### EPA/540/1-89/002 December 1989



# Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual

(Part A) Interim Final

Office of Emergency and Remedial Response U.S. Environmental Protection Agency Washington, D.C. 20450Page ii 

### NOTICE The policies and procedures set forth here are intended solely as guidance to EPA and other governmen t e mployees and contractors. This guidance does not constitute rulemaking by the Agency, and cannot be relied on to c reate a substantiv e or procedural right enforceable by any party in litigation with the United States. EPA may take a c tion that is at variance with the policies and procedures in this manual and may change them at any time without public notice. T his interim final guidance is b ased on policies in the proposed revisions to the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), which were published on December 21, 1988 (53 Federal Register 51394). The final NCP may adopt policies different than those in this manual and should, when promulgated, b e conside redthe authoritative source. A final version of this manual will be published after the revised NCP i s promulgated. F ollowing the date of its publication, this manual is i ntended to be used as guidance for all human health risk a ssessments c onducted as part of Superfund remedial investigations and feasibility studies. Issuance of this manual d oes not invalidate human health risk assessments completed before (or in progress at) the publication date and based on previously released Agency guidance.Page iii 

### ABOUT THE REVISION . . . WHAT IT EPA's Human Health Evaluation Manualis a revision of the Superfund Public IS Health Evaluation Manual(SPHEM; October 1986); it is Volume I of the two-volume set called Risk Assessment Guidance for Superfund . This manual has three main parts: the baseline ris k ass essment(Part A); refinement of preliminary remediation goals (Part B); and evaluation o f remedial alternatives (Part C). (Only Part A is included in the first distribution; see below.) WHO IT'S Risk assessors, risk assessment reviewers, remedial project managers (RPMs), and risk FOR managers involved in Superfund site cleanup activities will benefit from this revision. WHAT'S This revision builds upon the process established in SPHEM and provides more detailed NEW g uidance on many of the procedures used to assess health risk. New information and techniques are presen tedthat reflect the extensive Superfund program experience conducting health ris k assessments at Superfund sites. Policies established and refined over the years

-- especially those resulting from the proposed National Oil and Hazardous Substances Pollutio n Contingency Plan (NCP) -- have been updated and clarified. Additionally, the links between the h uman health evaluation, the environmental evaluation, and the remedial investigation/feasibility study (RI/FS) have been strengthened. In Part A you will find: F or the risk assessor -- Updated procedures and policies, specific equations and variable values for estimating exposure, and a hierarchy of toxicity data sources. For the risk assessment reviewer-- A baseline risk assessment outline for consisten t presentation of risk information and format, and a reviewer's checklist to ensur e appropriate quality and content of the risk assessment. F or the RPM -- A comprehensive overview of the risk assessment process in the RI/FS, achecklis t for RPM involvement throughout the process, and a complete index for quick reference. F or the risk manager -- An expanded ch apter on risk characterization (Chapter 8) to help su mmarize and present risk information for the decision-maker, and more detaile d descriptions of uncertainties in the assessment. DISTRIBU- This manual is being distributed as an interim final document while the proposed NCP is TION PLAN b eing finalized. After the final NCP is published, the manual will be updated and finalized. Parts B and C -- which were not distributed as interim final becau se they are highly dependent on possible revisions to the NCP -- will be added. Periodically, updates of portions of the manual will b e distributed. WHERE Toxics Integration Branch TO SEND Office of Emergency and Remedial Response COMMENTS 401 M Street, SW (OS-230) Washington, DC 20460

Phone: 202-475-9486Page iv 

### WORKGROUP EPA HEADQUARTERS Office of Emergency and Remedial Response: Marlene Berg David Cooper Linda Cullen Carla Dempsey Steve Golian Bruce Means Pat Mundy Sandra Panetta Office of Solid Waste: Stephanie Irene Office of Waste Programs Enforcement: Georgia Valaoras Office of Solid Waste and Emergency Response: Larry Zaragoza Office of Policy, Planning, and Evaluation: Charlotte White Craig Zamuda Office of General Counsel: Joe Freedman Office of Research and Development: Rebecca Madison Sue Norton Office of Water: Frank Gostomski Robert Zeller EPA REGIONAL OFFICES Region I: Sarah Levinson Region V: Dan Bicknell Pamela Blakley Region VI: Fred Reitman Region X: Dana Davoli David Tetta OTHER EPA OFFICES Great Lakes National Program Office, IL: Cynthia Fuller Office of Health and Environmental Assessment, OH: Chris DeRosa Office of Air Quality Planning and Standards, NC: Fred HauchmanPage v 

