十四运期间西安市PM_(2.5)中无机元素的污染特征及来源解析

Pollution characteristics and source analysis of inorganic elements in PM_(2.5)in Xi'an during The 14th National Games

为了解十四运期间西安市PM_(2.5)中无机元素的污染特征及来源,利用重金属在线分析仪(Amms-100)于2021年9月(7日—30日)进行实时观测,运用富集因子(EF)和正交矩阵因子分解法(PMF)进行来源解析、健康风险评价模型进行风险评估.结果表明,PM_(2.5)日均值在常规期为(16.2±5.8)μg·m^(–3),管控期为(11.9±5.2)μg·m^(–3),均低于国家一级日平均限值(35μg·m^(–3));无机元素的平均质量浓度在常规期为2.7μg·m^(–3),在管控期为2.0μg·m^(–3),表明十四运期间的管控措施对PM_(2.5)及其无机元素有治理效果.富集因子结果表明,Cu、Zn、Br和Se全部来自于人为活动排放;Cr、Co、As和Pb主要受人为排放影响,因管控期间各种限制政策影响,以上元素在管控期较低.PMF分析结果表明十四运前后PM_(2.5)中无机元素主要来源于扬尘(48.5%)、工业(23.7%)、燃烧(18.7%)和交通源(9.0%).健康风险评价结果表明,常规期Mn在儿童群体中存在非致癌风险,Cr和As对人体存在致癌风险;除V以外,其他元素危险系数(HQ)和终生增量致癌风险(ILCR)均为常规期>管控期.

In order to understand the characteristics and sources of inorganic elements in PM_(2.5)in Xi'an during The 14th Nation Games,on-line monitoring instrument Amms-100 is used to collect the elements in September from 7 to 30,2021,combined with enrichment factor method,matrix factorization method and health risk assessment to analyze the source and health risk of the metal elements in the atmosphere.The average daily mass concentration of PM_(2.5)in the regular period was(16.2±5.8)μg·m^(–3),and in the control period was(11.9±5.2)μg·m^(–3).The average mass concentration of inorganic elements was 2.7μg·m^(–3)in the regular period and 2.0μg·m^(–3)in the control period,indicating that the control measures had a certain effect on the pollution of inorganic elements in PM_(2.5).The enrichment factor results showed that Cu,Zn,Br and Se were all from human activities.Cr,Co,As and Pb are mainly affected by anthropogenic emissions,which is mainly related to various restriction policies during the control period.The results of PMF showed that the inorganic elements in PM_(2.5)were mainly from dust(48.5%),industrial(23.7%),combustion(18.7%)and traffic sources(9.0%).The results of health risk assessment showed that Mn had non-carcinogenic risk in children,Cr and As had carcinogenic risk in human body.Except for V,other elements hazard quotient(HQ)and incremental lifetime cancer risk(ILCR)were in the control period<conventional period,indicating that the control had a significant effect on the control of element pollution.