陕西苹果园土壤砷和重金属污染评价

Evaluation on Arsenic and Heavy Metal Pollution in Apple Orchard Soil in Shaanxi Province

应用地积累指数和生态危害指数,对陕西苹果主产区果园土壤砷(As)和重金属污染进行了评价。结果表明:从应用黄土母质土壤背景值计算的平均地积累指数结果来看,果园土壤中Hg达到轻-中度污染,Cd,Cr,Pb,Cu,As 5种元素都没有造成污染。从6种元素的地积累指数分级频率来看,Hg和As的污染频率最大,达到46.8%;其次是Cd和Cu,分别是27.4%和4.8%;Pb和Cr均没有造成污染。从6种元素的潜在生态危害系数来看,果园土壤中Hg的生态风险危害最大,其次为Cd,其余4种元素都为轻微危害程度,生态危害系数均小于20;从果园土壤As和重金属的生态危害指数来看,有27.42%的果园达轻微危害,56.45%达中等危害,16.13%达强危害程度。

Arsenic and heavy metal pollution in apple orchard soil in Shaanxi Province is evaluated on the basis of geo-accumulation index and ecological risk. Hg pollution is classified as the slight level and moderate level, and there is no pollution of Cd, Cr, Pb, Cu and As according to Igeo based on the background value of arsenic and heavy metals in loess. The pollution frequencies of both Hg and As were 46.8 % , they were the highest among the 6 elements, and that of Cd and Cu were 27.4% and 4.8% respectively. The orchard soil was not polluted by Pb and Cr. In the view of the potential ecological risk index, Hg pollution caused the severest hazard, and then by Cd. The remained 4 elements had a slight hazardousness with Er^i being less than 20. RI analysis shows that 27.42% of the orchard soil was slightly hazardous, 56.45% moderately hazardous, and 16.13% heavily hazardous.