Analysis Of PAHs Characteristics,Risk Assessment And Health Effects Marked By EMT On PM_2.5 In Different Cities

In recent years,with the frequent occurrence of heavy pollution incidents,air pollutio n has become a hot issue.In this study,the particulate matter(PM2.5)from four cities includ ing Taiyuan,Beijing,Hangzhou,and Guangzhou was collected,the polycyclic aromatic hydrocarbons(PAHs)on PM2.5 was detected.Then,the following analysis were performed: The concentrations of various PAHs on the particulate matter were analyzed and compared in different cities and different seasons.The discrete coefficients were used to analyze whether there are significant differences in the PAHs between different cities and seasons.The source apportionments of PAHs were conducted by characteristic ratio analysis.A health risk assessment model was used to explore the non-carcinogenic risk and carcinogenic risk.The potential ecological risk of PAHs was conducted by ecological risk assessment model.The expressions of epithelial-mesenchymal transition(EMT)markers and cytokines in the lungs of mice exposed to PM2.5 were studied by real time PCR,then the scratching experiments,transwell experiments,and real time PCR techniques were used to verify the results on human adenocarcinoma cel s(A549).Finally,the m RNA expression levels of the EMT markers and cytokines were correlated with PAHs components on PM2.5 in different cities.The results are as follows: 1.The content of PAHs in PM2.5 in Beijing and Taiyuan was higher than that in Guangzhou and Hangzhou all the year.2.By analyzing and comparing the PAH components in different cities in the same season,it was found that the PAH components in Hangzhou and Guangzhou showed significant differences compared with Taiyuan in all four seasons.There are significant differences in summer between Beijing and Taiyuan.By analyzing and comparing the PAH components in different seasons in the same city,it was found that there was no significant difference in the composition of particles between autumn and winter.In addition,there was a significant difference between spring and winter,as well as summer and winter.3.In Taiyuan and Beijing,the PAHs with 4 rings and 5 rings account for the majority.In Hangzhou and Guangzhou,the PAHs with 5 rings and 6 rings account for the majority.4.The main sources of PAHs in Taiyuan and Beijing include coal,biomass combustion and petroleum mixed sources,and the PAHs in Hangzhou and Guangzhou were mainly from biomass combustion and vehicle emissions.5.Carcinogenic risk could be predicted in four cities at different degree.The carcinogenic risk value of Taiyuan is 3.89 times higher than that of Beijing,11.8 times higher than that of Hangzhou,and 15 times higher than that of Guangzhou.No non-carcinogenic risk could be predicted in the four cities.The potential ecological risk of PAHs in four cities is serious.6.The PM2.5 in the four cities could promote the expression of EMT markers and cytokines at transcription level in mice and A549 cells,and enhance the ability of A549 cells to migrate and invade.The effect of Taiyuan was the most significant,followed by Beijing.The effects of Guangzhou and Hangzhou were the least obvious.The result of correlation analysis showed that the expressions of Fibronectin,IL-1? and TNF-? were closely related to most PAH components.