Relationships among Mercury Concentration, and Stable Isotope Ratios of Carbon and Nitrogen in the Scalp Hair of Residents from Seven Countries: Effects of Marine Fish and C4 Plants Consumption

We analyzed the Hg concentration, and δ¹³C and δ¹⁵N values in the scalp hair of residents from seven countries; Vietnam, New Zealand, Spain, the USA, South Korea, Brazil and Japan. Relationships among the data in each country and among the seven countries were then examined. The highest Hg concentration as well as the highest or higher δ¹⁵N value in each country was found in the hair of a heavy marine fish-eater, whereas the lowest Hg concentration and δ¹⁵N value were found in the hair of a vegetarian or non (marginal)-fish eater. Hg concentrations were positively correlated with the δ¹⁵N values in each country, and increased markedly in samples with δ¹⁵N values exceeding 9.0 ‰, probably due to fish consumption. The highest Hg concentration could be found in sample, with a δ¹³C value between -19 and -18‰, probably reflecting the δ¹³C value of the marine food web.