衡阳市工业园区周边菜地土壤污染特征及其风险评价

Characteristics of Soil Contamination and Risk Assessment of Vegetable Fields Around Industrial Parks in Hengyang

菜地土壤重金属污染不仅影响蔬菜质量还对人体产生潜在的健康风险。本文以衡阳市三大工业园区周边菜地土壤为研究对象,通过分析Cu、Zn、Pb、Mn和Hg五种重金属的含量特征,并利用地累积指数、潜在生态风险指数和人体健康风险指数法对其污染现状及潜在风险进行评价。结果表明:(1)以土壤环境质量农用地土壤污染风险管控值为标准,衡阳市三大工业园区周边菜地土壤中重金属Cu、Pb、Zn含量超过风险管控值的点位为68%、66%、10%,其中在Cu和Pb超标点位中白沙洲工业园区周边菜地分别占76.5%和50%,Mn和Hg尚未超标。(2)通过地累积指数评价,白沙洲工业园区周围菜地土壤中Zn呈偏中度污染,Hg、Cu轻度污染;松木工业园区周围菜地土壤中Zn呈偏中度污染,Pb、Hg轻度污染;衡钢产业区周围菜地土壤中Cu、Zn、Hg存在轻度污染。(3)潜在生态风险指数(RI)显示三大工业园区菜地土壤5种重金属RI贡献大小依次为:RI(松木工业园区)>RI(衡钢产业区)>RI(白沙洲工业园区),这三个工业园区的菜地土壤属于轻微生态危害。(4)研究区土壤中5种重金属目前均不会对成人和儿童造成非致癌风险。衡阳市三大工业园区周边菜地虽部分已受到了一定的污染,但其致癌风险可以忽略。

The soil contaminated by heavy metals not only affects vegetable quality, but also has potential health risks to human health.Vegetable field soil samples were sampled at the three major industrial parks in Hengyang City. By analyzing the content characteristics of five heavy metals, Cu, Zn, Pb, Mn and Hg, and using the methods of land accumulation index, potential ecological risk index and human health risk index, the pollution status and potential risks were evaluated. The results showed that:(1) By comparing the soil environmental quality, agricultural land and soil pollution risk control value standards, the content of heavy metals Cu, Pb and Zn in the vegetable soil of sample points exceeded the risk management control value were 68%, 66% and 10% respectively. Among the samples, the account points of Cu and Pb exceed the standard reaches 76.5% and 50% respectively in the vegetable fields around Baishazhou Industrial Park, while Mn and Hg have not exceeded.(2) According to the evaluation of land accumulation index, the vegetable soil around Baishazhou Industrial Park is moderately polluted by Zn, and slightly polluted by Hg and Cu;Zn is moderately polluted,and Pb and Hg are slightly polluted in vegetable soil around the Songmu Industrial Park;There is slight pollution of Cu, Zn and Hg in vegetable soil around Henggang Industrial Zone.(3) The potential ecological risk index(RI) shows that the RI contribution of five heavy metals in vegetable soil of the three industrial parks is in the following order: RI(Songmu Industrial Park)>RI(Henggang Industrial Park)>RI(Baishazhou Industrial Park). there are lightly ecological hazards.(4) At present, none of the five heavy metals in the soil will pose a non-carcinogenic risk to adults and children. To some extent, some vegetable fields have been contaminated, however, their health risks can be ignored around the three major industrial parks in Hengyang City.