四川盆地某石化基地周边街尘重金属污染及风险评价

Contamination and Risk Assessment of Heavy Metals in Ambient Street Dust from One Petrochemical Industrial Base in Sichuan Basin

为探究石化型城市道路灰尘中重金属污染状况及对人体健康的潜在危害与潜在环境风险,该研究以四川盆地某石化基地为研究对象,采集基地周边26个街尘样品,测定了街尘中重金属Cu、Pb、Cr、Ni、Zn、Mn和As的含量,分别采用地累积污染指数法、美国环境保护署人体健康风险评价法和潜在生态风险指数法对街尘重金属污染程度及人体健康风险水平和生态风险进行评价。结果表明,研究区26个样品中Cu、Pb、Cr、Ni、Zn、Mn和As 7种重金属的平均浓度依次为48.49、48.91、135.19、58.72、286.70、718.61和21.74 mg/kg。除Mn外的6种元素平均值均高于成都市背景值。地累积指数平均值排序为Zn>Ni>As>Cr>Pb>Cu>Mn。其中,Ni、Cr、As均为轻度污染,Pb、Cu、Mn处于无污染状态,Zn除个别样点为严重污染之外,其余样点为中度、轻度或无污染状态。健康风险评价结果表明,所有重金属中,As、Cr、Mn和Pb对儿童具有很高的非致癌风险,As的HI高达5.79,对儿童健康威胁极高。生态风险评价结果显示,该石化基地未对区域生态安全构成风险。

In order to explore the heavy metal pollution status of road dust in petrochemical industrial base and the potential harm to human health as well as ecological risks.A total of 26 street dust samples were collected from one petrochemical industrial base of Sichuan Basin to determine the concentration of Cu,Pb,Cr,Ni,Zn,Mn and As.The geo-accumulation index method was adopted to evaluate the pollution levels of heavy metals.In addition,human health risks and ecological risks were also assessed.The results showed that the average concentrations of Cu,Pb,Cr,Ni,Zn,Mn and as were 48.49,48.91,135.19,58.72,286.70,718.61 and 21.74 mg/kg,respectively.The average values of six elements except Mn were higher than the local background values.The geo-accumulation index showed that Ni,Cr,and As are moderately contaminated while Pb,Cu,and Mn are between practically uncontaminated and uncontaminated conditions.The geo-accumulation index of Zn in few samples reached 3.22,which was a strongly contaminated pollution,all the other sample sites are in the range of uncontaminated to moderately contaminated.The results of human health risk assessment showed that among all the heavy metals,only as,Cr,Mn and Pb caused a high non carcinogenic risk to children.Among them,the HI of As reached 5.79,which posed a high threat to children’s health.The results of ecological risk assessment showed that the petrochemical industrial base did not cause risk to regional ecological health.