Identification of Key Anthropogenic Voc Sources Controlling O3 and Soa Formation in Fuzhou, China, by Combining Multi-Site Observation and Emission Inventory

To evaluate the volatile organic compounds (VOCs) pollution characteristics and identify their key sources in Fuzhou, China, which is one of the central cities in the economic zone on the west side of the Taiwan Straits, ambient air collection and measurement were conducted at nine sampling sites covering the urban district of Fuzhou and its surrounding area from December 2018 to October 2019. Meanwhile, a county-level anthropogenic VOC emission inventory was established by the “bottom-up” method for 2019. Then, the comparison and combination of the results of ambient observation and emission inventory were made in speciated emissions, spatial variations, source structures, and secondary pollutants formation contributions. The annual average mixing ratios of VOCs in Fuzhou were 41.17 ppbv, which is mainly dominated by OVOCs (45.6%) and alkanes (24.10%). The ambient VOCs in Fuzhou have distinct spatiotemporal characteristics, with a higher concentration in the northwest and southeast of the urban district and the highest concentration in April. The spatial distribution of VOCs estimated by the emission inventory was in correspondence with ambient observation. The source structures resulting from the positive matrix factorization (PMF) model were also comparable with that of emission inventory. Both methods showed that the VOCs emitted from mobile vehicles contributed the most to ozone (O3) formation in Fuzhou, whereas the industry had the most prominent impact on secondary organic aerosol (SOA) formation. Based on the verified emission inventory,passenger cars, synthetic fibers manufacturing, furniture coating, and paint & related manufacturing were key VOC sources that should be preferentially controlled to effectively improve air quality in Fuzhou. Moreover, it is necessary to update local source profiles of aromatics and halocarbons by field measurements for more targeted VOC emission management