Remedial Options Report
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TRAIL LEAD PROGRAM IDENTIFICATION, EVALUATION AND SELECTION OF REMEDIAL OPTIONS January, 2001 S.R. Hilts, P. Geo., Environmental Coordinator E.R. White, R.P. Bio. Environmental Consultant C.L. Yates, R.N., B.S.N. Health Coordinator 300-843 Rossland Avenue Phone: (250) 368-5323 Trail, BC Canada, V1R 4S8 I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS AUTHOR FORWARDING ADDRESSES: Steve Hilts Cominco, Ltd. PO Box 1000 Trail, BC V1R 4L8 Phone: (250) 364-4385 Fax: (250) 364-4144 e-mail: [email protected] Cheryl Yates Kootenay Boundary Community Health Services Society 1051 Farwell St. Trail, BC V1R 4S9 Phone: (250) 368-5323 Fax: (250) 364-0580 e-mail: [email protected] I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS PREFACE Trail, British Columbia has been the site of a major lead and zinc smelting facility for over 80 years. In 1975, children's blood lead levels in Trail were found to be significantly higher than those in a nearby comparison community. A 1989 study found that although the average blood lead level had declined since 1975, 39% of the Trail children tested in 1989 were above the U.S. Environmental Protection Agency's "level of no concern" of 15 µg/dl. The 1989 study prompted the formation in 1990 of the Trail Community Lead Task Force. The Task Force was composed of representatives from the provincial and municipal governments, Cominco Limited, the general public, the local School District, the United Steelworkers of America, and a network of environmental groups. The Trail Lead Program was the operational arm of the Trail Community Lead Task Force. BC Environment, the Ministry of Health, Cominco Ltd. and the City of Trail shared responsibility for funding the program. In 1990, the Task Force embarked on comprehensive programs of community education and case management, as well as investigations of lead exposure pathways and intervention options. The reporting and decision-making process is shown in the chart on the following page. In 1997, the Task Force began studying whether any other smelter-related contaminants might represent potential health risks. A separate, comprehensive human health risk assessment of other contaminants (focussing on arsenic and cadmium) was concluded in early 2000. That assessment is also summarized in this report. The purpose of this report is to present, in one coordinated volume, the information which the Trail Community Lead Task Force and the public used in making decisions regarding future remedial actions to be taken in Trail. The report answers important questions about the blood lead issue, such as: • how has environmental lead contamination occurred? • why is lead contamination a health concern? • how and when was the concern identified in Trail? • why are we only concerned about children? • where are the highest lead levels in Trail? • how does the lead get into children? • how high are children’s blood lead levels in Trail compared with other sites? • what actions have been taken so far and how successful have they been? • what are the options for dealing with the lead contamination in the future? I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS Framework for Development and Evaluation of Remedial Options (need to print this page separately from Excel) I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS TABLE OF CONTENTS LIST OF TABLES I LIST OF FIGURES II GLOSSARY III ACKNOWLEDGEMENTS VI EXECUTIVE SUMMARY ES1 1. INTRODUCTION 1 1.1 BRIEF WORLD HISTORY OF LEAD PRODUCTION AND HUMAN EXPOSURE 1 1.2 BRIEF HISTORY OF LEAD EXPOSURE IN TRAIL 5 2. HEALTH EFFECTS OF LOW LEVEL LEAD EXPOSURE 10 2.1 EXPOSURE, ABSORPTION AND DISTRIBUTION IN THE HUMAN BODY 10 2.2 ADVERSE HEALTH EFFECTS 11 2.3 NEUROLOGIC EFFECTS IN INFANTS AND CHILDREN 12 2.4 OTHER EFFECTS OF LEAD 13 3. SOURCES AND PATHWAYS OF LEAD EXPOSURE 14 3.1 SOURCES OF LEAD EXPOSURE (SITE CHARACTERIZATION) 14 3.2 PATHWAYS OF LEAD EXPOSURE 24 3.3 HISTORICAL VERSUS CURRENT EMISSIONS 30 3.4 EVIDENCE OF IMPROVED ENVIRONMENTAL CONDITIONS SINCE 1997 31 4. COMMUNITY BLOOD LEAD TRENDS: 1989-2000 38 4.1 BLOOD LEAD MONITORING METHODS 39 4.2 BLOOD LEAD RESULTS 41 5. RISK ASSESSMENT 51 5.1 REGULATORY FRAMEWORK 51 5.2 COMPONENTS OF RISK ASSESSMENT 52 5.3 RISK ASSESSMENT FOR LEAD 54 5.4 RISK ASSESSMENT FOR OTHER SMELTER CONTAMINANTS 66 6. REMEDIAL GOALS 68 6.1 CONTAMINANTS OF CONCERN 68 6.2 MEDIA OF CONCERN 68 6.3 SENSITIVE POPULATION 69 I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS 6.4 PRIMARY AND SECONDARY EXPOSURE ROUTES 70 6.5 EXPOSURE PATHWAYS 70 6.6 REMEDIAL GOAL 70 6.8 SUMMARY OF ISSUES AND REMEDIAL ACTION OBJECTIVE 71 7. REMEDIAL OPTIONS: IDENTIFICATION 72 7.1 CONTINUATION OF CURRENT ACTIONS 73 7.2 OPTIONS FOR NEW