钱塘江流域鱼肉中重金属含量特征及食用安全性评价

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

摘要:

根据钱塘江流域鱼类的调查和监测结果，2015年对鱼类肌肉中重金属Cu、Zn、Pb、Cd、Hg和As的含量水平、空间分布特征进行了分析讨论。采用单项污染指数（Pi）和每周可耐受摄入量（PTWI）指标分别评价其污染程度和食用安全性。结果显示，重金属As在钱塘江流域鱼肉中有3.0%的超标现象，以《无公害食品水产品中有毒有害物质限量》为依据，As已达到轻污染水平，其余各重金属在鱼肉中的含量均处于较低水平。不同区段水域鱼类中重金属Cu、Zn、Cd、Hg和As的含量无显著性差异（P> 0.05），但Pb的含量下游闻堰三江口显著高于上游建德三江口，这可能是流域周边含Pb废水排放污染和工厂大气沉降污染共同作用的结果。食用安全性评价结果显示，周边居民食用钱塘江流域鱼类，重金属的摄入低于JECFA推荐的暂定每周可耐受摄入量，总体处于安全范围内，但个别鱼类Hg的摄入量已超过PTWI值，可能存在风险，需要予以关注。

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.