机械厂遗留场地重金属污染特征及健康风险评价

以西南某机械厂遗留场地为研究对象,利用主成分分析法和克里金插值法分析了5种重金属(Ni、Pb、As、Co、V)的污染特征及来源,并在健康风险评价中引入蒙特卡罗模拟进行了不确定性分析。结果表明:研究区表层土壤中Ni、Pb、As和Co存在富集现象,V分布相对均匀。污染主要来源包括厂区内工业活动人为源、土壤母质自然源和周边工业活动大气沉降污染源。非致癌风险主要危害因子为As和Co,As为主要致癌因子。成人和儿童主要的暴露途径分别为皮肤接触和经口摄入。成人和儿童非致癌风险超过阈值的概率分别为11.60%和60.88%,致癌风险超过阈值的概率为4.36%和2.31%,对于成人和儿童最敏感参数分别为皮肤黏附系数和体重。研究结果可为重金属污染场地土壤风险管控或修复工作提供科学指导和技术支撑。

POLLUTION ANALYSIS AND HEALTH RISK ASSESSMENT OF HEAVY METALS IN AN ABANDONED MACHINERY PLANT

In this study, an abandoned machinery plant in Southwestern China was taken as the research object. The pollution characteristics and sources were mainly analyzed by combining the principal component analysis method and the Kriging interpolation method, and Monte Carlo simulation in the health risk assessment was introduced for uncertainty analysis. The result showed that Ni, Pb, As and Co were concentrated distributed, and V was evenly distributed. The main sources of pollution were man-made sources of industrial activities in the factory, natural sources of soil parent material, and atmospheric deposition from surrounding industrial activities. The main hazards factors of non-carcinogenic risks were As and Co, and the main carcinogen factor was As. The principal exposure pathway for adults was skin contact, but for children it was oral ingestion. The probability of the non-carcinogenic risk exceeded the threshold for adults and childrenwas 11.60% and 60.88%, and those for carcinogenic risk exceeded the threshold was 4.36% and 2.31%. The most sensitive parameters for adults and children were skin adhesion coefficient and body weight. The significance of the research was to provide guidance and technical support for risk management or remediation of soil in heavy metal contaminated sites.