贵阳市郊区菜地土壤铅含量及影响因素研究

Investigation on Lead Contents in Vegetable Soil and Influencing Factors in Guiyang City Suburb

为了解贵阳市城郊菜地土壤铅状况,为无公害蔬菜生产提供基础资料,2005年采用现场采样及室内测试方法对贵阳市城郊菜地耕层土壤铅含量进行了调查研究。结果表明,贵阳市郊区菜地耕层土壤铅含量不同地区差异较大,最高值为最低值的5.97倍。菜地耕层土壤铅污染现状总体上不严重,尚处于清洁和基本清洁水平。影响贵阳市郊区菜地耕层土壤铅含量的自然因素主要是土壤母质和土壤类型,人为因素主要是冶炼厂、工业垃圾、汽车尾气等带来的点源污染,其分布有一定的规律性。

Lead is a heavy metal element that is easily absorbed and accumulated by living organism. When lead s accumulation was enough high, it could destroy protein and enzyme in animal body and cause animal diseases. To detect lead status vegetable soil, the survey was conducted in Guiyang city suburb in 2005 and the content of lead in 55 vegetable soil samples and its influence factors in were analyzed. The results showed that the contents of lead in different soil samples varied considerably, the highest content was 57.78 mg·kg^-1, lower than state standard （GB/T 18407.1-2001）, and was 5.97 times of the lowest, suggesting the lead contamination in vegetable soil was slight in Guiyang city. Soil parents, types and pH were main natural factors influencing lead content. Lead content varied with different soils and different soil parents： stone rock 〉 quaternary period red clay 〉 purplish sandy shale rock. Lead smelting, waste heap containing lead and waste gas by car were main artificial-shift factors and might result in serious point contamination of lead. The contents of soil lead in vicinity of lead smelter were higher than those in other regions, and lead pollution emerged in according to some order.