PUBLIC HEALTH ASSESSMENT

PADUCAH GASEOUS DIFFUSION PLANT (U.S. DOE)
PADUCAH, MCCRACKEN COUNTY, KENTUCKY
EPA FACILITY ID: KY8890008982

May 21, 2002

Prepared by:

Energy Section
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry

DOCUMENT NOTE

This public health assessment addresses potential off-site exposures to radioactive and non-radioactive substances released from the Paducah Gaseous Diffusion Plant. It does not address on-site exposures of the Paducah Gaseous Diffusion Plant workers to radioactive or hazardousmaterials. Workers may be expected to be exposed to radioactive and hazardous materials that havebeen used at the site at higher levels than the general public. Workers should be trained in the use andsafe handling of hazardous materials, and their exposures should be monitored.

Since 1997, the United States Enrichment Corporation (USEC), which currently operates the gaseousdiffusion plant, has been required to meet worker safety and health standards developed by theDepartment of Labor, Occupational Safety and Health Administration (OSHA); the plant also mustmeet standards developed by the U.S. Nuclear Regulatory Commission (NRC). Before the plant wasprivatized, however, the facility was subject to the U.S. Department of Energy regulations andstandards but was exempt from external regulation and enforcement.

The U.S. Department of Health and Human Services, Centers for Disease Control, National Institutefor Occupational Safety and Health (NIOSH), is responsible for researching potential health hazardsexperienced in the workplace and for providing recommendations for exposure standards to OSHA.NIOSH is research-oriented, and is not a regulatory agency. NIOSH has conducted studies ofworkers in the gaseous diffusion plants at Oak Ridge, Paducah, and Portsmouth. For furtherinformation about worker studies, contact the NIOSH Division of Surveillance, Hazard Evaluations,and Field Studies, in Cincinnati, Ohio, at (513) 841-4400.

Some of the terminology used in this document reflects the latest terminology and definitions as usedby the International Commission on Radiological Protection (ICRP) starting with ICRP Publication60: 1990 Recommendations of the International Commission on Radiological Protection, Oxford (UK): Pergamon Press; 1991.

TABLE OF CONTENTS

LIST OF APPENDICES

LIST OF TABLES

LIST OF FIGURES

LIST OF ABBREVIATIONS

EXECUTIVE SUMMARY

BACKGROUND

Site Description and History
Site Visits and Collection of Community Concerns
Demographics
Land Use and Natural Resources

ENVIRONMENTAL CONTAMINATION, EXPOSURE PATHWAYS, AND POTENTIALLY EXPOSED POPULATIONS

Introduction
Groundwater
Background and Site Hydrogeology
Contaminants of Concern
Groundwater Exposure Pathways
Current Exposure
Past Exposure
Past Exposure Evaluation
Potential Future Exposure
Air
Background
Contaminants of Concern
Uranium Isotopes and Technetium 99
Uranium as a Chemical
Hydrogen Fluoride
Trichloroethylene
Sulfur Dioxide and Nitrogen Oxides
Chromium
Airborne Exposure Pathways
Current Exposure
Past Exposure
Potential Future Exposure
Surface Water
Background
Contaminants of Concern
Surface Water Exposure Pathways
Current and Past Exposure
Potential Future Exposure
Soil and Sediment
Background
Contaminants of Concern
Soil and Sediment Exposure Pathways
Scenario 1--WKWMA Workers and Visitors
Scenario 2--Residents
Food and Biota
Background
Contaminants of Concern
Food and Biota Exposure Pathways
Current Exposure
Past Exposure
Potential Future Exposure
Other Hazards
Storage of Depleted Uranium Cylinders
Storms
Earthquakes
Transportation and Plane Accidents
Health Hazard Evaluation
Hydrogen Fluoride
Uranyl Fluoride
Additional Facilities
Concrete Rubble

PUBLIC HEALTH IMPLICATIONS

Introduction
Special Considerations of Women and Children
Identifying Potentially Affected Groups
Specific Substances
Antimony
Arsenic
Cadmium
Chromium, Hexavalent
Hydrogen Fluoride
Lead
Manganese
Nitrates and Nitrites
Pentachlorophenol
Polychlorinated Biphenyls
Radioactive Materials (Radiation Exposures)
Thallium
Trichloroethylene
Uranium
Vanadium
Vinyl Chloride
Zinc