### TABLE OF CONTENTS Page 

### INTRODUCTION CHAPTER 1 INTRODUCTION ....................................................... 1-1 1.1 OVERVIEW OF THE HUMAN HEALTH EVALUATION PROCESS IN THE RI/FS ........................................................ 1-3 1.1.1 Project Scoping ....................................................... 1-4 1.1.2 Site Characterization (RI) ............................................... 1-4 1.1.3 Feasibility Study ...................................................... 1-8 1.2 OVERALL ORGANIZATION OF THE MANUAL ................................ 1-10 CHAPTER 2 STATUTES, REGULATIONS, GUIDANCE, AND STUDIES RELEVANT

TO THE HUMAN HEALTH EVALUATION ................................. 2-1 2.1 STATUTES, REGULATIONS, AND GUIDANCE GOVERNING HUMAN HEALTH EVALUATION ................................................... 2-1 2.1.1 CERCLA and SARA .................................................. 2-1 2.1.2 National Contingency Plan (NCP) ........................................ 2-4 2.1.3 Remedial Investigation/Feasibility Study Guidiance .......................... 2-5 2.1.4 ARARs Guidance .................................................... 2-7 2.1.5 Superfund Exposure Assessment Manual .............................. 2-8 2.2 RELATED SUPERFUND STUDIES ........................................... 2-8 2.2.1 Endangerment Assessments ............................................. 2-8 2.2.2 ATSDR Health Assessments ............................................ 2-9 2.2.3 ATSDR Health Studies ................................................ 2-10 CHAPTER 3 GETTING STARTED: PLANNING FOR THE HUMAN HEALTH

EVALUATION IN THE RI/FS ............................................ 3-1 3.1 Goal of the RI/FS .......................................................... 3-1 3.2 Goal of the RI/FS Human Health Evaluation ..................................... 3-1 3.3 Operable Units ............................................................ 3-2 3.4 RI/FS Scoping ....................................................... 3-2 3.5 Level of Effort/Level of Detail of the Human Health Evaluation ...................... 3-3 

### PART A -- BASELINE RISK ASSESSMENT CHAPTER 4 DATA COLLECTION ................................................... 4-1 4.1 BACKGROUND INFORMATION USEFUL FOR DATA COLLECTION ................ 4-1 4.1.1 Types of Data ........................................................ 4-1Page vi 4.1.2 Data Needs and the RI/FS ............................................... 4-2 4.1.3 Early Identification of Data Needs ......................................... 4-3 4.1.4 Use of the Data Quality Objectives (DQO) Guidance ........................... 4-4 4.1.5 Other Data Concerns .................................................... 4-4 4.2 REVIEW OF AVAILABLE SITE INFORMATION .................................. 4-4 4.3 ADDRESSING MODELING PARAMETER NEEDS ................................ 4-5 4.4 DEFINING BACKGROUND SAMPLING NEEDS .................................. 4-5 4.4.1 Types of Background ................................................... 4-5 4.4.2 Background Sampling Locations ........................................... 4-8 4.4.3 Background Sample Size ................................................. 4-8 4.4.4 Comparing Background Samples to Site-Related Contamination ................... 4-9 4.5 PRELIMINARY IDENTIFICATION OF POTENTIAL HUMAN EXPOSURE ............ 4-10 4.5.1 General Information ......................................................... 4-10 4.5.2 Soil ................................................................ 4-11 4.5.3 Ground Water ........................................................ 4-12 4.5.4 Surface Water and Sediment ............................................. 4-13 4.5.5 Air ................................................................. 4-14 4.5.6 Biota ............................................................... 4-15 4.6 DEVELOPING AN OVERALL STRATEGY FOR SAMPLE COLLECTION ............. 4-16 4.6.1 Determine Sample Size ................................................. 4-17 4.6.2 Establish Sampling Locations ............................................ 4-18 4.6.3 Determine Types of Samples ............................................. 4-19 4.6.4 Consider Temporal and Meteorological Factors ............................... 4-19 4.6.5 Use Field Screening Analyses ............................................ 4-20 4.6.6 Consider Time and Cost of Sampling ....................................... 4-21 4.7 QA/QC MEASURES ........................................................ 4-21 4.7.1 Sampling Protocol ..................................................... 4-21 4.7.2 Sampling Devices ..................................................... 4-21 4.7.3 QC Samples .......................................................... 4-22 4.7.4 Collection Procedures .................................................. 4-22 4.7.5 Sample Preservation ................................................... 4-22 4.8 SPECIAL ANALYTICAL SERVICES ........................................... 4-22 4.9 TAKING AN ACTIVE ROLE DURING WORKPLAN DEVELOPMENT AND DATA COLLECTION ............................................................. 4-22 4.9.1 Present Risk Assessment Sampling Needs at Scoping Meeting ................... 4-22 4.9.2 Contribute to Workplan and Review Sampling and Analysis Plan ................. 4-23 4.9.3 Conduct Interim Reviews of Field Investigation Outputs ........................ 4-24Page vii

