为了研究公路运营所造成的其两侧环境中Pb、Cd重金属污染,采集了崇明岛陈海、北沿公路两侧土壤、蔬菜和路面灰尘样品共394,测定了其中重金属Pb、Cd含量。结果表明在长期运营的前提下,交通量不大的公路两侧也会出现较严重的Pb、Cd污染。公路两侧土壤Pb、Cd平均含量分别为28.4和0.27mg·kg^-1,均高于对照点和崇明土壤背景含量。公路两侧蔬菜Pb平均含量为0.22mg·kg^-1,Cd平均含量为0.032mg·kg^-1,Pb含量高于无公害食品标准(NY5089-2005)。路面灰尘Pb、Cd平均含量分别达51.2和0.494mg·kg^-1是路侧土壤和作物的潜在污染源。
To assess lead and cadmium contamination induced by traffic at the vicinity of a road, a survey of lead and cadmium levels in farmland soil, vegetable and road dust was carried out alongside the Chenhai road and Beiyan road on the Chongming island. 394 roadside soft, vegetable and road dust samples were collected, and concentrations of lead and cadmium were measured by atomic absorption spectrophotometry. The results showed that farmland soils alongside the low traffic road were polluted by lead and cadmium after long service period. The average value of total lead and cadmium content in soil was 28.4 and 0.27 mg·kg^-1, which were higher than that of the control site and the background values of Chongming island. The maximum lead and cadmium concentrations of roadside farmland soil of Chenhai and Beiyan road appeared within 50 m from the road shoulder. The average value of total lead and cadmium content in vegetable was 0.22 and 0.032mg·kg^-1 fresh weights, and the lead content in vegetable was higher than agricultural product safety requirement for free-pollution vegetable (NY 5089-2005). The average value of total lead and cadmium content in dust was 51.2 and 0.494 mg·kg^-1, which were significantly higher than the roadside soil and vegetable samples. Road dust was a potential source of lead and cadmium contamination in the roadside environment.