贵阳市花溪城区PM_(2.5)中重金属元素的污染特征、来源及健康风险评价

Pollution characteristics,source apportionment and health risk assessment of heavy metal elements in PM_(2.5) collected in Huaxi urban areas,Guiyang

为研究贵阳市花溪城区大气PM_(2.5)中重金属元素的污染特征和健康风险,于2020年不同季节对花溪城区进行大气PM_(2.5)样品采集,并对大气PM_(2.5)中10种重金属元素的赋存特征、富集特征和健康风险进行了分析.结果表明:花溪城区大气PM_(2.5)中10种重金属在春、夏、秋、冬季的总平均浓度分别为(123.6±54.1)、(55.9±17.4)、(144.8±85.7)、(234.0±147.5)ng·m^(-3),呈现冬季浓度水平最高、夏季最低的变化规律.每种重金属元素平均浓度呈现Zn>Pb>Cu>Mn>As>Cr>Cd>Ni>V>Co的特点,其中,Zn、Pb、Cu、Mn 4种元素占总重金属元素质量的95%.富集因子分析表明,Co、V、Mn和Ni主要来自地壳源,As受地壳和人为源共同作用,Zn、Cu、Cd、Pb主要受人为源影响.PMF源解析表明,贵阳市花溪城区PM_(2.5)中10种重金属元素主要来自燃烧源、交通源和工业源,其贡献分别为49%、45%、6%.健康风险评估分析显示,观测期间花溪城区大气PM_(2.5)中Mn、Zn、Pb、Cu和V通过呼吸系统对人体的非致癌风险值均小于1,对人体的非致癌风险可以忽略.As、Cr和Cd对人体的致癌风险均高于1×10-6,说明As、Cr和Cd存在一定的致癌风险.

To study the pollution properties and health risks of heavy metal in atmospheric PM_(2.5) in the Huaxi urban area of Guiyang city.The PM_(2.5) samples were collected in different seasons of 2020 year from the Huaxi Urban Area,and the occurrence characteristics,enrichment characteristics,and health risk assessment of 10 heavy metal in PM_(2.5) were analyzed.The research results indicated that the total average concentrations of 10 heavy metals in Huaxi urban area were(123.6±54.1),(55.9±17.4),(144.8±85.7)and(234.0±147.5)ng·m^(-3) in spring,summer,autumn and winter,respectively,which presents a variation pattern of the highest concentration level in winter and lowest concentration level in summer.The average concentration of each heavy metal showed Zn>Pb>Cu>Mn>As>Cr>Cd>Ni>V>Co,and the content of Zn,Pb,Cu and Mn accounted for 95%of the total heavy metal mass.The enrichment factor analysis manifested that Co,V,Mn and Ni were mainly derived from crustal sources,As was influenced by both crustal and anthropogenic sources,as well as Zn,Cu,Cd and Pb were mainly influenced by anthropogenic sources.PMF source analysis showed that 10 heavy metal elements in PM_(2.5) in Huaxi urban area of Guiyang were mainly derived from combustion source,traffic source and industrial source,with contributions of 49%,45%and 6%respectively.Health risk assessment analysis showed that the non-carcinogenic risk values of Mn,Zn,Pb,Cu and V for respiratory system were all less than 1 during the observation period for atmospheric PM_(2.5) of Huaxi urban area,therefore carcinogenic risk of Mn,Zn,Pb,Cu and V to humans is negligible.The carcinogenic risk of As,Cr and Cd to humans is higher than 1×10-6,so there is a certain risk of cancer for As,Cr and Cd.