CHAPTER 5 DATA EVALUATION ..................................................... 5-1 5.1 COMBINING DATA AVAILABLE FROM SITE INVESTIGATIONS ................... 5-2 5.2 EVALUATION OF ANALYTICAL METHODS .................................... 5-5 5.3 EVALUATION OF QUANTITATION LIMITS ..................................... 5-7 5.3.1 Sample Quantitation Limits (SQLs) That Are Greater Than Reference Concentrations ......................................................... 5-7 5.3.2 Unusually High SQLs .................................................. 5-10 5.3.3 When Only Some Samples in a Medium Test Positive for a Chemical .............. 5-10 5.3.4 When SQLs Are Not Available ........................................... 5-11 5.3.5 When Chemicals Are Not Detected in Any Samples in a Medium ................. 5-11 5.4 EVALUATION OF QUALIFIED AND CODED DATA ............................. 5-11 5.4.1 Types of Qualifiers .................................................... 5-11 5.4.2 Using the Appropriate Qualifiers .......................................... 5-16 5.5 COMPARISON OF CONCENTRATIONS DETECTED IN BLANKS WITH CONCENTRATIONS DETECTED IN SAMPLES ................................................... 5-16 5.6 EVALUATION OF TENTATIVELY IDENTIFIED COMPOUNDS .................... 5-17 5.6.1 When Few TICs Are Present ............................................. 5-18 5.6.2 When Many TICs Are Present ............................................ 5-18 5.7 COMPARISON OF SAMPLES WITH BACKGROUND ............................. 5-18 5.7.1 Use Appropriate Background Data ......................................... 5-19 5.7.2 Identify Statistical Methods .............................................. 5-19 5.7.3 Compare Chemical Concentrations with Naturally Occurring Levels ............... 5-19 5.7.4 Compare Chemical Concentrations with Anthropogenic Levels ................... 5-19 5.8 DEVELOPMENT OF A SET OF CHEMICAL DATA AND INFORMATION FOR USE IN THE RISK ASSESSMENT ......................................... 5-20 5.9 FURTHER REDUCTION IN THE NUMBER OF CHEMICALS (OPTIONAL) ............ 5-20 5.9.1 Conduct Initial Activities ................................................ 5-20 5.9.2 Group Chemicals by Class ............................................... 5-22 5.9.3 Evaluate Frequency of Detection .......................................... 5-22 5.9.4 Evaluate Essential Nutrients ............................................. 5-23 5.9.5 Use a Concentration-Toxicity Screen ....................................... 5-23 5.10 SUMMARY AND PRESENTATION OF DATA ................................... 5-24 5.10.1 Summarize Data Collection and Evaluation Results in Text ..................... 5-27 5.10.2 Summarize Data Collection and Evaluation Results in Tables and Graphics ......... 5-27Page viii

CHAPTER 6 EXPOSURE ASSESSMENT ................................................ 6-1 6.1 BACKGROUND ............................................................ 6-1 6.1.1 Components of an Exposure Assessment ..................................... 6-1 6.1.2 Reasonable Maximum Exposure ........................................... 6-4 6.2 STEP 1: CHARACTERIZATION OF EXPOSURE SETTING ......................... 6-5 6.2.1 Characterize Physical Setting ............................................. 6-5 6.2.2 Characterize Potentially Exposed Populations ................................. 6-6 6.3 STEP 2: IDENTIFICATION OF EXPOSURE PATHWAYS ........................... 6-8 6.3.1 Identify Sources and Receiving Media ....................................... 6-8 6.3.2 Evaluate Fate and Transport in Release Media ................................ 6-11 6.3.3 Identify Exposure Points and Exposure Routes ............................... 6-11 6.3.4 Integrate Information on Sources, Releases, Fate and Transport, Exposure Points, and Exposure Routes Into Exposure Pathways ................................ 6-17 6.3.5 Summarize Information on All Complete Exposure Pathways .................... 6-17 6.4 STEP 3: QUANTIFICATION OF EXPOSURE: GENERAL CONSIDERATIONS ......... 6-19 6.4.1 Quantifying the Reasonable Maximum Exposure .............................. 6-19 6.4.2 Timing Considerations .................................................. 6-23 6.5 QUANTIFICATION OF EXPOSURE: DETERMINATION OF EXPOSURE CONCENTRATIONS ........................................................ 6-24

