Characteristic Of Elements Associated With PM₁₀and PM_2.5in Shuozhou City During The Heating Period

Elements are important components of atmospheric particulates,mainly from the burning of fossil fuels such as coal and oil and emission of industry such as metallurgy,plastics and vehicle.Elements from atmospheric particulates are easy to enter the body through respiratory tract,which can easily cause respiratory and cardiovascular disease and even lung cancer.Therefore,the study of elements distribution character in particle is important for the prevention of atmospheric particulate matter pollution.To investigate Shuozhou ambient air,PM10 and PM2.5 samples were collected by the medium volume sampler at five sampling sites during heating period,and the concentrations of 11 elements were analyzed using Plasma emission spectrometer.The characteristics including concentration levels of elements,spatial distribution and particle size distribution were investigated,the potential ecological risk of heavy metals and the main sources of elements were discussed.The main conclusions obtained are as follows:(1)The order of the 11 elements in PM10 in ambient air was Fe>Mn>Zn>Cu>Cr>Pb>Ni>V>As>Co>Cd,and the order of the 11 elements in PM2.5 was Fe>Zn>Cu>Cr>Mn>Pb>Ni>V>As>Co>Cd.The content of Cd,Cr,Cu,Ni,Pb,V and Zn in PM10 is over half of that in PM2.5 so elements are mainly enriched on the fine particulate matter.(2)The density spatial distribution characteristics of Cu,Fe,Pb,V,and Zn in PM10 are obvious.The concentrations of Cu?Pb and Zn in point QF are higher:183.23ng·m-3,66.65ng·m-3 and 148.47ng·m-3 respectively.The concentrations of Fe and V in point SW are higher:5776.91 ng·m-3 and 22.47ng·m-3 respectively.The density spatial distribution characteristics of As,Cr,Fe,Mn,Pb,Cd and Zn in PM2.5 are obvious.The concentrations of As,Cr,Fe,Mn and Pb in point SW are higher:8.65 ng·m-3,54.86 ng·m-3,1895.97ng·m-3,59.51ng·m-3 and 45.90ng·m-3 respectively.The concentrations of Fe and V in SW are higher:5776.91 ng·m-3 and 22.47 ng·m-3.The concentration of Cd is 1.35 ng·m-3 in point QF,significantly higher than that in other sampling points.The highest concentration of Zn is 42.10 ng·m-3 in point among all five points.(3)According to the results of ecological risk index of single metal and various metals joint,the ecological risk of fine particulate matter is the highest.At the same time Cd,Cu and Pb are main contribution of heavy metals in atmospheric particulate matter.It is indicated that Cd,Cu and Pb are main pollutants of heavy metals in Shuozhou.(4)The main sources of elements in PM10 were divided into three categories including soil dust,motor vehicle exhaust dust and coal dust.And in PM2.5 were divided into four categories including coal dust,waste incineration,and vehicle exhaust and soil dust through.the enrichment factor and the main factor analysis.Source of elements in PM2.5 were more complex than it in PM10,there was an increase of waste incineration source.