRATIONS
BASED ON FISH CONSUMPTION
Remedial Alternative:
Limited excavation
Chemical
1 . Benzene
2.
3.
4.
Exposure Point: Nearest residence
Human Intake Target
Target Factor Bio- Surface Water
GDI (kg fish/ concentra- Concentration
(mg/kg/day) kg/day) tion Factor (mg/1)
5x!0"6 .00009 5.2 l.lxlO*2 '
.00009
.00009
.00009
INSTRUCTIONS
1. List all indicator potential carcinogens with fish consumption as an
exposure pathway.
2. List the target chronic daily intake for each chemical (Worksheet 8-5 or
8-8).
3. Record the bioconcentration factors (Appendix C) for each chemical.
4. Determine target long-term surface water concentration using the following
formula:
fHuman Bioconcen^
Target = Target Chronic * I Intake x tration
Concentration Daily Intake Jjactor Factor
ASSUMPTIONS
List all major assumptions made in developing the data for this worksheet:
* October 1986 * * *
-------
OSVER Directive 9285.4-1
-128-
Name of Site:
Date:
Analyst:
QC:
WORKSHEET 8-10
FINAL TARGET CONCENTRATIONS OF POTENTIAL CARCINOGENS
-6"
Target Risk Level: _10
Remedial Alternative: Limited excavation
Exposure Point: Nearest residence
Exposure Target Target
Route Chemical Concentration Risk
Inhalation N/A N/A N/A
-4 -7
Drinking water Benzene • 1.7x10 mg/1 2 x 10
-2 -7
Surface water Benzene 1.1x10 mg/1 2 x 10
(fish consumption)
"'•"Risk level used for illustrative purposes only.
INSTRUCTIONS
1. Fill in target risk level.
2. List chemicals that account for exposures by each route.
3. List target concentrations from air route (Worksheet 8-6), drinking water
route (Worksheet 8-7), and fish consumption route (Worksheet 8-9).
4. List target risk associated with each chemical concentration from
Worksheet 8-5.
ASSUMPTIONS
List all major assumptions made in developing data for this worksheet:
* * * October 1986 * * *
-------
WORKSHEET 8-tl
SUMMARY Of EXPOSURE PATHWAYS, EXPOSURE POINTS,
AND TARGET CONCENTRATIONS
Remedial Alternative: Ground-wa ter pump imi/t rea inient
Name or Si te:
Date:
Analyst:
QC:
Exposure Point
Number of
People
Source
Exposure
Route
T ransport
Mud i um
Target Concentrations
at Point oT Human Exposiire
Chemicals Target Concentration
Nearest group of,
residences on private
wel 1 s
100 Effluent from Ingest Ion of Ground water 1. Benzene 1.7x10-4 OKI/
water treat- drinking water 2.
ment ( re- 3 .
injected) 4.
5.
1.
2.
3.
»i.
5.
1.
2.
3.
U.
5.
INSTRUCTIONS
1. Record exposure pathway information from Worksheet 8-3.
2. Record all potential indicator carcinogens for each pathway and their target exposure point concentrations (see
Worksheet 8-10).
ASSUMP1IONS
List all major assumptions made in developing data for this worksheet.
O
to
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rt
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vo
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oo
Ln
-------
OSVER Directive 9285.4-1
-130-
assessed to project allowable releases. Each exposure pathway will have an
identified medium of interest through which the contaminant travels, such as
chemicals released to the subsurface that move through ground water to a well.
For each potential carcinogen moving through a specific transport medium,
the output of this step will be a target release from the source, based on
public health considerations'at each exposure point. Using the pathways
already identified for each chemical, systematically consider the extent of
chemical fate and transport in each environmental medium. By doing so, the
predominant mechanisms of chemical transport, transfer, and transformation can
be considered and less significant processes disregarded.
Refer to the Superfund Exposure Assessment Manual for details on modeling
environmental fate and transport for air, ground water, and surface water.
Remember, in developing design criteria, you will be using "C", the
concentration, to solve for "R", the release rate of a substance (mass/time).
Some of the packaged computer models cannot be used for this because the
software is designed only to determine concentration. Examine the chosen
model carefully to ensure that it will work in this case. Otherwise, you may
have to determine the release rate iteratively. That is, one could
arbitrarily select a release rate and solve for concentration, repeating this
step until the correct exposure point concentration is determined. The
release rates calculated in this process can be used as design goals for the
remedial alternatives of interest.
8.4.2 Summarize Data
Use Worksheet 8-12 to present the average allowable release rates for each
chemical and each source modeled for each remedial alternatives.
8.5 ASSESS CHRONIC RISK FOR NONCARCINOGENS
Now that remedial alternatives have been considered to reduce estimated
carcinogenic risk to acceptable target levels, each alternative must be
checked to ensure that it reduces noncarcinogenic risk to acceptable levels.
This is done similarly to the quantitative analysis for noncarcinogens for the
no-action alternative -(Chapters 3 through 7).
Release sources and exposure routes for each remedial alternative have
already been determined on Worksheets 8-1 and 8-2. Significant exposure
points for each alternative have also been determined on Worksheet 8-3.
Contaminant releases should be obtained or estimated from the remedial design
specifications. These are then converted to environmental concentrations
using chemical fate and transport models as described in Section 4.2. Human
intakes for the environmental concentrations are calculated as described in
Chapter 5. Worksheet 8-13 should be used to summarize the release and
exposure data.
-A Chronic Hazard Index should be calculated, as described in Section 7.1,
to determine risk from noncarcinogens. Assessment of short-term risks is
discussed in the next section. Remember, the equation for the Hazard Index
is, for this situation:
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
-131-
Name of Site:
Date:
Analvst:
QC:
WORKSHEET 8-12
LONG-TERM TARGET RELEASES
Remedial Alternative: Limited excavation
Exposure Point: Nearest residence
Long-Term
Chemical Exposure Pathway Target Release
1. Benzene Site volatilization to air 0.00027 kg/day
INSTRUCTIONS
1. List indicator potential carcinogens.
2. Using Worksheet 8-2 indicate all the pathway/release sources identified
for each chemical.
3. List the long-term target release rates calculated for each combination of
chemical and pathway/release source, using the target concentrations
listed in Worksheet 8-10. Release rates should be listed in units of mass
per time (e.g. kg/day or Ibs/hr).
ASSUMPTIONS
List all assumptions made in developing the data for this worksheet:
* * * October 1986 * * *
\
\
-------
OSWER Directive 9285.4-1
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OSWER Directive 9285.4-1
-133-
HI = CDIj/AIC + CDI2/AIC2 + ... GDI
where GDI. = Chronic daily intake for the i toxicant
AIC. = Acceptable intake for chronic exposure for the i
toxicant (noncarcinogenic effects only).
Again, if the Hazard Index is less than 'one, no adverse effects are expected.
If the value is near or greater than unity, the toxicants should be considered
separately, according to the health endpoints they produce. If unity is
exceeded for any health endpoint, consider revising the design to reduce the
risk from noncarcinogens to a lower level. Worksheet 8-14 should be used to
summarize the intake and toxicity information used to calculate the
noncarcinogenic risk. Worksheets from Chapters 4 and 5 may be useful to
organize this information.
8.6 ASSESS POTENTIAL SHORT-TERM HEALTH EFFECTS OF REMEDIAL
ALTERNATIVES
After remedial alternatives have been analyzed for chemical risks, the
potential short-term public health effects of each alternative should be
considered. Short-term health risks should not be used as a selection
criterion for remedial alternatives, but should be used to determine
appropriate management practices during implementation of the remedial
action. In other words, if predicted short-term concentrations are likely to
exceed short-term toxicity thresholds in the process of constructing or
implementing a remedial alternative, certain management practices should be
employed to reduce the potential risks. For example, a remedial option at a
site may involve excavating and removing contaminated soil. In the absence of
precautionary measures, fugitive dust generation by heavy equipment and
remedial activities may create a short-term health hazard. These and other
temporary sources of chemical release associated with construction and
implementation of a remedy are not grounds for rejecting the remedial
alternative. However, management practices, such as the temporary relocation
of potentially exposed populations, should be considered to mitigate the
health risks associated with temporary sources of release.
Data on acceptable short-term exposures are often difficult to obtain, and
a qualitative analysis of short-term health effects from remedial actions may
be all that is possible. Also remember that the remedial action itself, in
addition to the initial implementation of an action, may increase short-term
exposure at a site. For example, a pump and treat alternative for
ground-water contamination may increase the concentration of volatiles in the
air near a site until the clean-up at the site is completed, which could be
several years.
Public health evaluation of short-term effects is similar to the preceding
evaluation for chronic noncarcinogenic effects. However, because new
exposures are possible, the exposure assessment must be reviewed. Review
Section 4.2 to assist in identifying possible human exposure points and in
characterizing sensitive human populations. Exhibit 8-3 lists some common
types of release sources at sites during remedial action. Worksheet 8-15
should be completed to document potential short-term exposure pathways.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
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OSWER Directive 9285.4-1
-135-
EXHIBIT 8-3
COMMON TEMPORARY CHEMICAL RELEASE SOURCES
DURING IMPLEMENTATION OF A REMEDIAL ALTERNATIVE
Release
Medium
Release
Mechanism
Source of Released Mat-erials
Air
Surface water
Ground water
Soil
Volatilization
Fugitive dust
generation
Direct effluent
discharge
Site runoff
Land application
of effluents
Underground injec-
tion of effluents
Land application
Contaminated deep soil "(during
excavation)
Water/wastewater treatment facilities
Contaminated surface soil
Contaminated deep soil (during
excavation)
Treatment of contaminated runoff
Treatment of contaminated ground water
Treatment of leachate
Contaminated surface soil
Treatment of various waste streams
Treatment of various waste streams
Treatment of various waste streams
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
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OSWER Directive 9285.4-1
-137-
Environmental concentrations of the indicator chemicals at the site for
the potential exposures must now be determined. Review Section 4.2 for the
details of this process. Releases of chemicals will probably have to be
estimated. Use any technical information available to generate a best
approximation. Environmental fate and transport should be modeled from the
release to obtain environmental concentrations. Intakes are calculated from
the environmental concentration. Review Chapter 5 for the details of this
process .
Short-term chemical concentrations are compared to the AIS, the acceptable
intake of contaminants for subchronic exposures, to assess health risk. A
Hazard Index should be calculated, as described in Section 7.1. Use Worksheet
8-16 to assess the short-term noncarcinogenic risk. If noncarcinogenic risk
exceeds unity, management practices to mitigate or eliminate releases must be
devised.
In this chapter, information from the baseline public health evaluation
has been used as input to the analysis and refinement of remedial
alternatives. For source control measures, best engineering judgment and
applicable or relevant and appropriate requirements were used to refine
remedial alternatives. For management of migration alternatives, applicable
or relevant and appropriate requirements and health-based performance goals
for potential carcinogens were used as inputs to the design process.
Predicted exposure levels for noncarcinogens were checked to ensure that they
would not be above their thresholds of safety. Short-term effects of remedial
alternatives were also considered. All that remains to be done for the public
health evaluation is organizing this information for use by the site
decis ion-makers .
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
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-------
OSWER Directive 9285.4-1
-139-
CHAPTER 9
SUMMARIZING THE PUBLIC HEALTH EVALUATION
At this point in the public health evaluation process, the following
analyses have been completed:
• Assessment of the baseline health risks posed by a
site, and
• Assessment of the proposed remedial alternatives based
on applicable or relevant and appropriate requirements
and, for management of migration alternatives and soil
excavation procedures, health-based performance goals.
The results of the public health evaluation should be reported to site
decision-makers for consideration in the remedy selection proess. For
fund-financed remedial investigations/feasibility studies, this reporting
requirement will typically be fulfilled by a public health evaluation chapter
in the feasibility study. A separate handbook has been distributed for
enforcement-lead sites; in general, the principles of public health evaluation
for those sites will be similar.
This chapter provides guidance for summarizing and reporting the results
of a Superfund public health evaluation. In general the report should provide
a rationale for the level of detail of the analysis, a description of each of
the steps discussed in Chapters 3 through 7, and a summary of the analysis of
remedial alternatives. The worksheets listed in Exhibit 9-1 (or their
equivalent) should be a part of the public health evaluation report.25J
Individual toxicity profiles are very useful and may be developed to describe
potential effects of the indicator chemicals or other chemicals of concern.
Relevant toxicity profiles also can be included as part of the public health
evaluation report.
It is important to note that the narrative component of all public health
evaluations plays a very important role. The narrative should be used to
clearly explain the data used in the evaluation and the results of the
evaluation. Recognizing that public health evaluation reports may be reviewed
by the public and especially by members .of the exposed or potentially exposed
population, care must be taken to explain the major steps and the results of
the evaluation in terms that are easily understood-by the general public.
In addition to the narrative report and worksheets, the two summary
exhibits'described in this chapter (or their equivalent) should be included as
a key part of the quantitative analysis report: Exhibit 9-2 for the baseline
evaluation and Exhibit -9-3 for remedial alternatives. Both exhibits require
qualitative and quantitative information. The qualitative entries are as
important as the numbers and, in some cases, perhaps more important;
consequently, be sure to complete the columns accurately and completely.
25J Other worksheets from Chapters 3 through 8 may be included as an
appendix to the feasibility study.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
.-140-
EXHIBIT 9-1
WORKSHEETS THAT SHOULD BE INCLUDED
IN A PUBLIC HEALTH EVALUATION SUMMARY
Title Number
Scoring for Indicator Chemical Selection: Koc Values 3-1
and Concentrations in Various Environmental Media
Scoring for Indicator Chemical Selection: Evaluation of 3-5
Exposure Factors
Matrix of Potential Exposure Pathways 4-2
Contaminant Concentrations at Exposure Points 4-4
Comparison of Applicable or Relevant and Appropriate Require- 4-5
ments to Estimated Exposure Point Concentrations
Comparison of Other Federal and State Criteria to 4-6
Estimated Exposure Point Concentrations
Pathways Contributing to Total Exposure 5-5
Total Subchronic Daily Intake (SDI) Calculation 5-6
Total Chronic Daily Intake (CDI) Calculation 5-7
Calculation of Subchronic Hazard Index 7-1
Calculation of Chronic Hazard Index 7-2
Calculation of Risk from Potential Carcinogens 7-3
Matrix of Potential Exposure Pathways for Remedial 8-2
Alternatives
Summary of Exposure Pathways, Exposure Points, and 8-11
Target Concentrations
Summary .Table: Chronic Intakes and Risks from 8-14
Nonca rc inogens
Summary Tables: Subchronic Intakes and Risks 8-16
* * * October 1986 * * *
-------
F.XIIIIMT 9-2
SUMMARY OF THE BASELINE PUBLIC HEALTH EVALUATION
Site:
Indicator Chemicals:
Human
Exposure
Point a/
1.
2.
Exposure
Pathway b/
I.
1.
Number
of People
Potentially
Exposed c/
1.
1.
Requirements/Criteria
Standard
concenlra-
Compared t ion rat in
if £/
1. |1.
2. |2.
3. |3.
4, |4.
5. 15.
1
1. |1.
2. |2.
3. 13.
4. |4.
5. |5.
1
Potential Carcinogenic Risk
Weight-of-
Risk Dominant Evidence
Estimate Chemicals f for Dam.
U g/ Chem. h/
1. |l. |l.
|2. 12.
13. |3.
1 1
1
1 t
1. |1. |1.
12. 12.
13. |3.
1
1 1
1
t 1
Noncarc inogenic Risk
Chronic I Severity
Hazard Dominant I Rating
Index Chemicals) for Dom.
i/ j/ I Chem. k/
1
1
I. |1. |1.
|2. |2.
13. |3.
1
1
I
I. |1. II.
12. |2.
13. |3.
1
1 1
1
1
Subchron ic
Hazard
Index I/
1.
1.
Significant
Sources of
Uncertainty
m/
I.
I.
Comme n t s n /
i.
i.
a/ List each human exposure point evaluated.
b/ Include information on release source, transport medium, and exposure route.
c/ List the population potentially exposed for each exposure point. Nearby populations also warrant listing separately if they are large or especially
sensitive.
d/ List all requirements/criteria that were compared to ambient concentration values for indicator chemicals. Record the chemical and its numerical value,
and indicate whether it is an applicable or relevant and appropriate requirement or other criterion.
e/ Record the ratio between the projected exposure point concentration and the requirement criterion.
f/ List the total potential carcinogenic risk for each exposure point. Include best estimate and upper-bound estimate, if available.
\l List the dominant chemicals that contribute most to the carcinogenic risk at the site. These chemicals may dominate because of high toxiclty, high
concentration, or large quantity.
h/ WeighI-of-evidence is a qualitative, graded scale based on the EPA classification scheme, to capture differences in amount and quality of toxicity data
(see Exhibit 0-2).
i/ Chronic Hazard Index is calculated for all noncarcinogenic indicator chemicals. If unity is exceeded, segregate chemicals by their health endpoints and
list separately for each endpoint. Include the health endpoint and the hazard index. Report best estimate and upper-bound estimate, if available.
j/ The chemicals that contribute most significantly to noncarcinogenic risk, whether due to high toxicity, high concentration, or large quantity.
k/ A qualitative, graded scale to capture differences in health endpoint severities (see Exhibit D-l).
I/ Subchronic Hazard Index is calculated for short-term exposures for all indicator chemicals.
m/ Sources of uncertainty for the assessment process may include data gaps, incomplete toxicity information, sample variation, uncertainty due to modeling.
n/ Comments may be necessary to explain assumptions, difficulties, results, or conclusions relating to the assessment process. Where available, background
~ concentrations should be noted. Organoleptic (taste and odor) thresholds may be relevant to compare to environmental concentrations and toxicity values.
O
C/l
t-l
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Site:
EXHIBIT 9-3
SUMMARY OF THE PUBLIC HEALTH EVALUATION OF REMEDIAL ALTERNATIVES
Target Risk Level for Potential Carcinogens: a/
Remedy b/
1.
2.
Potential
Exposure Indicator
Pathways c/ Chemicals d/
|
1. |1.
2.
M!
15.
2. |1.
12.
3.
14.
15.
1. |1.
1
1 1 i
App/Rel Target | Target Risk
Require- Concentrations | For Each Pot ' 1 .
raents e/ f/ | Carcinogen g/»
1
1 1
11. 11. 11.
2. |2. |2.
\4. \l.
|5. |5.
1 1
1. ll. |l.
2. |2. |2.
3- 1 3. 1 3.
4. |4.
15. |5.
1
1. |1. |1.
1
1
Non carcinogenic
Risk Summary h/*
1.
1.
1-
Short-term
Risk
Summary i/
I.
1.
I.
Significant Sources
of Uncertainty j/
1.
I-
1.
Comments k/
1.
1.
1.
a/ Separate sheets must be done for carcinogenic risk levels spanning the range from 10~4 to 10~7 unless all Indicator chemicals have applicable or
relevant and appropriate requirements.
b_/ List the remedies under consideration.
c/ Include information on sources of contaminants, transjxirt media am) routes, exposure points, and populations involved.
d/ List chemicals considered for remedial alternatives.
e/ Enter the Identity of and value for all applicable or relevant and appropriate requirements for indicator chemicals.
£/ List the concentrations calculated for potential carcinogens to achieve target risk level; also enter the EPA weight-of-evidence category. However, if
all Indicators have applicable or relevant and appropriate requirements, enter the value of the requirement.
g_/ Record the target risk apportioned to each potential carcinogen.
h/ Include Chronic Hazard Index. If subdivided by health endpoint, list both hazard index and health endpolnt. Include the chemicals that contribute most
significantly to noncarcinogenlc risk.
i/ Describe possible short-term risks, and Include synopsis of how these risks can be managed or eliminated.
V Sources of uncertainty may include incomplete toxicily information, apportionment of risk between chemicals, modeling difficulties, and other data gaps.
k/ Comments may be necessary to explain assumptions, difficulties, results or conclusions relating to the design goals process. Organoleptlc (taste-and
odor) thresholds may be Included to compare to environmental conpentratlons and target risks.
H
IP
O
rt
00
l/i
-------
OSVER Directive 9285.4-1
-143-
9.1 SUMMARIZE THE BASELINE PUBLIC HEALTH EVALUATfON
Complete Exhibit 9-2 to provide a summary table for the baseline public
health evaluation. First, list the indicator chemicals from Worksheet 3-5
which were used in the evaluation. Then describe the significant exposure
points associated with the site. Describe where they are in relation to the
site and how exposure might occur there. Next, discuss the exposure pathway
qualitatively. List the release source, the transport media (e.g., ground
water, surface water, air), and exposure routes (e.g., oral, inhalation,
dermal) for each significant exposure point. The exposure pathway summary
should be a combination of information from Worksheets 4-1 and 4-2. Also,
from Worksheet 4-2, record the number of people at each significant exposure
point and describe any other important populations that are nearby. For
example, a town which draws water from a well down gradient from the point of
maximum ground-water exposure or a school near the peak air exposure point
might be included.
The next major topic of the exhibit is a summary of ambient concentration
requirements that are relevant and appropriate or applicable to the site. You
should list all requirements that were considered and compared to predicted
ambient concentrations. In the next column, list any requirements that were
violated. For this column you should include the type of requirement (e.g.,
Safe Drinking Water Act MCLs)> the name of the chemicals which violated the
requirements (e.g., arsenic) and the numerical value of the requirements
(e.g., 0.05 mg/1). This information can' be found on Worksheet 4-5.
Information about carcinogenic risk will be summarized next.. First, enter
the total carcinogenic risk due to all potential carcinogens. This risk value
can be found on Worksheet 7-3. If possible include some measure of the
reliability of this information (e.g., 95% confidence level, standard
deviation). At many sites one, two, or three chemicals will be responsible
for most of the risk at the site because of high toxicity, large projected
releases, or high concentrations. List these especially important chemicals
here. The weight-of-evidence rating, a qualitative scale based on the amount,
relevance, and quality of the toxicity data, should be included. This value
can be found in Appendix C or on Worksheet 3-2.
Health risk due to noncarcinogens should be summarized in the next
section. From Worksheet 7-2, list the chronic hazard index calculated for all
noncarcinogens. If the index exceeds unity and was recalculated for each
health endpoint, that information should be included. For noncarcinogens, as
for carcinogens, one or two chemicals may dominate the risks. This (or these)
chemical(s) should be listed 'along with their severity rating, a qualitative
scale indicating the severity of their health endpoint (the severity rating
scale is given in Exhibit D-l). Also, list the subchronic hazard index
calculated for short-term exposures for all indicator noncarcinogens. This
index can be found on Worksheet 7-1. Subchronic hazards may require
qualitative description.
Sources of uncertainty, such as data gaps, incomplete toxicity
information, sample variation, and uncertainty contributed by modeling, that
were encountered in a particular assessment should be discussed briefly. If
ranges of uncertainty or confidence levels for particular circumstances are
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-144-
known, they should be included. Finally, any comments that are necessary to
explain assumptions, difficulties, results, or conclusions relating to the
assessment should be written in the final column.
Organoleptic (taste and odor) thresholds should be included if they are
known because they may affect consumption. Background concentration may be
important for some sites. Timing of exposures should also be noted if it can
be determined.