6.5.1 General Considerations for Estimating Exposure Concentrations .................. 6-24 6.5.2 Estimate Exposure Concentrations in Ground Water ........................... 6-26 6.5.3 Estimate Exposure Concentrations in Soil ................................... 6-27 6.5.4 Estimate Exposure Concentrations in Air .................................... 6-28 6.5.5 Estimate Exposure Concentrations in Surface Water ........................... 6-29 6.5.6 Estimate Exposure Concentrations in Sediments .............................. 6-30 6.5.7 Estimate Chemical Concentrations in Food .................................. 6-31 6.5.8 Summarize Exposure Concentrations for Each Pathway ........................ 6-32 6.6 QUANTIFICATION OF EXPOSURE: ESTIMATION OF CHEMICAL INTAKE ......... 6-32 6.6.1 Calculate Ground-water and Surface Water Intakes ............................ 6-34 6.6.2 Calculate Soil, Sediment, or Dust Intakes ................................... 6-39 6.6.3 Calculate Air Intakes ................................................... 6-43 6.6.4 Calculate Food Intakes ................................................. 6-43 6.7 COMBINING CHEMICAL INTAKES ACROSS PATHWAYS ........................ 6-47 6.8 EVALUATING UNCERTAINTY .............................................. 6-47 6.9 SUMMARIZING AND PRESENTING THE EXPOSURE ASSESSMENT RESULTS ....... 6-50CHAPTER 7 TOXICITY ASSESSMEN T ................................................. 7-1 7.1 TYPES OF TOXICOLOGICAL INFORMATION CONSIDERED IN TOXICITY ASSESSMEN T .................................................... 7-3 7.1. 1 Human Dat a .......................................................... 7-3 7.1. 2 Animal Dat a .......................................................... 7-5 7.1. 3 Supporting Dat a ........................................................ 7-5 7.2 TOXICITY ASSESSMENT FOR NONCARCINOGENIC EFFECT S ..................... 7-5 7.2. 1 Concept of Threshol d ................................................... 7-6 7.2. 2 Derivation of an Oral RfD (Rf D ) .......................................... 7-6

o 7.2. 3 Derivation of an Inhalation RfD (Rf D ) ...................................... 7-8

i 7.2. 4 Derivation of a Subchronic RfD (Rf D ) ...................................... 7-8

s 7.2. 5 Derivation of a Developmental Toxicant RfD (Rf D ) ........................... 7-9

dt 7.2. 6 One-day and Ten-day Health Advisorie s ..................................... 7-9 7.2. 7 Verification of RfD s ................................................... 7-10 7.3 TOXICITY ASSESSMENT FOR CARCINOGENIC EFFECT S ........................ 7-10 7.3. 1 Concept of Nonthreshold Effect s .......................................... 7-10 7.3. 2 Assigning a Weight of Evidenc e .......................................... 7-11 7.3. 3 Generating a Slope Facto r ............................................... 7-11 7.3. 4 Verification of Slope Factor s ............................................. 7-13 7.4 IDENTIFYING APPROPRIATE TOXICITY VALUES FOR SITE RISK ASSESSMEN T ................................................... 7-13 7.4. 1 Gather Toxicity Information for Chemicals Being Evaluate d ..................... 7-13 7.4. 2 Determine Toxicity Values for Noncarcinogenic Effects (RfDs ) .................. 7-15 7.4. 3 Determine Toxicity Values for Carcinogenic Effects (Slope Factors ) ............... 7-16 7.5 EVALUATING CHEMICALS FOR WHICH NO TOXICITY VALUES ARE AVAILABL E . 7-16 7.5. 1 Route-to-Route Extrapolatio n ............................................ 7-16 7.5. 2 Dermal Exposur e ...................................................... 7-16 7.5. 3 Generation of Toxicity Value s ............................................ 7-17 7.6 UNCERTAINTIES RELATED TO TOXICITY INFORMATIO N ...................... 7-17 7.7 SUMMARIZATION AND PRESENTATION OF THE TOXICITY INFORMATIO N ....... 7-20 7.7. 1 Toxicity Information for the Main Body of the Tex t ........................... 7-20 7.7. 2 Toxicity Information for Inclusion in an Appendi x ............................ 7-20Page x

