公路边土壤和水稻中铅的分布,累积及临界含量

在距公路５、１０、５０、１００、２００ｍ准备收割的稻田中同时采集土壤及稻米样品。对２条公路的样品分析结果表明，汽车尾气中铅的污染大多集中在公路两侧５０ｍ左右的范围内。土壤自身性质对路边土壤及水稻中铅的分布、累积具有显著影响。经壤水稻中铅的累积量小于重壤水稻土，但轻壤水稻糙米的含铅量却高于重壤。轻壤中土壤含铅量和糙米含铅量之间具有相关关系。探讨了公路边土壤的临界含量问题，推算出轻壤中此值为５８ｍｇ／

Study on the Distribution Accumulation and Critical Level of Lead in Soil and Rice Along Road Sides

he soil and rice samples were collected simultaneously at the sites of 5, 10, 50, 100 and 200meters away from road, respectively. The analysis results of samples collected along two roadsdemonstrated that the pollution of lead from automobile exhaust gas was within a range of about50 m along the roads. The soil characteristics hada significant effect on the distribution and accumulation of lead in soil and rice. The accumulation amount of lead in light loam was less thatnthat in heavy loam, but the lead content of brownrice was more than that in heavy one. Correlationbetween the lead content of soil and that of brownrice bud been shown in light loam. Based on it,the critical level of soil along road side had beendiscussed. The predicted value was 58 mg/kg,much less than that of pot experiments and thearea irrigated with waste water.