赣州市土壤重金属风险评价

Risk Assessment of Heavy Metals in Soils of Ganzhou

以赣州市6大功能区土壤重金属为研究对象，采取表层0～20cm土壤共50个样品，测定土壤中重金属As、Pb、Zn、Cu、Cd和Cr含量并分析其来源，采用改进BCR连续提取法进行形态分析，结合次生相与原生相分布比值法、潜在生态危害指数法和人体健康风险评价法进行污染评价。结果表明赣州市城区重金属Cd超标严重，超标率为100％，此外工业区受到重金属Cr污染，交通区受到重金属Pb污染。分析重金属Cd形态发现以残渣态为主，对环境危害较小。潜在生态危害指数法结果表明6个功能区的潜在危害系数（RI）值都在600左右。人体健康风险评价结果表明赣州市城区土壤6种重金属的总非致癌风险商为0．35，总致癌风险指数为2．24×10^-6。

Six functional areas of Ganzhou were selected as the study areas, surface soils （0-20 cm） were collected from 50 sites, heavy metals （As, Pb, Zn, Cu, Cd, Cr） contents were measured and their sources were analyzed, the risks of heavy metals were evaluated by using the modified BCR sequential extraction procedure and by comprehensively using the ratio of secondary phase and primary phase, potential ecological risk index and human health risk assessment method. The results showed that Cd exceeded the limit at all sites in study area, the industrial area was contaminated by Cr, and the traffic area polluted by Pb. Cd was mainly in residual speciation with a minor damage to the environmental. Potential ecological risk assessment indicated a moderate risk of soil pollution by heavy metals. Human health risk assessment showed that total non-carcinogenic risk quotient of six heavy metals was 0.35 and total carcinogenic risk index was 2.24 × 10^-6 in Ganzhou urban soil.