The Environmental Behavior Of Typical Organic Pollutants In Urban Atmosphere,China

Atmospheric pollution has been of great concern in recent years,as it can lead to the reduction of visibility and is detrimental to human health.Organic compounds are key indicators of air pollution emitted into the air by a variety of natural and human activities.As they can be suspended for a long time and travel over long distances in the atmosphere,the primary objective of this study is to preliminarily understand the environmental behavior of organic compounds in the urban atmosphere,which is important for managers to take effective measures to help improve the air quality as well as prevent hazardous organic compounds poisoning the public through contaminated air.A total of 125 particulate matter samples and 268 gas phase samples were collected from urban areas of the Hefei city,Anhui,China.The contamination levels,distribution,sources and potential risk of polycyclic aromatic hydrocarbons(PAHs)and volatile organic compounds(VOCs)in the air samples were monitored by using accelerated solvent extraction and gas chromatography-mass spectrometry analysis,based on data analysis methods such as isomer ratios,correlation analysis,factor analysis and health risk assessment.The major findings of the present research work were as follows:(1)Particulate matter monitoring evidenced that the concentrations of PM2.5 and PM10 in Hefei city were 90.5 and 114.5 ?g m-3,respectively,which were lower than those in megacities in China.(2)The average concentrations of particulate-bound PAHs exhibited obvious seasonal variability,with a higher level in winter than in summer.The results of source apportionment show that combustion of coal and vehicle exhaust are the predominant sources of PAHs in particulate matters.(3)The concentrations of VOCs varied significantly among different functional zones.It can be noted that the mean concentration in the traffic zone was the largest,followed by the industrial zone,development zone,residential zone and background zone.The sources of VOCs in Hefei city were influenced primarily by traffic emissions.(4)PAHs and VOCs present high risks to the atmospheric environment on the basis of the results of health risk assessment.The inhalation cancer risk(ICR)of particulate-bound carcinogenic PAHs was higher than the safe range,which in winter exhibited risks about 12 times higher than that in summer;the values of cancer risks for six carcinogenic VOCs were higher than the general acceptable risk level(1.0E-06).The potential non-carcinogenic risk levels of ten VOCs associated with inhalation were also estimated,and a relatively high value of HI was found in this study.(5)Forty-six VOCs from 80 measured VOC species were found to be capable of leading to odor pollution in this study,and olfactory odor concentration,odor index and coefficient of divergence analysis methods were used to study the characterizations of odorous VOCs.Automobile component manufacturing plants and electric product plants exhibited the highest concentrations of odorous VOC compo unds.In addition,1,4-diethylbenzene was the most abundant odorous contributor in this study.