LONG-TERM ACTIONS 78 8. REMEDIAL OPTIONS: EVALUATION 86 8.1 DESIGN OF REMEDIAL TRIALS 86 8.2 USE OF PATHWAYS MODELS AND RISK MODELS 89 8.3 COMMUNITY EDUCATION AND CASE MANAGEMENT 90 8.4 COMMUNITY DUST ABATEMENT 96 8.5 RELOCATION 97 8.6 SOIL REMEDIATION 97 8.7 HOUSE DUST REMEDIATION 111 8.8 LEAD-BASED PAINT REMEDIATION 115 9. REMEDIAL OPTIONS: SELECTION 117 9.1 PUBLIC CONSULTATION - PROCESS AND RESULTS 117 9.2 TRAIL COMMUNITY LEAD TASK FORCE RECOMMENDATIONS 121 9.3 PROJECTIONS FOR ACHIEVEMENT OF REMEDIAL GOALS 135 10. REFERENCES 141 APPENDIX A: ORIGINAL TASK FORCE TERMS OF REFERENCE APPENDIX B: DRAFT TERMS OF REFERENCE FOR MONITORING COMMITTEE I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS LIST OF TABLES Table 1 - Comparison of Past and Present Human Exposures to Lead ___________________________________ 1 Table 2 - Arithmetic Mean Blood Lead Levels in 1975 (Trail & Nelson) __________________________________ 7 Table 3 - Trigger Levels for Soil Investigation or Remediation in Various Jurisdictions ____________________ 16 Table 4 - Soil Lead Levels by Neighourhood, 1977 _________________________________________________ 17 Table 5 - Geometric Mean Soil Lead Concentration in Trail: 1977, 1989, 1992___________________________ 18 Table 6 - BC Air Quality Objectives _____________________________________________________________ 21 Table 7 - Canadian Lead in Produce Standards____________________________________________________ 23 Table 8 - Lead Concentrations (ppm) in Vegetable Samples from Trail, 1992 ____________________________ 23 Table 9 - Multiple Regression Models by Age Range ________________________________________________ 28 Table 10 - Participation Rates in Annual Fall Blood Screening Clinics _________________________________ 42 Table 11 - Participation Rates of Case-Management vs. Non Case-Management Children __________________ 43 Table 12 - Blood Lead Statistics 1991-2000_______________________________________________________ 43 Table 13 - Geometric Mean Blood Lead Levels by Age ______________________________________________ 44 Table 14 - Blood Lead Levels of Children Tested for 1st Time_________________________________________ 47 Table 15 - Statistical Comparison of Observed and Predicted Blood Leads ______________________________ 58 Table 16 - Observed and Predicted Blood Leads for Two Areas of Trail_________________________________ 60 Table 17 - 1996 and 2000 Model Run Data/Results_________________________________________________ 63 Table 18 - Blood Lead Levels and Concurrent Environmental Conditions _______________________________ 92 Table 19 - Children’s Blood Lead Levels Following Case Management Intervention_______________________ 93 Table 20 - Summary of Experiences with Community Education/Case Management _______________________ 96 Table 21 - Cost Estimates for Soil Remediation ___________________________________________________ 108 Table 22 - Summary of Soil Remediation Alternatives - Effectiveness __________________________________ 110 Table 23 - Summary of Soil Remediation Alternative Cost Estimates __________________________________ 111 Table 24 - Summary of Dust Control Trials ______________________________________________________ 115 I DENTIFICATION, EVALUATION AND S ELECTION OF R EMEDIAL O PTIONS I LIST OF FIGURES Figure 1 - World-wide Lead Production During the Past 6000 Years ____________________________________ 2 Figure 2 - U.S. Lead Consumption in Paint and Gasoline _____________________________________________ 4 Figure 3 - Blood Lead Declines in U.S. Children During Lead in Gasoline Phase-Out ______________________ 5 Figure 4 - Location of Trail Neighbourhoods_______________________________________________________ 6 Figure 5 - Trail Community Lead Task Force Structure ______________________________________________ 9 Figure 6 - Lowest Observed Effect Levels of Lead in Children ________________________________________ 11 Figure 7 - Soil Lead Concentrations in Trail in 1992 _______________________________________________ 18 Figure 8 - House Dust Lead Concentrations in Trail in 1992 _________________________________________ 20 Figure 9 - Annual Geometric Mean Air Lead Level at Four Stations in Trail Area_________________________ 21 Figure 10 - Monthly Average Dustfall at Butler Park, 1975-1987______________________________________ 22 Figure 11 - Exposure Pathways Model for Trail ___________________________________________________ 27 Figure 12 - Outdoor Dustfall Lead Before/After New Lead Smelter ____________________________________ 32 Figure 13 - Outdoor Dustfall Lead Loading by Geographic Area ______________________________________ 32 Figure 14 - Street Dust Lead Loadings Before/After New Smelter______________________________________ 33 Figure 15 - Indoor Dustfall Lead Loading Before/After