Emission controls and changes in air quality in Guangzhou during the Asian Games

With the new air quality standards forthcoming in China, the Pearl River Delta region is facing new challenges to achieve its air quality goal. The success of the emission reduction measures introduced by local authorities in the run-up to the Guangzhou Asian Games demonstrated that the Pearl River Delta air quality can be improved by introducing integrated emission reduction measures. This paper combines observation data, emission reduction measures, and air quality simulations that were applied during the Asian Games (12–27 November 2010) to analyze the relationship between emissions and concentrations of pollutants in Guangzhou. The Asian Games abatement strategy totally reduced emissions of 41.1% SO2, 41.9% NOx, 26.5% PM10, 25.8% PM2.5 and 39.7% VOC. The concentrations of SO2, NO2, PM10 and PM2.5 were reduced by 66.8%, 51.3%, 21.5% and 17.1%, respectively. In Guangzhou, the main challenge to be overcome with the new air quality daily requirements is mostly for NO2, PM2.5, and hourly ozone maxima. If pollutants maintain the same concentrations before and after the Asian Games, there will be 47.4% and 31.6% non-attainment days for NO2 and PM2.5 respectively as a period average. Although PM10 concentration can meet the daily limits (150 μg m−3), it is quite difficult to meet the annual limit value (70 μg m−3). One important implication is that the long-term, step-by-step integrated measures of the past six years work better than the strict, intensive, short-term measures on SO2, NO2 and VOC control. Dust control by limiting construction sites and watering the roads can further reduce 12.8% of the PM10 concentration. However, to reduce ambient PM2.5, the abatement strategy should be more complex and extensive. On the contrary, ozone pollution was not improved during the Asian Games, indicating that alleviation strategies should be improved by scientific studies to determine the appropriate control ratio of NO2 and VOC in the Pearl River Delta region.