川西茶区土壤重金属元素背景值及其评价

The Evalution for Heavy Metal Content in the Tea Garden Soil in West of Sichuan

采用等离子发射光谱仪ICP-AES对川西茶区29个县市茶园中的243份土壤样本的As、Cd、Cr、Cu、Hg、Pb等重金属元素的背景值进行了测定。结果表明:川西茶区土壤中不同重金属元素含量的差异较大,以GB15618-1995和NY5020-2001进行评价,243个取样点茶园土壤中Cd有5个超标样点,超标率为2.1%,他5种元素均无超标点;从单因子污染指数可以看出,各重金属元素对土壤的污染程度依次为Cd>Cr>As>Hg>Cu>Pb,其单因子污染指数均为Pi<1,各地的综合污染指数均为P综<0.7。据此可以认为,川西茶区茶园土壤未受这6种重金属元素的污染,土壤环境质量总体良好。

A study on the contents of heavy metals in the tea garden soil in 29 counties of West Sichuan Province showed that heavy metals As、Cd、Cr、Cu、Hg、Pb varied greatly in the soil of these tea gardens.Only 5 samples among 243 soil samples were found to had a Cd content which exceeded the soil standard NY5020-2001.Single factor index and composite index method were adopted in assessment of tea garden soil quality.Direct comparison between single factor indices showed that the probability of these 6 heavy metals which imposed the soil contamination risk was Cd>Cr>As>Hg>Cu>Pb.All the single factor pollution indices were less than 1;all the combined pollution indices were less than 0.7.This result indicated that the soil quality of the tea gardens in west of Sichuan had not been affected by the heavy metals.