| With the rapid development of social economy and the acceleration of urbanization and industrialization,the environmental pollution problem has becoming increasingly prominent.and the problem of atmospheric pollution has attracted more and more attention.Hefei,a newly developing city,not only has the problem of outdoor atmospheric pollution become more and more serious,but also people spend most of their time working and living indoor,and the degree of indoor atmospheric pollution may be more serious than outdoor.Therefore,it is urgent to study the indoor and outdoor atmospheric environment in this area.In this study,the atmospheric samples of Hefei in summer and winter were collected by the traditional PUF-GFF sampling system and the eight-stage non-biological impact sampler,including gaseous and particulate PAHs.The overall level,diurnal variation,particle size distribution and indoor-outdoor relationship of PAHs in the atmosphere of Hefei were analyzed.The assessment of health hazards of respiratory exposure for PAHs in the atmosphere was calculated.The main results and conclusions are as follows:（1）The average annual concentration of total PAHs is 439.16 ng/m3,and that of particulate PAHs is 87.49 ng/m3 in indoor air in Hefei.The annual average concentration of total PAHs atmosphere is 368.49 ng/m3,and that of particulate PAHs is 66.16 ng/m3 in the outdoor.The concentration of PAHs in the particulate phase is higher in winter than in summer.For gas-phase PAHs,indoor PAHs concentration in winter is slightly lower than that in summer,while outdoor PAHs concentration in winter is much higher than that in summer.（2）By day-night comparison,the concentration of PAHs in atmospheric particulate matter in Hefei in summer is higher than that in night,while in winter,the concentration in indoor is higher than that in daytime.The concentration in outdoor is equal.PAHs in indoor and outdoor atmospheric particulates mainly occur in coarse particulates in Hefei area.The proportion of indoor coarse particulates in summer is higher than that in winter,while the proportion of outdoor coarse particulates in winter and summer is comparable.（3）PAHs with low molecular weight in atmospheric particulates in Hefei area are more easily attached to coarse particulates.PAHs in the atmosphere are mainly caused by combustion sources,including combustion of biomass and coal and combustion of petroleum,with little pollution from petroleum directly.（4）The geometric mean particle size of PAHs is significantly correlated with the logarithm of saturated vapor pressure of the compounds in winter and summer in Hefei region.Apart from winter night,PAHs exhibit bimodal distribution at 0.7-1.1 and 4.7-5.8 microns in indoor and outdoor atmospheric particulates,and they are mainly concentrated in coarse particulates.（5）Most of the I/O ratios are less than 1 in Hefei during daytime,which indicates that there are obvious outdoor sources of PAHs in atmospheric particulates,and most of the I/O ratios are more than 1 at night,indicating that PAHs mainly come from indoor sources in atmospheric particulates,while decreased concentrations of most PAHs in outdoor atmospheric particulates.（6）PAHs have great differences in the risk of respiratory exposure to people of different ages in atmospheric particulate matter in Hefei.However,the probability of cancer caused by PAHs in the atmosphere is not very low,and there is a certain risk, which is higher than 10-6.Among them,PAHs in the atmosphere have greater impact on the health of adults than children and adolescents,and the risk is 16.57×10-6.In addition,the PAF values of respiratory exposure to PAHs varied in Hefei area,which were 14.22%indoors and 5.90%outdoors,respectively.The PAF values of indoor winter and summer season were 26.34%and 1.94%respectively,while those of outdoor winter and summer season were 9.10%and 2.70%respectively.These indicate that the PAF value of indoor winter particulate matter is higher,and the risk of extra lung cancer caused by PAH is higher. |
PDF Full Text Request