9.2 SUMMARIZE ANALYSIS OF REMEDIAL ALTERNATIVES
Exhibit 9-3 provides a format for a table to summarize remedial
alternatives. For each site, relevant information should be provided for all
remedial alternatives being considered and should include alternatives
-4 -7
spanning a carcinogenic risk range of 10 to 10 . Several remedies
under consideration for a site can be included on a single summary table as
long as they correspond to the isame risk level.
Describe the remedial action under consideration in the first column of
Exhibit 9-3. This action might be excavation, removal, a purap-and-treat
remedy, or air stripping. Next, qualitatively summarize the significant
potential.exposures pathways. The exposure pathways might be an air release
from air stripping towers or migration of contaminated ground water. Sources
of contaminants, the transport media and routes, possible exposure points,
timing and amount of releases should be included. The exposure pathway column
should be a synthesis of information appearing in Worksheets 8-1, 8-2, 8-3,
and 8-11.
The indicator chemicals used in the assessment of a particular remedy
should be listed Ln the next column. Any applicable or relevant and
appropriate requirements should also be listed. Include both the identity of
the requirement and its numerical value in this column. Next to this, list
target concentrations for potentially carcinogenic indicator chemicals.
Values for each chemical and each transport medium of concern have been
summarized on Worksheet 8-10 and should be recorded here also. In the next
column, list the individual target risks due to each potential carcinogen.
These target risks were the bases for the calculated target concentrations in
the previous column. The target risk column should display how carcinogenic
risk has been apportioned among the chemicals at the site, as determined on
Worksheet 8-10.
Noncarcinogenic risk should be summarized in the next column. Results of
the chronic hazard index calculation, should be included and risks from each
remedial alternative should be described. If no risks are expected, that
should be noted also. Information on noncarcinogenic risks can be found on
Worksheets 8-13 and 8-14. Short-term risks should also be qualitatively
described. Identify each and briefly discuss how they can be managed at the
site. These risks were identified on Worksheet 8-16.
The possible effects and public health consequences of remedy failure,
discussed in Section 8.9, should be summarized in the next column. Any
information concerning the significant sources of uncertainty involved in the
* * * October 1986 * * *
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OSWER Directive 9285.4-1
-145-
calculations, assumptions, or data inputs for the performance goals portion of
the risk assessment should be discussed next. Comments about assumptions,
difficulties, results, and conclusions should be written in the final column.
The process of public health evaluation is complete when all remedies
under consideration, including the no-action alternative, have been
summarized. Site decision-makers can use this information along with other
elements of the feasibility study (e.g. engineering reliability of
alternatives, life-cycle costs, and cost-effectiveness) in the selection of a
remedial alternative.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
A-l
APPENDIX A
Anderson, E., Browne, N., Duletsky, S., and Warn, T., 1984. Development
of Statistical Distributions or Ranges of Standard Factors Used in Exposure
Assessments, Draft Report. Prepared for U.S. EPA, Office of Health and
Environmental Assessment, Washington, D.C., Contract No. 68-02-3510.
Callahan,- M.A., Slimak, M.W. , Gabel, N.W. , May, I.P., Fowler, C.F., Freed,
J.R., Jennings, P., Durfee, R.L., Whitmore, F.C., Maestri, B., Mabey, W.R.,
Holt, B.R., and Gould, C., 1979. Water-Related Environmental Fate of 129
Priority Pollutants, Volumes I and II, Office of Water Planning and Standards,
Office of Water and Waste Management, U.S. Environmental Protection Agency,
Washington, D.C., EPA Contract Nos. 68-01-3852 and 68-01-3867.
Cowherd, C., Muleski, G.E., Englehart, P.J., and Gillette, D.A., 1984.
Rapid Assessment of Exposure to Particulate Emissions from Surface
Contamination Sites. U.S. Environmental Protection Agency, Washington, D.C.,
Contract No. 68-03-3116.
Cupitt, L.T., 1980. Fate of Toxic and Hazardous Materials in "the Air
Environment. Environmental Sciences Research Laboratory, ORD, U.S. EPA, PB
80-22/948.
Dobbs, R.A., and Cohen, J.M., 1980. Carbon Adsorption Isotherms for Toxic
Organics, Wastewater Research Division. Municipal Environmental Research
Laboratory, Office of Research and Development, U.S. Environmental Protection
Agency, Cincinnati, Ohio, EPA-600/8-80-023.
Donigian, A.S., Lo, T.Y.R., and Shanahan, E.W., 1983. Rapid Assessment of
Potential Ground Water Contamination Under Emergency Response Conditions.
U.S. Environmental Protection Agency, Washington, D.C., Contract No.
68-03-3116.
Food and Drug Administration, 1970. Radiological Health Handbook: Bureau
of Radiological Health. Rockville, Maryland.
Freeze, R. and Cherry, J., 1979. Groundwater. Prentice-Hall, Englewood
Cliffs, New Jersey.
GCA Corporation, 1982. Evaluation and Selection of.Models for Estimating
Air Emissions from Hazardous Waste Treatment, Storage, and Disposal
Facilities. Prepared for U.S. EPA, Office of Sol.id Waste, Washington, D.C.
Grain, C.F., 1982. Vapor Pressure. Chapter 14 in Lyman et al., Handbook
of Chemical Property Estimation Methods, McGraw-Hill, 1982.
International Committee on Radiologic Protection (ICRP), 1975. Report of
the Task Group on Reference Man. Pergamon Press, New York.
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OSWER Directive 9285.4-1
A-2
Jaber, H.M., Mabey, W.R., Liu, A.T., Chou, T.W., Johnson, H.L., -Mill, T.,
Podoll, R.T., and Winterle, J.S., 1984. Data Acquisition for Environmental
Transport and Fate Screening. Office of Health and Environmental Assessment;
U.S. Environmental Protection Agency, Washington, D.C., EPA 600/6-84-009.
Kenaga, E.E. and Goring, C.A.I., 1978. Relationship Between Water
Solubility, Soil-Sorption, Octanol/Water Partitioning, and Bioconcentration of
Chemicals in Biota. In: Aquatic Toxicology, ASTM STP 707, J.G. Eaton, P.R.
Parrish, and A.C. Hendricks, Eds. American Society for Testing and Materials,
Philadelphia, PA.
Kimbrough, R.D., Falk, H., Stehr, P., and Fries, G., 1984. Health
implications of 2,3,7,8-tetrachlorodibenzodioxin (TCDD) contamination of
residential soil. J. Tox. Environ. Health 14:47-93.
Loucks, D., Stedinger, J., and Haith, D., 1981. Water Resource Systems
Planning and Analysis. Prentice-Hall, Englewood Cliffs, New Jersey.
Lyman, W.J., Reehl, W.F., and Rosenblatt, D.H., 1982. Handbook of
Chemical Property Estimation Methods. McGraw-Hill Book Company, New York.
Lyman, W.J., 1982a. Solubility in Water. Chapter 2 in Lyman et al.,
Handbook of Chemical Property Estimation Methods, McGraw-Hill, 1982.
Lyman, W.J., 1982b. Adsorption Coefficient for Soils and Sediments.
Chapter 4 in Lyman et al., Handbook of Chemical Property Estimation Methods.
McGraw-Hill, 1982.
Mabey, W.R., Smith, J.H., Podoll, R.T., Johnson, H.L., Mill, T. , Chou,
T.W., Gates, J., Patridge, I.W., Jaber, H., and Vandenberg, D., 1982. Aquatic
Fate Process Data for Organic Priority Pollutants. Prepared by SRI
International, EPA Contract Nos. 68-01-3867 and 68-03-2981, prepared for
Monitoring and Data Support Division, Office of Water Regulations and
Standards, Washington, D.C.
Maki, A.W., Dickson, K.L., and Cairns, J., eds., 1980. Biotransforma-
tion and Fate of Chemicals in Aquatic Environments. American Society for
Microbiology, Washington, DC.
Menzer, R.E. and Nelson, J.O., 1980. Water and Soil Pollutants. Chapter
25 in Doull, J., Klaassen, C.D., and Amdur, M.D., Toxicology. MacMillan, 1980.
Mills, W.B., Dean, J.D., Porcella, D.B. et al., 1982. Water Quality
Assessment: A Screening Procedure for Toxic and Conventional Pollutants,
Parts One and Two. Office of Research and Development, U.S. Environmental
Protection Agency, Athens, GA. EPA 600/6-82-004 a and b.
National Academy of Sciences, 1977. Drinking Water and Health. NRC
Press, Washington, D.C.
Nelson, D.W., Elrick, D.E., Tangi, K.K., Krai, D.M., and Hawkins, S.L.,
eds., 1983. Chemical Mobility and Reactivity in Soil Systems: Proceedings of
a symposium sponsored by the American Society of Argonomy and the Soil Science
Society of America. American Society of Agronomy, The Soil Science Society of
America, Madison, Wisconsin.
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OSWER Directive 9285.4-1
A-3
NIOSH, 1980. Registry of Toxic Effects of Chemical Substances. DHHS
Publication No. 80-111.
Tabak, H.H., Quave, S.A., Mashni, C.I., and Earth, E.F., 1981. Biodegrad-
ability studies with organic priority pollutant compounds. J. Water Pollution
Control Fed. 53(10):1503-1518.
Turner, D.B., 1970. Workbook of Atmospheric Dispersion Estimates. AP-26,
U.S. Environmental Protection Agency, Office of Air Programs, Research
Triangle Park, North Carolina.
U.S. Environmental Protection Agency, 1986a. Guidelines for Carcinogen
Risk Assessment. Federal Register 51:33992-34003.
U.S. Environmental Protection Agency, 1986b. Guidelines for Exposure
Assessment. Federal Register 51:34042-34054.
U.S. Environmental Protection Agency, 1986c. Guidelines for Mutagenicity
Risk Assessment. Federal Register 51:34006-34012.
U.S. Environmental Protection Agency, 1986d. Guidelines for the Health
Assessment of Suspect Developmental Toxicants. Federal Register
51:34028-34040.
U.S. Environmental Protection Agency, 1986e. Guidelines for the Health
Risk Assessment of Chemical Mixtures. Federal Register 51:34014-34025.
U.S. Environmental Protection Agency, 1985a. Guidance on Feasibility
Studies Under CERCLA. Office of Emergency and Remedial Response, Washington,
D.C.
U.S. Environmental Protection Agency, 1985b. Guidance on Remedial
Investigations Under CERCLA. Office of Emergency and Remedial Response,
Washington, D.C.
U.S. Environmental Protection Agency, 1985c. National Oil and Hazardous
Substances Pollution Contingency Plan: Final Rule. Federal Register
50:47912-47979.
U.S. Environmental Protection Agency, 1984. Risk Analysis of TCDD
Contaminated Soil. Prepared by the Exposure Assessment Group, Office of
Health and Environmental Assessment, Washington, D.C., EPA-600/8-84-031.
U.S. Environmental Protection Agency, 1980. Water Quality Criteria
Documents: Availability. Federal Register 45: 79318-79379.
Zamuda, C.D., 1986. The Superfund Record of Decision Process: Part I--The
Role of Risk Assessment. Chemical Waste Litigation Reporter 11:847-859.
* * * October 1986- * * *
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OSWER Directive 9285.4-1
APPENDIX B
GLOSSARY
* * * October 1986 * * *
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OSWER Directive 9285.4-1
B-l
EXHIBIT B-l
LIST OF ACRONYMS
Acronym
Meaning
ACL Alternate Concentration Limit
ADI Acceptable Daily Intake
AIC Acceptable Intake for Chronic Exposures
AIS Acceptable Intake for Subchronic Exposures
ARAR Applicable or Relevant and Appropriate Requirement
ATSDR Agency for Toxic Substances and Disease Registry
CAG Carcinogen Assessment Group, U.S. EPA
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
GDI ' Chronic Daily Intake
ECAO Environmental Criteria and Assessment Office, U.S. EPA
ED Ten Percent Effective Dose
FRDS Federal Reporting Data System
FS Feasibility Study
HEA Health Effects Assessment
HRS ' Hazard Ranking System
IARC International Agency for Research on Cancer
IS Indicator Score
LD5Q Median Lethal Dose
LTC Long-term Concentration
MCL Maximum Contaminant Level
MCLG Maximum Contaminant Level Goal
MED Minimum Effective Dose
MOU Memorandum of Understanding . •
NAAQS . National Ambient Air Quality Standards
* * *October 1986* * *
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OSWER Directive 9285.4-1
B-2
EXHIBIT B-l
(Continued)
LIST OF ACRONYMS
Acronym
Meaning
NC Noncarcinogen
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NOAA National Oceanic and Atmospheric Administration
NOAEL No Observed Adverse Effect Level
NPL National Priorities List
OERR Office of Emergency and Remedial Response, U.S. EPA
OHEA Office of Health Effects Assessment, U.S. EPA
ORD Office of Research and Development, U.S. EPA
OSWER Office of Solid Waste and Emergency Response, U.S. EPA
PC Potential Carcinogen
PHE Public Health Evaluation
PHRED Public Health Risk Evaluation Database
QA/QC Quality Assurance/Quality Control
RCRA Resource Conservation and Recovery Act
RfD Reference Dose
RI Remedial Investigation
RMCL Recommended Maximum Contaminant Level
SDI Subchronic Daily Intake
SDWA • Safe Drinking Water Act
SEAM Superfund Exposure Assessment Manual
SPHEM Superfund Public Health Evaluation Manual
STC Short-term Concentration
WQC Water Quality Criteria
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OSWER Directive 9285.4-1
B-3
EXHIBIT B-2
DEFINITIONS OF TERMS DEVELOPED SPECIFICALLY
FOR THE SUPERFUND PUBLIC HEALTH EVALUATION PROCESS
Acronym Definition
STC Short-term Concentration. The projected chemical
concentration in an exposure medium averaged over a short
time period (10 to 90 days). The peak STC (i.e., highest
one projected over the entire evaluation period, usually
70 years) is used for subchronic risk characterization.
Unless otherwise stated, the STC refers to a best
estimate concentration value, not an upper bound estimate.
LTC Long-term Concentration. The projected chemical
concentration at an exposure point averaged over a long
time period, up to 70 years (assumed to be a human
lifetime). The LTC for the 70-year period beginning with
the date of the RI/FS is used for carcinogenic risk
characterization. Unless otherwise stated, the LTC
refers to a best estimate concentration value, not an
upper bound estimate.
SDI Subchronic Daily Intake. The projected human intake of
a chemical averaged over a short time period, expressed
as mg/kg/day. The SDI is calculated by multiplying peak
STC by human intake and body weight factors and is used
for subchronic risk characterization.
GDI Chronic Daily Intake. The projected human intake of a
chemical averaged over a long time period, up to 70
years, and expressed as mg/kg/da'y. The CDI is calculated
by multiplying LTC by human intake and body weight
factors and is used for chronic risk characterization.
AIS Acceptable Intake for Subchronic Exposure. The highest
human intake of a chemical, expressed as mg/kg/day, that
does not cause adverse effects when exposure is
short-term (but not acute). The AIS is usually based on
subchronic animal studies.
AIC Acceptable Intake for Chronic Exposure. The highest
human intake of a chemical, expressed as mg/kg/day, that
does not cause adverse effects when exposure is long-term
(lifetime). The AIC is usually based on chronic animal
studies.
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OSWER Directive 9285.4-1
B-4
EXHIBIT B-2
(Continued)
DEFINITIONS OF TERMS DEVELOPED SPECIFICALLY
FOR THE SUPERFUND PUBLIC HEALTH EVALUATION PROCESS
Acronym Definition
IS Indicator Score. A unitless score that is the product
of a media-specific concentration of a chemical and the
media-specific toxicity constant for that chemical. The
indicator score is one of the factors considered in the
selection of indicator chemicals.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
APPENDIX C
SUMMARY TABLES FOR CHEMICAL-SPECIFIC DATA
* * * October 1986 * * *
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OSWER Directive 9285.4-1
C-l
APPENDIX C
SUMMARY TABLES FOR CHEMICAL-SPECIFIC DATA
Appendix C contains the following six summary data tables:
Exhibit' C-l:
Exhibit C-2:
Exhibit C-3:
Exhibit C-4:
Exhibit C-5:
Exhibit C-6:
Physical, Chemical, and Fate Data
Half-Lives in Various Media
Toxicity Data for Potential Carcinogenic Effects
-- Selection of indicator Chemicals Only
Toxicity Data for Potential Carcinogenic Effects
-- Risk Characterization
Toxicity Data for Noncarcinogenic Effects --
Selection of Indicator Chemicals Only
Toxicity Data for Noncarcinogenic Effects -- Risk
Characterization
These tables summarize key quantitative parameters for more than 300
chemicals or chemical groups that were evaluated as part of the Superfund
reportable quantity (RQ) adjustment process or the intra-agency reference dose
(RfD) review process. These specific chemicals are included because of the
.amounts of readily available toxicity information. This list should not be
interpreted as a complete list of chemicals of concern at Superfund sites.
Other substances may.be important at certain sites. However, this appendix
covers many toxic chemicals commonly detected at Superfund sites.
Chemical-specific parameters listed in the tables are primarily those
referred to in this manual, although a limited amount of other useful
information (e.g., CAS number, molecular weight) is also provided. Values for
physical, chemical, and fate parameters given in Exhibits C-l and C-2 are
provided for the convenience of the user and have not been fully peer reviewed
within EPA. Conversely, values given in Exhibits C-4 and C-6 for acceptable
intake level and/or carcinogenic potency have been reviewed within EPA and
should generally be used in the public health evaluation process at Superfund
sites. The sources of values .and data transformation procedures, if any, are
described in the following sections.
In addition to the six data summary tables described above, a list of
chemicals for which EPA Health Effects Assessment documents are available is
provided in Exhibit C-7.
C.I EXHIBIT C-l: PHYSICAL, CHEMICAL, AND FATE DATA
The physical, chemical, and fate data shown in Exhibit C-l were either
recorded directly from standard secondary references or were derived based on
information contained in such references. A general hierarchy of sources was
established, and values were taken from sources in order of the hierarchy.
The hierarchy was ordered with documents developed specifically for the
Superfund program at the top, followed by other relevant EPA data
compilations, and then general reference texts at the bottom. In general,
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OSWER Directive 9285.4-1
C-2
succeeding references were used only when a value could not be obtained from a
reference higher in the hierarchy. Priority was given to more recent sources,
and measured values were chosen over estimated values even if obtained from a
source lower on the hierarchy. The hierarchy of sources used to select values
for Exhibit C-l is shown below and is lettered to correspond with the sources
referenced in the exhibit. More complete reference information for each of
these sources is in the reference list for Appendix C. A brief description of
the derivation of values for each parameter in Exhibit C-l follows the
hierarchy listed below.
A) ECAO, EPA, Health Effects Assessments, 1985
B) Jaber et al., 1984
C) Mabey et al., 1982
D) Callahan et al., 1979
E) ORD, EPA, 1981
F) Dawson et al., 1980
G) Lyman et a_l. , 1982
H) OWRS, EPA, 1980
I) Weast et al., 1979
J) Verschueren, 1983
K) Windholz et al., 1976
L) Perry and Chilton, 1973
M) OSW, EPA, 1984b
N) OSW, EPA, 1984a
Water Solubility is the maximum concentration of a chemical that
dissolves in pure water at a specific temperature and pH. It is a critical
property affecting environmental fate and transport. Values for water
solubility, in mg/1, were recorded in Exhibit C-l directly using the hierarchy
of sources and general decision rules outlined above. Values are given for a
neutral pH and a temperature range of 20 to 30 C. Chemicals listed in the
literature as being "infinitely soluble" were assigned a solubility value of
1,000,000 mg/1.
Vapor Pressure is a relative measure of the volatility of a chemical in
its pure state and is an important determinant of the rate of vaporization-
from waste sites. Values for this parameter, in units mm Hg, were recorded
directly from the hierarchy of sources described above. Values are given for
a temperature range of 20 to 30 C.
Henry's Law Constant is another parameter important in evaluating air
exposure pathways. Values for Henry's Law Constant (H) were calculated using
the following equation and the values previously recorded for solubility,
vapor pressure, and molecular weight:
3
H(atm-m /mole) = Vapor Pressure (atm) x Mole Weight (g/mole)
Water Solubility (g/m )
Organic Carbon Partition Coefficient (Koc) is a measure of the tendency
for organics to be adsorbed by soil and sediment and is expressed as:
Koc = mg chemical adsorbed/kg organic carbon
mg chemical dissolved/liter of solution
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OSWER Directive 9285.4-1
C-3
The Koc is chemical specific and is largely independent of soil properties.
Most Koc values in Exhibit C-l were recorded directly from the above hierarchy
of sources. However, some Koc values were estimated using methods specified
in Lyman (1982). Estimated values are clearly designated as such.
Octanol-Water Partition Coefficient (Kow) is a measure of how a chemical
is distributed at equilibrium between octanol and water. Although Kow is not
directly referenced in the text of this manual, it is an important parameter
and is used often in the assessment of environmental fate and transport for
organic chemicals. Additionally, Kow is a key variable used in the estimation
of other properties. For the convenience of the user, values for log Kow have
been included in Exhibit C-l. These values were recorded directly from the
hierarchy of sources referenced above.
Bioconcentration Factor as used in this manual is a measure of the
tendency for a chemical contaminant in water to accumulate in fish tissue.
The equilibrium concentration of a contaminant in fish can be estimated by
multiplying the concentration of the chemical in surface water by the fish
bioconcentration factor for that chemical. This parameter is therefore an
important determinant for human intakes via the aquatic food ingestion route.
Values for bioconcentration factors shown in Exhibit C-l were recorded
directly from the above hierarchy of sources.
C.2 EXHIBIT C-2: HALF-LIVES IN VARIOUS MEDIA
Chemical Half-Lives are used in this manual as measures of persistence,
or'how long a chemical will remain, in various environmental media. Exhibit
C-2 presents values for overall half-lives, which are the result of all
removal processes (e.g., phase transfer, chemical transformation, and
biological transformation) acting together rather than a single removal
mechanism. All of the half-life values in Exhibit C-2 were recorded directly
from two sources, ECAO Health Effects Assessments (ECAO, 1985) and exposure
profiles for the RCRA Risk-Cost Analysis Model (OSW, 1984b). The same source
lettering convention was followed for Exhibit C-2 as for Exhibit C-l.
C.3 EXHIBIT C-3: TOXICITY DATA FOR POTENTIAL CARCINOGENIC '
EFFECTS -- SELECTION OF INDICATOR CHEMICALS ONLY
For the risk assessment process outlined in this manual, data presented in
Exhibit C-3 are used only in the selection of indicator chemicals and not in
actual risk characterization. These data were obtained from information
contained in the Reportable Quantity (RQ) data base (OHEA, 1986). The
procedures used to convert source data to the values given in Exhibit C-3 are
described brieflybelow.
The 10% Effective Dose (ED.Q) represents the dose at which a .10 percent
incremental carcinogenic response is observed. This parameter was calculated
for both oral and inhalation routes by taking the reciprocal of the Potency
Factor Estimate (PFE) given in the RQ data base (this source defines PFE =
I/ED ; therefore, ED = 1/PFE). The ED is in units of mg/kg/day.
