Cadmium pollution status and assessment of potential risk to human health of commercial aquatic products

Objective To understand the cadmium pollution in aquatic products of fish, shellfish, shrimp and crab, analyze the seasonal difference of cadmium content in the above aquatic products, classify the level of cadmium pollution and assess the health risks. Methods Totally 1 554 samples of commercial aquatic products were collected and the cadmium content in aquatic products was determined by graphite furnace atomic absorption spectrometry. The difference of cadmium concentration between seasons were compared through descriptive analysis. Pollution index (Pi) methodology was employed to evaluate the pollution level of aquatic products. The provisional tolerable monthly intake (PTMI) of cadmium was taken as the reference value to assess the health risks of aquatic products. Results The average concentration of cadmium in 1 554 aquatic products was 0.116 4 mg/kg. The total detection rate was 45.56% (708/1 554), including 86.26% (496/575) of shellfish, 66.43% (93/140) of crabs, 32.48% (102/314) of shrimps and 3.24% (17/525) of fish. The total violation rate was 1.74% (27/1 554), of which crabs were 7.86% (11/140), shrimps were 2.87% (9/314), shellfish were 1.22% (7/575), fish were 0.00% (0/525). The result of pollution index indicated that crabs were lightly polluted in autumn (Pi=0.36), moderately polluted in spring and winter (Pi were 0.70 and 0.89 respectively), and the other aquatic products were clean in each season. The result of health risk assessment showed that at the general intake level, the maximum percentage of estimated monthly intake (EMI) in PTMI of various aquatic products in different seasons was 0.35%, while at the high intake level, the maximum percentage was 49.33%. Conclusion There were some differences of the violation rate of cadmium in aquatic products between seasons. The cadmium pollution was the lightest in summer. Except for crabs, which had light or moderate pollution level, the other kinds of aquatic products were clean. Either at the general level or high level of intake, the health risks of cadmium exposure caused by taking aquatic products was relatively low