闽北某新建水库周边土壤重金属生态与健康风险评价

Ecological and Health Risk Assessment of Heavy Metals in Soil around a New Reservoir in Northern Fujian Province,China

为探究闽北某新建水库周边土壤重金属污染程度及存在的生态与健康风险,在该区域采集了10个具有代表性的土壤样品,用原子荧光、AAS和ICP-MS测定土壤中25种重金属含量,结果表明:除了Ni、Cr、Hg、Li、Sc、V、Co和Fe外,其余重金属不同程度超出福建省土壤背景平均值,其中Cd和Pb分别达到背景值的26.42倍和8.42倍;地累积指数法和潜在生态风险指数法的评价结果表明:Cd为偏重污染,表现出很高潜在生态风险,Pb为中度污染,表现出中等潜在生态风险,其余重金属无污染,5#百步溪A和7#百步溪B处于中等潜在生态风险,10#外屯村处于较高潜在生态风险,其余点位均为很高潜在生态风险;手-口途径摄入是土壤重金属引起非致癌风险的主要途径,总非致癌风险顺序为Pb>Zn>Cr>Cu>As>Ni>Cd>Hg,其中手-口途径对儿童Pb的暴露风险值HQa为1.07>1,易对儿童健康造成危害,其余重金属风险值均小于1,不会对人体健康造成危害,Ni、Cr、As、Cd通过呼吸途径不具有致癌风险。

In order to evaluate the ecological and health risk of heavy metals in soil around a new reservoir in Northern Fujian Prov- ince, China, 10 representative samples of soil were collected from this area and the concentrations of 25 heavy metals in the soils were determined by using AFS, AAS and ICP-MS. Results show that except for Ni, Cr, Hg, Li, Se, V, Co and Fe, the others exceed the average background value of the soil of Fujian Province. The assessment results of geo-accumulation index and potential ecological risk index indicate that the pollution of Cd is classified as extreme degree and Cd presents very high potential ecological risk, while Pb shows moderate pollution and presents medium potential ecological risk, and the others present no pollution. 5#BaibuxiA!and 7# BaibuxiB are both in medium potential ecological risk, but 10#Waituncun is in high potential ecological risk, and other sampling sites are all in very high potential ecological risk. Health risk assessment indicates that the heavy metals in the soils are mainly ingested by human bodies through hand-mouth ingestion. The order of non-cancer hazard indexes of heavy metals is Pb〉Zn〉Cr〉Cu〉As〉Ni〉Cd〉 Hg. The hand-mouth ingestion risk of Pb to children reaches 1.07〉 1, easy to effect children＇s health. The ingestion risk values of the other metals are lower than 1 and may not cause harm to human body health. Ni, Cr, As, and Cd can not cause any cancer risk by in- halation.