Building a dynamic model linking human exposure to mercury emission regulations: Step one: Risk to susceptible populations

The goal of this project is to model the reduction in human risk that could be obtained by the regulation of mercury emissions in Kentucky. A system dynamics approach will be used to predict changes in mercury concentration in environmental compartments in response to reductions in atmospheric loading, paying particular attention to time frame and percent emission reduction needed to reach desired water quality standards and risk levels to susceptible populations deemed acceptable by the EPA and the state of Kentucky. These modeled effects are expected to include reductions in environmental compartments, fish tissue levels, and risk to human consumers. The main hypothesis to be tested is that reduction in local emissions will lead to reduction in mercury concentrations in environmental compartments and risk to susceptible populations. The first step in this project is to develop the model to predict the risk to susceptible populations by relating fish consumption to mercury levels in maternal and fetal blood based on a dynamic whole-body physiologically based pharmacokinetic model of hypothetical individuals with a distribution of intake rates representing the population of interest. Toxicological and pharmacological data will be used to characterize the disposition of mercury in the human body and the fetus. Exposure levels will be projected by modeling human intake rates based on the concentration of mercury in fish from local streams and the consumption characteristics of susceptible populations.