HEALTH OUTCOME DATA EVALUATION

Introduction
Statistics From Cancer Registries
Environmental Health Survey of Individuals Exposed to Contaminated Groundwater

COMMUNITY HEALTH CONCERNS

Exposure Concerns
Air
Soil
Surface Water and Sediment
Groundwater
Biota
Waste Materials
Health Concerns
Procedural Concerns
Management of Wildlife
Agencies That May Be Contacted for Other Concerns

CONCLUSIONS

RECOMMENDATIONS

PUBLIC HEALTH ACTION PLAN

Public Health Actions Taken
Public Health Actions Planned

PREPARERS OF REPORT

REFERENCES

LIST OF APPENDICES

APPENDIX A: DEMOGRAPHIC INFORMATION

APPENDIX B: DESCRIPTION AND TABULATION OF COMMUNITY HEALTH CONCERNS

APPENDIX C: HEALTH GUIDELINES, COMPARISON VALUES, AND EXPOSURE FACTORS

APPENDIX D: ESTIMATION OF EXPOSURE DURATION FOR GROUNDWATER PATHWAY

APPENDIX E: EXPOSURE TO AIRBORNE RADIONUCLIDES

APPENDIX F: EXPOSURE TO AIRBORNE HYDROGEN FLUORIDE

APPENDIX G: AIRBORNE TRICHLOROETHYLENE DISTRIBUTION AND POTENTIAL OFF-SITE EXPOSURE

APPENDIX H: AIRBORNE HEXAVALENT CHROMIUM DISTRIBUTION FROM THE PGDP WATER COOLING TOWERS AND POTENTIAL OFF-SITE EXPOSURE

APPENDIX I: EXPOSURE ASSESSMENT OF AIRBORNE NICKEL AND OTHER METAL PARTICULATES FROM HISTORIC SMELTER OPERATIONS AT THE PADUCAH GASEOUS DIFFUSION PLANT

APPENDIX J: PUBLIC COMMENTS ON THE PADUCAH GASEOUS DIFFUSION PLANT PUBLIC HEALTH ASSESSMENT AND ATSDR'S RESPONSES

APPENDIX K: ATSDR GLOSSARY OF TERMS

LIST OF TABLES

Table 1. Groundwater contaminant sources at the Paducah Gaseous Diffusion Plant

Table 2. Off-site groundwater contaminants

Table 3. Groundwater contaminants detected off site, comparison values, and locations

Table 4. Groundwater contaminants (on and off site) excluded from further analysis

Table 5. Summary of contaminants of concern and exposure doses in completed exposure pathways for off-site groundwater

Table 6. Summary of contaminants of concern and exposure doses in potential exposure pathways for off-site groundwater

Table 7. Airborne releases (from PGDP processes) and major release sources

Table 8A. Annual estimated release quantities of uranium and technetium 99 from process operations at PGDP for 1952 through 1993 and 1996

Table 8B. Annual estimated release quantities of major airborne contaminants other than uranium and technetium 99 for 1985 through 1993 and 1996

Table 9. Off-site estimated annual committed effective doses from uranium 234, uranium 235, uranium 238, and technetium 99 air releases from PGDP to the maximally exposedindividual (approximately 1,500 meters north of the source)

Table 10. Summary of completed and potential exposure pathways for airborne contaminants

Table 11. Estimated exposure doses for chemical contaminants in off-site surface water at PGDP and health guidelines

Table 12. Past and current maximum estimated exposure doses (annual committed effective doses) for radioactive contaminants in surface water

Table 13. Summary of potential exposure pathways for off-site surface water contaminants of concern

Table 14A. Estimated exposure doses to WKWMA workers and visitors for chemical contaminants in buffer zone soil and sediment (Scenario 1)

Table 14B. Estimated exposure doses (annual committed effective doses) to WKWMA workers and visitors for radioactive contaminants in buffer zone soil and sediment (Scenario 1)

Table 15A. Estimated exposure doses to residents for chemical contaminants in off-site soil (Scenario 2)

Table 15B. Estimated exposure doses (annual committed effective doses) to residents for radioactive contaminants in off-site soil (Scenario 2)

Table 16. Summary of potential exposure pathways for contaminants of concern in off-site soil and sediment

Table 17. Biota Categories

Table 18A(1). Maximum concentrations of chemical contaminants (except PCBs) in biota (fish, game, and food crops) near PGDP (in µg/g or ppm)

