Seafood, mercury, and human health in coastal South Carolina: Findings from a community-based study

Mercury (Hg), an environmental pollutant, can harm human health. Seafood consumption is a major way that people are exposed to Hg and the analysis of human hair is a standard method to measure Hg exposure. This community-based study identified demographic and dietary factors associated with elevated Hg concentrations and health outcomes of individuals with elevated Hg concentrations throughout two coastal South Carolina (SC) counties. We collected hair samples (n = 85) at local barbershops and salons; participants completed an online survey with questions on demographics, diet, and health histories; and we analyzed hair samples using a DMA-80. Between 4.9–8.4% of respondents had Hg concentrations exceeding the US EPA’s reference dose of 1.0 part-per-million (ppm). Male respondents and those who consume seafood once per month or more—particularly certain fish species—were more likely to show elevated Hg. Other demographic factors were not significantly correlated with Hg concentrations. The most significant health effect associated with elevated Hg concentration was heart disease. These results suggest an opportunity for additional research into the pathways taken by Hg within the aquatic and marine ecosystems of coastal SC, as well as the need for better communication about the environmental-health risk factors faced by the public in this area.