Ag<elllCY for Toxic Substances and Disease Registry JDiVR§iOJl1l of Health Studies 1111111111111111111111111111111 PB99-156259 FINAL REPORT CONSUMPTION OF SEAFOOD AND WILDGAME CONTAMINATED WITH MERCURY BRUNSWICK? GLYNN COUNTY? GEORGIA GLYNN COUNTY HEALTH DEPARTMENT July 1999 REPRODUCEOBY: ~ U S Department of co~merce . National Technical .lnf~)I..ma2t~1~~ervlce Springfield, Virginia u.s. DEPARTMENT OF HEALTH AND HUMAN SERVICES Agency for Toxic Substances and Disease Registry Atlanta, Georgia 30333 Additional copies ofthis report are available from: National Technical Information Services, Springfield, Virginia (800) 553-6847 or (703) 605-6340 Request publication number PB99-156259 FINAL REPORT PRINTED BY u.s. DEPARTMENT OF HEALTH AND HUMAN SERVICES AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY ATLANTA,GA CONSUMPTION OF SEAFOOD AND WILDGAME CONTAMINATED WITH MERCURY, BRUNSWICK, GLYNN COUNTY, GEORGIA SUBMITTED BY HAZARDOUS WASTE PROGRAM ENVIRONMENTAL HEALTH SECTION GLYNN COUNTY HEALTH DEPARTMENT BRUNSWICK, GEORGIA PROTECTED UNDER INTERNATIONAL COPYRIGHT ALL RIGHTS RESERVED. NATIONAL TECHNICAL INFORMATION SERVICE U.S. DEPARTMENT OF COMMERCE JULY 1999 Reproduced from o best available copy. This study was wholly supported by funds from theComprehellsive Environmental Response, . Compensation, and Liability Act (CERCLA) trust fund to the Glynn County Health department tinder Grant Number UT501 ATU482229~02-3 from the Agency for Toxic Substances and Disease Registry, US. Department ofHealth and Human Services. This document, presented in its entirety as submitted by the grantee, has not been revised or edited to conform with agency guidance. DISCLAIMER Mention ofthe name ofany company or product does not constitute endorsement by the Agency for Toxic Substances and Disease Registry, U.S. Department ofHealth and Human Services orthe Glynn County Health Department. 11 TABLE OF CONTENTS DISCLAThffiR II LIST OF TABLES v LIST OF APPENDICES vii ABSTRACT 1 INTRODUCTION 2 OBJECTIVES 3 BACKGROUND 3 SIlECHARACTERIZATION 4 SEAFOOD CHARACTERIZATION 4 SEAFOOD CONSUMPTION ADVISORIES AND GUIDELINES 5 ADVERSE REALlH EFFECTS RESULTING FROM EXPOSURE TO MERCURY 5 BIOMARKERS USED To IDENTIFY EXPOSURE To MERCURY 6 METHODS 7 STUDY DESIGN RATIONALE 7 SELECTION OF TARGET AND COMPARISON GROUPS 7 DATA COLLECTION 8 DATA ENTRY AND MANAGEMENT 10 DATA ANALYSIS 10 RESULTS 10 SECTION I: ENROLLMENT RATES 10 SECTION II: QUESTIONNAIRE 11 SECTION III: DIETARY DIARY 15 SECTION IV: DEVELOPING RECOMMENDATIONS FOR SEAFOOD CONSUMPTION ADVISORIES 17 SECTION V: BIOMARKER RESULTS 18 DISCUSSION 18 STUDY STRENGlHS AND LIMITATIONS 20 CONCLUSIONS 22 RECO~NDATIONS 23 111 REFERENCES 25 AUTHORS AND ACKNOWLEDGMENTS 27 TABLES 29 APPENDICES 51 IV LIST OF TABLES Table 1: Participation Rates for Target and Comparison Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 30 Table 2: Demographic and other Characteristics ofTarget and Comparison Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 > ••• > ••••••• > •••••••• > 31 Table 3: Self-Reported Symptoms ofTarget and Comparison Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 32 Table 4: Logistic Regression Models for Selected Self-reported Symptoms ofTarget and Comparison Group Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 ... 34 Table 5: Crude Odds Ratios for Self-Reported Illnesses ofTarget and Comparison Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 35 Table 6: Crude Odds Ratios for Self-Reported Reproductive Problems ofTarget and Comparison Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 37 Table 7: Patterns ofEating, Catching, and Buying Seafood and Wildgame for the Past Month among Target and Comparison Group Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 38 Table 8: Frequency of Seafood and Wildgame Consumption During Past Month among Target and Comparison Group Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 39 Table 9: Patterns ofEating, Catching, and Buying Seafood and Wildgame for the Past Six Months among Target and Comparison Group Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 ................................................... 40 Table 10: Frequency of Seafood and Wildgame Consumption During Past Six Months among Target and Comparison Group Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 41 Table 11: Seafood and Wildgame Harvesting Locations among Target Group Participants, Seafood Consumption Study, Brunswick, Georgia, 1996 42 Table 12: Advisory Compliance among Target Group Participants, Seafood Consumption Study, Brunswick, Georgia, 1996 43 v Table 13: Demographic and other Characteristics ofTarget and Comparison Populations Who Completed the Dietary Diary Section ofthe Seafood Consumption Study, Brunswick, Georgia, 1996 44 Table 14: Source ofDietary Protein in Target and Comparison Group Populations, Seafood Consumption Study, Brunswick, Georgia, 1996 45 Table 15: Type ofSeafood Meals Consumed During the Two-Week Dietary Diary among Target and Comparison Group Participants, Seafood Consumption Study, Brunswick, Georgia, 1996 .................................................. 