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OSWER Directive 9285.4-1
C-4
Toxicity Constants vary for different, exposure media. As such, Exhibit
C-3 contains toxicity constant values specific to water (wTc) and soil (sTc)
for the oral route, and a value for air (aTc) for the inhalation route. Each
of these constants for potential carcinogens is based on the ED-n, standard
intake assumptions for the respective media, and a standard body weight. The
specific equations and assumptions used to calculate the various toxicity
constants are presented and discussed in further detail in Appendix D.
C.4 EXHIBIT C-4: TOXICITY DATA FOR POTENTIAL CARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Data presented in Exhibit C-4 are for use in risk characterization, as
opposed to the selection of indicator chemicals. Values in this exhibit were
derived in the following manner.
Carcinogenic Potency Factors are upper 95 percent confidence limits on the
slope of the dose-response curve. These values were recorded directly from
HEAs or CAG summary tables, with the actual source cited in the exhibit for
each value and then fully referenced at the end of the exhibit. Potency
factors are used to estimate potential carcinogenic risk. These factors,
specific to different exposure routes, are given in Exhibit C-4 in units of
(mg/kg/day) .
Weight of Evidence ratings qualify the level of evidence that supports
designating a chemical as a human carcinogen. Exhibit C-4 lists ratings based
on EPA categories for potential carcinogens, which are fully itemized in
Exhibit D-2. The ratings were recorded directly from the RQ data base.
(Note: Weight-of-evidence ratings are also used in the procedure for
selecting indicator chemicals.)
C.5 EXHIBIT C-5: TOXICITY DATA FOR NONCARCINOGENIC EFFECTS --
SELECTION OF INDICATOR CHEMICALS ONLY
The data in Exhibit C-5 were generated based on information contained in
the RQ data base for chronic effects (ECAO, 1984). Values for the parameters
in Exhibit C-5, which are used in the selection of indicator chemicals but not
in risk characterization, were derived in the following manner. In addition,
chemicals marked in Exhibit C-5 with "@" also exhibit potential carcinogenic
effects. The reader is referred to Exhibits C-3 and C-4 for information
concerning these effects.
To determine the human Minimum Effective Dose (MED), the RQ data base was
reviewed to identify the studies with the highest composite score (a score
that combines MED and severity of effect) for oral and for inhalation exposure
routes. These MEDs were recorded under the appropriate exposure route in
Exhibit C-5. If composite score values were reported to be equal, the study
that yielded the lowest MED was used. For metals, one MED value was derived
from all studies for the various compounds of a given metal. Human MED values
are expressed in Exhibit C-5 in terms of mg/day. If an MED was available for
only one exposure route, it was recorded in Exhibit C-5 for the other exposure
routes without modification unless the toxic effect was at the site of entry.
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OSWER Directive 9285.4-1
C-5
Severity of Effect Ratings, or RVe's, were recorded from the RQ data base
for the same study used to determine MED values. These rating constants are
unitless integers ranging from 1 to 10, corresponding to various levels of
s-everity of effects. The severity scale is presented in Exhibit D-l.
Toxicity Constants for noncarcinogenic effects, like those for
carcinogens, are specific to water, soil, and air and are designated in
Exhibit C-5 as wTn, sTn, and aTn, respectively. Again, these toxicity
constants are used only in the indicator chemical selection step of the
process. Values in Exhibit C-5 are based on standard intake assumptions as
well as a chemical's RVe and MED values. Refer to Appendix D for the specific
toxicity constant equations and for a discussion on their application.
C.6 EXHIBIT C-6: TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Exhibit C-6 gives values for parameters that are used in actual risk
characterization. The methods used to derive these values are described
below. Although the data in Exhibit C-6 are for noncarcinogenic effects,
several of the chemicals listed in the exhibit (those marked with an "@") also
exhibit potential carcinogenic effects. Exhibits C-3 and C-4 should be
referred to for information concerning carcinogenic effects.
Subchronic acceptable intake (AIS) values are short-term acceptable
intake levels and are recorded directly from the appropriate HEA. Likewise,
values for chronic acceptable intake (AIC), which is the long-term acceptable
intake level for noncarcinogenic effects, were recorded directly from the
appropriate HEA or from compilations of Agency-verified reference dose (RfD)
values. These verified reference doses were developed by an EPA work group
chaired by the Office of Research and Development in 1985 and 1986. The
actual source used for each value is cited in Exhibit C-6 and is referenced
fully at the end of the exhibit. AIS and AIC are used to characterize risks
of noncarcinogenic effects. Both AIS and AIC values are in units of mg/kg/day.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
C-6
REFERENCES FOR APPENDIX C
CAG, U.S. EPA, 1985. Relative Carcinogenic Potencies Among 54 Chemicals
Evaluated by the Carcinogen Assessment Group As Suspect Human Carcinogens.
Callahan et al., 1979. Water-Related Environmental Fate of 129 Priority
Pollutants, Volumes I and II, Office of Water Planning and Standards, Office
of Water and Waste Management, U.S. EPA, EPA Contract Nos. 68-01-3852 and
68-01-3867. [Source D*]
Dawson, et al., 1980. Physical/Chemical Properties of Hazardous Waste
Constituents. Prepared By Southeast Environmnetal Research Laboratory for
U.S. EPA. [Source F*]
ECAO, U.S. EPA, 1985. Health Effects Assessment for [Specific Chemical].
[Note: 58 individual documents available for specific chemicals or chemical
groups] [Source A"]
ECAO, U.S. EPA, 1984. Summary Data Tables for Chronic Noncarcinogenic
Effects. [Note:, Prepared during RQ adjustment process]
Jaber, et al., 1984. Data Acquisition for Environmental Transport and Fate
Screening. Office of Health and Environmental Assessment, U.S. EPA,
Washington, DC, EPA 600/6-84-009 [Source B*]
Lyman, 1982. Adsorption Coefficient for Soils and Sediments. Chapter 4 in
Lyman et a_l. , Handbook of Chemical Property Estimation Methods.
McGraw-Hill, New York.
Lyman, et a_l. , 1982. Handbook of Chemical Property Estimation Methods.
McGraw-Hill, New York. [Source G*]
Mabey, et al., 1982. Aquatic Fate Process Data for Organic Priority
Pollutants. Prepared by SRI International, EPA Contract Nos. 68-01-3867 and
68-03-2981, prepared for Monitoring and Data Support Division, Office of Water
Regulations and Standards, Washington, DC. [Source C-']
OHEA, U.S. EPA, 1986. Methodology for Evaluating Reportable Quantity
Adjustments Pursuant to CERCLA Section 102, External Review Draft. OHEA-C-073.
ORD, U.S. EPA, 1981. Treatability Manual, Volume I, EPA 600/2-82-OOla.
[Source E*]
OSW, U.S. EPA, 1984a. Characterization of Constituents from Selected Waste
Streams Listed in 40 CFR Section 261. Prepared by Environ Corporation.
[Source N*]
^Source letters correspond to Exhibits C-l and C-2.
* * October 1986 * •* *
-------
OSWER Directive 9285.4-1
C-7
OSW, U.S. EPA, 1984b. Exposure Profiles for RCRA Risk-Cost Analysis Model.
Prepared by Environ Corporation. [Source M*]
OWRS, U.S. EPA, 1980. Ambient Water Quality Criteria Documents for [Specific
Chemical]. [Source H*]
Perry and Chilton, 1973. Chemical Engineers' Handbook, McGraw-Hill, 5th Ed.
[Source L*]
Verschueren, 1983. Handbook of Environmental Data for Organic Chemicals.
Van Nostrand Reinhold Co., New York, 2nd ed. [Source J*]
Weast et a_l. , 1979. CRC Handbook of Chemistry and Physics. [Source I*]
Windholz, et al., 1976. The Merck Index. [Source K*]
^Source letters correspond to Exhibits C-l and C-2,
* * * October 1986 * *
-------
r:
ChemicaI Name
Acenaphthene
Acenaphthylene
Acetone
AcetonltrI le
2-Acetylamlnofliiorene
Ac ry I i c Ac I d
Acryloni trile
Aflatoxln B1
AidIcarb
Aldrln
Allyl Alcohol
Aluminum Phosphide
4-Aminobiphenyl
Am 11 roIe
Ammonia
Anthracene
Antimony arid Compounds
Arsenic and Compounds
Asbestos
Auramine
Azaserlne
AzI rid I no
Barium and Compounds
Benefin
Benzene
Benzldine
Benz(a)anthracene
Benzjcjacridlne
Benzo(a)pyrene
Benzoj b)rIuoranthene
Benzojghi Jperylene
Benzo(k)rIuoranthene
Benzotrfchloride
Benzyl Chloride
Beryllium and Compounds
1,1-BiphenyI
Bls(2-chloroethyl)ether
81 s(2-chlorolsopropyl)ether
BlsjchloromethylJether
Bls(2-ethylhexyl)phthalate (DEHP)
Bromomethane
Bromoxynil Octanoate
1,3-Butadiene
n-Butanol
ButyIphthalyl ButyIglycolate
Cacodylic Acid
Cadmium and Compounds
Captan
Ca rba ry I
Carbon OfsuI fide
Carbon Tetrachloride
Chlordane
Chlorobenzene
Chlorobenz!late
ChIo rod Ib romome t ha ne
EXHIBIT C-1
PHYSICAL, CHEMICAL, AND FATE DATA
"3 : '71 .' ' .1 r^-.i c.:,i
Date Prepared: October 1. 1986
Mole Water
Weight Solubi 1 1 ty
CAS ff (g/mole) (mg/l ) S»
83-32-9
308-96-8
67-6'l-1
75-05-8
53-96-3
79-10-7
107-13-1
1162-65-8
116-06-3
309-00-2
107-18-6
20859-73-8
92-67-1
61-82-5
766'l-H1-7
120-12-7
7'i '10-36-0
7440-38-2
1332-21-4
2'l65-27-2
115-02-6
151-56-'!
7140-39-3
1861-'IO-1
71-1)3-2
92-87-5.
56-55-3
225-51-'!
50-32-8
205-99-2
191-2'i-2
207-08-9
98-07-7
100-111-7
7110-11-7
92-52-1
111-41-1
108-60-1
512-88-1
117-81-7
74-83-9
1689-99-2
106-99-0
71-36-3
85-70-1
75-60-5
7710-43-9
133-06-2
63-25-2
75-15-0
56-23-5
57-74-9
108-90-7
510-15-6
124-18-1
151
152
58
41
223
72
53
312
190
365
58
58
169
84
17
178
122
75
NA
267
173
43
137
335
78
184
228
229
252
252
276
252
195
127
9
154
143
171
115
391
95
403
54
74
336
138
112
301
201
76
154
410
113
325
208
3.42E+00
3.93E+00
1 .OOE+06
1.00E+06
6.50E+00
1.00L+06
7.90E+04
1.80E-01
5.10E+05
8.42E+02
2.80E+05
5.30E+05
1.50E-02
NA
2. 10E+00
1.36E+05
2.66E+06
1.75E+03
1.00E+02
5.70E-03
1.40E+01
1.20E-03
1.40E-02
7.00E-04
4.30E-03
3.30E+03
1.02E+04
1.70E+03
2.20E+04
7.35E+02
8.30E+05
5.00E-01
4.00E+01
2.91E+03
7.57E+02
5.60E-01
1.66E+02
2. 19E+01
C
C
ff
ff
0
ff
C
C
B
0
B
r
A
B
B
B
A
C
C
B
A
C
A
C
F
C
C
C
F
F
E
E
E
A
A
A
B
Vapor
Pressure
(mm Hcj )
1.55E-03
2.90E-02
2.70E+02
7.40E+01
4.00E+00
1 .OOE+02
6.00E-06
2.46E+01
6.00E-05
7.60E+03
1.95E-04
1.00E+00
O.OOE+00
NA
2.55E+02
9.52E+01
5.00E-04
2.20E-08
5.60E-09
5.00E-07
1.03E-10
5. 10E-07
1.00E+00
O.OOE+00
7. 10E-01
8.50E-01
3.00E+01
1.84E+03
O.OOE+00
6.00E-05
5.00E-03
3.60E+02
9.00E+01
1.00E-05
1.17E+01
1 .20E-06
1.50E+01
S*
C
C
J
F
F
C
C
B
B
F
A
N
E
B
A
C
C
A
C
A
C
E
E
C
C
C
F
E
E
E
E
A
A
A
B
D
Henry's Law
Constant Koc
(atm-m3/inol) (ml/g)
9.20E-05
1.48E-03
2.06E-05
4.00E-06
NA
8.84E-05
NA
1 .60E-05
3.69E-06
1.59E-00
NA
3.21E-04
1.02E-03
NA
NA
NA
NA
NA
5.13E-06
NA
5.59E-03
3.03E-07
1. 16E-06
NA
1.55E-06
1. 19E-05
5-31E-08
3.94E-05
5.06E-05
NA
1.31E-05
1.13E-04
2.06E-04
1.78E-01
NA
NA
4.75E-05
1.23E-02
2.41E-02
9.63E-06
3.72E-03
2.34E-08
NA
4600
2500
2.2
2.2
1600
0.85
96000
3.2
107
4.4
3. 1
14000
NA
2900
6.6
1.3
03
10.5
1380000
1000
5500000
5500OO
1600000
550000
50
13.9
61
1.2
120
2.4
6400
54
110
140000
330
800
S»
C
C
&
&
&
C
C
PC
ff
ff
&
C
&
ff.
&
G
C
G
&
C
C
C
C
%
C
C
C
ff
tt
ff.
&
&
C
C
&
1 og
Kow
4.00
3. 70
-0.24
-0. 34
3.28
0.13
0.25
'
5. 30
-0.22
2. 78
-2.00
O.OO
4.45
NA
4.16
-1 .OS
-1.01
2. 12
1 .30
5.60
4.56
6.06
6.06
6.51
6.06
2.63
1.50
2. 10
0.38
1.99
0.00
2.35
2.36
2 . 00
2.64
3.32
2.84
4.51
2.09
S*
C
C
J
F
B
r
C
C
B
B
B
F
A
B
B
A
C
C
B
C
A
A
C
F
C
C
C
r
F
r
F
F
A
A
A
B
D
Fish
BCF
< I/kg)
242
0
48
28
0
1
44
0
5.2
87.5
19
6.9
0
0.63
81
0
19
14000
10
S*
II
r
r.
ii
F
ti
M
o
ii
M
II
II
0
II
II
F
II
M
M
o
in
O
H-
H
(0
O
rt
m
\o
00
tn
-------
rXIIIBjT C-1
(Gout i tilled)
PHYSICAL, CHEMICAL, AND FATE DATA
Date Prepared: October 1. 1986
Client i cat Nnmo
Chloroform
Chloromethyl Methyl Ether
ll-Chloro-o-toluid ine llydrochloride
Chromium I I I and Compounds
Chromium VI and Compounds
Chrysene
Copper and Compounds
Creosote
Creso I
CrotonaIdehyde
Cyanides
-- Barium Cyanide
-- Calcium Cyanide
-- Copper Cyanide
-- Cyanogen
-- Cyanogen Chloride
-- Hydrogen Cyanide
— Nickel Cyanide
-- Potassium Cyanide
-- Potassium Silver Cyanide
-- SiIver Cyanide
-- Sodium Cyanide
-- Zinc Cyanide
Cyc lophosphamide
Dalapon
DDO
DDE
DDT
DecabromodiphenyI Ether
Dia I late
2,14-DI ami no toluene
1,2,7,8-Dibenzopyrene
Dibenz(a,h)anthracene
1,2-Dibromo-3-chIoropropane
Dibutylni trosamine
Dibutyl Phthai ate
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1 ,l|-Dichlorobenzene
3,3'-Dichlorobenz idine
Dichlorodi fluoromethane
1,1-Dichloroethane
1,2-Dichloroethane (EDC)
1,1-Dichloroethylene
1,2-Dichloroethylene (trans)
1,2-Dichloroethylene (cis)
Dichloromethane
2,'l-Dichlorophenol
2, ti-0 i ch I o rophenoxyace t i c
Acid (2,l|-D)
i4-(2,
-------
-------
EXHIBIT C-1
(Continued)
PHYSICAL, CIICHICAL, AND FATE DATA
Date Prepared: October 1. 1986
Chemlca 1 Name
Formic Acid
Furan
G lye Ida Idehyde
Glycol Ethers
-- Diethylene Glycol,
Monoetliyl Ether
-- 2-Ethoxyethanol
— Ethylene Glycol,
Monobutyl Ether
-- 2-Methoxyethanol
— Propylene Glycol,
Monoottiyl Ether
-- Propylene Glycol,
Monomethyl Ether
lleptachlor
lleptachlor Epoxide
llexach 1 o robenzene
llexachlorobutad iene
llexach lorocyc lopentadiene
a Ipha -llexach lorocyclohexane (HCCII)
beta-HCCII
gamma -HCCII (Lindane)
delta-IICCH
Hexachloroethane
Hexachlorophene
Hydra zine
Hydrogen Sulfide
lndeno( 1 ,2,3-cd)pyrene
lodomethane
1 ron and Compounds
1 sobutanol
1 soprene
1 sosafro le
1 sophorone
1 sopropa 1 in
Kepone
Lasiocarpine
Lead and Compounds ( Inorganic)
Llnuron
Malathion
Manganese and Compounds
Me Ipha Ian
Mercury and Compounds (Alkyl)
Mercury and Compounds ( Inorganic)
Mercury Fulminate
Mo t ha no 1
Methyl Chloride
Methyl Ethyl Ketone
Methyl Ethyl Ketone Peroxide
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl Pa rath ion
2-Methyl-1-chlorophenoxyacetic Acid
2(2-Methyl )-1-Chlorophenoxy-
prop ionic Acid
Mo 1 e Wa te r
Weight Sol ub i 1 i ty
CAS H (g/molo) (mg/l )
6'i-18-6
110-00-9
765-3'i-H
NA
111-90-0
110-80-5
111-76-2
109-86-'!
52125-53-8
107-98-2
76-11-8
10211-57-3
118-71-1
87-68-3
77-17-1
319-8'l-6
319-85-7
58-89-9
319-86-8
67-72-1
70-30-U
302-01-1
7783-06-1
193-39-5
77-88-11
15'l38-31-0
78-83-1
78-79-5
120-58-1
78-59-1
33820-53-0
113-50-0
303-31-1
7'l39-92-1
330-55-2
121-75-7
7'l39-96-5
1'l8-82-3
7'l39-97-6
7139-97-6
628-86-11
67-56-1
7'l-87-3
78-93-3
1338-23-1
108-10-1
80-62-6
298-00-0
91-71-6
93-65-2
'16
68
72
NA
13'l
90
1 18
76
104
90
371
389
285
261
273
291
291
291
291
237
'107
32
3 '1
276
Hl2
56
71
68
168
138
309
'191
112
207
2'l9
330
55
305
201
285
32
50
72
176
100
100
263
201
215
1.00E+06
1.70E+08
1 .OOE+06
1. OOE+06
1. OOE+06
1.80E-01
3.50E-01
6.00E-03
1.50E-01
2. 10L+00
1.63E+00
2.10E-01
7.80E+00
3.11E+01
5.00E+01
1.00E-03
3.11E+08
1.13E+03
5.30E-OI4
1.10E+01
1.09E+03
9.90E-03
1.60E+03
1.15E+02
6.50E+03
2.68E+05
2.00E+01
6.00E+01
S*
0
F
F
K
C
C
A
A
A
C
C
C
C
C
F
B
K
C
J
B
B
B
E
C
A
F
E
Vapor
Pressure
( mm Hg )
ll.OOE+01
1 .97E+01
3.00E-01
3.00F-01
1.09E-05
2.00E+00
8.00E-02
2.50E-05
2.80E-07
1.60E-01
1.70E-05
1.00E-01
1.10E+01
1.00E-10
1.00E+02
1.00E+02
1.60E-08
O.OOE+00
1.00E-05
2.00E-03
1.31E+03
7.75E+01
3.70E+01
9.70E-06
Henry's Law
Constant Hoc
S*(atm-m3/mol ) (ml/g)
E
B
C
C
A
A'
,A
C
C
C
C
C
B
C
J
E
B
E
E
E
B
A
E
E
1 . 10E-08
NA
8. 19E-0'I
1.39L-01
6.81E-OII
1.57E+00
1.37E-02
5.87E-06
I4.II7E-07
7.85E-06
2.07E-07
2.19E-03
NA
1.73E-09
6.86E-08
5.3I4E-03
NA
NA
3.25E-12
NA
NA
NA
NA
NA
NA
1.10E-02
2.7I4E-05
2.13E-01
5.59E-08
0. 1
12000
220
3900
29000
1800
3800
3800
1080
6600
20000
91000
0.1
1600000
23
93
55000
76
35
. t-5
B'lO
160
S*
&
C
C
G
C
C
C
C
G
C
C
&
&
C
&
&
&
&
&
&
&
&
l.o<;
Kow
-U.5'i
- 1 . 55
0 . 00
0.00
n.'io
?.. 10
5.23
'1.78
5.0'l
3 . 90
3.90
3.90
i|. 10
'1.60
7.5'l
-3.08
6.50
1.69
2.66
2.00
0.99
2.89
0.95
0.26
0.79
1.91
S»
F
B
F
F
C
C
A
A
A
C
C
C
C
C
F
B
C
J
B
B
B
J
B
A
F
F
Fish
BCF
(I/kg)
0
15700
I'l'l 00
8690
2.8
'4.3
130
130
130
130
87
8'400
19
0
3750
5500
0
15
S"
r
ii
G
II
II
II
II
II
II
II
II
G
II
F
II
II
F
F
o
H-
H
ID
O
rt
H-
10
vo
NJ
00
tn
li-, J
-------
EXIIIDIT C-1
(Continued)
PHYSICAL, CHEMICAL, AND FATE DATA
, . 1 rr—, -^ -;-
Do to Prepared: October 1. 1906
Ghent ica 1 Name
Mole Wnter
Woight Sol lib i 1 I ty
CAS H ( g/mo 1 e ) ( mg/ 1 )
3-Melhylcholanthrene 56-'l9-3
i|,l|'-Mctliylone-bis-2-chloroani line 101-11-1
Methylnl trosourea 681-93-5
Methyl thlouracl 1
Methylvlnylni trosamfne
56-01-2
1519-10-0
N-Methyl -N' -nl tro-N-ni trosoguanadln70-25-7
Mi tomycln C
Mustard Gas
1-Napthylamlne
2-Napthylamine
Nickel and Compounds
Nitric Oxide
Nl trobenzene
Nitrogen Dioxide
Nl trosomethylurethane
N-Nltrosopiperldine
N-NI trosopyrrol idine
5-NI tro-o-to lu Idine
Osmium Tetroxide
Pentachlorobenzene
Pen t a chloron I trobenzene
Pentnchlorophenol
Phenacetln
Phenanthrene
Phenobarbi ta 1
Phenol
Phenylalanine Mustard
m-Phenylened iamine
Phenyl Mercuric Acetate
Phosphine
Polychlorlnated Biphenyls (PCBs)
Propane Sultone
Propylenlmine
Pyrene
Pyr idine
Saccharin
Safrole
Selenium and Compounds
-- Selenlous Acid
-- SelenoUrea
-- Thallium Sclenite
Sliver and Compounds
Sodium Dlethyldi thloca rbamate
Streptozocin
Strychnine
Styrene
1 , 2,1,5- Tetrachlo robenzene
2,3,7,8-TCDD (Dloxln)
1,1, 1,2-Tetrachlo roe thane
1,1 ,2,2-Tetrachloroethane
Te t rach 1 o roe thy 1 ene
2,3,1,6-Tetrachlorophenol
2, 3, 5,6-Tetrachloroterephtha late
Acid (DCPA)
50-07-7
505-60-2
131-32-7
91-59-8
7110-02-0
10102-'i3-9
98-95-3
10102-11-0
615-53-2
100-75-'!
