大气多环芳烃的浓度水平、来源与健康风险评价综述

Concentration levels,sources and health risk assessment of atmospheric polycyclic aromatic hydrocarbons

多环芳烃(PAHs)主要源于有机材料的不完全燃烧,具有生物蓄积性和毒性(致癌、致畸形和致突变),是一类持久性有毒物质。本文综述了大气PAHs的分类、排放特征、时空分布特征、来源解析和健康风险评价,根据不同相对分子质量、存在形式、化学结构进行PAHs分类。指出了PAHs浓度呈现季节性变化,变化趋势由高到低为:冬季、春季、秋季和夏季。比较了分子诊断比率(DRs)和受体模型,包括主成分分析(PCA)、化学质量平衡模型(CMB)、正矩阵分解(PMF)和多变量受体模型(Unmix)等多种PAHs源解析方法的优缺点。来源解析表明:DRs和PCA是应用最广泛的方法,但是其来源解析结果的准确性受到诸多因素的影响;PMF和Unmix相结合来解析PAHs来源,能仅根据受体部位的测量浓度来分配源,提供了PAHs源贡献的时间序列并且弥补了需要人为解读的局限性。文中展示了如何利用终身癌症风险增量(ILCR)模型将PAHs的来源分配用于评估健康风险,并在此过程中,确定了影响ILCR准确性的关键因素。以期为进一步开展大气PAHs污染相关研究提供参考。

Polycyclic aromatic hydrocarbons(PAHs)mainly from the incomplete combustion of organic materials,and are bioaccumulative and toxic(carcinogenic,teratogenic and mutagenic),are a kind of persistent toxic substance.This paper reviews the classification,emission characteristics,temporal and spatial distribution characteristics,source analysis and health risk assessment of atmospheric PAHs,and lists the ways of classifying PAHs according to different molecular weight,existence form and chemical structure.It is pointed out that PAHs concentration presents seasonal variation,and the variation trend is from high to low:winter,spring,autumn and summer.The advantages and disadvantages of molecular diagnostic ratio(DRs)and receptor models,including principal component analysis(PCA),chemical mass balance(CMB),positive matrix factorization(PMF)and Unmix were compared.Source analysis shows that DRs and PCA are the most widely used methods,but the accuracy of source analysis results is affected by many factors.The combination of PMF and Unmix to resolve PAHs sources can assign sources based solely on measured concentrations at the receptor site,providing a time series of PAHs source contributions and making up for the limitations that require human interpretation.This paper shows how the incremental lifetime cancer risk(ILCR)model can be used to assign sources of PAHs to assess health risk,and identify key factors that affect the accuracy of ILCR.We hope this review can provide reference for further research on atmospheric PAHs pollution.