In this paper, a total of 62,712 aquatic product samples were collected from 32 provinces of China during 2015-2017. By analyzing the spatial distributions and non-parametric tests of five heavy metals (lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr), and arsenic (As)) in four aquatic product (fish (n = 44,353), shrimp (n = 8453), crab (n = 5367), and shellfish (n = 4539)), it was found that the concentrations of the five heavy metals in the same aquatic product are significantly different in different regions. Furthermore, we calculated daily estimated intake (EDI) of each of the five heavy metals and assessed non-cancer risk and cancer risk using target hazard quotient (THQ) and target cancer risk (TR), respectively. The results showed that for mean exposure levels, the THQ values in four aquatic products were all below one, meaning that there was no non-carcinogenic risk. For high exposure levels, the hazard index (HI) value exceeded one in fish in North China, which means the potential non-carcinogenic risk should not be ignored. As for cadmium, most of the TR values in crab and shellfish exceed 1 × 10-4 in North China, East China, and South China. For chromium, except for Northeast China, the TR values in fish in other regions exceed 1 × 10-4; it indicated that the cancer risk caused by cadmium or chromium should not be ignored.
Keywords: Aquatic products; Exposure; Health risk assessment; Heavy metals.