Evaluating the public health risks of methylmercury exposure and benefits from omega-3 fatty acids and selenium from fish consumption

Graduation date: 2015Although fish are a nutritious food source, they also are the main source of methylmercury exposure in U.S. populations. This research examined the risks from methylmercury and benefits from omega-3 fatty acids and selenium from fish consumption. The first study provided the first region-specific quantitative risk/benefit analysis for nine commonly consumed freshwater fish species in the Columbia River Basin; which is home to many Native American Tribes and subsistence fishermen who consume large quantities of locally caught fish. (Donatuto and Harper 2008; Harper and Harris 2008)(Donatuto and Harper 2008; Harper and Harris 2008) My results showed that mountain whitefish and rainbow trout provided a net benefit for cardiovascular risk and improved infant visual response memory scores across all consumption rates in all subregions in which they were sampled. The second study examined the associations between region of residence, demographic characteristics and total blood mercury concentrations in a nationally representative sample of women of childbearing age, using the 1999-2010 NHANES database. Women who live in the Atlantic and Pacific coastal regions have the highest, and women in the Midwest have the lowest, methymercury concentrations in their blood.\ud The third study analyzed intra-and inter-specific variability in selenium: mercury molar ratios in ten species of freshwater fish from the Columbia River Basin to determine the potential application for fish consumption guidelines. Variability in selenium:mercury molar ratios was high within the fish species regardless of fish size. This variability within fish species warrants caution in using selenium:mercury ratios in risk assessment calculations. Overall, this research demonstrates the complexities involved in crafting guidelines that consider both the risks and benefits of fish consumption