Occurrence and health risks of heavy metals in crayfish (Procambarus clarkii) from Jiangsu province, China

Concentrations of arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) in crayfish from Jiangsu province, China, were measured and their health risks were evaluated. For crayfish from both crayfish-rice culture system (CRCS) and crayfish intensive culture system (CICS), concentrations of As, Cd and Pb in whole body of crayfish (WB) were significantly higher than those in abdominal muscle of crayfish (AM), while concentration of Hg in WB was significantly lower than that in AM. No significant difference in concentrations of the heavy metals was found between CRCS and CICS. Concentrations of the heavy metals in AM from both systems were below the limit set by the national standard of China. Estimated daily intake values of the heavy metals were far below the provisional tolerable daily intakes set by Joint FAO/WHO committee on Food Additives, and the corresponding hazard quotient and hazard index were below one. Therefore, consumption of crayfish with the average daily consumption rate (DCR) could be generally regarded as safe. For the consumption with two more times of average DCR during peak season, there might be a potential health risk from intakes of As and Hg in abdominal muscle of crayfish.