Characteristics and sources of VOCs in urban and suburban environments in Shanghai, China, during the 2016 G20 summit

Özet

To improve air quality for the period of the G20 Hangzhou Summit, comprehensive and stringent emissioncontrols were implemented over the Yangtze River delta region, China. To evaluate the impacts of emissioncontrols on variations of atmospheric volatile organic compounds (VOCs), field measurements of VOCs wereconducted at urban and suburban sites in Shanghai from August 24 to September 15, 2016. At both sites, thetotal budgets of VOCs were determined by alkanes (48.05–57.62%), followed by alkenes (4.74–10.17%), acetylene(0.16–3.90%), and aromatics (32.16–45.64%). As indicated by maximum incremental reactivity methods,aromatics were likely the most important VOCs groups for the ozone formation potential. All of VOCs presentedto have significant increases, the maximum rate of change 74.47% at PD and 147.92% at DSL, after the G20summit were compared with the G20 summit, suggesting the substantial reduction in VOCs due to emissioncontrols over regional scales. Positive matrix factorization analysis of VOCs identified five sources, includingpetrochemical industry, vehicle exhaust, LPG/NG/fuel vaporization (for suburban the source appended incompletecombustion), solvent usage, organic synthetic materials (only for urban) and plant sources were (onlyfor suburban), at the two sites, respectively. On average, petrochemical industry was the largest contributor(22.11–33.89%) to the total VOCs, followed by vehicle exhaust (22.22–27.27%) and solvent usage(15.01–20.11%). High loadings of VOCs were observed associating with westerly and northerly wind, reflectingthe impact of regional transport from surrounding regions on VOCs pollution in Shanghai.