Table 18A(2). Average concentrations of PCBs in biota (fish and game) near PGDP (in µg/g or ppm)

Table 18B. Maximum concentrations of radioactive contaminants in biota near PGDP (in pCi/g)

Table 19. Average food consumption rates for children and adults

Table 20A. Maximum estimated child exposure doses and health guidelines for consumption of biota near PGDP for chemical contaminants (in milligrams per kilogram of body weight per day)

Table 20B. Maximum estimated adult exposure doses and health guidelines for consumption of biota near PGDP for chemical contaminants (in milligrams per kilogram of body weight per day)

Table 21A. Estimated child exposure doses (annual committed effective doses) for annual consumption of biota near PGDP in millirems (and in millisieverts)

Table 21B. Estimated adult exposure doses (annual committed effective doses) for annual consumption of biota near PGDP in millirems (and in millisieverts)

Table 22. Summary of potential exposure pathways for human consumption of contaminants of concern in biota near PGDP

Table 23. Probabilities of Occurrence for Different Magnitude Earthquakes

Table 24. Summary of completed and potential exposure pathways for each contaminant

Table 25. Estimated number of persons potentially exposed per exposure pathway based on 1990 Census data and potential exposure pathways

Table 26. Range of Possible Exposure Doses to Hexavalent Chromium

Table 27. Estimated lead doses in adults and infants from various water concentrations

Table 28. Maximum estimated annual committed effective doses for radiation exposure near PGDP

Table 29. Range of sample detection limits for vinyl chloride in residential well water

Table 30. Agencies that may be contacted for other concerns

Table A-1. County population data table

Table A-2. Length of residence in current household, 1990: Ballard, McCracken, and Massac Counties

Table A-3. County housing and socioeconomic data

Table A-4. City or town population data table

Table A-5. Length of residence in current household, 1990: cities of Paducah, Metropolis, and Joppa

Table A-6. City or town housing and socioeconomic data

Table A-7. Census tract population data

Table A-8. Census tracts: length of residence in current household, 1990

Table A-9. Census tract housing and socioeconomic data, 1990

Table B-1. Community concerns

Table C-1. Dose equations and factors used in calculating exposure doses at PGDP

Table D-1. Estimated plume migration rates based on plume locations for different time periods

Table D-2. Estimated exposure durations, based on 125 meters per year migration rate and distance of plume migration downgradient of residential wells

Table E-1. Annual radionuclide emissions for selected isotopes and years

Table F-1. Summary of RASCAL 3.0 model for assessing accidental releases of HF from November 17, 1960, UF₆ cylinder rupture

Table H-1. Maximum estimated airborne hexavalent chromium concentrations

Table I-1. Maximum estimated nickel air concentrations for different weather years and distances

Table I-2. Comparison of amounts of various metals smelted at PGDP with Inhalation Health-Based Comparison Values

Table J-1. Age-Adjusted Total and Bladder Cancer Incidence Rates per 100,000 Population (Average Rates for 1991 through 1999)

Table J-2. Estimated Bladder Cancer Crude Incidence Rates per 100,000 Population

Table J-3. Age-Adjusted Skin Melanoma and Digestive Tract Cancer Incidence Rates per 100,000 Population (Average Rates for 1991 through 1999)

Table J-4. Estimated Skin Melanoma and Digestive Tract Cancer Crude Incidence Rates per 100,000 Population

LIST OF FIGURES

Figure 1. Plant location and vicinity

Figure 2. Property boundaries and other features

Figure 3. Pathways to exposure from contamination

Figure 4. TCE concentrations in residential wells

Figure 5. Tc-99 concentrations in residential wells

Figure 6. TCE and Tc-99 groundwater contamination, 1997

Figure 7. Areas of contamination and potential human exposures

Figure 8. Effects of lead on children and adults--lowest-observable-adverse-effect levels

Figure A-1. Paducah Gaseous Diffusion Plant (demographics)

Figure D-1. TCE isocontours (1991-1995) and contaminated off-site well locations

Figure F-1. Correlation coefficient of PGDP uranium emissions and hydrogen fluoride measurements at the perimeter north station

Figure F-2. Measured and predicted HF concentrations at the perimeter north and one mile north sampling stations

Figure I-1. Average annual airborne nickel concentration estimated using EPA ISC Short Term air dispersion model (1984-1986 emission data; 1990 weather data)

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