Investigation of metals in crustaceans in parts of Hainan Province, China

Objective To analyze the distribution of metal and metalloid elements in crustaceans and to evaluate the human health risk of whom consume them in Hainan coastal areas.

Methods The contents of cadmium, lead, arsenic and mercury in 245 samples of crabs and shirmps collected from Changjiang, Wenchang, Wanning and Danzhou in 2015, 2017 and 2019 were determined. The single factor pollution index (P_i) and a simple distribution model were used to evaluate the degree of heavy metals pollution and the human health risk in the areas.

Results The contents of cadmium, inorganic arsenic and methylmercury in crabs were significantly higher than those in shrimps (P < 0.05). There were no significant differences in the contents of lead between crabs and shrimps (P > 0.05). The average contents of cadmium, inorganic arsenic, and methylmercury in crustaceans from four areas showed an upward trend in these three years except lead (P < 0.05). In 2019, the P_i values of cadmium in crustaceans from four areas were above 1, and those of lead, inorganic arsenic and methylmercury, were all less than 1. The exposure levels of cadmium, lead, inorganic arsenic and methylmercury in crustaceans from four regions were all lower than their corresponding allowable intake or reference dose, and there was no significant difference in population exposure in the four areas(P>0.05). However, the exposure levels in children were twice than those of adults (P < 0.05).

Conclusion Crabs were more likely to accumulate cadmium, inorganic arsenic and methylmercury than shrimps. The pollution levels of cadmium, inorganic arsenic and methylmercury in crustaceans in the four areas had an upward trend in these three years. Cadmium pollution in crustaceans was serious in 2019, and the supervision of marine environment should be strengthened in these areas. The human health risk from exposure to cadmium, lead, inorganic arsenic and methylmercury through eating crustaceans in the four regions were all within the safe limits in 2019. Children had higher health risks from exposure to the four metals than adults, and should consume these crustaceans in moderation.