CHAPTER 8 RISK CHARACTERIZATION .............................................. 8-1 8.1 REVIEW OF OUTPUTS FROM THE TOXICITY AND EXPOSURE ASSESSMENTS ............................................................. 8-1 8.1.1 Gather and Organize Information ........................................... 8-4 8.1.2 Make Final Consistency and Validity Check .................................. 8-4 8.2 QUANTIFYING RISKS ....................................................... 8-6 8.2.1 Calculate Risks for Individual Substances .................................... 8-6 8.2.2 Aggregate Risks for Multiple Substances ................................... 8-11 8.3 COMBINING RISKS ACROSS EXPOSURE PATHWAYS ........................... 8-15 8.3.1 Identify Reasonable Exposure Pathway Combinations ......................... 8-15 8.3.2 Sum Cancer Risks ..................................................... 8-16 8.3.3 Sum Noncancer Hazard Indices .......................................... 8-16 8.4 ASSESSMENT AND PRESENTATION OF UNCERTAINTY ........................ 8-17 8.4.1 Identify and Evaluate Important Site-Specific Uncertainty Factors ................ 8-17 8.4.2 Identify/Evaluate Toxicity Assessment Uncertainty Factors ..................... 8-22 8.5 CONSIDERATION OF SITE-SPECIFIC HUMAN STUDIES ......................... 8-22 8.5.1 Compare with ATSDR Health Assessment ................................. 8-24 8.5.2 Compare with Other Available Site-Specific Epidemiological or Health Studies ..... 8-24 8.6 SUMMARIZATION AND PRESENTATION OF THE BASELINE RISK CHARACTERIZATION RESULTS ............................................. 8-25 8.6.1 Summarize Risk Information in Text ...................................... 8-25 8.6.2 Summarize Risk Information in Tables ..................................... 8-26 CHAPTER 9 DOCUMENTATION, REVIEW, AND MANAGEMENT TOOLS FOR THE RISK ASSESSOR, REVIEWER, AND MANAGER .................................... 9-1 9.1 DOCUMENTATION TOOLS .................................................... 9-1 9.1.1 Basic Principles ........................................................ 9-1 9.1.2 Baseline Risk Assessment Report ........................................... 9-2 9.1.3 Other Key Reports ...................................................... 9-3 9.2 REVIEW TOOLS ............................................................. 9-3 9.3 MANAGEMENT TOOLS ...................................................... 9-14Page xi

CHAPTER 10 RADIATION RISK ASSESSMENT GUIDANCE ............................. 10-1 10.1 RADIATION PROTECTION PRINCIPLES AND CONCEPTS ....................... 10-3 10.2 REGULATION OF RADIOACTIVELY CONTAMINATED SITES ................... 10-8 10.3 DATA COLLECTION ...................................................... 10-10 10.3.1 Radiation Detection Methods ........................................... 10-10 10.3.2 Reviewing Available Site Information .................................... 10-14 10.3.3 Addressing Modeling Parameter Needs .................................... 10-14 10.3.4 Defining Background Radiation Sampling Needs ............................ 10-14 10.3.5 Preliminary Identification of Potential Exposure ............................. 10-15 10.3.6 Developing a Strategy for Sample Collection ............................... 10-15 10.3.7 Quality Assurance and Quality Control (QA/QC) Measures .................... 10-16 10.4 DATA EVALUATION ...................................................... 10-16 10.4.1 Combining Data from Available Site Investigations .......................... 10-17 10.4.2 Evaluating Analytical Methods .......................................... 10-17 10.4.3 Evaluating Quantitation Limits .......................................... 10-17 10.4.4 Evaluating Qualified and Coded Data ..................................... 10-20 10.4.5 Comparing Concentrations Detected in Blanks with Concentrations Detected in Samples .................................................. 10-20 10.4.6 Evaluating Tentatively Identified Radionuclides ............................. 10-21 10.4.7 Comparing Samples with Background ..................................... 10-21 10.4.8 Developing a Set of Radionuclide Data and Information for Use in a Risk Assessment .............................................. 10-21 10.4.9 Grouping Radionuclides by Class ........................................ 10-21 10.4.10 Further Reduction in the Number of Radionuclides .......................... 10-21 10.4.11 Summarizing and Presenting Data ....................................... 10-22 10.5 EXPOSURE AND DOSE ASSESSMENT ....................................... 10-22 10.5.1 Characterizing the Exposure Setting ...................................... 10-23 10.5.2 Identifying Exposure Pathways .......................................... 10-23 10.5.3 Quantifying Exposure: General Considerations ............................. 10-24 10.5.4 Quantifying Exposure: Determining Exposure Point Concentrations ............. 10-25 10.5.5 Quantifying Exposure: Estimating Intake and Dose Equivalent ................. 10-26 10.5.6 Combining Intakes and Doses Across Pathways ............................. 10-27 10.5.7 Evaluating Uncertainty ................................................ 10-27 10.5.8 Summarizing and Presenting Exposure Assessment Results .................... 10-27 10.6 TOXICITY ASSESSMENT .................................................. 10-27 10.6.1 Hazard Identification .................................................. 10-28 10.6.2 Dose-Response Relationships ........................................... 10-30Page xii 10.7 RISK CHARACTERIZATION ................................................ 10-32 10.7.1 Reviewing Outputs from the Toxicity and Exposure Assessments ................ 10-32 10.7.2 Quantifying Risks .................................................... 10-32 10.7.3 Combining Radionuclide and Chemical Cancer Risks ......................... 10-33 10.7.4 Assessing and Presenting Uncertainties .................................... 10-33 10.7.5 Summarizing and Presenting the Baseline Risk Characterization Results .......... 10-34 10.8 DOCUMENTATION, REVIEW, AND MANAGEMENT TOOLS FOR THE RISK ASSESSOR, REVIWER, AND MANAGER ...................................... 10-34 

