Population-Based Fish Consumption Survey and Probabilistic Methylmercury Risk Assessment

ABSTRACT

A fish consumption survey was developed and administered by telephone to 820 Wyoming fishing license holders. Survey respondents provided the frequency, species, and quantity of Wyoming-caught and store-bought fish consumed for license holder and household members. Deterministic and probabilistic methylmercury exposure distributions were estimated by multiplying fish consumption by species-specific mercury concentrations for each household member. Risk assessments were conducted for children, women of childbearing age, and the rest of the population by comparing methylmercury exposure distributions to levels of concern. The results indicate that probabilistic risk assessment likely provides a more realistic view of the risk to the study population. The results of this study clearly indicate that: (1) there is no level of fish consumption that is without risk of methylmercury exposure, (2) fish advisories may be warranted for children and women of childbearing age, and (3) that store-bought fish generally contribute more to methylmercury exposure than do Wyoming-caught fish.

Key Words:

• mercury
• methylmercury
• fish consumption
• exposure
• risk
• probabilistic

ACKNOWLEDGMENTS

We acknowledge Nicole Lindsey, Wyoming Department of Health, for her assistance in supervision of data collection and Karla Holgers for data entry. We acknowledge the Wyoming Department of Health for funding this project and the Wyoming Game and Fish Department for their support and sharing of fish residue and fishing license holder data that were crucial to the successful execution of this study. We also acknowledge the useful input of Randy Stahl, Bruce Kimball, and Richard Engeman, National Wildlife Research Center, regarding the statistical analysis.

Notes

¹0.1 μ g/kg BW * day.

²0.4 μ g/kg BW * day.

¹Substitution of low methylmercury species (dark tuna) for species with mean methylmercury concentration exceeding 1 ppm.