Investigator: David Taylor, Roger Williams University

Scientific Theme: Molecular Toxicology

Abstract: Fish are an excellent source of omega-3 fatty acids that provide numerous health benefits to human consumers. However, contaminant concentrations in some fish may be sufficiently high to adversely affect human health. For example, methylmercury (MeHg) is a toxic environmental contaminant that poses significant risk to human health, and exposure occurs mainly through dietary intake of contaminated fish. To minimize MeHg exposure, government agencies issue consumption advisories to inform the public of potential health risks of eating fish. The successful development and implementation of consumption advisories for marine fishes, however, are limited by several key factors. First, advisories focused on marine fish consumption lack geographic specificity, and thus, are possibly misguided and ineffective because they do not account for small-scale spatial variations in MeHg contamination. Second, national advisories emphasize fish species that are identified as high-risk for MeHg, and thus, there is sparse information for presumed low-risk species. This undermines health benefits provided by fish that pose little threat to the health of fish-consuming citizens. Third, there are limited available data on the co-occurrence of nutrients in fish tissue that mitigate or counteract MeHg toxicity, e.g., protective effects of selenium (Se) and the health benefits of dietary omega-3 fatty acids, respectively. This study will examine inter- and intra-specific variations in mercury (Hg), Se, and fatty acid concentrations in coastal marine fishes of Rhode Island. Fish Hg data will be incorporated into exposure assessment models to estimate human exposure to Hg due to local fish consumption. To evaluate the efficacy of this modeling approach, results will be compared to national estimates of human Hg exposure and the reference dose established by the U.S. Environmental Protection Agency. Moreover, measurements of species-specific Se and fatty acid concentrations will provide a synoptic examination of the health benefits provided by fish consumption. Acquiring these data will support public health risk-benefit assessments and management decisions related to the issuance of fish consumption advisories and guidelines.

Human Health Relevance: The risks and benefits of fish consumption are intrinsically linked to the respective contaminant and nutrient concentrations in fish tissue. This study will measure Hg and Se levels in Rhode Island coastal fishes, the latter due to its mitigating effect on Hg toxicity. Moreover, fatty acid profiles will be determined for target fishes in order to assess the potential health benefits associated with fish consumption. This study will therefore support public health risk-benefit assessments related to the issuance of fish advisories and guidelines.