Health risk assessment of heavy metal contamination in carps from Three Gorges

The purpose of this study was to assess the pollution degree of four heavy metals in carp and their health risks to local residents in the Three Gorges Reservoir area. The carp samples were digested by microwave digestion instrument and the concentrations of Pb, Cd, Cu and Cr in carp were detected by flame atomic absorption spectrometry. Target hazard quotient (THQ) and maximum allowable consumption rate (CRLim) were used to assess the health risk of eating carp. The results of research showed that the average concentration of Pb, Cd, Cu and Cr in carp was 0.348，0.147，5.837 and 1.270 mg/kg，respectively. The detected levels of the studied metals were below the legal national and inter national limited standards. Compared with Yangtze River, Nansi Lake, Beijiang River, Tuojiang River, the Pb level was lower, Cd level was quite，and Cu, Cr were higher. Compared with the reservoir area before impoundment, the pollution of heavy metals had been improved, and the pollution degree of heavy metals had increased relative to the water area after impoundment. The results showed that the maximum allowable consumption rate of carp was 0.268-0.753, 0.158-0.446, 0.160-0.449 and 0.055-0.155 kg/d for Pb，Cd，Cu and Cr, respectively. The THQ for Pb, Cd, Cu and Cr were less than 1, and the total target hazard quotient value（TTHQ）was also below 1. According to the comprehensive evaluation of THQ and CRLim, carp in the Three Gorges Reservoir Area had no health risk to coastal residents.