Methylmercury and trace elements in the marine fish from coasts of East China

Abstract

Fish consumption is an important source of human exposure to heavy metals. To determine the health risks for metals by consumption of marine fish in China, three species of fish, namely large yellow croaker (Pseudosciaena crocea), small yellow croaker (Pseudosciaena polyactis) and silver pomfret (Pampus argenteus) were collected and analyzed for methylmercury (MeHg), total mercury (T-Hg), selenium, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, strontium and zinc. The large yellow croakers had the highest concentrations of mercury, lead, nickel and zinc, and the levels of MeHg were positively correlated to T-Hg. The ratios of MeHg to T-Hg in yellow croakers were significantly higher than those in silver pomfret, indicating differences in accumulation and magnification of MeHg in these two types of fish. The concentration of T-Hg was found to decrease as the Se level in fish tissues increased. Cadmium levels in 16% of the samples were higher than the criterion recommended by the European Commission Regulation. The concentrations of other metals were well below international standards. A human health risk assessment showed that the estimated daily intake of these metals did not exceed the reference dose established by the US Environmental Protection Agency. The hazard quotients (HQs) were all less than 1, indicating a situation of no risk for consumption of these fish.