930-55-?
99-55-8
20816-12-0
608-93-5
82-68-8
87-86-5
62-'l'l-2
85-01-8
50-06-6
108-95-2
118-82-3
108-'l5-2
62-38-1
7803-51-2
1336-36-3
1120-71-'!
75-55-8
129-00-0
110-86-1
81-07-2
911-59-7
7782-'l9-2
7783-00-8
630-10-'!
12039-52-0
7110-22-1
118-18-5
18883-66-1
57-21-9
100-12-5
95-9'l-3
1716-01-6
630-20-6
79-31-5
127-18-1
58-90-2
1861-32-1
268
267
103
112
86
117
331
159
113
113
59
30
123
16
132
111
100
152
251
250
295
266
179
178
232
91
305
108
337
31
328
122
57
202
79
183
162
79
129
123
HR8
108
171
157
331
101
216
322
168
168
166
232
332
6.89E+08
7.60E+05
8.00E+02
2.35E+03
5.86E+02
1 . 90E+03
1.90E+06
7.00E+06
1.35E-01
7. 11E-02
1.10E+01
1.00E+00
1.00E+03
9.30E+01
1.67E+03
3. 10E-02
9.11E+05
1.32E-01
1.00E+06
1.50E+03
-
1.56E+02 .
6.00E+00
2.00E-01
2.90E+03
2.90E+03
1.50E+02
1.00E+03
S*
D
B
B
B
B
C
B
B
F
B
C
A
B
A
K
C
B
A
F
B
E
F
A
J
A
A
F
Vapor
Pressure
( mm Hg )
1 .23E+01
1.70E-01
6.50E-05
2.56E-01
O.OOE+00
1.50E-01
1.10E-01
1. 10E-01
1 . 13E-01
1. 10E-01
6.80E-01
3.11E-01
7.70E-05
1.11E+02
2.50E-06
2.00E+01
9. 10E-01
O.OOE+00
O.OOE+00
1.70E-06
5.00E+00
5.00E+00
1.78E+01
Henry's Law
Constant Koo
SM(atm-m3/mol ) (ml/g)
B
B
B
B
D
B
B
B
B
C
A
A
C
B
A
F
B
E
D
A
J
A
A
NA
NA
NA
NA
1.83E-06
NA
NA
1.15E-05
5.21E-09
8.23E-08
NA
NA
1 . 1 IE-OS
2.07E-09
NA
NA
6. 18E-01
2.75E-06
NA
1.59E-01
NA
1.51E-07
NA
1.07E-03
NA
1. 12E-05
5.01E-06
NA
1.29E-07
NA
• NA
NA
NA
3.60E-03
3.81E-01
3.81E-01
2.59E-02
NA
0. 1
2.5
110
61
130
36
1.5
0.8
13OOO
19OOO
53000
11000
98
11.2
530000
2.3
38000
78
1600
3300000
51
118
361
98
S*
ft
ft
&
fe
&
C
&
fe
fe
&
C
C
&
C
C
&
C
ft
&
C
&
C
C
ft
Log
Kow
-3.81
-0.23
1.37
2.07
2.07
1.85
-0.19
-1 .06
'j. 19
5.15
5
1 . 16
-0. 19
1.16
6.01
-0.18
1.88
0.66
2.53
1.67
6.72
2.39
2.6
1. 1
S*
B
B
B
B
B
D
B
B
F
B
C
A
B
A
C
B
A
F
B
F
A
A
A
F
Fish
BCF
(I/kg) S»
17 H
2125 H
770 G
2630 0
1.1 H
100000 G
16 H
3080 1)
1125 II
5000 H
12 H
31 H
210 H
O
C/)
t)
H-
M
(D
O
rt
(-••
(B
oo
Cn
-------
EXHIBIT C-1
(Cont inued)
PHYSICAL, CHEMICAL, AND FATE DATA
Date Prepared: October 1. 1986
Chemical Name
Tetraethyl Lead
Thallium and Compounds
-- Thallium Acetate
-- ThaIIium.Carbonate
-- ThaI Iium Chloride
-- Tha11ium Ni trate
-- ThaI Iic Oxide
-- Tha II I urn Sul rate
Thioacetarnide
Thiourca
o-Tolidine
Toluene
o-loluidine Hydrochloride
Toxapheno
Tribromomcthane (BromoTorm)
1,2, i)-Tr ichlorobenzene
1,1,1-TrichIoroethane
1,1,2-Trlchloroethane
Trichloroethylene
TrichlorTon
T r i chIoromonorI no rome thane
2,'i,5-Trichlorophenol
2,'1,6-Trichlorophenol
2,'), 5-Trichlorophenoxyacet ic Acid
1,2,3-Trichloropropane
1,1,2-Trichloro-1,2,2,-
tri fI noroethane
Tris(2,3-dibromopropyl(phosphate
Trinitrotoluene (TNT)
Trypan Blue
I)rani I Mustard
Uranium and Compounds
Urethane
Vanadium and Compounds
Vinyl Chloride
WarTarin
o-Xylene
m-Xylene
p-Xylene
Xylene (mixed)
Zinc and Compounds
-- Zinc Phosphide
Zineb
Mole
Weight
CAS H (g/mole
78-00-2
7'l '10-28-0
563-68-8
6533-73-9
7791-12-0
10102-1)5-1
13HI-32-5
7'l'l6-18-6
62-55-5
62-56-6 ,
119-93-7
108-88-3
636-21-5
8001-35-2
75-25-2
120-82-1
71-55-6
79-00-5
79-01-6
52-68-6
75-69-')
95-95-1)
88-06-2
93-76-5
96-18-')
76-13-1
126-72-7
118-96-7
72-57-1
66-75-1
7'l'iO-61-1
51-79-6
7'l')0-62-2
75-01-1)
81-81-2
95-')7-6
108-38-3
106-1)2-3
1330-20-7
7MIIO-66-6
13T)-8i)-7
12122-67-7
323
20')
263
1)69
2MO
266
'157
505
75
76
212
92
I'l'l
1)1 ')
253
181
133
133
131
257
137
197
197
255
11)7
187
698
227
961
252
238
89
51
63
308
106
106
106
106
65
258
276
Water
So I ub i 1 i ty
» (mg/l) S*
8.
2.
2.
1.
7.
5.
1.
5.
3.
3.
1 .
I).
1 .
1.
1.
1.
8.
1.
1.
6.
2.
1.
1.
1.
1 .
OOE-01
90E+03
OOE+02
72E+06
35E+01
35E+02
50E+0')
OOE-01
01E+03
OOE+01
50E+03
50E+03
10E+03
5')E+05
10E+03
19E+03
OOE+02
OOE+01
20E+02
M1E+02
67E+03
75E+02
30E+02
98E+02
98E+02
J
E
E
I)
D
A
J
C
C
C
A
A
A
E
C
A
A
r
B
B
A
F
F
F
F
Va po r
Pressure
(mm llg)
1.50E-01
O.OOE+00
O.OOE+00
O.UOE+00
2.81E+01
1. OOE-01
'). OOE-01
5.00E+00
2.90E-01
1 .23E+02
3. OOE+01
5.79E+01
7.BOE-06
6.67E+02
1.00E+00
1.20E-02
2.70E+02
2.66E+03
1. OOE+01
1 .OOE+01
1 .OOE+01
1 .OOE+01
O.OOE+00
Henry's Law
Constant
S»(atm-m3/mol )
J
E
E
E
A
J
C
C
C
A
A
A
E
C
A
A
F
A
E
F
F
F
D
7.97E-02
NA
NA
NA
6.37E-03
9.39E-07
'I.36E-0!
5.52E-0')
2.31E-03
1.l|'lE-02
1 . 17E-03
9. 10E-03
1 . 71E-11
2. 18E-0')
3.90E-06
NA
NA
NA
NA
NA
NA
8.19E-02
7.0')E-03
NA
Koc
(ml/g)
'1900
1.6
1)10
300
22
96')
116
9200
152
56
126
6.1
159
89
2000
310
120
57
2'10
S»
&
&
&
C
&
C
C
C
C
C
C
&
C
&
C
&
&
&
&
Log
Kow
-0.')6
-2.05
2.88
2.73
1 .29
3.3
2.<4
'1.3
2.5
2.D7
2.38
2.29
2.53
3.72
3.87
2.00
it. 12
-1.09
.1 .38
2.95
3.26
3. 15
3.26
S»
J
B
B
A
J
C
C
C
C
A
A
A
D
A
A
F
B
B
A
F
F
F
F
Fish
BCF
(I/kg)
10. 7
13100
2800
5.6
5
10.6
110
150
2.7
1.17
1)7
S*
H
II
0
II
II
II
II
II
G
II
II
* Letters denote the source or the data, as listed in Section 3.1.
H Solubility or 1,000,000 mg/l assigned because or reported "inrinite solubility" in the literature.
& Koc estimated by the following equation: log Koc = (-0.55HlogS) + 3.6U (Note: S In mg/l).
O
to
O
H-
H
O
rt
(D
vo
DO
Ln
U.-J
-------
Chemical Name CAS ff
Chlorod ibromomethane 121-'i8-1
Chloroform 67-66-3
Chloromethyl Methyl Ether 107-30-2
(4-Chloro-o-toluidine HydrochlorIde 3165-93-3
Chromium III and Compounds 7'l'lO-'i7-3
Chromium VI and Compounds 7'i'l()-'l7-3
Chrysene 21B-01-9
Copper and Compounds 7'l'lO-50-8
Creosote 8001-58-9
Cresol 1319-77-3
CrotonaIdehyde 123-73-9
Cyanides 57-12-5
-- Darium Cyanide 5't2-62-1
— Calcium Cyanide 502-01-8
— Copper Cyanide 5'i'i-92-3
-- Cyanogen 1(60-19-5
-- Cyanogen Chloride 506-77-M
-- Hydrogen Cyanide 7*1-90-8
-- Nickel Cyanide 557-19-7
-- Potassium Cyanide 151-50-8
— Potassium Silver Cyanide 506-61-6
— Silver Cyanide 506-6'i-9
-- Sodium Cyanide 113-33-9
-- Zinc Cyanide 557-21-1
Cyclophosphamide • 50-18-0
Dalapon 75-99-0
ODD 72-51-8
DDE 72-55-9
DDT 50-29-3
Decabromodiphcnyl Ether 1163-19-5
Dial late 2303-16-1
2,1-Diaminotoluene 95-80-7
1,2,7,8-Dibenzopyrene 189-55-9
Dlbenz(a,hjanthracene 53-70-3
1,2-Dibromo-3-chIoropropane 96-12-8
Dibuty Ini trosamine 9214-16-3
Dibutyl Ph thai ate 8'l-7'l-2
1,2-Dichlorobenzene 95-50-1
1,3-Dichlorobenzene 511-73-1
1,1-Dichlorobenzene 106-'i6-7
3,3'-Dichlorobenzidine 91-914-1
Dlchlorod! Duoromethane 75-71-8
1,1-Dichloroethane 75-31-3
1,2-Dichloroethane (EDC) 107-06-2
1,1-Dichloroethylene 75-35-1
1,2-Dichloroethylene (trans) 510-59-0
1,2-Dichloroethylene (cis) 510-59-0
Dichloromethane 75-09-2
2,1-Dichlorophenol 120-83-2
2,i|-Dichlorophenoxyacetic
Acid (2,i4-D) 91-75-7
U-( 2,1-Dichlorophenoxy)butyric
. Acid (2,1-DB) 91-82-6
EXHIBIT C-2
(Continued)
HALF-LIVES IN VARIOUS MEDIA
Date Prepared: October 1. 1986
Hair-Life Range (Days)
Soi I
Low
High
Air Surface Water Ground Water
Low High S» Low High S» Low Hiflh
80.00
'4.00
5.50
73000.00
1000.00 5500.00 A
5.50
26.00
23.00
15.00
36.00
2.00
2.10
1.30
53.20
2.30
127.00
0.30 30.00
M 3.00
M 0.20
0.33
M 0.0208
M
M
0.80 M
56.00 110.00
2.08
M
M
A
A
A
A
A
M
M
1.50
1.50
1.00
0.17
1.00
1.00
1.00
1.20
6.00
8.50
8.50
5.00
-
6.00
6.00
6.00
5.80
-
M
M
A
A
A
A
A
M
M
o
H-
H
(P
O
rt
(-••
(B
vo
N)
CO
In
-------
Chemical Nnme CAS ff
Dlchlorophenylarsine 696-28-6
1,2-Dichloropropane 78-87-*)
1,3-Dlchloropropcne 512-75'-6
Dieldrin 60-57-1
Dlepoxybutane 1161-53-5
Dlethanolni trosamine 1116-51-7
Diethyl Arsine 692-12-2
1.2-Diethylhydrazine 1615-80-1
Dlothylnitrosamine 55-18-5
Diethyl Phthalate 81-66-2
DiethylstiIbestrol (DES) 56-53-1
Dlhydrosarrole 9'l-58-6
Dimethoate 60-51-5
3. S'-Oimethoxybenzidine 119-90-'!
Dimethylamine 121-10-3
Dimethyl Sulfate 77-78-1
Dimethy.l Terephtha la tc 120-61-6
Dimethylaminoazobenzone 60-11-7
7,12-Dimethylbenz(a)anthracene 57-97-6
3,3'-Dimothylbenzidine 119-93-7
DimethyIcarbamoyl Chloride 79-'i'i-7
1,1-Dimothylhydrazine 57-1'l-'i
1,2-Dimethylhydrazlne 510-73-8
Dlmethylnltrosamine 62-75-9
1,3-Dinitrobenzene 99-65-0
1,6-Dlnitro-o-cresol 531-52-1
2,1-Dinltrophenol 51-28-5
2,3-Dinltrotoluene 602-01-7
2,l|-Dlnltrotoluene 121-11-2
2,5-Dinltrotoluene 619-15-8
2.,6-Dlni trotoluene 606-20-2
3,'l-Dini trotoluene 610-39-9
Dlnoseb 88-85-7
1,'l-Dloxane 123-91-1
N,N-Dlphenylamlne 122-39-U
1,2-Dlphenylhydrazlne 122-66-7
DIpropylnl trosamine 621-6'l-7
Dlsulfoton 298-0'l-M
Endosulfan 115-29-7
Epichlorohydrin 106-89-8
Ethanol 61-17-5
Ethyl Acetate 111-78-6
Ethyl Methanesulronate 62-50-0
Ethylbenzene 100-11-'!
Ethyl-'!,I'-dichlorobenz! late 510-15-6
Ethylene Dibromlde (EDB) 106-93-1
Ethylene Oxide 75-21-8
Ethylenethiourea 96-15-7
1-Ethyl-nitrosourea 759-73-9
Ethylphthalyl Ethyl Glycolate 81-72-0
Ferric Dextran 9001-66-1
Fluoranthene 206-11-0
Fluorene 86-73-7
EXHIBIT C-2
(Continued)
Date Prepared: October 1. 1986
HALF-LIVES IN VARIOUS MEDIA
Half-Lire Range (Days)
Sol I
low High
Air
low High S«
SurTace V/atnr
Low High
S»
Ground Watnr
Low High
80.00
1 .10
1 .00
7.70 M
M
133.00
96.00
M 0.10 10.00 M
2. 70
1.16
M 3.50 10.80 M
1.50 7.50 A
O
t/i
O
H-
H
fl>
O
r»
H-
00
tn
5.50
M 1.00 2.00 M
-------
EXHIBIT C-2
(Cont inucd)
HALF-LIVES IN VARIOUS MEDIA
Date Prepared: October 1. 1986
Hair-Li To Range (Oays)
Chemical Name CAS ff
Fluorides 7782-41-4
Fluridone 59756-60-4
Formaldehyde 50-00-0
Formic Acid 64-18-6
Furan 110-00-9
Glyclda Ideliyde 765-34-4
Glycol Ethers NA
-- Diethylene Glynol,
Monoethyl Ether 111-90-0
-- 2-Etnoxyethanol 110-80-5
-- Ethylene Glycol,
Monobutyl Ether 111-76-2
— 2-Mcthoxyethanol 109-86-iJ
— Propylene Glycol,
Monoethyl Ether 52125-53-8
-- Propylene Glycol,
Monomethyl Ether 107-98-2
Meptachlor 76-'i'4-8
lleptachlor Epoxlde 1024-57-3
Hexachlorobenzene 118-74-1
llexachlorobutad iene 87-68-3
llexachlorocyclopentad iene 77-47-4
a Ipha-llexachlorocyclohexane (IICCH) 319-8'i-6
beta-HCCH 319-85-7
gamma-MCCM (Llndane) 58-89-9
delta-HCCH 319-86-8
llexachloroethane 67-72-1
Hexachl orophene 70-30-'!
Hydrazine 302-01-1
Hydrogen Sulflde 7783-06-4
lndeno(1,2,3-cdJpyrene 193-39-5
lodomethane 77-88-4
Iron and Compounds 15438-31-0
Isobutanol 78-83-1
Isoprene 78-79-5
Isosafrole 120-58-1
Isophorone 78-59-1
Isopropalin 33820-53-0
Kepone 143-50-0
Lasiocarpine 303-34-4
Lead and Compounds ( Inorganic) 7439-92-1
Linuron 330-55-2
Malathlon 121-75-7
Manganese and Compounds 7039-96-5
Melphalan 148-82-3
Mercury and Compounds (Alkyl) 7'i39-97-6
Mercury and Compounds (Inorganic) 7439-97-6
Mercury Fulminate 628-86-4
Methanol 67-56-1
Methyl Chloride 71-87-3
Methyl Ethyl Ketone 78-93-3
Methyl Ethyl Ketone Peroxide 1338-23-4
Methyl Isobutyl Ketone 108-10-1
Sol I
Low High
S*
Ai r
Low High
Surface Water
Low
Ground Water
Low High S"
0.80
0.90
3.50 M
1100.00 2200.00 A
40.00
80.00
0.20
0. 14
7900
5.50
M
M
M
0.96 - M
0.30 300.00 A
29.00 2300.00 A
0.007 - M
1.10
M 0.0208
9.50 M
2.08 M
4.80
4.80
0.58
PERS
PERS
1.00
10.00
M
A
O
C/>
$
»
D
H-
H
(P
O
rt
H-
»
vo
oo
In
V-
i
-------
ChcmicaI Name
CAS H
Methyl MethncryI ale 80-62-6
Methyl Pa rath ion 290-00-0
2-Methy l-'i-chlorophenoxyacet ic Acid 9'i-7U-6
2( 2-Mo thy I ) -i|-Ch I orophenoxy-
propionlc Acid 93-65-2
3-MethyIcholanthrene 56-M9-3
ll.'l1 -Melhylene-bl s-2-chloronni I Ine 101-1'4-'i
Methylni trosourea 68'i-93-5
Methyl ihlouracl I 56-0'i-2
Methylviny Ini trosamine fi5'i9-'lO-0
N-Melhyl-N'-ni tro-N-nItrosognanadin70-25-7
Mitomycin C 50-07-7
Mustard Gas 505-60-2
1-Napthylamine 13M-32-7
2-Napthylamlne 91-59-8
Nickel and Compounds 7'»'iO-02-0
Nitric Oxide 10102-M3-9
Nitrobenzene 98-95-3
Nitrogen Dioxide 10102-')'i-0
Nitrosomethylurethane 615-53-2
N-NItrosopiperldlne 100-75-M
N-Nitrosopyrrolidine 930-55-2
5-Nitro-o-toluidlne 99-55-8
Osmium Tetroxlde 20816-12-0
Pentachlorobenzene 608-93-5
Pentachloronltrobenzene 82-68-8
Pentachlorophenol 87-86-5
Phenacetin 62-'l'l-2
Phenanthrene 85-01-8
PhenobarbltaI 50-06-6
Phenol 108-95-2
Pheny la lanine Mustard 1'i8-82-3
m-PhenyIenedfamine 108-M5-2
Phenyl Mercuric Acetate 62-38-'i
Phosphine 7803-51-2
Polychlorinated Biphenyls (PCBs) 1336-36-3
Propane Sultone • 1120-71-'*
Propylenlmlne 75-55-8
Pyrene 129-00-0
Pyridlne 110-86-1
Saccharin 81-07-2
Safrole 9M-59-7
Selenium and Compounds 7782-'i9-2
-- Selenious Acid 7783-00-8
-- Selenourea 630-10-U
— Thallium Selenite 12039-52-0
SI Iver and Compounds 7'i'iO-22-i|
Sodium Diethyldlthiocarbamate 1M8-18-5
Streptozocin 18883-66-'i
Strychnine 57-2M-9
Styrene 100-U2-5
1,2,M, 5-Tetrachlorobenzene 95-9'l-3
2,3,7,8-TCDD (Dioxin) 17'l6-01-6
EXIIIOI f C-2
(Continued)
HALF-LIVES IN VARIOUS MEDIA
Date Prepared: October 1. 1986
Hair-Life Range (Days)
Soi I
Low High
Ai r
Low High
Surface Water
Low High
15 .00
S"
M
Ground Water
Low High
12.50
21.00 - M 5.00 - M
0.38 2.00 A
0.62 9.00 A 0.62 9.00 A
58.00
0.08 2.00 A
2.00 12.90 M
2.00
O
I
O
rt
(-••
(V
vo
to
do
tn
3650.00 14380.00 A
365.00 730.00 A
-------
Oatc Prepared: October 1. 1986
ChcmicaI Name
1,1,1,2-Totrachloroeihnne
1,1,2,2-Tetrachloroelhane
Tetrachloroethylone
2, 3,4,6-Tetrachlorophonol
2,3,5,6-Tetrachloroterephthala te
Acid (DCPA)
Tetracthyl Lead
Thallium and Compounds
-- Thallium Acetate
-- Thallium Carbonate
-- Thallium Chloride
-- ThaI Iium Ni trate
-- ThaI Iic Oxide
-- ThaI Iium SuI fate
Thioncetamide
Thiourea
o-Tolid ine
Toluene
o-Toluldinc llyd roch I oride
Toxaphone
Tribromomethane (Bromoform)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
TrichIoroethylene
Trichlorfon
Trichloromonofluoromethane
2,4,5-Trichlo rophenoI
2,4,6-Trichlorophenol
2,4,5-Trichlo ropherioxyace t i c Ac i d
1,2,3-Trichloropropane
1,1,2-Trichloro-1,2,2,-
tri fIuoroethane
Tri s(2, 3-dibromopropyl(phosphate
Trinitrotoluene (TNT)
Trypan Blue
Uracil Mustard
Uranium and Compounds
Urethane
Vanadium and Compounds
Vinyl Chloride
Warfarin
o-Xylene
m-Xylene
p-Xylene
Xylene (mixed)
Zinc,and Compounds
-- Zinc Phosphide
Zineb
CAS H
630-20-6
79-34-5
12/-18-4
58-90-2
1861-32-1
78-00-2
7440-28-0
563-68-8
6533-73-9
7791-12-0
10102-45-1
1314-32-5
7446-18-6
62-55-5
62-56-6
119-93-7
108-88-3
636-21-5
8001-35-2
75-25-2
120-82-1
71-55-6
79-00-5
79-01-6
52-68-6
75-69-4
95-95-4
88-06-2
93-76-5
96-18-4
76-13-1
126-72-7
118-96-7
72-57-1
66-75-1
7440-61-1
51-79-6
7440-62-2
75-01-4
81-81-2
95-47-6
108-38-3
106-42-3
1330-20-7
7440-66-6
EXHIBIT C-2
(Continued)
HALF-LIVES IN VARIOUS MEDIA
Half-Life Range (Days)
Soil Air Surface Wntnr C round Water-
Low High S* Low High S* Low Iliijh S* Low High S"
1.40 - M
584.00 - A 0.04 - A
47.00 - A 1.00 30.0(1 A
1 .30 - A 0.17 - A
40.00 - M 2.00 14.20 M
1.20 - M
803.00 1752.00 A 0.14 7.00 A
24.00 - A 1.90 - A
3.70 - A 1.00 90.00 A
72.00 - A
5.00 - A 1.00 - A 1.00 19.00 A
1.20 - A 1.00 5.00 A
0.50 - M 1.50 9.00 M
4.80 20.00 M PERS - M
12122-67-7
O
C/i
o
H-
H
(B
O
rt
H-
(ft
VO
KJ
CD
Ln
* Letters denote the source of the data, as listed in Section C.I.
