DERIVATION OF HEALTH-BASED ENVIRONMENTAL SCREENING

1,06
MB LEVELS FOR CHEMICAL WARFARE AGENTS

188
stron

3828
ID United States Army Center for Health Promotion & Preventive Medicine

1999
rok

TABLE OF CONTENTS

ACKNOWLEDGMENTS . v

EXECUTIVE SUMMARY vi

1. INTRODUCTION

1.1 Purpose . 1-1

1.2 Background 1-2

1.3 Applications/Limitations 1-9

2. EXPOSURE ASSESSMENT

2.1 Exposure Scenarios . 2-1

2.2 Exposure Pathways . 2-2

2.3 Exposure Parameters . 2-3

3. METHODS FOR DERIVING SCREENING LEVELS

3.1 Risk-Based Concentrations (RBCs) 3-1

3.2 Preliminary Remediation Goals (PRGs) . 3-4

3.3 Soil Screening Levels (SSLs) . 3-7

4. AGENT HD (SULFUR MUSTARD) 4-1

4.1 Risk-based Concentrations (RBCs) 4-3

4.2 Preliminary Remediation Goals (PRGs) . 4-3

4.3 Soil Screening Levels (SSLs) . 4-4

4.4 Summary . 4-5

5. AGENT VX . 5-1

5.1 Risk-based Concentrations (RBCs) 5-2

5.2 Preliminary Remediation Goals (PRGs) . 5-3

5.3 Soil Screening Levels (SSLs) . 5-3

5.4 Summary . 5-4

6. AGENT GB (SARIN) . 6-1

6.1 Risk-based Concentrations (RBCs) 6-2

6.2 Preliminary Remediation Goals (PRGs) . 6-3

6.3 Soil Screening Levels (SSLs) . 6-3

6.4 Summary . 6-4

7. AGENT GA (TABUN) 7-1

7.1 Risk-based Concentrations (RBCs) 7-2

7.2 Preliminary Remediation Goals (PRGs) . 7-3

7.3 Soil Screening Levels (SSLs) . 7-3

7.4 Summary . 7-4

8. AGENT GD (SOMAN) 8-1

8.1 Risk-based Concentrations (RBCs) 8-2

8.2 Preliminary Remediation Goals (PRGs) . 8-3

8.3 Soil Screening Levels (SSLs) . 8-3

8.4 Summary . 8-4

9. LEWISITE 9-1

9.1 Risk-based Concentrations (RBCs) 9-3

9.2 Preliminary Remediation Goals (PRGs) . 9-3

9.3 Soil Screening Levels (SSLs) . 9-3

9.4 Summary . 9-4

10. COMPARISON OF SCREENING METHODS

10.1 Ingestion . 10-1

10.2 Dermal . 10-1

10.3 Migration to Groundwater . 10-2

10.4 Airborne Dust . 10-4

10.5 Volatiles . 10-4

10.6 Multipathway . 10-4

11. SUMMARY AND RECOMMENDATIONS

11.1 General 11-1

11.2 Comparisons of Screening Methodologies . 11-2

11.3 Conclusions . 11-4

11.4 Uncertainties Associated With the Chemical Warfare Agent HBESLs . 11-5

11.5 Recommendations 11-9

12. REFERENCES . 12-1

13. GLOSSARY 13-1

Appendix A. Derivation of Chemical Parameters . A-1

Appendix B. Carcinogenic Potency of Sulfur Mustard B-1

Appendix C. Screening Values for Trespassers . C-1

Appendix D. Agricultural/Grazing Scenarios D-1

Appendix E. Modeling Potential Chemical Agent Contamination of Ground Water . E-1

Appendix F. Primary Breakdown Products of Chemical Agents F-1

Appendix G. Toxicity of Agents GA and GD Relative to the Toxicity of Agent GB . G-1

Appendix H. Derivation of Dermal Absorption Factors for Chemical Agents in Soil . H-1

LIST OF TABLES

1-1. Physical/chemical properties and known environmental properties of chemical warfare agents

1-6

1-2. Available reference doses, slope factors and inhalation exposure limits . 1-7

2-1. USEPA and regional default values for risk assessment calculations . 2-4

2-2. Body surface areas for 50th percentile of population 2-8

2-3. Chemical/environmental parameters for chemical agents . 2-13

2-4. Dermal absorption values for chemical agents 2-14

3-1. Parameters used in Risk-based Concentration (RBC) equations . 3-2

3-2. Parameters used in equations for Preliminary Remediation Goals (PRGs) . 3-5

3-3. Parameters used in equations for Soil Screening Levels (SSLs) . 3-9

4-1. Summary of calculated HBESLs for agent HD 4-1

4-2. Toxicity values and environmental parameters for agent HD . 4-2

5-1. Summary of calculated HBESLs for agent VX 5-1

5-2. Toxicity values and environmental parameters for agent VX . 5-2

6-1. Summary of calculated HBESLs for agent GB 6-1

6-2. Toxicity values and environmental parameters for agent GB . 6-2

7-1. Summary of calculated HBESLs for agent GA 7-1

7-2. Toxicity values and environmental parameters for agent GA . 7-2

8-1. Summary of calculated HBESLs for agent GD 8-1

8-2. Toxicity values and environmental parameters for agent GD . 8-2

9-1. Summary of calculated HBESLs for Lewisite . 9-1

9-2. Toxicity values and environmental parameters for Lewisite 9-2

11-1. Key areas of uncertainty and effect on conservatism of HBESL 11-6

11-2. Range of Estimated HBESLs for Chemical Warfare Agents . 11-8

A-1. Vapor pressure, solubility and Henry's Law Constants . A-2

B-1. Estimate of the upper limit for carcinogenic potency (risk per mg/kg-d) of sulfur mustard . B-5



C-1. Values used for calculating HBESLs . C-5

C-2. Calculated trespasser HBESL values for chemical warfare agents . C-6

C-3. Key areas of uncertainty and type of effect on conservatism of HBESL C-7 tres E-1.

Chemical-specific parameters E-3

E-2. Landscape parameters used in VLEACH modeling . E-4

E-3. Maximum concentrations of chemicals reaching water table E-9

E-4. Predictions of ground-water flow before complete hydrolysis of chemical agent . E-10