有色金属冶炼厂周围居民镉暴露致癌风险评估

目的了解有色金属冶炼厂周围镉污染现状,评估调查区居民镉暴露致癌风险。方法对湖北某有色金属冶炼厂周围地区多种环境介质土壤、地下水、大气及农作物((蔬菜和大米)]进行采样,分析其中镉(Cd)含量,利用美国EPA致癌风险评估模型评估研究调查区居民经多种途径接触多种环境介质引起的Cd的致癌暴露剂量和致癌风险。结果调查区土壤、大气及农作物均存在镉污染,蔬菜和大米中镉的平均含量分别为我国食品中污染物限量标准的14倍和5倍,土壤中镉均不同程度超标,大气中镉含量均高于国内外其他地区的调查结果。镉经所有暴露途径总致癌风险高达2.2×10~(-3),远高于国内外所规定的可接受致癌风险水平;致癌贡献率分析结果表明蔬菜和大米是该地区最主要的镉致癌风险来源。结论有色金属冶炼厂周围调查区域环境受到了不同程度的镉污染,且对居民的健康存在风险。

Carcinogenic risk assessment of cadmium exposure around a non-ferrous metal smelting plant

Objective To understand the cadmium (Cd) pollution status around a non-ferrous metal smelting plant in Hubei,and to assess the carcinogenic risk of cadmium exposure in the polluted area.Method Samples of a variety of environmental media,such as soil,groundwater,air and crops (vegetable and rice) were collected around the non-ferrous metal smelting plant in Hubei for analysis of concentrations of Cd.The carcinogenic exposure dose and risk of Cd to people living in that environment and being exposed to the multi-media through multi-pathway were assessed,using the carcinogenic risk assessment model of USEPA.Result All the investigated media such as soil,air and crop.were heavily polluted by Cd.The concentration of Cd in the vegetable and rice reached 14 and 5 times as higher as the threshold value for the pollutants in the food of China,respectively.The levels of Cd in soil exceeded the limit in different degree.The levels of Cd in air were all higher in this area than in other areas in and out of the country.The total Carcinogenic risk was 2.2×10-3,much higher than the acceptable carcinogenic risks stipulated by other countries and regions.Carcinogenic contribution rate analysis results showed that the vegetables and rice in the area were the main Cd carcinogenic risk sources.Conclusion The environment of the investigated area arotmd the non-ferrous metal smelting plant is polluted by cadmium,and there is a higher risk for the health of the residents.