46 Table 16: Type and Location ofCaught Seafood and Wildgame Meals Consumed During the Two-Week Dietary Diary among Target Group Participants, Seafood Consumption Study, Brunswick, Georgia, 1996 47 Table 17: Seafood Consumption Levels (Questionnaire) Compared to Actual Consumption Levels (Dietary Diary), Seafood Consumption Study, Brunswick, Georgia, 1996 48 Table 18: Agreement of Seafood Consumption as reported in the Questionnaire and the Dietary Diary, Target and Comparison Group Participants, Seafood Consumption Study, Brunswick, Georgia, 1996 49 Table 19: Characteristics ofTarget Group Population by Urine Mercury Concentrations, Seafood Consumption Study, Brunswick, Georgia, 1996 50 Vi LIST OF APPENDICES Appendix A- Map ofthe LCP Area, Including Turtle River and its Tributaries A-I Appendix B- Screening Survey B-1 Appendix C- Study Questionnaire C-l Appendix D- Dietary Diary D-l vii V111 ABSTRACT Seafood sampling results from the Turtle River and its tributaries in Glynn County, Georgia raised concerns that the consumption ofmercury-contaminated seafood and wildgame from these areas could result in adverse health effects. Seafood from Purvis Creek, Gibson Creek, and the Turtle River between Georgia Highway 303 and channel marker 9 had the highest levels of mercury contamination based on data from Georgia Department ofNatural Resources fish sampling surveys. This community-based study compared residents who may have been exposed to mercury by consuming seafood and wildgame from these waters (target group) to residents who reported that they had not consumed seafood and wildgame from these waters (comparison group). The objectives ofthis study were: 1) to compare the prevalence ofself-reported symptoms and illnesses between target and comparison group participants; 2) to determine seafood and wildgame consumption levels among study participants and assess the accuracy ofthese self-reported consumption levels; 3) to provide a basis for developing sound recommendations for seafood consumption advisories to the community; and 4) to assess individuals for evidence of mercury exposure using biological evidence (24-hour urine creatinine clearance test). Results from this study indicate a higher potential exposure ofthe target group to mercury­ contaminated seafood and wildgame. Urine mercury concentrations, however, were below the reference level in all study participants. There were statistically significant differences in several self­ reported neurological symptoms between the two groups. Some differences were found between the two groups in self-reported illnesses, but none were statistically significant. Analysis ofthe data showed that study participants generally under-estimated their amount ofseafood consumption on the interviewer-administered questionnaire when compared to the amount they reported actually consuming as measured by the two-week dietary diary. Despite this finding, seafood comprised a smaller proportion ofprotein in study participants' diet than anticipated. The majority ofthe target group participants do not harvest seafood in the advisory area. Of the eight participants who reported fishing in the restricted area, seven stated that they were aware ofthe advisory. Overall, the current risk-based seafood consumption guidelines are protective for the general public because evaluation of the amounts of seafood consumed on a per meal basis during the two week dietary diary showed that individuals did not eat more than values used by Georgia Department ofNatural Resources in calculating the consumption guidelines. Ongoing monitoring of mercury levels in seafood and other wildlife in the area is recommended, as well as ongoing public education concerning consumption ofmercury-contaminated seafood. 1 INTRODUCTION The Linden Chemical and Plastics (LCP) Company Ross Road site in the city ofBrunswick, Georgia is iocated on 550 acres along the Turtle River and adjacent to tidal creeks and marshlands (Site map, Appendix A). From 1957 to 1994, the facility produced chlorine, sodium hydroxide, and muriatic acid by electrolysis of sodium chloride using mercury cells (1). The site borders extensive tidal marshes, across which a causeway was constructed to carry a sewer allowing discharge of treated process wastewater into Purvis Creek, which flows into the Turtle River,