** PERS indicates the chemical is persistent for that medium.
-------
C-20
OSWER Directive 9285.4-1
Date Prepared: October 1, 1986
EXHIBIT C-3
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY 1J
Oral Route
Inhalation Route
Chemical Name
2-Acetylaminofluorene
Acrylonitrile
Aflatoxin Bl
Aldrin
Amitrole
Arsenic and Compounds
Asbestos
Auramine
Azaserine
Aziridine
Benzene
Benzidine
Benz(a)anthracene
Ben2(c)acridine
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzotrichloride
Benzyl Chloride
Beryllium and Compounds
Bis(2-chloroethyl)ether
Bis(chloromethyl)ether
Bis(2-ethyIhexyl)phthalate (DEHP)
Cacodylic Acid
Cadmium and Compounds
Carbon Tetrachloride
Chlordane
Chloroform
A-Chloro-o-toluidine Hydrochloride
Chromium VI and Compounds
Chrysene
Cyclophosphamide
DDD
DDE
DDT
Diallate
10%
Effective
Dose
(ED10)
mg/kg/day
2
A
1
1
7
1
3
3
A
A
6
6
8
8
7
5
1
6
5
8
5
7
2
1
A
.60E-02
.39E-01
NA
.52E-02
.89E-01
.03E-03
NA
.08E+00
NA
.60E-03
.70E+00
.50E-OA
.92E-02
.67E-05
.28E-03
NA
NA
.91E-03
NA
NA
.23E-02
.22E-OA
.OOE+01
NA
NA
.52E-02
.61E-02
.08E-01
.13E-.01
NA
NA
.70E-02
.69E-01
.53E-01
.79E-01
.2AE-01
Toxicity
Constant
Water
(wTc)
1/mg
1
6
1
1
A
2
7
7
6
5
A
A
3
3
3
5
1
A
5
3
5
3
1
1
6
. 10E+00
.51E-02
NA
.88E+00
.51E-01
.07E+00
NA
.66E-02
NA
.93E+00
.71E-03
.3AE+01
.61E-01
.29E+02
.55E+00
NA
NA
.21E+00
NA
NA
.A7E-01
.96E+01
.71E-OA
NA
NA
.88E+00
.32E-01
.63E-02
.51E-02
NA
NA
.01E-01
.71E-02
.13E-01
.59E-01
.7AE-02
5
3
9
7
2
1
3
3
3
2
2
2
1
1
1
2
9
2
2
1
2
1
5
7
3
Soil
(sic)
kg/mg
.50E-05
.26E-06
NA
.AOE-05
.56E-06
.03E-OA
NA
.33E-06
NA
.97E-OA
.86E-07
.17E-03
.91E-05
.1AE-02
.28E-OA
NA
NA
.60E-OA
NA
NA
.7AE-05
.98E-03
.86E-08
NA
NA
.A1E-05
.16E-05
.81E-06
.76E-06
NA
NA
.50E-05
.86E-06
.6AE-06
.97E-06
.37E-06
10%
Effective
Dose
(ED10)
mg/kg/day
2
A
1
1
7
1
3
3
A
A
6
6
8
1
8
7
5
1
1
6
5
8
2
5
7
2
1
A
.60E-02
.39E-01
NA
.52E-02
.89E-01
.03E-03
NA
.08E+00
NA
.60E-03
.70E+00
.50E-OA
.92E-02
.67E-05
.28E-03
NA
NA
.91E-03
NA
.25E-02
.23E-02
.22E-OA
.OOE+01
NA
.73E-02
.52E-02
.61E-02
.08E-01
.13E-01
.57E-03
NA
.70E-02.
.69E-01
.53E-01
.79E-01
.2AE-01
Air
Toxicity
Constant
(aTc)
(m3/mg)
1
6
1
1
A
2
7
7
6
5
A
A
3
2
3
3
5
1
1
A
5
3
1
5
3
1
1
6
. 10E+01
.51E-01
NA
.88E+01
.51E+00
.07E+01
NA
.66E-01
NA
.93E+01
.71E-02
.3AE+02
.81E+00
.29E+03
.55E+01
NA
NA
.21E+01
NA
.28E+01
.A7E+00
.96E+02
.71E-03
NA
.65E+01
.88E4-01
. 32E-f 00
.63E-01
.51E-01
. HE-f02
NA
.01E+00
.71E-01
. 13E+00
.59E+00
.7AE-01
* * * October 1986 * * *
-------
C-21
OSWER Directive 9285.4-1
Date Prepared: October 1. 1986
EXHIBIT C-3
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Diaminotoluene (mixed)
1,2,7,8-Dibenzopyrene
Dibenz(a,h)anthracene
1,2-Dibromo-3-chloropropane
Dibutylnitrosamine
3,3'-Dichlorobenzidine
1,2-Dichloroethane (EDC)
1,1-Dichloroethylene
Dichloromethane
Dieldrin
Diepoxybutane
Diethanolnitrosamine
Diethyl Arsine
1,2-Diethylhydrazine
Diethylnitrosamine
Diethylstilbestrol (DES)
Dihydrosafrole
3,3'-Dimethoxybenzidine
Dimethyl Sulfate
Dimethylaminoazobenzene
7,12-Dimethylbenz(a)anthracene
3,3'-DimethyIbenzidene
Dimethylcarbamoyl Chloride
1,1-DimethyIhydrazine
1,2-Dimethylhyd.razine
DimethyInitrosamine
Dinitrotoluene (mixed)
2,4-Dinitrotoluene
2,6-Dinitrqtoluene
1,4-Dioxane
1,2-DiphenyIhydrazine
DipropyInitrosamine
Epichlorohydrin
Ethyl-4,4'-dichlorobenzilate
Ethylene Dibromide (EDB)
Ethylene Oxide
10%
Effective
Dose
(ED10)
mg/kg/day
3
2
6
2
1
4
2
7
3
1
2
9
2
9
5
3
1
7
1
3
2
2
2
2
2
5
2
4
.40E-01
NA
.83E-03
.OOE-03
.29E-02
.20E-01
.88E-01
.33E-01
NA
.81E-03
.58E-02
NA
NA
NA
.03E-03
. 11E-04
.26E-01
.OOE+01
NA
.52E-03
.23E-06
.70E-02
.98E-03
.44E-02
.87E-04
.91E-02
.62E-01
.62E-01
NA
.94E+01
.19E-01
NA
.70E+00
.59E-01
.56E-03
.13E-01
Toxicity Constant
Water
(wTc)
I/rag
8
1
4
1
2
5
1
3
7
2
1
3
1
3
5
7
1
3
1
7
1
1
9
1
1
5
1
6
.40E-02
NA
.01E+01
. 76E+00
.25E+00
.39E-01
.86E-02
.23E-01
NA
.66E+00
.98E-01
NA
NA
NA
. 77E+01
.35E+02
.09.E-02
.43E-03
NA
.OOE-i-00
.46E+03
.71E-01
.44E+01
.84E-01
.53E+02
.30E-01
.09E-01
.09E-01
NA
.71E-04
.31E-01
NA
.06E-02
.11E-02
.11E+01
.91E-02
Soil
(sic)
kg/mg
4
5
2
6
1
2
6
1
3
1
6
1
7
1
2
3
7
1
7
3
5
5
4
6
5
2
5
3
.20E-06
NA
. 04E-04
.38E-04'
.24E-05
. 19E-05
.93E-06
. 14E-06
NA
.83E-04
.99E-05
NA
NA
NA
.38E-03
. 77E-03
.54E-06
. 14E-08
NA
.50E-04
.73E-01
.86E-05
.22E-04
.92E-05
.65E-03
.65E-05
.46E-06
.46E--06
NA
.86E-08
.53E-06
NA
.29E-07
.56E-06
.57E-04
.46E-06
10%
Effective
Dose
(ED10)
mg/kg/day
3
2
6
2
1
'4
2
7
3
1
2
9
2
9
5
3
1
7
1
3
2
2
2
2
2
5
2
4
.40E-01
NA
.83E-03
.OOE-03
.29E-02
.20E-01
.88E-01
.33E-01
NA
.81E-03
.58E-02
NA
NA
NA
.03E-03
. 11E-04
.26E-01
.OOE+01
NA
.52E-03
.23E-06
.70E-02
.98E-03
.44E-02
.87E-04
.91E-02
.62E-01
.62E-01
NA
.94E+01
.19E-01
NA
. 70E+00
.59E-01
.56E-03
.13E-01
Air
Toxicity
Constant
UTc)
m3/mg
8
1
4
1
2
5
1
3
7
2
1
3
1
3
5
7
1
3
1
7
1
1
9
1
1
5
1
6
.40E-01
NA
.OlE-t-02
.76E+01
.25E+01
.39E+00
.86E-01
.23E+00
NA
.66E+01
.98E+00
NA
NA
NA
.77E+02
.35E+03
.09E-01
.43E-02
NA
.OOE+01
. 46E+04
. 72E+00
.44E+02
. 84E+00
.53E+03
.30E+00
.09E+00
.09E+00
NA
.71E-03
.31E+00
NA
.06E-01
.11E-01
.11E+02
.91E-01
* * * October 1986 * * *
-------
C-22
OSWER Directive 9285.4-1
Date Prepared: October 1, 1986
EXHIBIT C-3
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Ethylenethiourea
Ethyl Methanesulfonate
1-Ethyl-nitrosourea
Formaldehyde
Glycidaldehyde
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorobutadiene
alpha-Hexachlorocyclohexane (HCCH)
beta-HCCH
gamma-HCCH (Lindane)
Hexachlorbethane
Hydrazine
IndenoCl,2,3-cd)pyrene
lodomethane
Isosafrole
Kepone
Lasiocarpine
Melphalan
Methyl Chloride
3-Hethylcholanthrene
4,4'-Methylene-bis-2-chloroaniline
Methylnitrosourea
Methylnitrosourethane
Methylthiouracil
Methylvinylnitrosamine
N-Methyl-N'-nitro-N-nitrosoguanadine
Mitomycin C
1-Napthylamine
2-Napthylamine
Nickel and Compounds
N-Nitrosopiperidine
N-Nitrosopyrrolidine
5-Nitro-o-toluidine
Pentachloronitrobenzene
10%
Effective
Dose
(ED10)
mg/kg/day
7
5
1
4
3
8
3
8
1
1
5
5
1
1
1
2
2
9
1
4
8
9
3
e 1
1
3
5
7
7
.69E-01
.58E-03
.14E-01
.90E-02
.45E-01
.93E-03
.45E-03
.51E-02
.69E+00
.83E-02
.75E-01
.46E-01
.25E+01
.27E-02
NA
NA
.67E+00
.09E-02
.66E-02
.09E-04
.05E+01
.64E-02
.20E-01
.48E-05
NA
.50E-02
- NA
.79E-02
NA.
NA
.98E-01
NA
.S8E-02
.36E-03
. 14E+00
.04E-01
Toxicity Constant
Water
(wTc)
1/mg
3
5
2
5
8
3
8
3
1
1
4
5
2
2
1
1
1
3
2
6
3
3
8
1
1
7
5
4
4
.71E-02
. 12E+00
.50E-01
.S3E-01
.29E-02
.20E+00
.28E+00
.36E-01"
.69E-02
.56E-I-00
.97E-02
.23E-02
.29E-03
.25E+00
NA
NA
.71E-02
.37E+00
.08E+00
.14E+01
.71E-03
.16E-01
.49E-02
.01E+02
NA
. 16E-01
NA
.59E+00
NA
NA
.44E-01
NA
.37E-01
.33E+00
.OOE-03
.06E-02
1
2
1
2
4
1
4
1
8
7
2
2
1
1
8
6
5
1
1
3
1
1
4
7
7
3
2
2
2
Soil
(sic)
kg/mg
.86E-06
.56E-04
.25E-05
.92E-05
.14E-06
.60E-04
.14E-04
.68E-05
.43E-07
.79E-05
.49E-06
.61E-06
.14E-07
.13E-04
NA
NA
.57E-07
.85E-05
.38E-05
.57E-03
.36E-07
.08E-05
.74E-06
.51E-02
NA
.08E-05
NA
.97E-05
NA
NA
.21E-06
NA
.68E-05
.66E-04
.OOE-07
.03E-06
10i
Effective
Dose
(ED10)
mg/kg/day
7
5
1
4
3
8
3
8
1
1
5
5
1
1
1
2
2
9
1
4
8
9
3
1
1
1
3
5
7
7
.69E-01
.58E-03
.14E-01
.90E-02
.45E-01
.93E-03
.45E-03
.51E-02
.69E+00
.83E-02
.75E-01
.46E-01
.25E+01
.27E-02
NA
NA
.67E+00
.09E-02
.66E-02
.09E-04
.05E+01
.64E-02
.20E-01
.48E-05
NA
.50E-02
NA
. 79E-02
NA
NA
.98E-01
.OOE-01
.88E-02
.36E-03
. 14E+00
.04E-01
Air
Toxicity .
Constant
(aTc)
m3/mg
3.
5.
2.
5.
8.
3.
8.
3.
1.
1.
4.
5.
2.
2.
1.
1.
1.
3.
2.
6.
3.
3.
8.
1.
1.
2.
7.
5.
4.
4.
71E-01
12E+01
50E+00
83E+00
29E-01
20E+01
28E+01
36E+00
69E-01
56E+01
97E-01
23E-01
29E-02
25E+01
NA
NA
71E-01
37E+01
08E+01
14E+02
71E-02
16E+00
49E-01
01E+03
NA
16E+00
NA
59E+01
NA
NA
44E+00
85E+00
37E+00
33E+01
OOE-02
06E-01
* * * October 1986
* *
-------
C-23
OSWER Directive 9285.4-1
Date Prepared: October 1. 1986
EXHIBIT C-3
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Chemical Name
Pentachlorophenol
Phenacetin
Polychlorinated Biphenyls (PCBs)
Polynuclear Aromatic Hydrocarbons
Propane Sultone
1,2-Propylenimine
Saccharin
Safrole
Streptozocin
2,3,7,8-TCDD (Dioxin)
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrachloroethane
Tetrachloroethylene
Thioacetamide
Thiourea
o-Toluidine hydrochloride
Toxaphene
1,1,2-Trichloroethane
Trichloroethylene
2,4,6-Trichlorophenol
Tris(2,3-dibromopropyl)phosphate
Trypan Blue
Uracil Mustard
Urethane
Vinyl Chloride
Oral -Route
10%
Effective
Dose
(ED10)
nig/kg/day
1
5
2
3
2
5
9
8
1
6
3
4
9
6
1
2
6
1
1
2
1
6
NA
.25E+01
.OOE-02
NA
.85E-02
.35E-02
.44E+02
.OOE+00
.17E-03
.33E-06
.20E+00
.02E-01
.23E+00
.04E-02
.52E-01
.37E-01
.02E-01
.78E+00
.67E+00
.25E+01
.02E-01
.78E+00
NA
.56E+00
.67E+00
Toxicity Constant
Water
(wTc)
1/mg
2
5
1
8
1
5
3
3
2
4
"8
7
3
4
2
1
4
2
2
1
1
4
NA
.29E-03
.71E-01
NA
.OOE+00
.53E-01
. 17E-04'
.71E-03
. 12E+00
.43E+03
.37E-02
.74E-02
.86E-03
.07E-01
.OOE-02
.49E-02
.80E-01
.03E-02
.29E-03
.29E-03
. 79E-01
.03E-02
NA
.83E-02
.29E-03
Soil
(sTc)
kg/mg
1
2
5
4
5
2
1
1
1
2
4
3
1
2
1
5
2
1
1
5
9
2
NA
.14E-07
.86E-05
NA
.01E-05
.27E-05
.86E-09
.86E-07
.56E-04
.71E-01
.19E-06
.37E-06
.43E-07
.54E-05
.50E-06
.24E-06
.40E-05
. 14E-07
. 14E-07
. 14E-07
.39E-05
. 14E-07
NA
. 14E-07
. 14E-07
Inhalation Route
10%
Effective
Dose
(ED10)
mg/kg/day
1
5
2
3
2
5
9
8
1
6
3
4
9
6
1
2
6
1
1
2
1
6
NA
.25E+01
.OOE-02
NA
.85E-02
.35E-02
.44E+02
.OOE+00
. 17E-03
.33E-06
.20E+00
.02E-01
.23E+00
.04E-02
.52E-01
.37E-01
.02E-01
.78E+00
.67E+00
.25E+01
.02E-01
. 78E+00
NA
.56E+00
.67E+00
Air
Toxicity
Constant
(aTc)
m3/mg
2
5
1
8
1
5
3
3
2
4
8
7
3
4
2
1
4
2
2
1
1
4
NA
.29E-02
.71E+00
NA
.OOE+01
.53E+00
.17E-03
.71E-02
.12E+01
.43E+04
.37E-01
.74E-01
.86E-02
.07E+00
.OOE-01
.49E-01
.80E+00
.03E-01
.29E-02
.29E-02
. 79E+00
.03E-01
NA
.83E-01
.29E-02
1J The list of chemicals presented in this exhibit is based on EPA's Reportable
Quantities Analysis and should not be considered an all-inclusive list of suspected
carcinogens. Refer to Exhibit C-4 for toxicity data for risk characterization for the
chemicals listed here.
* October 1986 * *
-------
C-2i
OSWER Directive 9285.4-1
Date Prepared: October 1. 196o
EXHIBIT C-4
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION l-
Oral Route
Inhalation Route
Chemical Name
2-Acety 1 ammo f luorene
Acrylonitrile
Aflatoxin Bl
Aldrin
Amitrole
Arsenic and Compounds
Asbestos
Auramine
Azaserine
Aziridine
Benzene
Benzidine
Benz(a)anthracene
Benz(c)acridine
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranrhene
Benzotrichloride
Benzyl Chloride
Beryllium and Compounds
Bis(2-chloroethyl)ether
Bis(chloromethyl)ether
Bis(2-ethylhexyl)phthalate (DEHP)
Cacodylic Acid
Cadmium and Compounds
Carbon Tetrachloride
Chlordane
Chloroform
4-Chloro-o-toluidine Hydrochloride
Chromium VI and Compounds
Chrysene
Cyclophosphamide
DDD
DDE
DDT
Potency
Factor
(PF)
(mg/kg/d)-l
2
1
1
5
1
1
6
1
.1
8
3
.90E+03
. 14E+01
.50E+01
.20E-02
. 15E+01
NA
. 10E+00
.84E-04
NA
.30E-01
.61E+00
. 10E-02
NA
.40E-01
EPA Potency EPA
Weight Factor Weight
of (PF) of
Source2- Evidence (mg/kg/dl-1 Source2- Evidence
CAG
CAG
HEA
HEA
HEA
CAG
CAG
HEA
HEA
HEA
HEA
B2
Bl 2.40E-01 CAG
B2
B2
B2
A 5.00E+01 HEA
A
B2
B2
B2
A 2.60E-02 HEA
A 2.30E+02 CAG
B2
C
B2 6.10E+00 HEA
B2
D
B2
C
Bl 4.86E+00 CAG
B2
A 9 . 30E+03 CAG
B2
D
6.10E+00 HEA
B2
B2
B2
B2
4.10E+01 HEA
B2
Bl
B2
B2
B2
B2
Bl ,
B2
B2
B2
A
A
B2
B2
B2
A
A
B2
C
B2
B2
D
B2
C
Bl
B2
A
B2
D
Bl
B2
B2
B2
B2
A
B2
Bl
B2
B2
B2
October 1986
-------
OSWER Directive 9285.4-1
Dare Prepared: October i, 1956
EXHIBIT C-4
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Same
Diallate
Diaminotoluene (mixed)
1,2,7,8-Dibenzopyrene
Dibenz(a,h)anthracene
1,2-Dibromo-3-chloropropane
Dibutylnitrosamine
3,3'-Dichlorobenzidine
1,2-Dichloroethane (EDC)
1,1-Dichloroethylene
Dichloromethane
Dieldrin
Diepoxybutane
Diethanolnitrosamine
Diethyl Arsine
1,2-Diethylhydrazine
Diethylnitrosamine
Diethylstilbestrol (DES)
Dihydrosafrole
3,3'-Dimethoxybenzidine
Dimethyl Sulfate
Dimethylaminoazobenzene
7,12-Dimethylbenz(a)anthracene
3,3'-Dimethylbenzidene
Dimethylcarbamoyl Chloride
1,1-Dimethylhydrazine
1,2-Dimethylhydrazine
Dimethylnitrosamine
Dinitrotoluene (mixed)
2, "i-Dinitro toluene
2,6-Dinitrotoluene
1,4-Dioxane
1,2-Diphenylhydrazine
Dipropylnitrosamine
Epichlorohydrin
Ethyl-4,4'-dichlorobenzilate
Ethylene Dibromide (EDB)
Potency
Factor
(PF)
(mg/kg/d)-l Source1- E
5.40E+00 CAG
1 . 70E+00 CAG
9.10E-02 HEA
5.80E-01 HEA
7.50E-03 HEA
3.00E+01 CAG
4.40E+01 CAG
2.60E+01 CAG
3.10E-01 CAG
7.70E-01 CAG
9.90E-04 CAG
4.10E+01 CAG
EPA Potency
Weight Factor
of (PF)
Evidence (mg/kg/d)-l Source2- !
