Source and sectoral contribution analysis of PM_2.5 based on efficient response surface modeling technique over Pearl...

Identifying and quantifying source contributions of pollutant emissions are crucial for an effective control strategy to break through the bottleneck in reducing ambient PM_2.5 levels over the Pearl River Delta (PRD) region of China. In this study, an innovative response surface modeling technique with differential method (RSM-DM) has been developed and applied to investigate the PM_2.5 contributions from multiple regions, sectors, and pollutants over the PRD region in 2015. The new differential method, with the ability to reproduce the nonlinear response surface of PM_2.5 to precursor emissions by dissecting the emission changes into a series of small intervals, has shown to overcome the issue of the traditional brute force method in overestimating the accumulative contribution of precursor emissions to PM_2.5. The results of this case study showed that PM_2.5 in the PRD region was generally dominated by local emission sources (39-64%). Among the contributions of PM_2.5 from various sectors and pollutants, the primary PM_2.5 emissions from fugitive dust source contributed most (25-42%) to PM_2.5 levels. The contributions of agriculture NH₃ emissions (6-13%) could also play a significant role compared to other sectoral precursor emissions. Among the NO_X sectors, the emissions control of stationary combustion source could be most effective in reducing PM_2.5 levels over the PRD region.