部分中国城市公园重金属生态风险及健康风险评价

Ecological risk assessment and health risk assessment of heavy metals in some China urban parks

城市公园土壤环境质量会对城市环境质量和人体身心健康造成潜在影响.研究中国城市公园土壤重金属的含量并对其进行生态风险评价和健康风险评价,有利于了解城市环境质量,控制重金属对人体的危害.本研究在收集的全国25个省38个地区公园土壤重金属数据的基础上,应用美国EPA人体暴露风险评价方法对全国公园土壤重金属进行健康风险评价,采用地积累指数法分析其污染程度.结果表明,公园土壤重金属Cr、Cu、Mn、Ni、Pb、Zn、As、Cd和Hg等9种重金属的平均含量分别为66.02、39.47、498.65、24.97、48.11、148.32、12.82、0.67、0.26 mg·kg^(-1),除了Mn和Ni外均高于中国土壤背景值,存在不同程度的积累;健康风险评价表明,3种途径中儿童和成人的日均暴露剂量排序均为Mn>Zn>Pb>Cu>Cr>Ni>As>Hg>Cd;儿童和成人的致癌排序均为As>Cr>Ni>Cd.土壤重金属的致癌风险指数除了As元素外均小于致癌风险值范围.总体而言,公园土壤与城市土壤重金属的含量大致相当,人们在游园时应注意其潜在的健康风险.

Quality of soil environment in urban parks has a potential impact on the urban environment quality and human health.Studies on soil heavy metals content in China parks and conducting the ecological risk assessment and health risk assessment are beneficial to understand urban environmental quality and control the harm of heavy metals to human body.The research was carried out by US EPA Health Risk Assessment Model and the geo-accumulation index method based on 9 heavy metal concentration in soil samples from 38 parks in 25 Provinces in China.The results showed that the average contents of Cr,Cu,Mn,Ni,Pb,Zn,As,Cd and Hg in the soil were 66.02,39.47,498.65,24.97,48.11,148.32,12.82,0.67 and 0.26 mg·kg-1,respectively.Their concentration except Mn and Ni,which were higher than the soil background value of China,and had different degrees of accumulation.The health risk assessment results showed that the average daily exposure dose ranking of children and adults in the three pathways was Mn>Zn>Pb>Cu>Cr>Ni>As>Hg>Cd;and the carcinogenic risk sequence of children and adults was As>Cr>Ni>Cd.The carcinogenic risk index of heavy metals in soil,except As,is lower than the carcinogenic risk range.Generally speaking,the content of heavy metals in park soil and urban soil is roughly the same,people should pay attention to the potential health risks when they visit in the park.