### PART B -- REFINEMENT OF PRELIMINARY REMEDIATION GOALS

[Reserved] PART C -- RISK EVALUATION OF REMEDIAL ALTERNATIVES

[Reserved] APPENDICES APPENDIX A ADJUSTMENTS FOR ABSORPTION EFFICIENCY ......................... A-1 A.1 ADJUSTMENTS OF TOXICITY VALUE FROM ADMINISTERED TO ABSORBED DOSE ......................................................... A-1 A.2 ADJUSTMENT OF EXPOSURE ESTIMATE TO AN ABSORBED DOSE ............... A-3 A.3 ADJUSTMENT FOR MEDIUM OF EXPOSURE ................................... A-3 APPENDIX B INDEX .............................................................. B-1Page xiii 

### LIST OF EXHIBITS Exhibit Page 1-1 Risk Information Activities in the RI/FS Process .................................... 1-5 1-2 Part A: Baseline Risk Assessment ............................................... 1-7 2-1 Relationship of Documents Governing Human Health Evaluation ....................... 2-2 2-2 Role of the Human Health Evaluation in the Superfund Remedial Process ................. 2-6 4-1 Elements of a Conceptual Evaluation Model ........................................ 4-6 4-2 Examples of Modeling Parameters for Which Information May Need To Be

Obtained During a Site Sampling Investigation ...................................... 4-7 5-1 Data Evaluation ............................................................. 5-3 5-2 Example of Output Format for Validated Data ...................................... 5-4 5-3 Examples of the Types of Data Potentially Unsuitable for a Quantitative

Risk Assessment ............................................................. 5-6 5-4 CLP Laboratory Data Qualifiers and Their Potential Use in Quantitative

Risk Assessment ............................................................ 5-12 5-5 Validation Data Qualifers and Their Potential Use in Quantitative

Risk Assessment ............................................................ 5-14 5-6 Example of Table Format for Presenting Chemicals Sampled in

Specific Media ............................................................. 5-25 5-7 Example of Table Format for Summarizing Chemicals of Potential

Concern in All Media Sampled ................................................. 5-26 6-1 The Exposure Assessment Process ............................................... 6-3 6-2 Illustration of Exposure Pathways ................................................ 6-9 6-3 Common Chemical Release Sources at Sites in the Absence of

Remedial Action ............................................................ 6-10 6-4 Important Physical/Chemical and Environmental Fate Parameters ...................... 6-12 6-5 Important Considerations for Determining the Environmental Fate and

Transport of the Chemicals of Potential Concern at a Superfund Site .................... 6-13 6-6 Flow Chart for Fate and Transport Assessments .................................... 6-14 6-7 Matrix of Potential Exposure Routes ............................................. 6-18 6-8 Example of Table Format for Summarizing Complete Exposure Pathways at a Site ......... 6-20 6-9 Generic Equation for Calculating Chemical Intakes ................................. 6-21 6-10 Example of Table Format for Summarizing Exposure Concentrations ................... 6-33 6-11 Residential Exposure: Ingestion of Chemicals in Drinking Water

(and Beverages Made Using Drinking Water) ...................................... 6-35 6-12 Residential Exposure: Ingestion of Chemicals in Surface Water While Swimming ......... 6-36 6-13 Residential Exposure: Dermal Contact with Chemicals in Water ....................... 6-37 6-14 Residential Exposure: Ingestion of Chemicals in Soil ............................... 6-40 6-15 Residential Exposure: Dermal Contact with Chemicals in Soil ........................ 6-41 6-16 Residential Exposure: Inhalation of Airborne (Vapor Phase) Chemicals ................. 6-44 6-17 Residential Exposure: Food Pathway -- Ingestion of Contaminated Fish

and Shellfish ............................................................... 6-45 6-18 Residential Exposure: Food Pathway -- Ingestion of Contaminated

