Characteristics,Sources And Health Risk Assessment Of Elements In PM_2.5 And PM₁₀ In Liaoning Center Urban Agglomeration

In order to study the pollution characteristics,sources and health risks of elements in atmospheric particulates in central Liaoning urban agglomerations,PM_2.5and PM₁₀in the ambient air were synchronously sampled seasonally from May to December in 2018,and 39 elements were analysed by using of ICP-MS and ICP-OES.The concentration of particulate matters and its elements was studied and the sources of contaminated elements were analyzed by using the ground accumulation index method and PMF analysis method.Finally,the non-carcinogenic and carcinogenic risk of heavy metals through respiratory pathways was evaluated by using health risk assessment.This study shows that:（1）It was usualy occurred in autumn and winter that PM₁₀and PM_2.5concentrations exceeded the Grade II limit(PM_2.5:75μg m^–3;PM₁₀:150μg m^–3)for daily average concentration stipulated by the Chinese National Ambient Air Quality Standard（GB 3096-2012）in central Liaoning urban agglomeration.The annual concentration of PM_2.5in urban agglomeration was 47.9μg/m3.The mean PM_2.5/PM₁₀in urban agglomeration and most of the seven cities followed the order winter>autumn>summer>spring.And the mean ratios in seasonal average were great than 0.5 in summer,autumn and winter.Six major crustal elements（Na,Al,Mg,Ca,Fe and Si）were mostly concentrated in coarse particle,while heavy metal elements（V,Cr,Mn,Ni,Cu,Zn,As,Mo,Cd,Sn,Sb and Pb）were mostly concentrated in fine particulate matter.（2）The analysis by using the local accumulation index shows that V,Cr,Mn,Ni,Cu,Zn,As,Mo,Cd,Sn,Sb,Pb and Bi were mostly concentrated in PM_2.5and were all polluted in different degrees.PMF result shows that the PM₁₀come from 5 sources,namely motor vehicle sources 12.0%,industrial sources 23.8%,dust sources 41.9%,magnesite industrial sources 8.8%,and coal sources 13.5%,while PM_2.5come from 5sources,namely dust source 28.9%,coal source 29.8%,magnesia industry7.2%,industrial source 23.9%and motor vehicle source 10.0%.（3）Children’s daily exposure of heavy metals and the risk of cancer were greater than adults’in urban agglomeration.There was high non-carcinogenic risk for children and adults due to Mn and Cr,and coal combustion and mobile emission were the main contributor.There was high carcinogenic risk to human caused by As and Cd,and coal combustion was the main contributor,which need to be paied attention to.Based on the risk assessment of pollution sources in urban agglomeration,it is concluding that the non-carcinogenic risk caused by coal combustion was high for children and adults,while the carcinogenic risk caused by motor vehicles was high.