摘要
为了解武汉市城郊蔬菜种植区土壤-蔬菜-地下水系统中重金属积累造成的健康风险,在武汉市城郊5个辖区内采集土壤、蔬菜、地下水样品,分析其中As、Cd、Hg、Pb 4种重金属的含量及积累特征;采用健康风险评价模型,并考虑区域人群特点及工作特性等进行参数优化,对研究区人群在不同暴露途径、不同暴露介质下的健康风险进行评价.结果表明:土壤重金属单项污染指数呈Cd>As>Hg>Pb的分布特征,Cd、Hg的土壤累积指数分别为6.51、2.00;叶菜类、瓜果类、根茎类和豆类4个类别新鲜蔬菜中,叶类蔬菜的w(Pb)显著高于其他蔬菜种类,瓜果类的w(As)和w(Hg)相对较高,根茎类的w(Cd)最高;蔬菜-土壤、地下水-土壤系统中同种重金属元素含量存在较高的相关性;3种暴露介质下的健康风险水平表现为蔬菜>地下水>土壤,经口暴露风险占总个人年风险的98.90%;总个人年风险为1.97×10-5a-1,其中致癌年风险占99.60%,该总个人年风险未超出国际辐射防护委员会(ICRP)推荐的最大可接受风险值(5.0×10-5a-1),但要防止土壤-蔬菜-地下水系统的进一步污染.
The present research attempts to understand the health risks induced by heavy metals in the soil-vegetables-groundwater system in suburban agricultural areas of Wuhan,China. In order to assess the health risks of the population in the research area by different exposure pathways and exposure routes,samples of soils,vegetables and groundwater were collected from five different regions in the area,and the concentration characteristics of As,Cd,Hg and Pb were analyzed. A model of health risk assessment was utilized,and the parameters were optimized by taking into consideration the regional characteristics and job features of the population. Six conclusions were drawn from the research results. First,the values of soil single factor contamination index ranked as Cd As Hg Pb,and the values of soil cumulative indices of Cd and Hg were 6. 51 and 2. 00,respectively. Second,mean values of heavy metals in four categories of fresh vegetables-w（ Pb） in leafy vegetables,w（ As） and w（ Hg） in gourd and fruit vegetables,and w（ Cd） in root and stem vegetables-were significantly higher than other vegetable categories. Third,each heavy metal showed a high correlation among its concentration in vegetable and soil,or groundwater and soil. Fourth,the levels of human health risks induced by the three exposure pathways ranked as vegetables groundwater soil,and the health risk resulting from oral exposure was more than 98. 90% of the total risk. Fifth,the total personal risk in the research area was 1. 97 × 10- 5a- 1,in which the risk of developing tumors accounted for 99.60%. Sixth,the total personal risk did not exceed the maximum acceptable risk（ 5.0 ×10- 5a- 1） recommend by the International Commission on Radiological Protection（ ICRP）,indicating that the health risk was not high in the research area. However,further contamination from heavy metals must be prevented in the soil-vegetablesgroundwater system of this area.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2014年第8期881-887,共7页
Research of Environmental Sciences
基金
国家自然科学基金项目(41071159
41371485)
"十一五"国家科技支撑计划项目(2008BADA7B03)
关键词
武汉市城郊
重金属
健康风险
suburban area of Wuhan
heavy metals
health risk
