Heavy metal accumulation and health risk assessment of crayfish in the middle and lower reaches of Yangtze River during 2015-2017.

This study performed statistical analysis and risk assessment of five heavy metals (As, Cd, Cr, Hg, Pb) in crayfish samples collected from six provinces in the middle and lower reaches of Yangtze River during 2015-2017. The Spearman correlation test and the results of hierarchical cluster analysis (HCA) indicated that As, Pb, and Cd in crayfish were significantly correlated, and the results of HCA showed that Jiangxi, Jiangsu, and Zhejiang were clustered into one group; Hubei, Hunan, and Anhui were clustered into another group; and provinces in the same group had spatial similarities in heavy metals. The pollution index (PI) values of five heavy metals in all provinces were below 1, implying that crayfish samples in this area were not highly contaminated. The target hazard quotient (THQ) values of five heavy metals were mainly below 1 except Hg in Anhui (2.9709), which was far beyond 1, indicating that the health risk posed by Hg exposure should not be ignored in Anhui.