United States
Enwonrnont&l Protection
Agency
Office of Solid Waste and
Emergency Response
Washington. D.C. 20460
8285.7-01/FS
April 1990
EPA
Risk Assessment Guidance
for Superfund: Volume I
Human Health Evaluation Manual
(Part A)
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division, OS-230
Quick Reference Fact Sheet
The overarching mandate of the Superfund program is to protect human health and the environment from current and
potential threats posed by uncontrolled releases of hazardous substances. To help meet this mandate, the U.S.
Environmental Protection Agency's (EPA's) Office of Emergency and Remedial Response (OERR) has developed a human
health evaluation process as part of its remedial response program. EPA's Human Health Evaluation Manual describes the
process of gathering information and assessing the risk to human health, and together with the Environmental Evaluation
Manual comprise a two-volume set (Volumes I and n, respectively) called Risk Assessment Guidance for Superfund (RAGS).
RAGS replaces two previous EPA guidance documents: the Superfund Public Health Evaluation Manual (SPHEM; 1986) and
the Draft Endangerment Assessment Handbook (1985).
The Human Health Evaluation Manual has three main parts: baseline risk assessment (Part A), refinement of preliminary
remediation goals (Part B), and risk evaluation of remedial alternatives (Part C). Part A of this manual is being distributed as
an Interim Final document. Remedial project managers (RPMs) should ensure that the procedures in this guidance be used
for all new human health risk assessments conducted as part of the remedial investigation/feasibility study (RI/FS) process.
Copies of Part A can be obtained by calling EPA's Center for Environmental Research Information at 513-569-7562 (FTS
684-7562). Parts B and C are targeted for completion in 1990.
This fact sheet is designed to alert RPMs and other personnel to (1) new aspects of the Human Health Evaluation Manual
(Part A), (2) the purpose and steps of the baseline risk assessment, and (3) where additional help can be obtained.
PURPOSE OF THE HUMAN HEALTH
EVALUATION
The human health evaluation is used in the Superfund
program to:
help identify which sites warrant remedial action;
provide a consistent process for evaluating and
documenting human health risk;
ensure protectiveness by the refinement of
risk-based, site-specific remediation goals;
provide focus for the FS;
help to measure the effectiveness of remedial
alternatives; and
aid in priority setting for remedial design/
remedial action.
HUMAN HEALTH EVALUATION IN THE
RI/FS PROCESS
The RI/FS is the methodology that the Superfund program
has established for characterizing the nature and extent of
risks posed by uncontrolled hazardous waste sites and for
developing and evaluating remedial options. The
Superfund Amendments and Reauthorization Act of 1986
reemphasized the original statutory mandate that remedies
meet the threshold requirement to protect human health
and the environment. Because the RI/FS is an analytical
process designed to support risk management
decision-making, the assessment of health and
environmental risk plays an essential role in the RI/FS.
Highlight 1 shows the stages of the RI/FS, relating health
risk evaluation activities to each stage. Although the RI/FS
process and related risk evaluation activities are presented
in a fashion that makes the steps appear sequential and
distinct, in practice the steps are usually highly interactive.
HUMAN HEALTH EVALUATION AND
ENDANGERMENT FINDINGS
One of EPA's goals in the Superfund program is to use
more CERCLA section 106 (i.e., imminent and substantial
endangerment) orders to compel potentially responsible
parties to design and conduct the remedial actions. In order
for EPA to issue and enforce a section 106 order, the
baseline risk assessment must be sufficient to support the
finding that there may be an imminent and substantial
endangerment to public health or welfare or the
environment because of an actual or threatened release of
a hazardous substance. By requiring careful adherence to
the Human Health Evaluation Manual (together with the
Environmental Evaluation Manual), the resulting baseline
risk assessment should be adequate to support an
endangerment finding and thus a CERCLA section 106
order.
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Highlight 1
Human Health Risk Evaluation Activities in the RI/FS Process
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PART A OF THE MANUAL:
BASELINE RISK ASSESSMENT
The baseline risk assessment process described in Part A of
the manual consists of four main steps as shown in
Highlight 2. Relevant information identified through data
collection and evaluation (Step 1) is used to develop
exposure and toxicity assessments (Steps 2 and 3). Risk
characterization (Step 4) summarizes and integrates both
the toxicity and exposure steps into quantitative and
qualitative expressions of risk.
