为评估典型水产养殖型湖泊中的重金属含量水平及其人体健康风险特征,系统采集并测定了宿鸭湖湖水、周边地下水、沉积物及鱼体中的重金属含量.在此基础上计算了不同重金属在不同介质间(湖水-鱼体、湖水-沉积物及沉积物-鱼体)的转移因子,并通过健康风险指数计算定量分析了宿鸭湖水生态系统中重金属对人体的健康影响,以及不同暴露途径的风险贡献率.结果表明:Zn、Ba和Sr在不同介质体内含量均较高,而Sn和Cd的含量均比较低.Cr和Zn在鱼体中的均值含量超过WHO鱼类产品中重金属的含量限值,具有潜在毒性;湖水和地下水中的所有重金属浓度均低于饮用水标准中的相关限值;部分沉积物样品中Cr、Ni、Cu、Zn、Cd和Pb含量超出环境保护部《土壤环境质量标准》(GB15618—2008)自然背景值,但低于美国华盛顿州沉积物化学标准(WAC 172-204-320)中的含量限值,已构成轻微污染.不同介质间的转化因子分析表明,鱼体对湖水中的Zn、Sr、Ba、Cu、Cr、Ni、Co、Sn和Cd均存在富集作用;但除Zn以外,鱼体对沉积物中的其他重金属无明显的富集作用;宿鸭湖水生态系统中的重金属Cr对人体的HRI值为1.6,其健康危害效应不可忽视;食用鱼类是导致Cr人体健康危害的主要途径,贡献率高达94%;最后,与非养殖型湖泊相比,宿鸭湖水库中鱼体内Pb和Cr的含量明显偏高,且重金属从湖水到沉积物的转移因子明显偏高,而从湖水到鱼的生物浓缩因子相对较低.
To estimate the metal concentration in typical artificial lake for aquaculture,as well as their influence on human health,the concentration of metals in surface and sub-surface water,sediment and fishes were examined. Based on this,the transfer factor( TF) of different metals in fish from water and sediment were calculated to analyze the migration and transformation role of metal among different mediums,and the Health Risk Index( HRI) were calculated to estimate the potentially detrimental effect of metals in Suya Lake ecosystem on human health. It can be identified that: the Zn,Ba and Sr are elements that occur in all four media at the highest concentration,while Sn and Cd are elements that at the lowest concentration; the concentrations of Cr and Zn in the edible part of fish exceed limit values adopted by FAO and WHO for fish products,therefore being potentially toxic for eating; theconcentrations of all elements in water body are lower than the limit value regulated in drinking water standards,therefore being innocuous for drinking;the concentrations of Cr,Ni,Cu,Zn,Cd and Pb in part of sediment samples are larger than the background value adopted by Environmental Quality Standard for Soils( GB15618—2008) but smaller than that adopted by Sediment Chemical Criteria( WAC 172-204-320),which means that sediment,though being polluted,are not innocuous for touching. TF analysis indicates that fish can accumulate the heavy metal from water,but cannot accumulate the heavy metal from sediment with the exception of Zn; the HRI of Cr is 1.6 with the main exposure route from fish digestion,indicating that fish is not acceptable for eating; the concentration of Zn and Cu,as well as the TF value( lake water to sediment) are significantly high,while the Bio-accumulation Factor are relatively low.