The Characterization Of Particulate Matter And Risk Assessment

In order to better understand the characterization and risk assessment of particulate matter,carbonaceous aerosols and phthalic acid esters（PAEs）,we conducted several field campaigns in regional background areas（Mount Lu and Mount Tai）and urban area（Tianjin）in China.PM₁₀ samples were collected at Mount Lu（August and September of 2011;and March,April and May of 2012）.In PM₁₀ samples,daily average concentrations of PM₁₀ at Mount Lu were 97.87μg/m³ and 73.40μg/m³ in spring and autumn,respectively.The observed mean organic carbon（OC）and element carbon（EC）concentrations during spring in PM₁₀ were10.58μg/m³ and 2.58μg/m³,respectively,and those in autumn were 6.89μg/m³ and 2.40μg/m³,respectively.Secondary organic carbon（SOC）in PM_2.5 samples were higher than that in PM₁₀ samples at Mount Lu,indicated that SOC mainly enriched in fine particles.Back trajectory analysis and principal component analysis revealed that multiple sources contributed to carbonaceous aerosols.PM_2.5 samples were collected at Mount Tai（June to August of 2015）.In PM_2.5 samples,the average concentrations of PM_2.5,OC,EC and PAEs were 54.93μg/m³,5.83μg/m³,1.52μg/m³,and 19.48 ng/m³.PAE concentrations decreased at the beginning of cloud/fog events,while they increased after the cloud/fog events since the liquid-phase PAEs could be absorbed by solid-phase PAEs.Potential source contribution function analysis and principal component analysis revealed that air masses were mainly sourced from southwest of Mount Tai and multiple sources contributed to PAEs.A Monte Carlo simulation was applied to estimate the incremental lifetime cancer risks（ILCR）from inhalation exposure on the basis of DEHP concentrations.The estimated values of ILCR for the general population were lower than the U.S.Environmental Protection Agency threshold,which is 10^-6.Health impacts associated with particulate matters can vary by regional area,which may relate to differences in characterization and emission sources or populations.We investigated the hypothesis that high level exposure to PM_2.5 and PM₁₀ during pregnancy increases the risk of preterm birth in Tianjin.The results of our study indicated a significant association between air pollution and preterm birth during the first trimester of pregnancy and one month before pregnancy.