Mercury, specifically methylmercury (MeHg), has been shown to cause developmental and neurologic effects, with the severest effects being observed after catastrophic exposure to communities in Japan and Iraq [Bakir et al. 1973; Harada 1995; Kondo 2000; National Research Council (NRC) 2000]. Exposure to MeHg can come from many routes, but the most prominent nonoccupational pathway is fish consumption (NRC 2000). For the purpose of public health protection, the U.S. Environmental Protection Agency (EPA) has established a reference dose (RfD) for MeHg of 0.1 ?g/kg/day (NRC 2000; U.S. EPA 2000). A hair Hg level of 1.2 ppm is considered to be the exposure equivalent of the RfD (NRC 2000).