公路系统沿线作物铅累积状况的研究

Lead Accumulation and Distribution in the Plants along Highways

为研究株洲地区公路系统汽车尾气排放产生的铅污染对路边作物铅累积状况的影响 ,以株洲地区周围的三条公路为研究样区 ,对公路旁农田种植的作物中重金属铅采用原子吸收光谱进行了测定 .结果表明 :公路系统汽车尾气排放已导致路旁作物茎叶和根部中有一定程度的铅累积 ,而且全部超过食品卫生标准 .公路系统作物铅含量随土壤铅含量的增加而增加 .作物地上部分和地下部分对铅的累积状况在车流量不同的地段表现出不同的特征 ,在高车流量区和中车流量区 ,作物地上部分累积的铅高于地下部分 ,而在低车流量区却出现与之相反的特征 。

Atomic absorption spectrophotometer was used to analyze the lead accumulation and distribution patterns in the plants along highways. The plants along three sample highways near Zhuzhou were studied. Results show that the plant ( Lectuca sativa ) roots, stalks and leaves along the highways are all polluted by lead from gasoline combustion; that the lead content either in the part above the soil or in the part under it is well beyond the food and health standard; and that a positive correlation has been found between the lead content of plants and that of the soil. The lead accumulation and distribution patterns of plants are different among the three samples. For high and moderate traffic volume categories, the lead content levels are higher in the part above the soil than in the part under it, while for lower traffic volume categories, it is the lead content in the part under the soil rather than in the part above the soil that is higher.