城镇化进程对沈抚新区土壤重金属分布的影响及风险评价

通过系统研究沈抚新区不同土地类型的58个地表土壤采样点重金属(Pb、Cd、Zn、Cu、Ni和As)的分布状况,对比研究区域表层土壤背景值,评估沈抚新区城镇化进程对土壤重金属分布的影响及其存在的风险。结果表明:污染物浓度总体趋势为东部地区高于西部地区;土壤中Zn、Cd和Pb的污染状况在高速公路附近以及公路交叉点较为严重;Cu和Ni的污染高值区在工业区内的化工厂、钢铁厂和电控设备厂附近,说明工业生产对该地区的Cu和Ni的贡献率较高;As的分布特征受土壤系统结构影响相对较大,同时人为因素或外源物质干扰也起到了一定的影响作用。采用内梅罗指数法对不同用地类型表层土壤中重金属污染水平的评价排序为城镇用地林地耕地农村居住地。

Distribution and risk assessment of soil heavy metals in Shenfu new city during urbanization process

We mapped the spatial distribution of heavy metals(Pb, Cd, Zn, Cu, Ni and As) in 58 surface soil samples from different land use types of Shenfu new city and evaluated the impact of urbanization on the distribution and risks of heavy metals by comparing with their background values. Results showed that the concentrations of heavy metals in the east part were higher than those in the west part of the region. Soil Zn, Cd and Pb mainly concentrated in the vicinity of the highways and crossover, while high concentrations of Cu and Ni were mainly found in the industrial area with Chemical Plants, Steel Plants and Electrical Control Equipment Plants. These indicated that industrial activities contributed a lot to the Cu and Ni pollution. The As distribution was affected relatively greatly by the soil system structure and at the same time by human factor or exogenous substances to certain extent. We evaluated the level of heavy metals in surface soils from different land types using the Nemerow pollution index. The pollution levels followed order of urban land >woodland >farmland >rural land.