西安市区主要大气污染物暴露水平及健康风险评价

Exposure Level and Health Risk Assessment of Major Air Pollutants in Xi'an City

为探索西安市区主要大气污染物暴露水平及健康风险状况,基于空气质量监测数据和问卷调查数据,使用GIS方法、美国国家环境保护局健康风险评价模型和多元线性回归模型,对2015—2020年西安市区6种主要大气污染物(PM_(2.5)、PM_(10)、SO_(2)、NO_(2)、CO和O_(3))的时间和空间变化特征,以及年均健康风险、季均健康风险及其影响因素进行了分析和评价。结果表明:①西安市区2015—2020年PM_(2.5)、PM_(10)和NO_(2)年均浓度值均超出了环境空气质量二级标准。除O_(3)外,其余5种污染物的年均浓度在2020年最小,整体呈下降趋势,说明西安市区空气质量逐年好转。②PM_(2.5)、PM_(10)、CO的空间分布特征基本一致,SO_(2)和O_(3)的空间分布特征基本一致。经开区和阎良区监测点空气污染较严重,兴庆小区(碑林区)和曲江文化产业集团(曲江新区)监测点空气质量相对较好。③PM_(2.5)、PM_(10)、SO_(2)、NO_(2)和CO等5种污染物的非致癌风险指数(HI)在冬季最高,在夏季最低;O_(3)的HI在夏季最高,在冬季最低。在冬季,PM_(2.5)和PM_(10)的HI平均值均大于1,存在非致癌健康风险;SO_(2)、NO_(2)、CO和O_(3)等4种污染物的HI平均值均小于1,不存在非致癌健康风险。在夏季,O_(3)存在一定的非致癌健康风险,超阈值天数占4%;其余5种污染物的HI平均值和最大值均小于1,不存在非致癌健康风险。从年均值来看,6种污染物的HI年均值均小于1,不存在非致癌健康风险。④男性、户外劳动者和老年人面临更高的大气污染物健康风险。

To explore the exposure level and health risks of major air pollutants in Xi'an City,through air quality monitoring data and questionnaire survey data,the GIS method,U.S.EPA health risk assessment model and multiple linear regression model were used to analyze the temporal and spatial variation characteristics of six haze pollutants(PM_(2.5),PM_(10),SO_(2),NO_(2),CO and O_(3))in Xi'an City from 2015 to 2020,and the average annual,seasonal health risks of six public pollutants and as well as their influencing factors were evaluated.The results showed that:①The concentration values of PM_(2.5),PM_(10)and NO_(2)in Xi'an from 2015 to 2020 all exceeded the second-level ambient air quality standards.Except for O_(3),the annual average concentration of the other five pollutants was the lowest in 2020,showing a trend of overall downward,indicating that the air quality of Xi'an improved year by year.②The spatial distribution of PM_(2.5)was coincided with PM_(10)and CO.Similarly,the distribution of SO_(2)and O_(3)were basically the same.Among the 13 monitoring sites,Jingkai district and Yanliang district had serious haze pollution,while Beilin district and Qujiang district had good air quality.③The non carcinogenic risk index(HI)of five pollutants,PM_(2.5),PM_(10),SO_(2),NO_(2)and CO,was highest in winter and lowest in summer;the HI of O_(3)was highest in summer and lowest in winter.In winter,the average HI values of PM_(2.5)and PM_(10)were both greater than 1,indicating a non carcinogenic health risk;the average HI values of four pollutants,SO_(2),NO_(2),CO and O_(3),were all less than 1,indicating no non carcinogenic health risk.In summer,there were non carcinogenic health risks associated with O_(3)values,with 4%of days exceeding the threshold;the average and maximum HI values of the remaining 5 pollutants were all less than 1,indicating no health risk hazards.From the annual average,the average HI values of the six pollutants were all less than 1,indicating no non carcinogenic health risks.④Men,outdoor professionals,and older adults were at higher risk of haze health.