高速公路两侧农田土壤重金属污染特征及评价

为探讨高速公路对两侧农田土壤重金属污染的影响,对沪昆高速和贵黄高速某路段两侧40个土壤样品中Cu、Zn、Ni、Pb、Cd和Cr的分布格局和污染水平进行分析。结果表明,高速公路两侧在距路基0～150 m范围之间,Ni、Zn、Cr、Pb含量整体上呈现随路侧距离增加而先增加后减小的趋势,峰值出现在断面两侧10～20 m范围之间,而Cu、Cd含量随公路两侧距离的增加而逐渐降低。高速公路两侧土壤已出现不同程度的污染风险,其中Cd的风险系数最大;在路侧10～15 m范围内,综合潜在风险指数由强度风险向中度风险过渡,应及时采取措施进行防治。

Pollution characteristics and assessment of heavy metals in farmland soil beside superhighway

In order to further understand the effect of superhighway on the heavy metals pollution of farmland soils, forty soil samples were collected from the farmland beside a certain section of Shanghai-Kunming superhighway and Guiyang-Huangguoshu superhighway, the distribution patterns and pollution levels of Cu, Zn, Ni, Pb, Cd and Cr were analyzed. The results showed that the concentrations of Ni, Zn, Cr, Pb increased firstly and then decreased with the increasing of distance away from the superhighway within 150 m range, and the peak values were appeared in 10-20 m, while the concentrations of Cu and Cd decreased with the increasing of distance. Various contamination risk of heavy metals in farmland soils have appeared on both sides of superhighway, and the risk index of Cd was largest. In the range of 10 to 15 m on roadside, the comprehensive potential risk index transitions from intensity risk to moderate risk, the effective measures should be taken to prevent and control pollution.