某金矿区农田土壤重金属污染的人体健康风险

Human health risk under the condition of farmland soil heavy metals pollutionin a gold mining area

环境重金属污染的人体健康效应是当今社会最为关注的重大环境问题。某金矿区矿业活动导致土壤、地下水、农作物中重金属元素存在不同程度的累积或超标。通过土壤、地下水、蔬菜及粮食作物的样品采集,人群暴露问卷调查,获得了暴露人群的膳食结构参数。以农田土壤中7种重金属元素的综合污染分区内的土壤、地下水、蔬菜、小麦玉米等样品中的重金属元素的平均含量为依据,采用USEPA推荐的人体健康风险评价模型,计算了经口食入、皮肤接触等暴露途径对成年人的健康风险概率。研究表明,研究区存在因重金属导致的不可接受的人体健康高非致癌风险和致癌风险。总体而言,土壤重金属污染愈重地区,区内人体健康风险愈高。地下水中的Cr元素、土壤综合污染区内的Hg元素、污染区内的蔬菜及粮食是危害人体健康的重要因素。因此,禁饮Cr含量高的地下水、禁食污染区内的农作物、修复土壤重金属污染、调整农作物种植结构是保护研究区人群健康的重要环境管理工作。

Human health effects of heavy metal pollution have constituted a major environmental problem at present. Mining activi-ties lead to different degrees of accumulation or excess of heavy metals in soil, groundwater and crops in a gold mining area. The di-etary structural parameters were obtained through sample collection and population exposure questionnaire. Based on the average con-tent of heavy metals in the sample and using human health risk assessment model recommended by USEPA, the authors calculated adult health risk probability derived from oral ingestion （soil, groundwater, wheat, corn, vegetables）, skin contact （soil, groundwater） and other exposure pathways. The results show that there are unacceptably high non-carcinogenic risks and cancer risks that threat human health because of the existence of heavy metals pollution in the study area. The severer the heavy metal pollution in soil, the higher the human health risks. There are some important factors that harm human health, such as chromium in groundwater, mercu-ry in soil as well as vegetables and grains growing in polluted soil. Therefore, the following measures seem to be very important in protection of human health：to persuade local people not to drink groundwater with high chromium content and not to eat contami-nated crops, to remedy polluted soil, and to adjust crop planting structure.