WHAT'S NEW IN THE MANUAL
The Human Health Evaluation Manual revises and builds
upon the health evaluation process established in SPHEM.
Provided are new information and techniques gleaned from
several years of program experience conducting risk
assessments at hazardous waste sites. Policies established
and evolved over the years including those resulting
from the revised National Oil and Hazardous Substances
Pollution Contingency Plan (NCP) have been updated
and clarified. In addition, the link between the human
health evaluation, the environmental evaluation, and the
RI/FS has been strengthened.
HIGHLIGHTS OF THE REVISION
i
Introduction. Emphasizes shift in NCP and RI/FS
philosophy toward efficiency, effectiveness, and a bias for
action.
Data Collection (new chapter). Encourages assessors' early
involvement in RI/FS planning and effective
communication with RPMs. Describes procedures for
acquiring reliable chemical release and exposure data for
quantitative assessment. The topics discussed in the Data
Collection chapter are shown in Highlight 3.
Data Evaluation (new chapter). Provides nine steps to
organize data and to identify a set of chemicals and
concentrations that are of acceptable quality for use in the
quantitative risk assessment. The nine data evaluation
steps are shown in Highlight 4.
Highlight 2
Part A: Baseline Risk Assessment
JL
Exposure Assessment
AnHyz* conun*urt raton**
M«nt8y
E*tknM* xpooira concwttnUon*
torpMtiwiy*
EitknM* contamkunt MakM tor
pathway*
: DaU Collection and Evaluation:
Utnttty potential chmteato d concern
Risk Characterization
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Highlight 3
Topics Discussed in
Data Collection Chapter
Available alto Information
Modeling parameter needs
Background sampling needs
Preliminary Identification of human ex-
posure
Overall strategy for sample collection
Need for Special Analytical Services
Activities during workplan development
and data collection
Exposure Assessment Gives specific equations and
parameter values for common Superfund site exposure
pathways. Defines the revised NCP's reasonable maximum
exposure (RME) concept under both current and future
land-use conditions. Highlight 5 defines the RME and
describes the specific terms in the general exposure
equation used to generate the RME.
Toxicity Assessment Discusses EPA guidances, toxicity
data bases, and Superfund technical assistance groups.
Provides updated discussion of EPA's tenacity assessment
methods. Defines hierarchy of toxicity data sources, as
shown in Highlight 6.
Risk Characterization. Provides guidance for summarizing
risk information for use in decision-making. Presents
Highlight 4
Data Evaluation Steps
Stepl: Gather all data available from the she
Investigation and sort by medium.
Step 2: Evaluate the analytical methods used.
Step 3: Evaluate the quality of data with respect to
sample quantisation limits.
Step 4: Evaluate the quality of data wtth respect to
qualifiers and codes.
Step 5: Evaluate the quality of data with respect to
blanks.
Step 6: Evaluate tentatively Identified compounds.
Step 7: Compare potential site-related contamination
with background.
Step 8: Develop a set of data for use In the risk
assessment
Step 8: If appropriate, further limit the number of
chemicals to be carried through the risk
assessment
expanded discussion of uncertainty. Includes examples of
helpful visual presentations of risk assessment as shown in
Highlights 7 and 8.
Documentation, Review, and Management Tools (new
chapter). Presents new tools for the RPM, risk assessor,
and risk assessment reviewer. These new tools are
described in Highlight 9. They include an RPM
involvement checklist (see Highlight 10), recommended
format for a baseline risk assessment report, and a risk
assessment reviewer's checklist.
Highlight 5
Reasonable Maximum Exposure (RME)
The reasonable maximum exposure (RME) is de-
fined as the highest exposure that could reasonably
be expected to occur at a site. RME Is calculated
using the following general equation.
I « C x CRxEFD x J_
BW AT
where:
I «= Intake; the amount of chemical at the
exchange boundary (mg/kg body
weight- dy).
C « Concentration; the average chemical
concentration contacted over the
exposure period (e.g.. mg/l).
