基于重金属的区域健康风险评价——以成都经济区为例

开展重金属的区域健康风险评价,对于探讨重金属的风险及为区域的生态地球化学预测预警服务有重要的意义。以成都经济区植物和大气为研究对象,应用国外的风险评价理论对As、Cd、Hg和Pb 4种重金属进行了健康风险评价,探讨了区域风险评价的填图思路。对于非致癌效应,计算通过食物摄入和空气吸入2种暴露途径产生的危害指数。对于致癌效应,计算由吸入Cd引起的致癌风险。结果表明,对于非致癌效应,成都经济区生态风险较高的重金属为Cd和Pb,从总的风险来看,地域差别较明显,以德阳和成都存在的风险最高。谷类对总风险的贡献比例最高,其中又以Cd的贡献最大,其次为Pb。对于致癌效应,研究区的平均致癌风险为7.6×10-6,基本上处于可接受的风险水平,高风险区主要为德阳西部的什邡、广汉和乐山市周围地区,这些地区的大气环境问题应该引起更多的关注。

Regional Health Risk Assessment on Heavy Metals in Chengdu Economic Region

It is of great significancy to carrying out regional health risk assessment on heavy metals,which can further discuss healthy risk of heavy metals and serve for forecasting and early warning of regionally ecological geochemistry.Foreign risk assessment theory is applied to develop risk assessment on arsenic,cadmium,mercury and lead through investigating plant and atmosphere in Chengdu economic region.For noncarcinogenic risk,hazard index is calculated in the base of two exposure pathways including food intake and inhalation.And risk level resulting from cadmium inhalation is accounted for carcinogenic risk.It is indicated that cadmium and lead have upper ecological risk in Chengdu economic region,and hazard index of cadmium is the highest.According to total risk,risk difference between areas is obvious and the upper risk exists in Deyang and Chengdu districts.Comparing different exposure routes' contributing proportion to total risk,proportion of grain is the highest,which holds 71.19% of total risk,other are potato,vegetable,bean and inhalation by decreasing sequence respectively.For carcinogenic risk,investigated region,where average value of carcinogenic risk is 7.6×10-6,locates acceptable risk level on the whole,and high risk areas mostly locate west of Deyang and suburb of Leshan city,in which atmosphere environmental problem should be taken more attention.