盘州市三大茶区土壤重金属和砷的监测与评价

Monitoring and Evaluation of Heavy Metals and Arsenic in Soil of Three Tea Areas in Panzhou City

为了研究盘州市老厂、火铺、保基3个乡镇土壤中铜(Cu)、铬(Cr)、镉(Cd)、铅(Pb)、汞(Hg)5种重金属和砷(As)的浓度及污染水平,用多点采集混合法制得72份土样进行测定、分析。结果表明,盘州市三大茶区大部分的土壤质量符合无公害茶园土壤环境标准,但个别区域因重金属和砷的含量较高,不宜种植无公害有机茶叶。火铺、老厂2个乡镇茶区土壤的单因子污染指数和综合污染指数均<1,表明其土壤未受到重金属和砷的污染,属安全、清洁水平;保基乡茶园土壤因重金属(Cd)单项污染指数>1,综合污染指数介于0.7~1.0之间,即茶区土壤和作物已被重金属(Cd)轻度污染,综合污染级别属警戒范围。

In order to study the concentration and pollution level of five heavy metals including copper(Cu),chromium(Cr),cadmium(Cd),lead(Pb),mercury(Hg)and arsenic(As)in Laochang Town,Huopu Town and Baoji Town of Panzhou City,72 soil samples were collected by multi-point collection and mixing method for determination and analysis.The results showed that the soil quality of most areas in Panzhou City′s three tea areas conformed to the environmental standard of pollution-free tea garden.However,due to the high contents of heavy metals and arsenic in some areas,it was not suitable to cultivate pollution-free organic tea.The single factor pollution index and comprehensive pollution index of the soils in Huopu Town and Laochang Town were both less than 1,indicating that the soils were not polluted by heavy metals and arsenic and were safe and clean.The single pollution index of the soils in Baoji Town was greater than 1,and the comprehensive pollution index was 0.7-1.0,indicating that the soils of tea areas and crops had been slightly polluted by heavy metals(Cd),and the comprehensive pollution level was within a warning range.