Fruits and Vegetables ........................................................ 6-46Page xiv 6-19 Residential Exposure: Food Pathway -- Ingestion of Contaminated Meats, Eggs, and Dairy Product s ............................................... 6-48 6-20 Example of Table Format for Summarizing Values Used to Estimate Exposur e .................................................................. 6-49 6-21 Example of Uncertainty Table for Exposure Assessmen t ............................. 6-51 6-22 Example of Table Format for Summarizing the Results of the Exposure Assessment -- Current Land Us e ........................................ 6-52 7-1 Steps in Toxicity Assessmen t ................................................... 7-4 7-2 Example of Table Format for Toxicity Values: Potential Noncarcinogenic Effect s ......... 7-18 7-3 Example of Table Format for Toxicity Values: Potential Carcinogenic Effect s ............ 7-19 8-1 Steps in Risk Characterizatio n .................................................. 8-3 8-2 Example of Table Format for Cancer Risk Estimate s ................................. 8-7 8-3 Example of Table Format for Chronic Hazard Index Estimate s .......................... 8-8 8-4 Example of Table Format for Subchronic Hazard Index Estimate s ....................... 8-9 8-5 Example of Presentation of Impact of Exposure Assumptions on Cancer Risk Estimat e ........................................................ 8-21 8-6 Example of Presentation of Impact of Exposure Assumptions on Hazard Index Estimat e ....................................................... 8-23 8-7 Example of Presentation of Relative Contribution of Individual Chemicals to Exposure Pathway and Total Cancer Risk Estimate s ...................... 8-27 8-8 Example of Presentation of Relative Contribution of Individual Chemicals to Exposure Pathway and Total Hazard Index Estimate s ..................... 8-28 9-1 Suggested Outline for a Baseline Risk Assessment Report ............................. 9-4 9-2 Reviewer Checklis t ........................................................... 9-9 9-3 Checklist for Manager Involvemen t ............................................. 9-15 10-1 Radiological Characteristics of Selected Radionuclides Found at Superfund Site s .......... 10-5 10-2 Types of Field Radiation Detection Instrument s ................................... 10-11 10-3 Types of Laboratory Radiation Detection Instrument s .............................. 10-13 10-4 Examples of Lower Limits of Detection (LLD) For Selected Radionuclides Using Standard Analytical Method s ............................................ 10-18 10-5 Summary of EPA's Radiation Risk Factor s ....................................... 10-31Page xv 