CR * Contact Rate; the amount of
contaminated medium (e.g.. soil. air.
water) contacted per unit time or event
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Hlghllght 6
Hierarchy of Toxicity Data Sources
Integrated Risk Information System (IRIS)
Provides verified reference doses
(RfDs) and slope factors
Updated monthly
EPA's preferred source of toxicity
information
Health Effects Assessment Summary Tables
(HEAST)
Provides Interim as well as
verified RfDs and slope factors
Should be used only for
chemicals not addressed in IRIS
Other EPA References
Do not necessarily provide verified
RfDs and slope factors
Should be used only for chemicals
not found or referenced In IRIS or
HEAST
EPA's Environmental Criteria and
Assessment Office must be contacted
first (513-569-7300; FTS 684-7300)
Highlight 8
Example of Presentation of Relative
Contribution of Individual
Chemicals to Exposure Pathway
and Total Hazard Index Estimates
Nearby Resident Population
Chronic Hazard Index - 0.6
1.2
1.1
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SI .0 Mfcitts that R Is unlllwty tor mm Mntttlwt human populations to
Mptrtmo* advw
Radiation Risk Assessment Guidance (new chapter).
Provides basic principles and concepts of radiation
protection and supplemental baseline risk assessment
guidance for use at sites contaminated with radioactive
substances.
Appendices (new). Provide technical information on
absorbed vs. administered dose, and a complete index for
quick reference.
Highlight 7
Example of Presentation of Relative
Contribution of Individual Chemicals
to Exposure Pathway and Total
Cancer Risk Estimates
Nearby Resident Population
Excess Lifetime Cancer Risk 5 3 x 10 *
I10"1"
8 10-8-
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NEED MORE HELP?
Superfund Health Risk Assessment Technical Support
Center. This center provides program staff and their
contractors access to the Office of Health and
Environmental Assessment (OHEA) and other Agency
experts in the area of health risk assessment. The center is
coordinated by OHEA's Environmental Criteria and
Assessment Office in Cincinnati (513-569-7300 or FTS
684-7300); it offers technical guidance in all areas of health
risk assessment, including project scoping, sampling
methods, exposure assessment, toxicity assessment, and
risk characterization. ECAO may respond to questions
directly or refer callers to other OHEA or Agency offices.
In addition, callers may be referred initially to regional
Toxics Integration Coordinators for responses to
site-specific requests (see next section).
Highlight 9
New Documentation, Review,
and Management Tools
RPM Involvement Checklist (see Highlight
10). The checklist addresses risk information
needs and Includes pointers on planning and
involvement for the RPM. Involvement of
managers In the direction and development of
the risk assessment helps to avoid serious
mistakes or costly misdirections in focus or level
of effort
Recommended Format for a Baseline Risk
Assessment Report Consistency of
Superfund risk assessment format encourages
completeness, consistent use of results, and
allows for easier review.
Risk Assessment Reviewer's Checklist The
checklist is intended as a guide to ensure that
critical issues concerning the quality and
adequacy of risk information are not overlooked.
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Hlghllght 10
Checklist for RPM Involvement
1. Getting Organized
Ensure that the workplan for the risk assessment
contractor support is In place (If needed).
- Identify EPA risk assessment support personnel (to be
used throughout the risk assessment process).
Gather relevant Information, such as appropriate
guidances and she-specific data and reports.
e Identify available state, county, and other non-EPA
resources.
e Prior to Special Notice, determine whether the PRPa will
be allowed to do the risk assessment
2. Before the Scoping Meeting
e Make Initial contact with risk assessor.
e Provide risk assessor with available guidances and she
e Determine (or review) data collection needs for risk
assessment, considering:
modeling parameter needs;
type and location of background samples;
alternate future land use;
possible exposure scenarios;
location(s) In ground water that will be used to
evaluate future ground-water exposures;
the preliminary Identification of environmental
concerns;
strategies (Including medium and location) for sample
collection appropriate to she/risk assessment needs;
statistical methods;
QA/QC measures of particular Importance to risk
assessment; and
special analytical services needs.
3. At the Scoping Meeting
e Present risk assessment data collection needs.
e Ensure that the risk assessment data collection needs
will be considered In development of the sampling and
analysis plan.
