Study on heavy metal concentration and their food safety assessment in the muscle of fishes in Qiantang River

Abstract:

The contents and distributions of heavy metals Cu, Zn, Pb, Cd, Hg, As in fishes were investigated with the samples collected from the Qiantang River in 2015.Then we evaluated the pollution degree and assessed the food safety based on the single factor pollution index(P_i) and the provisional tolerable weekly intake(PTWI),respectively. Results showed that the contents of Cu, Zn, Pb, Cd, Hg in the muscle of fishes in Qiantang River were rather low. However, compared with the limit values of the safety requirements for non-environmental pollution aquatic product, the contents of As were somehow higher with the exceeding rates of 3% than the standard limit and reached ‘Light Pollution’. The statistics results showed that although there was no significant difference among Cu, Zn, Cd, Hg and As(p> 0.05), the contents of Pb had obvious variation with sampling areas, which may be mainly caused by the waste water and atmospheric deposition of nearby factories. Assessment results showed that the dietary exposures of heavy metals in the muscle of fishes in Qiantang River were lower than PTWI, indicating overall in a safe range of the fish meat, namely no harm to health. However, we found that the Hg intake of a minority of fish species exceeded the PTWI value, suggesting possible risk to health. Therefore, more attention should be paid to the heavy metal Hg.