Blood mercury reporting in NHANES: identifying Asian, Pacific Islander, Native American, and multiracial groups

Asians, Pacific Islanders, and Native Americans are a potentially high-risk group for dietary exposure to methylmercury through fish consumption. However, blood mercury levels in this group have not been identified in recent reports of the National Health and Nutrition Examination Survey (NHANES) for the years 1999-2002.

We used NHANES data from 1999-2002 to obtain population estimates of blood mercury levels among women of childbearing age classified as belonging to the "other" racial/ethnic group (Asian, Pacific Islander, Native American, and multiracial; n = 140). Blood mercury levels in this group were compared with those among all other women participants, classified as Mexican American, non-Hispanic black, non-Hispanic white, and "other" Hispanic.

An estimated 16.59 +/- 4.0% (mean +/- SE) of adult female participants who self-identified as Asian, Pacific Islander, Native American, or multiracial (n = 140) had blood mercury levels > or = 5.8 microg/L, and 27.26 +/- 4.22% had levels > or = 3.5 microg/L. Among remaining survey participants (n = 3,497), 5.08 +/- 0.90% had blood mercury levels > or = 5.8 microg/L, and 10.86 +/- 1.45% had levels > or = 3.5 microg/L.

Study subjects in NHANES who self-identified as Asian, Pacific Islander, Native American, or multiracial had a higher prevalence of elevated blood mercury than all other racial/ethnic participants in the survey. Future studies should address reasons for the high mercury levels in this group and explore possible interventions for lowering risk of methylmercury exposure in this population.