### PREFACE The Comprehensive Environmental Response , sho uldbe coordinated. An example of this type o f C ompensati on, and Liability Act (CERCLA) requires coordination is the sampling and analysis of fish o r that actions selected to remedy hazardous waste sites other aquatic organisms; if done properly, data fro m be protective of human health and the environment . s uch sampling can be used in t he assessment of human CERCLAalso mandates that when a remedial action health risks from ingestion andin the assessment o f resul ts in residual contamination at a site, futur e dama ges to and potential effects on the aquati c r eviews must be planned and conducted to assure that ecosystem. hu man health and the environment continue to b e p rotected. As part of its effort to meet these and other The two manuals in this set target somewha t CERCLA requirements, EPA has developed a set o f dif ferentaudiences. The Environmental Evaluatio n m anuals, together entitled Risk Assessment Guidance Man ualis addressed primarily to remedial projec t f or Superfund . The Human Health Evaluation Manual m anagers (RPMs) and on-scene coordinators (OSCs), (Volu me I) provides guidance for developing health w ho are responsible for ensuring a t horough evaluation risk information at Superfund sites, while th e of potential environmental effects at sites. Th e EnvironmentalEvaluation Manual(Volume II ) EnvironmentalEvaluation Manualis not a detaile d provides guidance for environmental assessment a t "h ow-to" type of guidance, and it does not provid e Sup erfundsites. Guidance in both human health "c ookbook" approaches for evaluation. Instead, i t e valuation and environmental assessment is needed so i dentifies the kinds of help that RPMs/OSCs are likely that EPA can fulfill CERCLA's requirement to protect to ne ed and where they may find that help. Th e human health and the environment. m anual also provides an overall framework to be used The Risk Assessment Guidance for Superfun d environmental evaluation methods compendiu m manuals were developed to be used in the remedia l publ ishedby EPA's Office of Research an d inv estigation/feasibility study (RI/FS) process at De velopment, Ecological Assessments of Hazardou s Sup erfundsites, although the analytical framework Wa ste Sites: A Field and Laboratory Referenc e and s pecific methods described in the manuals ma y Document (EPA/600/3-89/013), is an importan t also be applicable to other assessments of hazardou s reference to be used with the manual. wast es and hazardous materials. These manuals ar e companion documents to EPA's Guidance fo r The Human Health Evaluation Manuali s Conducting Remedial Investigations and Feasibilit y add ressedprimarily to the individuals actuall y Studies Under CERCLA (October 1988), and user s con ducting health risk assessments for sites, wh o shoul dbe familiar with that guidance. The tw o fr equently are contractors to EPA, other federa l Sup erfundrisk assessment manuals were develope d agencies, states, or potentially responsible parties. It w ith extensive input from EPA workgroups comprised als o is targeted to EPA staff, including thos e of bo th regional and headquarters staff. Thes e responsible for review and oversight of ris k m anuals are interim final guidance ; final guidance will assess ments (e.g., technical staff in the regions) an d be issued when the revisions proposed in Decembe r those responsible for ensuring adequate evaluation of 1988 to the National Oil and Hazardous Substance s human health risks (i.e., RPMs). The Human Health Pollution Contingency Plan (NCP) become final. Evaluation Manual r eplaces a previous EPA guidance Alt houghhuman health risk assessment an d Manual(October 1986), which should no longer b e e nvironmental assessment are di fferent processes, they used. The new manual incorporates lessons learne d s hare certain common information ne eds and generally fr omapplication of the earlier manual and addresse s can use some of the same chemical sampling an d a numbe r of issues raised since the earlier manual' s enviro nmental setting data for a site. Planning fo r publ ication. Issuance of the new manual does no t bot hassessments should begin during the scopin g invalidate human health risk assessments complete d stag e of the RI/FS, and site sampling and other dat a before (or in progress at) the publication date. colle ction activities to support the two assessment s in considering environmental effects. A n

docu ment, The Superfund Public Health Evaluatio nPage xvi

The Human

Health Evaluation Manualprovides E ven though the H uman Health Evaluation Manualis abasic framework for health risk assessment a t cons iderably more specific than the Environmenta l Superfundsites, as the Environmental Evaluatio n Eva luation Manual , it also is not a "cookbook," an d Ma nualdoes for environmental assessment. Th e p roper application of t he guidance requires substantial Human Health Evaluation Manualdiffers, however, expertise and professional judgment. by providing more detailed guidance on many of th e p rocedure s used to assess health risk. This additional lev el of detail is possible because of the relativel y large body of information, techniques, and guidanc e ava ilable on human health risk assessment and th e ex tensive Superfund program experience conductin g such assessments for sites.Page xvii 

### ACKNOWLEDGEMENTS This manual was developed by the Toxics Integration Branch (TIB) of EPA's Office of Emergency and Remedial Response, Hazardous Site Evaluation Division. Linda Cullen provided overall project management, contrac t supervision, and technical coordination for the project under the direction of Bruce Means, Chief of TIB's Health Effects Program. The EPA Workgroup (comprised of members listed on the following page) provided valuable input regarding the organization, content, and policy implications of the manual throughout its development. The project manager e specially wishes to acknowledge the assistance of the Workgroup Subcommittee Chairpersons: Rebecca Madison, Bruce Means, Sue Norton, Georgia Valaoras, Craig Zamuda, and Larry Zaragoza. Other significant contributors to the manual included Joan Fisk, Michael Hurd, and Angelo Carasea of th e Analytica l Operations Branch (Office of Emergency and Remedial Response); Paul White, Anne Sergeant, an d J acqueline Moya of th e Exposure Assessment Group (Office of Research and Development); and Barnes Johnson of the Statistical Policy Branch (Office of Policy, Planning, and Evaluation). In addition, many thanks are offered to the more than 60 technical and policy reviewers who provided constructive comments on the document in its final stages of development. ICF Inco rporated provided technical assistance to EPA in support of the development of this manual, unde r Contract No. 68-01-7389. RobertDyer, Chief of the Environmental Studies and Statistics Branch, Office of Radiation Programs, served a s project manager for Chapter 10 (Radiation Risk As sessment Guidance), with assistance from staff in the Bioeffects A nalysis Branch and the regional Radiation Program Managers. Chapter 10 was prepared by S. Cohen and Associates, Incorporated (SC&A), under Contract No. 68-02-4375.