Pollution Characteristics And Health Risk Assessment Of Heavy Metals In Atmospheric Particulate Matter Of Jinhua In Winter

Atmospheric particulate matter is an important form of air pollution.Due to its small particle size and large specific surface area,it can be suspended in the atmosphere for a long time and transported over long distances.It is easy to adsorb harmful elements such as metal elements,ions and organic matter,which is harmful to the atmospheric environment quality and human health,so heavy metal pollution in atmospheric particulates and its research on human health risks are increasingly concerned and have important social value.In this study,the entire Jinhua was selected as the research area,with eight heavy metals Cu,Zn,Ni,Mn,Cr,Pb,Cd,As as the main research objects.We collected samples in ten areas including Yongkang,Yiwu,Lanxi,Wuyi,Dongyang,Pujiang,Pan'an,Wucheng,Jindong and urban area,analyzed their concentration and morphological characteristics,then discussed the present situation about the heavy metal pollution in PM₁₀,PM_2.5,dust and soil;combined with principal component analysis,backward trajectory and other methods,we further analyzed the sources of heavy metals,calculated the carcinogenic and non-carcinogenic risks of different heavy metals in adults and children through respiratory inhalation,hand-mouth intake,and skin contact under the exposure model.Finally,we have improved and perfected research on the current status,sources and health risks of heavy metal pollution in atmospheric particulate matter of Jinhua in winter.The research results are as follows:?1?In atmospheric PM_2.5 in Jinhua winter,the content ranges of Pb,Cr,Ni,Cd,Cu,Zn,As and Mn are 0.7?57.3,0.5?12.3,0.7?6.0,0?9.8,0.4?19.3,1.5?3233.0,10.4?30.2,5.2?478.3ng/m³.The contents of above heavy metals in PM₁₀ vary 12.5?54.6,0.5?20.2,3.1?7.9,0?9.8,2.2?28.1,1.5?8862.3,7.4?51.3,14.5?456.8ng/m³.In dust,the content ranges of Pb,Cr,Ni,Cd,Cu,Zn,As and Mn are 31.90?124.66,47.09?620.06,11.06?173.09,0?0.01,42.46?358.09,171.24?4030.01,0?0.005 and 260.33?1035.04mg/kg.The content ranges in soil are 12.16?44.68,6.31?81.73,7.37?25.24,0?0.10,0.20?28.17,31.53?112.94,0?0.01and 101.29?932.36mg/kg.?2?According to the enrichment factor,it could be seen that Cd and Zn in PM₁₀ of Jinhua in winter were extremely polluted,mainly affected by anthropogenic pollution sources,especially in Jindong and Pujiang.PM_2.5 showed the similar heavy metal enrichment trend as PM_10.The enrichment coefficient of heavy metals in dust and soil were significantly lower than those of PM₁₀ and PM_2.5 in Jinhua.According to the geo-accumulation index,the pollution of Cd and Zn in PM₁₀ were the most serious,which was consistent with the evaluation results of enrichment factors.The pollution degree of heavy metals in PM_2.5 in each sampling area of Jinhua was similar to that of PM₁₀,and the geo-accumulation index was much higher than that of dust and soil.The pollution of heavy metals in dust was relatively small,except for Zn.?3?Through correlation analysis and principal component analysis,the heavy metals in PM₁₀ mainly came from industrial pollution sources,mobile pollution sources such as fuel and automobile exhaust,and natural pollution sources.Heavy metals in dust mainly came from industrial pollution sources and traffic pollution sources.Combined with backward trajectory clustering analysis,it was found that the pollution situation of Jinhua in winter was mainly affected by land transportation from Shandong Province,the northern region of the Yangtze River Delta and the local area,and also affected by some close-range pollutants from Jiangxi Province.?4?The health risk assessment results indicated that the main route of exposure of all heavy metal elements to non-carcinogenic risks for children and adults was hand-oral ingestion,followed by skin contact and respiratory inhalation.In the ten regions studied,the average non-carcinogenic risk of heavy metals to adults and children had the same order.The non-carcinogenic risk value and the sum of non-carcinogenic risk of heavy metals in different exposure routes showed that children were higher than adults.Cr,Ni,Cd,As in atmospheric particles of Jinhua have no carcinogenic risk to human body through the respiratory route.