Fish consumption: Methylmercury risks and omega-3 fatty acids benefits. Population-specific consumption analysis & recommendations for sensitive population groups in the Puget Sound Region

Background: State and local health officials need tools and methods to develop fish consumption advice considering the benefits as well as the risks related to fish consumption. This research offers a new method that health assessors can use to consider the omega-3 benefits and methylmercury risks. Traditional approaches utilize ‘consumption rate limits' (CRLs) to calculate a maximum species consumption rate where the methylmercury dose does not exceed the RfD. Methods: Authors evaluated methods for deriving fish consumption advice, researched approaches considering nutritional benefits and selected an existing risk-benefit model for use. Authors identified a study providing consumption and contaminant data for fish consumed by Asian women in Washington State. CRLs were calculated and species were ranked by these values and by the scores generated from the risk-benefit model. Similarities and differences in the output from each individual approach were identified and contrasted with the results using a hybrid of the two approaches. The authors provide guidance for examining output and making benefit and risk-based recommendations using site-specific data. Results: The hybrid approach identified salmon, mackerel, squid, shishamo and jack mackerel as the best fish to consume. Conclusions:Fish and shellfish recommendations can vary based on approach. These varying results support the authors' hybrid approach that identifies the best omega-3 choices within CRLs that do not exceed the methylmercury RfD. This study demonstrates the difficulty in drawing consistent conclusions from a broad sample of species since benefits and risks depend on the amount and types of species consumed by a population.