Photochemical ozone formation oriented VOC source apportionment and health economic burdens in Pearl River Delta

Abstract Clarifying the source apportionment of volatile organic compounds (VOCs) and their correlation with photochemical losses and ozone formation is critically important. However, addressing this issue remains a significant challenge. To address this challenge, we proposed a novel photochemical ozone formation potential (PL-OFP)-oriented source apportionment method that facilitates the quantitative evaluation of VOC source contributions to ozone formation and associated health-economic burdens in the Pearl River Delta (PRD) urban agglomeration. Our findings indicate that PL-OFP values in the urban agglomeration ranged from 18.4 to 34.4 ppbv. Alkenes and aromatics were the dominant loss species because their unsaturated bonds are more susceptible to free-radical attack. Although natural gas and biomass combustion were the highest-concentration sources of VOCs, vehicle emissions had the greatest potential to form ozone. Notably, after photochemical reaction, over 70% of VOCs from biological sources were consumed, making them the dominant actual ozone contributor. Control measures should therefore prioritize these low-concentration but highly reactive VOC emissions. By quantifying health-economic burdens, it was estimated that the PRD region had 8522 O 3 -related mortalities annually, resulting in economic losses of $4933.4 M. Among these losses, PL-VOCs contributed $1195.6 M. This research offers critical insights for the synergistic control of VOC and ozone.