C
B2
B2
B2
B2
B2
B2
B2 3.50E-02 HEA
C 1.16E+00 HEA
B2 1.43E-02 HEA
B2
B2
B2
D
B2
B2
A
B2
B2
B2
B2
B2
B2
B2
B2
B2
B2
B2
S2
C
B2
Bl
B2
B2
B2
B2
EPA
Weight
of
lvidenc<
B2
B2
B2
B2
B2
B2
B2
B2
C
B2
B2
B2
B2
D
B2
B2
A
B2
B2
B2
B2
B2
B2
B2
B2
B2
B2
B2
B2
C
B2
B2
B2
B2
B2
B2
* * * October 1986 * * *
-------
C-26
OSWER Directive 9285.4-1
Dare Prepared:" October 1. 195c
EXHIBIT C-4
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Ethylene Oxide
Ethylenethiourea
Ethyl Methanesulfonate
1-Ethyl-nitrosourea
Formaldehyde
Glycidaldehyde
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorobutadiene
alpha-Hexachlorocyclohexane fHCCH1
beta-HCCH
gamma-HCCH (Lindane)
Hexachloroethane
Hydrazine
Indeno(l,2,3-cd)pyrene
lodomethane
Isosafrole
Kepone
Lasiocarpine
Melphalan
Methyl Chloride
3-Methylcholanthrene
4,4'-Methylene-bis-2-chloroaniline
Methylnitrosourea
Methylnitrosourethane
Methylthiouracil
Methylvinylnitrosamine
N-Methyl-N'1 -nitro-N-nitrosoguanadine
Mitomycin C
1-Napthylamine
2-Napthy1amine
Nickel and Compounds
N-Nitrosopiperidine
N-Nitrosopyrrolidine
5-Nitro-o-toluidine
Potency
Factor
(PF)
(mg/kg/d)-l 3ource2-
3
3
2
1
7
1
1
1
1
3
ne
2
. 30E+01 CAG
.40E+00 CAG
. 60E+00 CAG
.69E+00 HEA
.75E-03 HEA
. 10E+01 CAG
. 60E+00 CAG
. 33E+00 HEA
.40E-02 CAG
.OOE+02 CAG
NA
. 10E+00 CAG
EPA Potency
Weight Factor
of (PF)
Evidence (mg/kg/d)-l Source2-
B1/B2 3.50E-01 CAG
B2
B2
B2
B2
B2
B2
B2
B2
C
B2
C
B2/C
C
B2
C
C
B2
B2
B2
Bl
C
B2
B2
B2
• B2
B2
B2
B2
B2
C
A
A 1.19E+00 HEA
B2
B2
C
EPA
Weight
of
Evidence
B1/B2
B2
B2
B2
B2
B2
B2
B2
B2
C
B2
r
W
B2/C
C
B2
C
C
C
B2
B2
Bl
C
B2
B2
B2
B2
B2
B2
B2
B2
C
A
A
B2
B2
C
* * * October 1986 * * *
-------
C-27
OSWER Directive 9285.4-1
Date Prepared: October 1. 1956
EXHIBIT C-4
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION
Chemical Name
Pentachloronitrobenzene
Pentachlorophenol
Phenacetin
Polychlorinated Biphenyls (PCBs)
Polynuclear Aromatic Hydrocarbons
Propane Sultone
1,2-Propylenimine
Saccharin
Safrole
Streptozocin
2,3,7,8-TCDD (Dioxin)
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrachloroethane
Tetrachloroethylene
Thioacetamide
Thiourea
o-Toluidine hydrochloride
Toxaphene
1,1,2-Trichloroethane
Trichloroethylene
2,4,6-Trichlorophenol
Tris(2,3-dibromopropyl)phosphate
Trypan Blue
Uracil Mustard
Urethane
Vinyl Chloride
Oral Route
Inhalation Route
Potency EPA
Factor Weight
(PF) of
(mg/kg/d)-l SourceZj Evidence
Potency EPA
Factor Weight
(PF) of
(mg/kg/d)-l Source2j Evidence
4.34E+00
1.15E-KI1
1.56E-I-05
2.00E-01
5.10E-02
1.10E+00
5.73E-02
1.10E-02
1.98E-02
2.30E+00
HEA
HEA
HEA
HEA
HEA
CAG
HEA
HEA
HEA
HEA
C
D
B2
B2
B2
B2
C
B2
B2
B2
B2
C
B2
B2
B2
B2
B2
C
B2
B2
B2
B2
B2
B2
A
6.11E+00
HEA
1.70E-03
HEA
4.60E-03
HEA
2.50E-02
HEA
C
D
B2
B2
B2
B2
C
B2
B2
B2
C
C
B2
B2
B2
B2
B2
C
B2
B2
B2
B2
B2
B2
A
IJ The list of chemicals presented in this exhibit is based on EPA's Reportable Quantities
Analysis and should not be considered an.all-inclusive list ot suspected carcinogens. Refer
to Exhibit C-3 for toxicity constants for indicator selection for the chemicals listed here.
2J Sources for Exhibit C-4:
HEA = Health Effects Assessment, prepared by the Environmental Criteria and
Assessment Office, U.S. EPA, Cincinnati, Ohio, 1985 (updated in May 1986).
CAG = Evaluation by Carcinogen Assessment Group, U.S. EPA, Washington, D.C., 1985.
* * * October 1986 * * *
-------
OSVER Directive 9285.4-1
Date Prepared: October 1, 1986
EXHIBIT C-5
TOXICITY DATA FOR NONCARCINOGEN 1C EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY >-'
Oral Route
Inhalation Route
Chemical Name
Acenaphthene @
Acenaphthylene @
Acetone
Acetonitrile •
2-Acetylaminofluorene @
Acrylic Acid
Acrylonitrile @
Aflatoxin Bl @
Aldicarb
Aldrin @
Allyl Alcohol
Aluminum Phosphide
4-Aminobiphenyl @
Amitrole @
Ammonia
Anthracene @
Ant imony and Compounds
Arsenic and Compounds @
Asbestos @
Auramine @
Azaserine @
Aziridine @
Barium and Compounds
'Benefin
Benzene @
Benzidine (3
Benz(a)anthracene @
Benz(c)acridine @
Benzo(a)pyrene @
Benzo(b)fluoranthene @
Benzo(ghi)perylene @
Benzo(k)fluoranthene @
Benzotrichloride
-------
OSWER Directive 9285.4-1
C-29
Date Prepared: October 1. I9S6
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Bromoxynil Octanoate
1,3-Butadiene
n-Butanol
Butylphthalyl Butylglycolate
Cacodylic Acid
-------
OSVER Directive 9285.4-1
C-30
Date Prepared: October 1. l°So
EXHIBIT C-5
(Continued)
TOXIC1TY DATA FOR NONCARCINOGEN 1C EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Chemical Name
DDE @
DDT @
Decabromodiphenyl Ether
Diallate (?
2,4-Diaminotoluene @
1,2,7,8-Dibenzopyrene (3
Dibenz(a,h)anthracene @
1,2-Dibromo-3-chloropropane @
Dibutylnitrosamine @
Dibutyl Phthalate
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
3,3' -Dichlorobenzidine (3
Dichlorodifluoromethane
1,1-Dichloroethane
1,2-Dichloroethane (EDC) @
1,1-Dichloroethylene @
1,2-Dichloroethylene (cis)
1,2-Dichloroethylene (trans)
Dichloromethane @
2,4-Dichlorophenol
2,4-Dichlorophenoxyacetic
Acid (2,4-D)
4- (2 ,4-Dichlorophenoxy)butyric
Acid (2,4-DB)
Dichlorophenylarsine @
1,2-Dichloropropane
1,3-Dichloropropene
Dieldrin @
Diepoxybutane (3
Diethanolnitrosaraine @
Diethyl Arsine @
1,2-Diethylhydrazine (3
Diethylnitrosamine @
Diethyl Phthalate
Diethylstilbestrol (DES) @
Dihydrosafrole (3
Dimethoate
3,3'-Dimethoxybenzidine (§
Inhalation Route
Minimum
Effective
Dose
(MED)
rag/day
Toxicitv Constant
RVe
Water
(win)
1/mg
Soil
(sin)
kg/mg
Minimum
Effective
Dose
(MED)
mg/day
Air
Toxicitv
Constant
(aTn)
RVe m3/kg
L,
1
1
1
5
1
3
1
1
2
1
1
2
6
.20E+02
.54E+02
.54E+02
.54E+02
.42E+02 *
.14E+03
.77E+01
.89E+02 *
.89E+02 *
.18E+04
.21E+02
.29E+02
.OOE+02 *
.OOE-01
8
4
U
U
1
10
7
5
5
10
5
8
10
1
3
5
5
5
2
1
3
5
5
9
8
1
1
3
.81E-02
.19E-02
.19E-02
.19E-02
.58E-02
.76E-02
.71E-01
.29E-02
.29E-02
.20E-04
.26E-02
.24E-01
.OOE-01
.33E-I-00
1
2
2
2
1
6
1
2
2
A
4
6
5
1
.90E-06
.60E-06
.60E-06
.60E-06
.29E-06
'. 80E-07
.86E-05
.65E-06
.65E-06
.60E-08
. 13E-06
.20E-06
.OOE-06
.67E-04
4
2
2
2
5
1
1
1
1
2
1
1
2
3
.20E+02 *
.77E+02 *
.77E+02
.77E+02
.42E+02
.45E+02
.77E+01
.89E+02
.89E+02
.18E+04 *
.21E+02 *
.29E+02 *
. OOE+02
. 24E+00
8
5
5
5
7
8
5
5
5
10
5
8
10
5
3
3
3
3
2
1
5
5
5
9
8
1
1
3
.81E-01
.61E-01
.61E-01
.61E-01
.58E-01
. 10E+00
.65E+00
.29E-01
.29E-01
.20E-03
.26E-01
.24E+00
.OOE+00
.09E+01
2.99E+04
2.67E-04 1.34E-08 2.99E+04 * 4 2.67E-03
* * October 1986 * * *
-------
OSWER Directive 9285.4-1
C-31
Date Prepared: October 1. 1986
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Dimethylamine
Dimethyl Sulfate (3
Dimethyl Terephthalate
Dimethylaminoazobenzene (3
7,12-Dimethylbenz(a)anthracene (2
3 ,3 '-Dimethy Ibervzidine @
Dimethylcarbamoyl Chloride @
1,1-DimethyIhydrazine @
1,2-DimethyIhydrazine @
DimethyInitrosamine @
1,3-Dinitrobenzene
4,6-Dinitro-o-cresol
2,4-Dinitrophenol
2,3-Dinitrotoluene @ .
2,4-Dinitrotoluene @
2,5-Dinitrotoluene @
2,6-Dinitrotoluene @
3,4-Dinitrotoluene @
Dinoseb
1,4-Dioxane (?
N'.N-Diphenylamine !?
1,2-DiphenyIhydrazine (3
DipropyInitrosamine @
Disulfoton
Endosulfan
Epichlorohydrin @
Ethanol
Ethyl Acetate
Ethyl Methanesulfonate @
Ethylbenzene
Ethyl-4,4'-dichlorobenzilate @
Ethylene Dibromide (EDB) @
Ethylene Oxide @
Ethylenethiourea (§
1-Ethyl-nitrosourea @
Ethylphthalyl Ethyl Glycolate
Ferric Dextran @
Fluoranthene (§
Fluorene (§
Fluorides
Minimum Toxicity Constant Minimum Air
Effective Effective Toxicir
Dose Water Soil Dose Constan
(MED) (win) (sin) (MED) (aTn)
mg/day RVe 1/mg kg/mg
3.70E+01 * 6 3.24E-01 1.62E-05
mg/day RVe m3/kg
3.70E4-01 6 3.24E+O
1
2
1
2
2
.35E+00
.45E+00
.40E+01
.05E+01
.99E+01
6
8
8
9
9
8.89E+00 4.44E-04
6.53E+00 3.27E-04
1.14E+00 5.71E-05
8.78E-01 4.39E-05
6.02E-01 3.01E-05
1.35E+00 * 6 8.89E+0
2.45E-HDO * 8 6.53E+0
1.40E-f01 * 8 1.14E+0
2.05E+01 * 9
2.99E+01 * '9
5.98E+01 10 3.34E-01 1.67E-05 5.98E+01* 10 3.34E+OI
2.40E+04 10 8.33E-04 4.17E-08 2.40E+04 * 10 8.33E-0!
7.24E+02 * 4 1.10E-02 5.52E-07 7.24E+02 4 1.10E-0:
8.01E+00
1.25E+00 6.24E-05
October 1986
* * *
-------
OSVER Directive 9285.4-1
C-32
Date Prepared: October 1. 19S6
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Jnhalstion Route
Monoethyl Ether
Monoethyl Ether
Monomethyl Ether
Chemical Name
Fluridone
Formaldehyde
Formic Acid
Furan
Glycidaldehyde (2
Glycol Ethers (n.o.s.)
-- Diethylene Glycol
-- 2-Ethoxyethanol
-- Ethylene Glycol, Monobutyl Ether
-- 2-Methoxyethanol
-- Propylene Glycol
-- Propylene Glycol
Heptachlor (j
Heptachlor Epoxide
Hexachlorobenzene (?
Hexachlorobutadiene @
Hexachlorocyclopentadiene
alpha-Hexachlorocyclohexane (HCCH)@
beta-HCCH (2
gamma-HCCH (Lindane) <§
delta-HCCH (2
Hexachloroethane @
Hexachlorophene
Hydrazine (?
Hydrogen Sulfide
lndeno(l,2,3-cd)pyrene @
lodomethane @
Iron and Compounds
Isobutanol
Isoprene
Isosafrole @
Isophorone
Isopropalin
Kepone @
Lasiocarpine (?
Lead and Compounds (Inorganic)
Linuron
Malathion
Manganese and Compounds
Melphalan @
Minimum
Effective
Dose
(MED)
mg/day
Toxicity Constant
RVe
Water
(win)
1/mg
Soil
CsTn)
kg/mg
Minimum
Effective
Dose
(MED)
Air
Toxicity
Constant
(aTn)
mg/day RVe m3/kg
l.OOE+00
5.00E+01
10
1.81E+03
2.99E+01
6.62E-03 3.31E-07
6.02E-01 3.01E-05
4.49E+02
2.99E-I-01
5.50E+02 * 4 1.45E-02 7.27E-07 5.50E+02
1.40E+02
4.00E-01 2.00E-05 5.00E+01 * 10 4.00E-I-00
10 4.45E-01
9 6.02E+00
1.45E-01
2.24E+01 10 8.93E-01 4.46E-05 2.24E+01 * 10 8.93E-HJO
* *
October 1986 * * *
-------
C-33
OSWER Directive 9285.4-1
Date Prepared: October 1. 1966
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Mercury and Compounds (Alkyl)
Mercury and Compounds (Inorganic)
Mercury Fulminate
Methanol
Methyl Chloride
Methyl Ethyl Ketone
Methyl Ethyl Ketone Peroxide
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl Parathion
2-Methyl-A-Chlorophenoxyacetic Acid
2(2-Methyl-4-Chlorophenoxy)
propionic Acid
3-Methylcholanthrene @
4,4' -Methylene-bis-2-chloroaniline(?
Methylnitrosourea @
Methylthiouracil @
Methylvinylnitrosamine @
N-Methyl-N'-nitro-N-nitrosoguanadine@
Mitomycin C (2
Mustard Gas @
1-Napthylamine @
2-Napthylamine @
Nickel and Compounds @
Nitric Oxide
Nitrobenzene
Nitrogen Dioxide
Nitrosomethyl-urethane @
N-Nitrosopiperidine @
N-Nitrosopyrrolidine @
5-Nitro-o-toluidine @
Osmium Tetroxide
Pentachlorobenzene
Pentachloronitrobenzene @
Pentachlorophenol
Phenacetin @
Phenanthrene @
Phenobarbital @
Phenol
Phenylalanine Mustard @
Minimum
Dose
(MED)
mg/day
Toxicitv
Water
(win)
RVe 1/mg
Constant
Soil
(sin)
kg/mg
Minimum
_ _ „
Ertective
Dose
(MED)
mg/day
Air
Toxicity
Constant
(aTn)
RVe m3/kg
7.60E-01
2.21E+02 *
2.5SE+03 *
4.70E+00
10
10
1.76E+03 4
1.07E+01 10
10
8.62E+02 10
2.20E-01 6
5.98E+01
1.84E+01 9.21E-04 8.60E-01
8 1.86E+02
9.05E-02 4.52E-06
7.75E-03 3.87E-07
4.55E-03 2.28E-07
1.87E+00 9.35E-05
2.21E+02 10 9.05E-01
2.58E+03 10 7.75E-02
1.22E+02
2.40E-02
7 1.15E+00
5 4.17E+03
4.26E+00 2.13E-04 1.27E+00 10 1.57E+02
2.32E-02 1.16E-06
5.45E+01 2.73E-03
8.62E+02 * 10 2.32E-01
2.20E-01 * 6 5.45E+02
l.OOE-01 5.02E-06 8.02E+01 10 2.49E-MDO
October 1986
* * *
-------
C-34
OSVER Directive 9285.4-1
Date Prepared: October 1. 19S6
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
m-Phenylenediamine
Phenyl Mercuric Acetate
Phosphine
Polychlorinated Biphenyls (PCBs) @
Propane Sultone @
Propylenimine (2
Pyrene @
Pyridine
Saccharin @
Safrole
-------
C-35
OSVER Directive 9285.4-1
Date Prepared: October 1. 1986
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGEN 1C EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Toxaphene (3
Tribromomethane (Bromoform)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane @
Trichloroethylene (?
Trichlorofon
Trichloromonofluoromethane
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol §
2,4,5-Trichlorophenoxyacetic Acid
1,2,3-Trichloropropane
1,l,2-Trichloro-l,2,2-trifluoroethane
Tris(2,3-dibromopropyl)phosphate @
Trinitrotoluene (TNT)
Trypan Blue (§
Uracil Mustard @
Uranium and Compounds
L'rethane (?
Vanadium and Compounds
Vinyl Chloride (?
Warfarin
o-Xylene
m-Xylene
p-Xylene
Xylenes (mixed)
Zinc and Compounds
-- Zinc Phosphide
Zineb
Minimum
Effective
Dose
(MED)
6
3
5
9
4
mg/day
.60E+00
.73E+01
.45E+03 *
.50E+00
.52E+01
RVe
6
4
' 2
5
10
Toxicity
Constant
Water
(wTn)
1
2
7
1
4
1/mg
.82E+00
. 14E-01
.33E-04
.05E+00
.42E-01
9.
1.
3.
5.
2.
Soil
(sTn)
kg/mg
09E-05
,07E-05
.67E-08
,26E-05
,21E-05
Minimum
Effective
Dose
(.MED)
6
1
5
2
4
mg/day
.60E+00 *
.32E+01
.45E+03
.70E+00
. 52E+01 *
RVe
6
1
2
4
10
Air
Toxicity
Constant
(aTn)
1
1
7
2
4
m3/kg
.82E+01
.52E+OC
.33E-03
.96E+01
.42E+OC
1.18E+02
1.02E-01 5.10E-06 1.18E+02 * 6 1.02E+OC
1.70E+00
7.06E+00 3.S3E-04 1.70E+00 * 6
1.
2.
40E+01 1
28E+02 * 10
1.43E-01 7.14E-06
8.77E-02 4.39E-06
1.50E+02
1.07E-01 5.33E-06 1.50E+02
7.06E+01
1.40E+01 -•••- 1 1.43E+OC
2.28E+02 10 8.77E-0]
8 1.07E+OC
@ Potential carcinogenic effects also. See Exhibits C-3 and C-4.
* MED and RVe values marked with an asterisk, are based on values for the other exposure
route.
1J Refer to Exhibit C-6 for toxicity data for risk characterization for the chemicals
listed here.
2J N.O.S..= not otherwise specified.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
Date Prepared: October 1. 19Sc
EXHIBIT C-6
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION >-
Oral Route
Acceptable Intake
Inhalation Route
Acceptable Intake
Chemical Name
Acenaphthene 5
Acenaphthyiene §
Acetone
Aceton'itnle
2-Acetylaminofluorene (2
Acrylic Acid
Acrylonitrile (?
Aflatoxin Bl £
Aldicarb
Aldrin (|
Allyl Alcohol
Aluminum Phosphide
--Aminobipheny 1 (B
Amitrole (j
Ammonia
Anthracene (2
Antimony and Compounds
Arsenic and Compounds (2
Asbestos
-------
OSWER Directive 9285.4-1
C-3"
Date Prepared: October 1, 1956
EXHIBIT C-6'
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Same
n-Butanol
Butylpthalyl Butylglycolate
"Cacodylic Acid @
Cadmium and Compounds @
Captan
Carbaryl
Carbon Bisulfide
Carbon Tetrachloride @
Chlordane @
Chlorobenzene
Chlorobenzilate @
Chlorodibromomethane
Chloroform (§
Chloromethyl Methyl Ether @
4-Chloro-o-toluidine Hydrochloride@
Chromium III and Compounds
Chromium VI and Compounds @
Chrysene (?
Copper and Compounds
Creosote (?
Cresol
Crotonaldehyde
Cyanides (n.o.s.) 5J
-- Barium Cyanide
-- Calcium Cyanide
-- Cyanogen
-- Cyanogen Chloride
-- Copper Cyanide
-• Hydrogen Cyanide
-- Nickel Cyanide
— Potassium Cyanide
-- Potassium-Silver Cyanide
-- Silver Cyanide
-- Sodium Cyanide
-- Zinc Cyanide
Cyclophosphamide (§
Dalapon
DDD @
DDE @
DDT @
Decabromodiphenyl Ether
Diallate @
* * *
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
2.70E-01
l.OOE-01
l.OOE+00
l.OOE-02
2.90E-04'
l.OOE-01
l.OOE-01
5.00E-OS
2.70E-02
l.OOE-02
1.40E+01
2.50E-02
l.OOE+00
5.00E-03
3.70E-02 3.70E-02
RfD
RfD
RfD
HEA
RfD
RfD
RfD
HEA 5.30E-02 5.70E-03
RfD
HEA
RfD
HEA
HEA
5.00E-02
l.OOE-02
2.00E-02
7.00E-02
4.00E-02
4.00E-02
5.00E-02
7.00E-02
2.00E-02
2.00E-02
5.00E-02
2.00E-01
l.OOE-01
4.00E-02
5.00E-02
8.00E-02
5.00E-04
l.OOE-02
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
5.10E-03
l.OOE-02
l.OOE-01
HEA
HEA
HEA
October 1986
* * *
-------
OSWER Directive 9285.4-1
C-3S
EXHIBIT C-6
(Continued)
Date Prepared: October 1. 198o
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Acceptable Intake
Inhalation Route
Acceptable Intake
Chemical Name
2 ,4-Diaminotoluene (3
1,2 , 7 ,6-Dibenzopyrene (3
Dibenz(a,h)anthracene (3
1,2-Dibromo-3-chloropropane @
Dibutylnitrosamine @
Dibutyl Phthalate
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
3,3'-Dichlorobenzidine (3
Dichlorodifluoromethane
1,1-Dichloroethane
1,2-Dichloroethane (EDC) (3
1,1-Dichloroethylene @
1,2-Dichloroethylene (cis)
1,2-Dichloroe-thylene (trans)
Dichloromethane @
2,4-Dichlorophenol
2,4-Dichlorophenoxyacetic
Acid (2,4-D)
4-(2,4-Dichlorophenoxy)butyric
Acid (2,4-DB)
Dichlorophenylarsine (3
1,2-Dichloropropane
1,3-Dichloropropene
Dieldrin (3
Diepoxybutane (2
Diethanolnitrosamine @
Diethyl Arsine (3
1,2-Diethylhydrazine (3
Diethylnitrosamine (3
Diethyl.Phthalate
Diethylstilbestrol (DES) @
Dihydrosafrole (3
Dimethoate
3,3 '-Dimethoxybenzidine (3
Dimethylamine
Dimethyl Sulfate (3
Dimethyl Terephthalate
Dimethylaminoazobenzene @
7,12-Dimethylbenz(a)anthracene (=
3,3'-Dimethylbenzidine (3
.* *
Subchron Chronic Subchron Chronic
(AIS) (AIC) (AIS) (AIC)
--mg/kg/day-- Source --mg/kg/day-- Source
l.OOE-01 RfD
2.00E-01
1.20E+00 1.20E-01
9.00E-03
6.00E-02
3.00E-03
8.00E-03
RfD
HEA 1.38E+00 1.38E-01
RfD
RfD
RfD
RfD
HEA
1.30E+01 RfD
2.00E-02 RfD
l.OOE-01 RfD
October 1986 * * *
-------
OSVER Directive 9285.4-1
C-39
EXHIBIT C-6
(Continued)
Date Prepared: October 1. 1986
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
DimethyIcarbamoyl Chloride @
1,1-Dimethylhydrazine @
1,2-Dimethylhydrazine @
Dimethylnitrosamine @
1, 3-Dinitrobenzene
i,6-Dinitro-o-cresol
2,-i-Dinitrophenol
2,3-Dinitrotoluene @
2,4-Dinitrotoluene @
2 ,5-Dinitrotoluene (2
2,6-Dinitrotoluene @
3 ,4-Dinitrotoluene @
Dinoseb
1 ,4-Dioxane (2
N,N-Diphenylamine (?