5. During Sampling and Analysis
e Ensure that risk assessment needs are being met
during sampling.
e Provide risk assessor with any preliminary sampling
results so that he/she can determine If sampling
should be refocused.
e Consult with ATSOR to obtain a status report on any
human monitoring that Is being conducted. Provide
any results to risk assessor.
6. During Development of Risk Assessment
e Meet wtth risk assessor to discuss basis for excluding
chemicals from the risk assessment (and developing
the list of chemicals of potential concern). Confirm
appropriateness of excluding chemicals.
e Confirm determination of alternate future land use.
e Confirm location(s) In ground water that will be used
to evaluate future ground-water exposures.
e Understand basis for selection of pathways and
potentially exposed populations.
e Facilitate discussions between risk assessor and EPA
risk assessment support personnel on the following
points:
the use of any major exposure, fate, and transport
models (e.g., air or ground-water dispersion
models);
she-specific exposure assumptions;
non-EPA-dertvod toxichy values; and
appropriate level of detail for uncertainty analysis,
and the degree to which uncertainties will be
quantified.
e Discuss and approve combination of pathway risks
and hazard indices.
e Ensure that results of risk characterization have been
compared wtth ATSDR health assessments and any
she-specific human studies that might be available.
7. Reviewing the Risk Assessment
e Allow sufficient time for review and Incorporation of
comments.
e Where limited resources require that less-than-optimal 8.
aampling be conducted, discuss potential Impacts on risk
assessment result*.
4. After the Scoping Meeting
e Ensure that the risk assessor reviews and approves the
sampling and analysis plan.
e Consult with the Agency for Toxic Substances and
Disease Registry (ATSDR) if human monitoring Is
planned.
e Ensure that reviewers' comments are addressed.
Communicating the Risk Assessment
e Plan a briefing among technical staff to discuss
significant findings and uncertainties.
e Discuss development of graphics, tools, and
presentations to assist risk management decisions.
e Consult wtth other groups (e.g., community relations
staff), as appropriate.
e Brief upper management
Regional Toxics Integration Coordinators and
Headquarters Contacts. Superfund Toxics Integration
Coordinators are located in each region. Questions
regarding site-specific Superfund risk assessment issues
should be referred to the appropriate individuals listed in
Highlight 11. The Toxics Integration Branch, OERR, may
be contacted at 202-475-9486 (FTS 475-9486) for
technical information sources, availability of guidances,
and related program directives.
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Hlghllght 11
Regional Toxics Integration Coordinators
Region Name and Address
i
I Sarah Levinson
Waste Management Division (HSS-CAN-7)
EPA Region I
John F. Kennedy Federal Building
Boston, MA 02203
II Peter Grevatt
Program Support Branch
ERR Division
EPA Region II
26 Federal Plaza
New York, NY 10278
III Richard Brunker
Hazardous Waste
Management Division (3HW15)
EPA Region III
841 Chestnut Street
Philadelphia, PA 19107
IV Elmer Akin
Waste Management Division
EPA Region IV
345 Courtland Street, NE
Atlanta, GA 30365
V Steve Ostrodka
Technical Support Unit (5HSM-12)
EPA Region V
230 South Deartiom Street
Chicago, IL 60604
VI Jon Rauscher
EPA Region VI (6H-SR)
First Interstate Bank Tower
1445 Ross Avenue
Dallas, TX 75202-2733
VII Superfund Branch
EPA Region VII
726 Minnesota Avenue
Kansas City, KS 66101
VIII Chris Weis
EPA Region VIII (8HWM-SR)
999 18th Street, Suite 500
Denver, CO 80202-2405
IX Gerald Hiatt
Technical Support Section (H-8-4)
Superfund Program
EPA Region IX
1235 Mission Street
San Francisco, CA 94103
X Pat Cirone
EPA Region X (ES-098)
1200 Sixth Avenue
Seattle, WA 98101
Phone Number
FTS 833-1504
617-223-5504
FTS 264-8775
212-264-6323
FTS 597-0804
215-597-0804
FTS 257-1586
404-347-1586
FTS 886-3011
312-886-3011
FTS 255-2198
214-655-2198
FTS 236-7052*
913-551-7052
FTS 330-7655
303-294-7655
FTS 484-1914
415-744-1914
FTS 399-1597
206-442-1597
Caller must have FTS 2000. If not. use commercial number.
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