Pollution Characteristics And Health Risk Assessment Of Volatile Organic Compounds In The Northern Suburbs Of Nanjing

In recent years,with the rapid development of petrochemical,packaging,motor vehicles and oil storage industries,air pollution has attracted more and more attention.Pollutant Control Program.Volatile organic compounds(VOCs)are important precursors such as ozone.In order to study the pollution characteristics and health risks of volatile organic compounds in the northern suburbs of Nanjing,continuous online monitoring of atmospheric VOCs was carried out to distinguish the pollution sources of atmospheric VOCs and determine the OH radical reactivity of VOCs in the atmospheric environment and the impact on O₃generation by OH radical loss rate(L_OH)and maximum incremental reactivity(MIR),assess the health risks of toxic VOCs,and different Relationship between source-partitioned OH reactivity,ozone generation potential,and health effects.The main findings are as follows:Firstly,the concentration variation characteristics of TVOCs(Total Volatile Organic Compounds)and their components were high in autumn and winter and low in spring and summer,among which alkanes are the components that contribute the most to the total.The toxic VOCs with the largest concentration contribution were halogenated hydrocarbons.1,2-Dichloroethane and dichloromethane are common substances that contribute to toxic VOCs.Secondly,the PMF model was used to determine the VOCs emission sources in the four seasons in the northern suburbs of Nanjing.It was found that the analysis results of PMF sources in different seasons showed that vehicle exhaust emission sources and industrial emission sources were the main sources of VOCs pollution.Finally,the OH·reactivity of VOCs is the strongest in autumn,while OFP is significantly higher in autumn and winter than in spring and summer.Aromatic hydrocarbons and alkenes are the most reactive components in the atmosphere in the northern suburbs of Nanjing,and they have the greatest contribution to OH·reactivity and OFP in different seasons.Vehicle emissions are the largest source of cancer risk during summer and winter.Industrial sources contributed less to the total VOCs mix ratio,but contributed the most to non-carcinogenic risks.Solvent use contributed minimally to the concentration of environmental VOCs and non-carcinogenic risk,but contributed more to L_OH.In the future,Nanjing should focus on industrial emissions and solvent use to control atmospheric VOCs pollution and improve air quality.