1,2-Diphenylhydrazine @
Dipropylnitrosamine @
Disulfoton
Endosulfan
Epichlorohydrin (5
Ethanol
Ethyl Acetate
Ethyl Methanesulfonate @
Ethylbenzene
Ethyl-4,4'-dichlorobenzilate
Ethylene Dibromide (EDB) @
Ethylene Oxice (§
Ethylenethiourea (3
1-Ethyl-nitrosourea (?•
Ethylphthalyl Ethyl Glycolate
Ferric Dextran @
Fluoranchene @
Fluorene @
Fluorides
Fluridone
Formaldehyde
Formic Acid
Furan
Glycidaldehyde @
Glycol Ethers (n.o.s.)
-- Diethylene Glycol,
Monoethyl Ether
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
2.00E-03
l.OOE-03
4.00E-03
1.50E-05
2.00E-03
9.00E-01
9.70E-01 l.OOE-01
3.OOE+OO
6.00E-02
8.00E-02
2.00E+00
l.OOE-03
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
* * *
5.00E+00 2.00E+00 HEA
October 1986 * * *
-------
OSVER Directive 9285.4-1
C-40
EXHIBIT C-6
(Continued)
Date Prepared: October 1, 1986
TOXICITY DATA FOR NONCARCINOGEN 1C
EFFECTS -- RISK CHARACTERIZATION
Chemical Name
-- 2-Ethoxyethanol
-- Ethylene Glycol,
Oral Route
Acceptable Intake'
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Inhalation Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
4.7E-KT) 3.60E-01 HEA
Monobutyl Ether
-- 2-Methoxyethanol
-- Propylene Glycol,
Monoethyl Ether
-- Propylene Glycol,
Monomethyl Ether
Heptachlor (2
Keptachlor Epoxide <§
Hexachlorobenzene (2
Hexachlorobutadiene (2
Hexachlorocyclopentadiene .
alpha-Hexachlorocyclohexane (HCCH)(2
beta-HCCH (?
gamma-HCCH (Lindane) @
delta-HCCH @
Hexachloroethane (2
Hexachlorophene
Hydrazine @
Hydrogen Sulfide
Indeno(l,2,3-cd)pyrene @
lodomethane (2
Iron and Compounds
Isobutanol
Isoprene
Isosafrole @
Isophorone
Isopropalin
Kepone @
Lasiocarpine (3
Lead and Compounds (Inorganic)
Linuron
Malathion
Manganese and Compounds
Melphalan @
Mercury and Compounds (Alkyl)
Mercury and Compounds (Inorganic) 2.00E-03 2.00E-03
Mercury Fulminate 3.00E-03
Methanol 5.00E-01
Methyl Chloride
Methyl Ethyl Ketorie ' 5.00E-02
* * * October' 1986 *
6.60E+00 6.80E-01
6.80E+00 6.80E-01
3.00E-05
2.00E-03
7.00E-02 7.00E-03
3.00E-04
3.00E-03
3.00E-01
2.00E-01
3.00E-02
1.40E-03
2.00E-02
5.30E-01 2.20E-01
2.80E-04 3.00E-04
HEA
HEA
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
HEA
RfD
HEA
RfD
RfD
RfD
RfD
6.9E-2(T) 5.00E-02 HEA
1.60E-01 1.60E-02 HEA
5.9E-2(T) 2.40E-02 HEA
4.90E+00 4.90E-01
2.90E-03 6.60E-05
8.60E-03
4.30E-04
3.00E-04 3.00E-04
1.00E--04 l.OOE-04
5.10E-04 5.10E-05
HEA
HEA
HEA
RfD 2.20E+00 2.20E-01
HEA
HEA
HEA
HEA
HEA
-------
C-41
OSWER Directive 9285.4-1
Date Prepared: October 1. 1986
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day--
Source
Acceptable Intake
Subchron Chronic
(AIS). (AIC)
--mg/kg/day--
Source
Methyl Ethyl Ketone Perioxide 8.OOE-03
Methyl Isobutyl Ketone 5.OOE-02
Methyl Methacrylate
Methyl Parathion
2-Methyl-4-Chlorophenoxyacetic Acid 1.OOE-03
2(2-Methyl-4-Chlorophenoxy)
propionic Acid 3.OOE-03
3-Methylcholanthrene @
4,4' -Methylene-bis-2-chloroaniline(?
Methylnitrosourea @
Methylthiouracil @
Methylvinylnitrosamine (§
N-Methyl-N1-nitro-N-nitrosoguanadine@
Mitomycin C @
Mustard Gas (?
1-Napthylamine @
2-Napthylamine (§
Nickel and Compounds @ 2.OOE-02
Nitric Oxide
Nitrobenzene
Nitrogen Dioxide
Nitrosomethylurethane @
N-Nitrosopiperidine @
N-Nitrosopyrrolidine @
5-Nitro-o-toluidine @
Osmium Tetroxide
Pentachlorobenzene
Pentachl'oronitrobenzene (§
Pentachlorophenol
Phenacetin @
Phenanthrene (?
Phenobarbital @
Phenol
Phenylalanine Mustard @
m-Phenylenediamine 6.OOE-03
Phenyl Mercuric Acetate 8.OOE-05
Phosphine 3.OOE-04
Polychlorinated Biphenyls (PCBs) @
Propane Sultone @
Propylenimine (?
Pyrene @
Pyridine 2.00.E-03
* * * October 1986 * * *
3.0E-2(T)
l.OOE-01 I'.OOE-Ol
RfD
RfL
RfD
RfD
1. OOE-02
l.OOE-01
5. OOE-04
l.OOE+00
1. OOE-05
8. OOE-04
8. OOE-03
3. OOE-02
HEA
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD 1.90E-01 2.OOE-02
RfD
RfD
RfD
RfD
HEA
-------
C-42
OSWER Directive 9285.4-1
Date Prepared: October 1. 1966
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCA'RCINOGEN 1C
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Saccharin (?
Safrole @
Selenium and Compounds (n.o.s.)
-- Selenious Acid
-- Selenourea
-- Thallium Selenite
Silver and Compounds
Sodium Diethvldithiocarbamate
Streptozocin @
Strychnine
Styrene
1,2,4 ,5-Tetrachlorobenzene
2,3,7,6-TCDD (Dioxin) @
1,1,1,2-Tetrachloroethane @
1,1,2,2-Tetrachloroethane @
Tetrachloroethylene @
2,3,4,6-Tetrachlorophenol
2,3,5 , 6-Tetrachloroterephth.alate
Acid (DCPA)
Tetraethyl Lead @
Thallium and Compounds (n.o.s.)
-- Thallium Acetate
-- Thallium Carbonate
-- Thallium Chloride
-- Thallium Nitrate
-- Thallic Oxide
-- Thallium Sulfate
Thioacetamide (2
Thiourea @
o-Tolidine @
Toluene
o-Toluidine Hydrochloride (|
Toxaphene (§
Tribromomethane (Bromoform)
1,2 ,4-Trichloroben.zene
1,1,1-Trichloroethane
1,1,2-Trichloroethane @
Trichloroethylene @
Trichlorofon
Trichloromonofluoromethane
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol @
* * *
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Acceptable Intake
Subchron Chronic
(A1S) (AIC)
--mg/kg/day-- Source
3.20E-03 3.00E-03
3.00E-03
5.00E-03
5.00Z-04
3.00E-03
3.00E-02
3.00E-04
2.00E-01
3.00E-04
2.00E-02
l.OOE-02
5.00E-02
l.OOE-07
4.00E-04
5.00E-04
4.00E-04
OOE-04
OOE-04
OOE-04
5.OOE-04
4.30E-01 3.00E-01
2.00E-02
5.40E-01
3.00E-01
l.OOE+00 l.OOE-01
HEA l.OOE-03
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD 1.50E+00 1.50E+00
HEA
RfD
HEA
RfD
RfD
1.10E+01 6.30E+00
HEA
HEA
October 1986
* * *
-------
OSVER Directive 9285.4-1
C-43
EXHIBIT C-6
(Continued)
Date Prepared: October 1. 1986
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Chemical Name
2,4,5-Trichlorophenoxyacetic Acid
1,2,3-Trichloropropane
l,l,2-Trichloro-l,2,2-
Trifluoroethane
Tris (2,3-dibromopropvl)phosphate (c
Trinitrotoluene (TNT)
Trypan Blue @
Uracil Mustard-§
Uranium and Compounds
Urethane @
Vanadium and Compounds
Vinyl Chloride (3
Warfarin
o-Xylene
m-Xylene
p-Xylene
Xylenes (mixed)
Zinc and Compounds
-- Zinc Phosphide
Zineb
Oral Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Inhalation Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
3
1
3
2
.OOE-02
.OOE-01
.OOE+01
.OOE-04
RfD
RfD
RfD
RfD
2.00E-02 RfD
3.00E-04 RfD
l.OOE-01 l.OOE-02 HEA
l.OOE-01 l.OOE-02 HEA
l.OOE-01 l.OOE-02 HEA
2.10E-01 2.10E-01 HEA
3.00E-04 RfD
5.00E-02 RfD
9.6E-KT) 2.00E-01 HEA
l.OOE+00 2.00E-01 HEA
6.9E-1(T) 4.00E-01 HEA
l.OOE-01 l.OOE-02 HEA
(§ Potential carcinogenic effects also. See Exhibits C-3 and C-4.
lj Refer to Exhibit C-5 for toxicity data for indicator selection for the
chemicals listed here.
2J Sources for Exhibit C-6:
RfD = Agency-wide reference dose value, developed by an inter-office work group
chaired by the Office of Research and Development, U.S. EPA, Washington, D.C. ,
1986.
HEA = Health Effects Assessment document, prepared by the Environmental Criteria
and Assessment Office, U.S. EPA, Cincinnati, Ohio, 1985 (updated in May 1986).
JJ The RfD values listed here are EPA-verified numbers. All RfD values were
derived based on oral exposure; however, in the absence of other more specific data,
these values may also be useful in assessing risks of inhalation exposure.
kj T indicates that teratogenic or fetotoxic effects are the basis for the AIS
value listed.
SJ N.O.S. = not otherwise specified.
* * * October 1986
* * *
-------
C-42
OSWER Directive 9285.4-1
Date Prepared: October 1. 1966
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Saccharin (5
Safrole @
Selenium and Compounds (n.o.s.)
-- Selenious Acid
-- Selenourea
-- Thallium Selenite
Silver and Compounds
Sodium Diethyldithiocarbamate
Streptozocin (£
Strychnine
Styrene
1,2,4,5-Tetrachlorobenzene
2,3,7,6-TCDD (Dioxin) @
1,1,1,2-Tetrachloroethane (3
1,1,2,2-Tetrachloroethane (?
Tetrachloroethylene @
2,3,4,6-Tetrachlorophenol
2,3,5 , 6-Tetrachloroterephth,alate
Acid (DCPA)
Tetraethyl Lead <§
Thallium and Compounds (n.o.s.)
-- Thallium Acetate
-- Thallium Carbonate
— Thallium Chloride
-- Thallium Nitrate
-- Thallic Oxide
-- Thallium Sulfate
Thioacetamide (2
Thiourea @
o-Tolidine @
Toluene
o-Toluidine Hydrochloride @
Toxaphene (3
Tribromotnethane (Bromoform)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane @
Trichloroethylene @
Trichlorofon
Trichloromonofluoromethane
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol @
* * *
Acceptable Intake
Subchron Chronic
IAIS) (AIC)
--mg/kg/day-- Source
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
3.20E-03 3.00E-03 HEA
3.00E-03 RfD
5.00E-03 RfD
5.00E-04 RfD
3.00E-03 RfD
3.00E-02 RfD
3.00E-04 RfD
2.00E-01 RfD
3.00E-04 RfD
2.00E-02 RfD
l.OOE-02 RfD
4.30E-01 3.00E-01
2.00E-02
5.40E-01
3.00E-01
l.OOE+00 l.OOE-01
October 1986 *
l.OOE-03
HEA
5
1
4
5,
4,
5.
5.
4,
5 ,
. OOE-02
.OOE-07
.OOE-04
. OOE-04
.OOE-04
.OOE-04
.OOE-04
.OOE-04
.OOE-04
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD 1.50E+00 1.50E-I-00
RfD
HEA
RfD
RfD
1.10E+01 6.30E+00
HEA
HEA
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OSVER Directive 9285.4-1
C-43
EXHIBIT C-6
(Continued)
Date Prepared: October 1. 1986
TOXICITY DATA FOR NONCARC1NOGENIC
EFFECTS -- RISK CHARACTERIZATION
Chemical Name
2,4,5-Trichlorophenoxyacetic Acid
1,2,3-Trichloropropane
l,l,2-Trichloro-l,2,2-
Trifluoroethane
Tris(2,3-dibromopropy 1)phosphate @
Trinitrotoluene (TNT)
Trypan Blue @
Uracil Mustard (S
Uranium and Compounds
Urethane (3
Vanadium and Compounds
Vinyl Chloride (§
Warfarin
o-Xylene
m-Xylene
p-Xylene
Xylenes (mixed)
Zinc and Compounds
-- Zinc Phosphide
Zineb
Oral Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Inhalation Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
3.
1.
3.
2.
OOE-02
OOE-01
OOE+01
OOE-04
RfD
RfD
RfD
RfD
2. OOE-02 RfD
3. OOE-04 RfD
1.OOE-01 1.OOE-02 HEA
1.OOE-01 1. OOE-02 HEA
1.OOE-01 1.OOE-02 HEA
2.10E-01 2.10E-01 HEA
3.OOE-04 RfD
5.OOE-02 RfD
9.6E-KT) Z.OOE-01 HEA
l.OOE+00 2.OOE-01 HEA
6.9E-HT) A.OOE-01 HEA
1.OOE-01 1.OOE-02 HEA
(3 Potential carcinogenic effects also. See Exhibits C-3 and C-4.
lj Refer to Exhibit C-5 for toxicity data for indicator selection for the
chemicals listed here.
2J Sources for Exhibit C-6:
RfD = Agency-wide reference dose value, developed by an inter-office work group
chaired by the Office of Research and Development, U.S. EPA, Washington, D.C.,
1986.
HEA = Health Effects Assessment document, prepared by the Environmental Criteria
and Assessment Office, U.S. EPA, Cincinnati, Ohio, 1985 (updated in May 1986).
IJ The RfD values listed here are EPA-verified numbers. All RfD values were
derived based on oral exposure; however, in the absence of other more specific data,
these values may also be useful in assessing risks of inhalation exposure.
*J T indicates that teratogenic or fetotoxic effects are the basis for the AIS
value listed.
5J N.O.S. = not otherwise specified.
* * * October 1986
* * *
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OSWER Directive 9285.4-1
C-44
EXHIBIT C-7
CHEMICALS AND CHEMICAL GROUPS HAVING'EPA HEALTH
EFFECTS ASSESSMENT (HEA) DOCUMENTS 1J
CHEMICAL
KTISrj PB NUMBER
Acetone
Arsenic and Compounds
Asbestos
Barium and Compounds
Benzene
Benzo ( a ) pyr ene
Cadmium and Compounds
Carbon Tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chromium III and Compounds
Chromium VI and Compounds
Coal Tars
Copper and Compounds
Cresol
Cyanides
DDT
1 , 1 -Dichl'oroethane
1,2-Dichloroethane (EDC)
1 , 1-Dichloroethylene
1 ,2-cis-Dichloroethylene
1 , 2-trans-Dichloroethylene
Dichloromethane
Ethylbenzene
Glycol Ethers
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
gamma -Hexachlorocyclohexane (Lindane)
Iron and Compounds
Lead and Compounds (Inorganic)
Manganese and Compounds
Mercury
Methyl Ethyl Ketone
Naphthalene
Nickel and Compounds
Pentachlorophenol
Phenanthrene
Phenol
Polychlorinated Biphenyls (PCBs)
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
86
134277/AS
134319/AS
134608/AS
134327/AS
134483/AS
134335/AS
13449 I/AS
134509/AS
134343/AS
134517/AS
134210/AS
13446 7 /AS
134301/AS
134350/AS
134368/AS
134616/AS
134228/AS
134376/AS
134384/AS
134137/AS
134624/AS
134269/AS
134525/AS
134392/AS
134194/AS
134632/AS
134285/AS
134640/AS
134129/AS
134673/AS
134657/AS
134665/AS
134681/AS
134533/AS
134145/AS
134251/AS
134293/AS
134541/AS
134400/AS
134186/AS
134152/AS
* * October 1986
* *
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OSVER Directive 9285.4-1
C-45
EXHIBIT C-7
(Continued)
CHEMICALS AND CHEMICAL GROUPS HAVING EPA HEALTH
EFFECTS ASSESSMENT (HEA) DOCUMENTS lj
CHEMICAL
NTLS2J PB NUMBER
Polynuclear Aromatic Hydrocarbons
Pyrene
Selenium and Compounds
Sodium Cyanide
Sulfuric Acid
2,3,7,8-TCDD (Dioxin)
1,1,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Vinyl Chloride
Xylene
Zinc and Compounds
Complete Set of 58 HEAs
86 134244/AS
86 134418/AS
86 134699/AS
86 134236/AS
86 134426/AS
86 134558/AS
86 134434/AS
86 134202/AS
86 134442/AS
86 134160/AS
86 134566/AS
86 134574/AS
86 134459/AS
86 134582/AS
86 134475/AS
86 134178/AS
86 134590/AS
86 134111/AS
lj As of the date of publication for this manual.
2J National Technical Information Service.
October 1986 * * *
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OSWER Directive 9285.4-1
APPENDIX D
DETAILED PROCEDURES FOR DETERMINING TOXICITY
CONSTANTS FOR INDICATOR CHEMICAL SELECTION
* * October 1986 * * *
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OSVER Directive 9285.4-1
D-l
APPENDIX D
DETAILED PROCEDURES FOR DETERMINING TOXICITY
CONSTANTS FOR INDICATOR CHEMICAL SELECTION
The method for selecting indicator chemicals for a site, described in
Chapter 3 of this manual, requires the determination of toxicity constants
(T). For many chemicals, these values are given in Appendix C. This appendix
(Appendix D) presents methods for calculating toxicity constants for chemicals
not listed in Appendix C. If, in the process of preparing a public health
evaluation for a site, such chemicals are found, you should request help from
EPA headquarters before doing these calculations. As new information becomes
available or new chemicals are identified as problems, the list in Appendix C
will be updated and expanded.
Toxicity constants, T, are medium-specific. A toxicity constant for use
w
with drinking water concentrations is referred to as T, whereas one for
concentrations in air is aT, and and one for concentrations in soil is
ST. Toxicity constants for potential carcinogens are based on the
ED nlj; for noncarcinogens they are based on the minimum effective dose
(MED) and a severity of effects rating. All toxicity constants also have
standard intake assumptions built in. Units of toxicity constants are the
inverse of concentration units.
Values of *7, ST, and WT for a variety of compounds are given in
Appendix C. In the event that values are not present in Appendix C, they can
be calculated as follows:
Potential Carcinogens
w 2 liters drinking water/day
Tc = [1]
70 kg • ED10
s 0.0001 kg soil/day
Tc = . [2]
70 kg • ED10
a 20 m3 air/day
Tc = ' [3]
70 kg • ED10
1J ED n = dose in mg/kg/day at which 10% incidence above control is
observed for a tumor type showing a-statistically significant incidence.
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
D-2
where the ED - is derived from carcinogenicity dose-response data and is
expressed in mg/kg/day.
Noncarcinogens
w 2 liters drinking water/day • RVe
Tn = _
MED (oral)
0.0001 kg soil/day • RVe
[5]
MED (oral)
20 in3 air/day • RVe
_
MED (inhalation)
[6]'
where RVe is a rating value based on the severity of effect and scored as
indicated in Exhibit D-l, and MED is the human minimum effective dose in
mg/day for a given effect. If the MED is given in mg/kg/day, multiply it by
70 and then substitute it into the above equation.
The soil toxicity constant ( T) is incorporated as a way to estimate the
overall exposure that might be contributed by contaminated soil. Inclusion of
T in the indicator selection process is a way to use the soil concentration
data gathered in most site characterizations, in part so that compounds found
in soil and not in air and water could be considered in indicator compound
scoring. The T equation is based on a child's consumption of contaminated
soil as detailed in a recent ORD risk assessment of contaminated soil (EPA,
1984).
The ORD document estimates that children between the ages of two and six
consume at least 100 mg of soil per day, and that in situations of direct
ingestion of soil (i.e., pica) the rate could go as high as 5 g per day. The
lower value was selected for this procedure because it was more comparable to
the standard consumption values used in calculating the other T values. The 5
g per day value is representative of a pathologic state (pica) , and using it
to calculate T would correspond to assuming 8 liters or more as the daily
consumption of water (to reflect the diabetic who consumes 8 liters of water
per day) .
Although Equations 2 and 5 are based on ingestion by a child, the intake
is not normalized to an equivalent lifetime intake. The equations use an
intake rate during childhood rather than an lifetime average daily intake to
ensure that compounds are identified on the basis of their potential to harm a
child. Thus, the equations compare a child's daily intake rate to a lifetime
average daily intake (expressed as an MED or an ED...), which, strictly
speaking, may be inappropriate. Unfortunately, the most appropriate data to
use, dose-response information for children, do not exist, and even data for
dose-response relationships in immature animals are rare. What little
* * * October 1986- - * * *
-------
OSVER Directive 9285.4-1
D-3
EXHIBIT D-1
RATING CONSTANTS -(RVe) FOR NONCARCINOGENS^
Severity
Effect Rating (RVe)
Enzyme induction or other biochemical change with no pathologic 1
changes and no change in.organ weights.
