Heavy metal contamination in fish and human health risks from lakes of a mega inter-basin water diversion

Abstract

Heavy metals in freshwater lakes under inter-basin water diversions may pose harms to lake ecosystems and human health but have rarely been studied. We studied fish heavy metals in water diversion lakes, Gao-Bao-Shaobo Lakes (GBSLs), along the South-to-North Water Diversion Project in China, and evaluated associated human health risks from fish consumption. A total of 322 muscle samples from 29 fish species were collected to characterize contamination patterns of copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb), and arsenic (As). The studied heavy metals in fish were found within China's food safety standards. Among the studied metals, Cu, Cd, Pb, and As had higher concentrations temporally in autumn and spatially in Gaoyou Lake. Moreover, Cd, Pb, and As in carnivores were significantly higher than other feeding groups, and Cd and As in upper-middle and upper water layers were significantly higher than other layers. Consumption of GBSLs fish did not pose a non-carcinogenic risk to human health. However, consumption of fish species such as Protosalanx hyalocranius, Carassius auratus, Culter alburnus may pose potential carcinogenic risks to human health due to Cr and Cd. The current study had implications for assessing aquatic ecological conditions and reducing human dietary health risks related to heavy metals in water diversion lakes.