福建土壤重金属地积累污染特征及潜在生态危害评价

Geo-accumulation Index and Potential Ecological Risk on Soil Heavy Metals:An Evaluation of Case in Fujian

基于地理信息系统软件,使用地积累指数和潜在生态危害指数分别研究了福建省土壤重金属（As、Cd、Cr、Cu、Hg、Ni、Pb、Zn）的地积累污染特征和潜在生态危害程度。通过分析结果表明：研究区土壤中各重金属元素均出现不同程度的累积污染状况,污染强弱为：Cd〉Pb〉Hg〉As〉Zn〉Cr〉Ni〉Cu,总体上累积污染主要处于0-3级,有小部分点位的累积污染程度在重度以上。主要污染元素为Cd、Hg、Pb和As,而Cr、Cu、Ni和Zn的累积污染程度相对较轻。土壤中Cd和Hg具有中等潜在生态危害,其他元素具有轻微潜在生态危害,各重金属元素潜在生态危害强弱为：Cd〉Hg〉As〉Pb〉Ni〉Cu〉Cr〉Zn,其中As、Cd、Cu和Hg有部分点位具有严重潜在生态危害。研究区主要土地利用类型土壤重金属综合潜在生态危害的强弱为：水田〉果园〉滩涂〉旱地〉林地〉茶园〉草地。研究认为人类活动包括农药、施肥、灌溉、交通、采矿等是造成研究区土壤重金属污染的主要原因。

Soil heavy metals （As, Cd, Cr, Cu, Hg, Ni, Pb, Zn） pollution, including levels and potential ecological risks, of Fujian Province, were assessed using geo-accumulation index method and potential ecological risk index method based on GIS. The analysis shows that, firstly the relative degree of soil heavy metals pollution is the order of Cd 〉 Pb 〉 Hg 〉 As 〉 Zn 〉 Cr 〉 Ni 〉 Cu in the study area. And the soil heavy metals pollution is characterized by 0 -3 degree, some area is characterized by heavily contaminated. The main contamination elements is Cd, Hg, Pb and As, relatively, the pollution level of Cr, Cu, Ni and Zn were slight. Secondly, Cd and Hg of soil have moderate potential ecological risk, other heavy metals have slight risk. The degTee of potential ecological risk is Cd 〉 Hg 〉 As 〉 Pb 〉 Ni 〉 Cu 〉 Cr 〉 Zn. Some soil sample sites from As, Cd, Cu and Hg have serious potential ecological risk. Thirdly, the degree of total potential ecological risk with different land use soils in study area is paddy field 〉 orchard 〉 tidal flat 〉 upland 〉 forest land 〉 tea plantation 〉 grassland. Pesticide, fertiliza- tion, irritation, traffic and mining are the major factors of soil heavy metals contamination in the study area.