Enzyme induction and subcellular proliferation or other changes 2
in organelles but no other apparent effects.
Hyperplasia, hypertrophy or atrophy, but no change in organ 3
weights.
Hyperplasia, hypertrophy or atrophy with changes in organ weights. 4
Reversible cellular changes: cloudy swelling, hydropic change, 5
or fatty changes.
Necrosis, or metaplasia with no apparent decrement of organ 6
function. Any neuropathy without apparent behavioral, sensory,
or physiologic changes.
Necrosis, atrophy, hypertrophy, or metaplasia with a detectable 7
decrement of organ functions. Any neuropathy with a measurable
change in behavioral, sensory, or physiologic activity.
Necrosis, atrophy, hypertrophy, or metaplasia with definitive 8
organ dysfunction. Any neuropathy with gross changes in behavior,
sensory, or motor performance. Any decrease in reproductive
capacity, any evidence of fetotoxicity.
Pronounced pathologic changes with severe organ dysfunction. Any 9
neuropathy with loss of behavioral or motor control or loss of
sensory ability. Reproductive dysfunction. Any teratogenic
effect with maternal toxicity.
Death or pronounced life-shortening. Any teratogenic effect with- 10
out signs of maternal toxicity.
1J Rating scale identical to that used by EPA in the RQ adjustment
process, as described in EPA (1983).
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1
D-4
information is available seems to indicate that the young are generally more
sensitive to the toxic effects of chemicals than adults. Although this
approach is not strictly accurate it errs on the more protective side, while
at the same time achieving the goal of being a simple way to incorporate soil
concentration information into the indicator selection process.
Although not used directly in the calculation of indicator scores for
potential carcinogens, a qualitative weight-of-evidence rating is considered
in the final selection of indicators. The EPA weight-of-evidence criteria
(EPA, 1986) are given in Exhibit D-2 and should be used to categorize
potential carcinogens not listed in Appendix C. The EPA approach for
determining weight of evidence is similar to the International Agency for
Research on Cancer (IARC) approach, differing primarily by having an
additional category for "no evidence of carcinogenicity in humans" and revised
criteria for defining evidence as "sufficient", "limited", or "inadequate."
REFERENCES FOR APPENDIX D
.U.S. EPA, 1983. Methodology and Guidelines for Reportable Quantity
Determinations Based on Chronic Toxicity Data, External Review Draft.
Prepared by the Environmental Criteria and Assessment Office, Office of Health
and Environmental Assessment. ECAO-CIN-R245.
U.S. EPA, 1986. Guidelines for Carcinogen Risk Assessment. Federal
Register 51:33992.
U.S. EPA, 1984. Risk Analysis of TCDD Contaminated Soil. Prepared by the
Exposure Assessment Group, Office of Health and Environmental Assessment. EPA
600/8-84-031.
* * * October 1986 * * *
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OSWER Directive 9285.4-1
D-5
EXHIBIT D-2
EPA WEIGHT-OF-EVIDENCE
CATEGORIES FOR POTENTIAL CARCINOGENS
EPA
Category
Description
of Group
Description of Evidence
Group A Human Carcinogen Sufficient evidence from epidemiologic studies
to support a causal association between exposure
and cancer
Group Bl
Probable Human
Carcinogen
Limited evidence of carcinogenicity in humans
from epidemiologic studies
Group.B2
Probable Human
Carcinogen
Sufficient evidence of carcinogenicity in
animals, inadequate evidence of carcinogenicity
in humans
Group C Possible Human Limited evidence of carcinogenicity in animals
Carcinogen
Group D Not Classified Inadequate evidence of carcinogenicity in animals
Group E
No Evidence of
Carcinogenicity
in Humans
No evidence for carcinogenicity in at least two
adequate animal tests or in both epidemiologic
and animal studies
* * * October 1986 * * *
-------
-------
OSVER Directive 9285.4-1
U-,
n
APPENDIX E
MEMORANDUM OF UNDERSTANDING
f BETWEEN
I
THE AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY
V
(. AND
r THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
W-
r April 2, 1985
i "
r
\_
* * * October 1986 * * *
-------
OSWER Directive 9285.4-1 ~
''
-2-
3. SCOPE OF RESPONSIBILITIES ^
This MOU covers the coordination of health-related ':*
activities by ATSDR and EPA as authorized bv CERCLA and I'j
delegated by Executive Order 12V16. ATSDR has statutory
responsibilities under CERCLA and Executive Order 12316 for -~j
activities related to illness, disease, or complaints thereof, ^
for disease registries and other responsibilities related to
response actions. EPA has statutory authority under CERCLA
and Executive Order 12316 for activities related to release .
or threat of release of hazardous substances, pollutants or ^
contaminants, and for determination of the extent of .danger
to public health, welfare or the environment, as well as, "'"
other responsibilities related to response actions.
ATSDR and EPA will carry out their responsibilities
according to CERCLA, Executive Order 12316, the NCP, and
this MOU. ATSDR's major responsibility will be the
evaluation of populations with current or potential exposure
to waste sites, development of health advisories, and_the •
follow up on populations for the evaluation of future health ')
effects. EPA's major resoonsibility in the health area will
be risk assessment and risk management as defined herein. "?
Health advisories will be based on ATSDR's evaluations of ,.-;
current health effects and will adapt EPA's risk assessments
at a site or sites. ATSDR will not perform risk assessments
as defined herein, using the funds made available from the
Hazardous Substances Response Trust Fund. If risk assessments J
are not available ATSDR will consult EPA on a case-by-case
basis. ATSDR will conduct some of its activities through ^
interagency agreements with other participating agencies of ^
the Public Health Service through cooperative agreements with
State health departments, and through contractual arrangements -~i
whenever appropriate. Such interaqency agreements include ""''•
those with the Centers for Disease Control to conduct health ~"
studies and conduct research and provide assistance on worker
health and safety issues; with the Library of Medicine to ',
establish and maintain the needed data bases on health effects
of toxic substances; and with the National Toxicology Program
to conduct standard toxicological assays.
Definitions for the key terms used in this section follow:
8 Health Consultation; Immediate or short-term ,-
consultation by ATSDR to orovide health advice and/or •-
health effects information regarding a specific site.
8 Health Assessment; Initial multi-disciplinary reviews '
by ATSDR of all readily available data to evaluate
-------
OSWER Directive 9285.4-1
MEMORANDUM 0"F UNDERSTANDING
BETWEEN
THE AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY
AND
THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
1. PURPOSE
The Agency for Toxic Substances and Disease Registry
(ATSDR) and the Environmental Protection Agency (EPA) agree
that guidance is required to define and coordinate joint and
respective responsibilities under the Comprehensive Environ-
mental Response, Compensation, and Liability Act (Public Law
96-510, 94 Stat. 2796, 42 USC.9601 et seq; CERCLA), Executive
Order 12316 (Responses to Environmental Damage), and the
National Oil and Hazardous Substances Contingency Plan (NCP;
40 CFR Part 300). This Memorandum of Understanding (MOU)
establishes oolicies and procedures for conducting response
and non-response health activities related to releases of
hazardous substances.
2. AUTHORITY
CERCLA section 104 authorizes the President to respond
to releases or substantial threats of releases into the
environment of hazardous substances and certain releases of
pollutants or contaminants. CERCLA also establishes the
Hazardous Substance Response Trust Fund. CERCLA section 104(i)
authorizes A.TSDR (part of the Department of Health and Human
Services (HHS)) to effectuate and implement specific health-
related activities with the cooperation of EPA and other agencies
Executive Order 12316 further delegates to the Secretary of
HHS certain investigatory authorities vested in the President
under CERCLA section 104 for conducting activities with the
cooperation of other agencies, relating to illness, disease or
complaints thereof. Executive Order 12316 delegates to EPA
the primary resoonse authority under CERCLA section 104
relating to release or extent of release of hazardous sub-
stances, pollutants, or contaminants, and determination of
the presence of an imminent and substantial danger to the
public health or welfare or the environment. Exceptions to
this authority include responses to releases from Department
of Defense (DOD) facilities or vessels (delega-ted to DOD) and
releases involving the coastal zone, Great Lakes waters,
ports, and harbors (delegated to the U.S. Coast Guard).
-------
OSWER Directive 9285.4-1
-4-
ATSDR activities in support of soecific removal
actions involve health consultations and health advisories.
In addition, ATSDR may monitor the health of residents who
have been exposed to the hazardous substances or who live
near the release site. ATSDR may also provide technical
assistance to EPA on matters of worker health and safety
durinq the removal and may provide community relations
assistance to EPA. ATSDR may become involved in removal
actions through a variety of mechanisms and at various stages
of a removal action. The On-Scene Coordinator (OSC) shall-
recommend that ATSDR be called in at any time during the
removal action, at the time that the criteria under Section
B.3 are met, unless in the OSC's opinion there is no need for
further public health input into the removal action. Altern-
atively, the recommendation for ATSDR involvement may be
initiated by ATSDR itself, the State, or the EPA Regional
Administrator.
B. Remedial Response
Remedial actions are those response actions consistent
with a permanent remedy at a site. Remedial action is
preceded by detailed planning. This section discusses
coordination of ATSDR and EPA efforts during the remedial
response process, which involves five major stages:
0 Site discovery, preliminary
assessment, and site inspection;
0 Site ranking and MPL listing?
0 Remedial investigation (RI);
0 Feasibility study (FS); and
0 Remedial design and construction.
The roles of ATSDR and EPA during these stages are
discussed in the subsections below.
B.l" Site Discovery, Preliminary Assessment, and Site
Inspection
There are different methods for identifying sites for
potential remedial response under the Superfund program.
CERCLA section 103 requires certain parties to notify the
National Response Center when they have knowledge of a
release of a hazardous-substance equal to or in excess of the
reportable quantity for that substance. Motificati'on is
forwarded to EPA and the affected State. In addition to this
formal notification process, EPA may receive notification of
a potential or actual release from a local, State, or Federal
agency that discovers the release in the performance of its
responsibilities. Following notification of a potential or
actual release, EPA conducts a preliminary assessment of the
site to determine whether further investigation and Hazard
Ranking System (MRS) scoring is warranted.
-------
OSVER Directive 9285.4-1
i.
i,-
^ -3-
the nature and magnitude of any threat to human
p health at a site. These evaluations will adapt
w/ , EPA's risk assessment for the characterization of
potential health threats at a site or sites, and may
include literature searches, information summari-
zation and evaluation of existing environmental data,
L' pilot samples, testing for food chain contamination,
_ and similar activities.
r
0 Public Health Advisory; An advisory issued by ATSDR
based on the results of its health assessment.
0 Epidemiologic Studies: Long-term epidemiologic study
by ATSDR involving a comprehensive protocol designed
to add knowledge of the health effects of a specific
substance or substances at a site or sites.
0 Health Registry; A site-specific or adverse health
P effects-specific registry established and maintained
L to track specific diseases and illnesses and long-
term health effects to persons exposed to toxic
r substances.
0 Pilot Study: A preliminary or short term medical,
r_ laboratory, or epidemiologic study on a limited human
(", pooulation to decide if additional, large scale
v-._ studies are warranted. The study populations can
include those living at, or near, a site and those
not residing at, or near, a site (control or reference
population).
p ° Risk Assessment; A qualitative/quantitative process
K conducted by EPA to characterize the nature and
magnitude of potential risks to public health from
exposure to hazardous substances, pollutants or
j contaminants released from specific sites. This
u process consists of hazard identification, dose-
response assessment, exposure assessment, and risk
characterization and supports EPA's risk management
process.
0 Risk Management; The process conducted by EPA to
determine the nature and extent of remedy for a site,
including alternative selection.
A. Removal Actions
(-..
Removal actions are Superfund response activities
H involving the short-term cleanup or removal of released
{_-" hazardous substances that pose an immediate hazard. These
actions generally are limited by CERCLA to $1 million in cost
and six months in duration.
['*
-------
OSWER Directive 9285.4-1
-6-
necessary. In deciding whether to request concurrent ATSDR 1
involvement, the Regional Administrator, or his designee,
will consider the following criteria: ._
• ai
° Whether the presence of ,toxic subs-tances has been --f
confirmed at the site;
• --1
0 Whether oathways of huma". exposure to toxic substances ~ ,'>
have been demonstrated to exist at the site, esoecially
if such pathways involve direct contact with toxic .—,
substances; and -^
;_;
8 Whether a human population has been exposed to toxic
substances via the identified pathways, and whether ' "'
there exists a threat of current or future health ,3.
effects to the population being so exposed, after
considering EPA's risk assessments or health , "i
effects information from other sources. (
If these criteria are met, the EPA Regional Administrator, or
his designee, shall request concurrent ATSDR involvement, \
unless in his opinion there is no need for further public
health input into the RI/FS. Alternatively, the recommendation
for ATSDR involvement may be initated by ATSDR itself, or the
State. ' ,
Elements of the remedial investigation in which ATSDR
participates may include review of site sampling plans and
analysis protocols, site sampling, data analysis and interpre-
tation, worker health and safety, community relations, and the
remedial investigation report. The division'of responsibilities 1
and coordination between EPA and ATSDR in conducting these J
activities is described in the following paragraphs. EPA and
ATSDR will agree to strict time schedules on a site-specific
basis for all activities to be performed by ATSDR, to ensure '!
that the response process is not delayed. Any changes in the
time schedule will be mutually aareed upon by EPA and ATSDR.
1
Site Sampling. Where -EPA has requested concurrent ATSDR -;
involvement, ATSDR will advise EPA during the preparation of
sampling and analysis protocols to ensure collection of data '
useful to ATSDR for health assessments and epidemiological ^
studies. EPA will be responsible for the development and
conduct of any environmental and biological (other than
human) sampling, and developing the tests therefor. ATSDR ' •
will consult with appropriate health agencies and will summarize
recommendations regarding the necessity for testinq of human
subjects. If human subject testing is determined to be -"";
necessary, ATSDR will be responsible for any such testing. '-'
EPA shall review the protocols or sampling plans for such
testing to ensure collection of data useful to EPA in perform-
ing subsequent risk assessment and risk management. __f
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OSWER Directive 9285.4-1
-5-
r^
•!_' Site discovery, preliminary assessment, and site
inspection are primarily the responsibility of EPA. If
r ATSDR discovers a potential or actual release during the
\' performance of its responsibilities, ATSDR will notify EPA
'•- of this release. EPA may perform preliminary assessments and
site inspections of such releases, as warranted, and will
p determine whether further investigation is necessary.
I ,
B.2 Site Ranking and NPL Listing
i CERCLA section 105(8) reauires the President to develop
criteria for determining priorities among releases or
threatened releases of hazardous substances and, based upon
{ ' those criteria, oublish and amend the NPL. Executive Order
e? 12316, section l(c) delegates to EPA "[t]he responsibility
for. . .all of the. . .functions vested in section 105" of
P CERCLA.
Decisions regarding snecific site scoring and listing of
:-- sites on the NPL are the responsibility of EPA. If ATSDR
1 discovers any information about potential candidates for the
'S- NPL during the performance of its responsibilities, ATSDR
will submit that information to ^PA. To facilitate this, EPA
|~. Keadouarters will notify ATSDR prior to each amendment of the
L. NPL to allow ATSDR to recommend sites to be considered for
the NPL, and EPA will consider such recommendations, based upon
p the data used by ATSDR to make the recommendation, before
1 publishing the amended NPL. EPA may decide to rank sites
^ identified by ATSDR, retain the site information on EPA files
for future reference, or seek further information about such
(- sites, and will notify ATSDR of its decision.
i- .
B.3 Remedial Investigation
r
H CERCLA section 104(b) authorizes the President to under-
take "such investigations, monitoring, surveys, testing, and
y- other information gathering" necessary to "identify the
f~: existence and extent of the release or threat thereof, the
*"-> source and nature of hazardous substances, pollutants or
contaminants involved, and the extent of danger to public
f~ health or welfare or the environment." Section 2(a) of
L Executive Order 1-2316 delegates to' the Secretary of HHS in
cooperation with other agencies, those functions of Section
f- 104(b) "relating to illness, disease, or complaints thereof."
l_ HHS's responsibilities are performed by ATSDR. Section 2(e)
• """ delegates to EPA most of the remaining authorities under
r.. section 104, including those functions under section 104(b)
! : listed above as they relate to the occurrence or potential
L" occurrence of a release.
f: The EPA Regional Administrator, or his designee, will
L determine as early as possible in the RI/FS process for a
site whether concurrent ATSDR involvement in the RI/FS is
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OSVER Directive 9285.4-1
-8-
Remedial Investigation Report. At the conclusion of the
remedialinvestigation at sites where ATSDR is involved, EPA
will send a copy of the remedial investigation report to ATSDR.
ATSDR will review health-related data and interpretations of
such data in the report and provide comments to EPA within a
mutually agreed upon time frame.
If EPA and ATSDR agree that ATSDR involvement is not
required at a site, ATSDR will not participate in the remedial
planning process at that site. ATSDR may undertake other •-,«
statutory activities, such as epidemiological studies or J
disease registries, at a site or sites. ATSDR will coordinate
all such activities with EPA and will advise EPA of imminent
threats to human health at any site and at any time during
EPA's remedial process. In addition, EPA may request ATSDR ;
assistance in disseminating health information to the public
and in responding to health concerns of local citizens. . "}
,i
8.4 Feasibility Study
EPA has the final authority for determining the extent
of remedy at a site and selecting a specific remedy during
the feasibility study. In conducting feasibility studies,
EPA will develop, evaluate, and select remedial options using >(
the approach described in its feasibility study guidance. For J
those sites where there has been concurrent ATSDR involvement,
EPA staff will consult ATSDR for its assessment of any
human health data (e.g., clinical, epidemiologic) and EPA's
risk assessment resulting from the remedial investigation.
EPA will be responsible for performing qualitative/quantitative
risk assessments evaluating long-term risks to the public that }
raay result from exposure to hazardous substances from Superfund -J
sites.
It is the responsibility of EPA (Office of Solid Waste ,j
and Emergency Response) to in-corporate the results of the
risk assessment process and of health assessments by ATSDR •-,
into risk management determinations of the extent of remedy ,
for a site. The goal of this process is to ensure that the
remedial action is adequate with reqard to eliminating or
mitigating the existing and future public health threats. '
EPA may consider and incorporate applicable information
provided by ATSDR on the current status of public health at
the site into the selection of the preferred remedy. At the
discretion of the appropriate Regional Administrator, EPA ^j
staff may also consult with ATSDR staff for any interpre-
tation of human health data at sites where ATSDR is not
concurrently involved. In addition, EPA may request ATSDR '"]
assistance at any site in disseminating health information to
the public and in responding to health concerns of local
citizens. In the course of performing its health activities, ~^
should ATSDR discover any site which, in its opinion, poses • _^
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OSWER Directive 9285.4-1
:
-7-
Sampling Protocol. Where EPA has reauested concurrent
ATSDR involvement, EPA and ATSDR will submit a draft of all
protocols to each other for review prior to institution of
any site sampling or monitoring. Any changes in the sampling
protocols will also be provided to ATSDR for review. With
regard to the review of non-site soecific protocols, (e.g.,
protocols- for standard Contract Laboratory Program analysis)
EPA will provide these to ATSDR for review as early as possible
to avoid the necessity of ATSDR review of these protocols on
a site specific basis.
Data Analysis and Interpretation. At sites where EPA
has requested -concurrent ATSDR involvement, EPA will-provide
its data from environmental, toxicolog>cal and other biolog-
ical sampling and testing to ATSDR. ATSDR will review all
available data for a site, including EPA's hazard identifi-
cation, dose-response assessment, exposure assessment, and
risk characterization information, drawing conclusions about
any threats to public health associ-ated with the site. Based
on its interpretation of the site data, ATSDR will characterize
the health threats based on its evaluation of current health
effects and in consultation with EPA concerning the magnitude
and timing of potential future health effects. ATSDR will
communicate all health concerns to regional EPA staff and
will provide copies of health assessments and advisories to
EPA.
Worker Health and Safety. EPA may request assistance
from ATSDR on worker health and safety issues during a
remedial investigation, includina consultation on the design
of worker health and safety plans and monitoring of plan
imnlementation. ATSDR will make arrangements for laboratory
and field testing related to worker health and safety and
worker surveillance.
L Community Relations. ATSDR may provide, at EPA's request,
assistance in conducting community relations activities durina
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OSWER Directive 9285.4-1
-10-
written notice of the other party. Nothing in the Memorandum
is intended to diminish or otherwise alter statutory authority
of the agencies involved.
5. AMENDMENTS
This Memorandum may be amended at any time by -the agree-
ment of both parties. Each amendment must be in writing and
signed by the appropriate ATSDR and EPA officials.
6.
EFFECTIVE DATE
This Memorandum will become effective at noon on the date
of the last signature below.
Date :
MAY ?
-2 r.
For the Agency for Toxic
Substances and Disease
Registry
Da tfe:
For the United States
Environmental Protection
Agency
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OSWER Directive 9285.4-j
il." ' -9-
p an imminent threat to public health, ATSDR will immediately
',••' notify the relevant EPA Regional Office and EPA Headquarters
^ • of this finding.
f~* For each remedial response site where ATSDR involvement
L is reouested , EPA will provide ATSDR with a copy of the
draft feasibility study, and where appropriate with rough
r~ draft sections of the feasibility study relating to human
I" health and interpretation, prior to' the public comment period
if possible. ATSDR will review the interpretation of the
,_. human health data in the draft feasibility study and provide
; comments to EPA during the public comment period. ATSDR will
-- also provide to EPA any health information it possesses on
the site during the public comment period
i
H' B.5 Remedial Design and Construction
/r-- The design and construction of the selected remedy at
S"-: Superfund sites is EPA' s responsibility. The Regional
k' Administrator may, at his•discretion, request a health
assessment from ATSDR with reaard to certain elements of the
I : remedial design. At the conclusion of the design stage,
£.* , EPA should provide advance copies of the Remedial Design and
Construction Plans to ATSDR whenever possible if they wish
r- 'review and comment by ATSDR. ATSDR will notify EPA if the
•^ remedial design does not, in its opinion, eliminate or miti-
gate the public health threat.
[.. C. Cost Recovery
Under CERCLA, EPA is authorized to recover from responsible
{-n" narties all government costs incurred during a response
t-A action. ATSDR agrees to conform with all procedures and
requirements for documenting costs that are to be recovered.
;-'
*• D. Funding
All costs incurred by ATSDR in performing its CERCLA
K-; responsibilities are funded by ATSDR through funds provided
£,: for this purpose. Funding for ATSDP activities performed
under CERCLA is from the Hazardous Substances Response Trust
p Fund and is provided by EPA through the budget task force
|\, required by Section 7 of Executive Order 12316 or through
seoarate interagency agreements for specific health studies.
r-~ ATSDR will comply with the financial and reporting requirements
>.'• outlined in the Interagency Agreements that transfer Fund
^ monies to ATSDR.
!:' 4. PERIOD OF AGREEMENT
Lk
This Memorandum of Understanding will continue in effect
r until modified or amended by the assent of both parties or
j.t terminated by either party uoon a thirty (30) day advance
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