Search

The PM2.5 and O3 pollution situation in the Yangtze River Delta (YRD) region is increasingly complex. Existing coordinated prevention and control programs are demarcated according to administrative regions, making fine-scale pollution control difficult. This study proposed a method for delineating regional control and pollution types based on the analysis of PM2.5 and O3 pollution characteristics. Four key indicators were used to comprehensively evaluate regional pollution trends: PM2.5 concentration ρ(PM2.5), O3 concentration ρ(O3), and the rates of change r(PM2.5) and r(O3). Our results demonstrate that from 2015 to 2020, cities in the YRD show a transition in the main pollution type from PM2.5 to O3. By 2020, the main types of pollution in the YRD region are co-pollution (ρ(PM2.5) > 35 µg/m3 and ρ(O3) > 100 µg/m3), O3 pollution (ρ(PM2.5) < 35 µg/m3 and ρ(O3) > 100 µg/m3), and low pollution (ρ(PM2.5) < 35 µg/m3 and ρ(O3) < 100 µg/m3), accounting for 41.9%, 26.3%, and 30% of the study area, respectively, which is roughly consistent with the remote sensing results (40.4%, 25.6%, and 33.7%, respectively). The proposed method can predict future trends in pollution and assist in decision-making for the coordinated prevention and control of PM2.5 and O3 pollution. [ABSTRACT FROM AUTHOR]