Pollution Characteristics And Health Risk Of VOCs Pollution In Handan

In this study,56 species of VOCs and the carbon composition data from PM_2.5 off-line sampling were observed by using the on-line monitor data in the monitoring station of Hebei University of Engineering in Handan during Sep.2017 to Aug.2018.The pollution characteristics of VOCs,source apportionment and health risk assessments of toxic VOCs were analyzed.The conclusions are as follows:?1?The average concentration of VOCs in Handan were 112.0?g/m³,which was in the middle level in domestic and foreign cities.The concentrations of the VOCs groups were listed as alkenes>aromatics>alkenes>alkyne,while the seasonal variations was obvious,the concentration was highest in winter,followed by autumn,in which light alkanes,short alkenes and BTEX made a big contribution in winter.The 2-methylpentane concentration increased from May to July,which contributed a big part to long alkanes.Ethane,propane and ethylene had a great influence on the concentrations of light alkanes and short alkenes respectively.?2?Different weathers?sunny,cloudy,rainy,snow?showed different influences on the concentrations and chemical degradations of VOCs.The light alkanes,short alkenes and BTEX decreased with the time in the daytime,while the long alkanes and long alkenes reached max concentrations at around for 14:00 both in sunny and rainy days.The oxidation reactions increased the chemical degradation of VOCs in cloudy and rainy days.The concentrations of VOCs were higher at night in heating period,while the concentrations were higher in the daytime in non-heating period?except other aromatics and acetylene?.The concentrations of light alkanes,short alkenes and BTEX were significantly higher in heating period than that in non-heating period.?3?The sources of VOCs in Handan were complex,among which benzene and acetylene originated from incomplete combustion of automobile fuel,butane from automobile exhaust,pentane from liquid oil,n-alkanes from incomplete combustion of fossil fuels,C6,C7 from combustion of fossil fuels respectively.The regional VOCs pollution in Handan included local sources and emissions from surrounding cities.Based on energy structure and statistical data of Handan,cooking oil fume,use of solvent,steel industry and mobile sources of VOCs could have a big influence on VOCs pollution in Handan.?4?The seasonal variations of non-cancer risk for BTEX in Handan were performed,highest in winter and lowest in summer.But the non-carcinogenic risk is lower than the safety threshold?HI=1?,which suggested the potential risk of BTEX in atmosphere had a less influence on human in Handan.The results of benzene,ethylbenzene and styrene showed that the cancer risk caused by styrene could be ignored,while benzene and ethylbenzene exceeded the threshold value?1E-06?.Benzene showed a higher carcinogenic risk indicated by Monte Carlo simulation results.Sensitivity analysis showed that controlling the concentration of benzene could effectively reduce the risk of carcinogenesis.