Characteristics and sources analysis of ambient volatile organic compounds in a typical industrial park: Implications for ozone formation in 2022 Asian Games

In this study, volatile organic compounds (VOCs) at a major industrial park in Yangtze River Delta Region, China, along with an urban site had been investigated for three years (2018-2020). The daily-mean concentration of total 97 VOCs in the industrial park (224.3 ± 139.1 μg/m3) was about twice that of urban site (112.0 ± 64.2 μg/m3). Halohydrocarbons were predominant VOCs species at both sites accounting for 39.0 % and 32.2 % in industrial and urban sites, respectively. Annual-average concentrations of total VOCs slowed down gradually in industrial park, while that of the urban site increased annually. Evident seasonal and diurnal variations were observed for VOCs concentration in both sites. Higher VOCs concentrations appeared in summer for industrial park, and high concentrations generally appeared at 8:00 and 19:00-20:00 in two sites. Diagnostic ratios of m/p-xylene to ethylbenzene indicated vehicle emissions and solvent volatilization were main sources of VOCs in industrial site during winter. Further positive matrix factorization identified fuel usage and industry source as major sources in industrial park and urban site, respectively. Ozone formation potential calculations showed aromatics contributed most to ozone formation, and benzyl chloride was a key species when its concentration was high. Further empirical kinetic modeling approach revealed ozone formation in industrial park was in VOCs-limited regime. Through air mass trajectory analysis, air pollutants especially ozone from industrial park will be transported to stadiums by northeast wind during the 2022 Asian Games. The reductions in VOCs emissions from industrials are highly recommended for ozone control in 2022 Asian Games.