不同粒径大气颗粒物中金属元素分布与风险评估研究进展

A review of research advances in the distributions and risk assessments of metal elements in atmospheric particles with different particle sizes

金属元素(MEs)是大气颗粒物的重要组成部分。综述了不同粒径大气颗粒物中MEs的分布、生态风险和人体健康风险评估的研究现状。在颗粒物中MEs主要呈现3种粒径分布:细模态单峰型、粗模态单峰型和双峰型,对应于不同的污染源。富集因子法、地累积指数法和潜在生态风险指数法是MEs生态风险评价最常用的3种方法,大部分MEs在细模态的富集程度远高于粗模态,我国城市大气颗粒物均呈现非常高的综合潜在生态风险(风险指数>1000)。Cd、Pb、As是目前主要的污染元素,应重点关注。不同粒径段的颗粒物会沉积在呼吸系统不同部位。健康风险评估结果显示,我国大部分城市地区均存在重金属元素对人体的致癌风险和非致癌风险,会对人体产生致癌风险的MEs有Cr、As和Cd,Mn可能引起非致癌风险。因此,将不同粒径段颗粒物中MEs的分布特征和风险评估结合起来是未来该领域的重点研究方向。

Metal elements(MEs)are important compositions of atmospheric particles.The research progress of distributions and ecological and human health risk assessments of MEs in atmospheric particles with different particle sizes were reviewed.In atmospheric particles,MEs mainly presented three particle size distributions:unimodal distribution with the peak in fine or coarse mode particles,and bimodal distribution,corresponding to different pollution sources.Moreover,enrichment factor,geo-accumulation index and potential ecological risk index were the common three methods for ecological risk assessment of MEs.The degrees of enrichment of fine mode particles were significantly higher than that of coarse mode particles for most MEs.Atmospheric particles in Chinese cities all showed a very high comprehensive potential ecological risks(Risk Index>1000).Cd,Pb,As were the main polluting elements at present,which should be paid special attention to.In addition,particles of different sizes would be deposited in different parts of the respiratory system.The health risk assessments showed that heavy metals had carcinogenic and non-carcinogenic risks to the human body in most Chinese cities.Cr,As and Cd showed carcinogenic risks to human health,and Mn may cause non-cancer risks.Thus,combining the distribution characteristics of MEs in particles with different particle sizes with their risk assessment was the key research direction in this field in the future.