| Abstract: |
Guangdong province (GD), one of the most prosperous and populous regions in China, still experiences haze events and growing ozone pollution, although it has seen substantial air quality improvement in recent years. Co-control of fine particulate matter (PM2.5) and ozone in GD calls for a systematic review of historical emission patterns. In this study, emission trends, spatial variations, source-contribution variations, and reduction potentials of sulfur dioxide (SO2), nitrogen oxides (NOx), PM2.5, inhalable particles (PM10), carbon monoxide (CO), ammonia (NH3), and volatile organic compounds (VOCs) in GD from 2006 to 2015 are revealed using a dynamic methodology, taking into account economic development, technology penetration, and emission controls. The relative change rates of anthropogenic emissions in GD during 2006-2015 were -48% for SO2, -0.5% for NOx, -16% for PM2.5, -22% for PM10, 13% for CO, 3% for NH3, and 13% for VOCs. The declines of SO2, NOx, PM2.5, and PM10 emissions are mainly attributed to the control-driven emission reductions in the Pearl River Delta (PRD) region, especially from power plants, industrial combustion, on-road mobile sources, and fugitive dust, and partly to the shift of industries from the PRD to the non-PRD (NPRD) region in GD. NPRD also contributed to part of the emission decline, but it was only effective until 2011 when GD's Clean Air Action of 12th Five-Year was implemented. Due to the growth of solvent use and the absence of effective control measures, VOC emissions in PRD and NPRD both steadily increased, and this might be one of the reasons that led to the slight upward trends of ozone concentrations in GD. To further reduce emissions, future work should focus on power plants and industrial combustion in GD and industrial process source in NPRD for emissions of SO2, NOx, and particulate matter, and on solvent use and on-road mobile sources for VOC emissions. This study provides solid scientific support for further air quality improvement in GD. In addition, it provides robust data to quantify the impact of emission and meteorology variations on air quality and unveil the primary cause of significant air quality change in the PRD region in recent decade. [ABSTRACT FROM AUTHOR] |
