Improving the Air Pollution Control Measures More Efficiently and Cost-Effectively: View from the Practice in the 7th Military World Games in Wuhan

During a mega-event, the air pollution control measures for the key city and surrounding regions were within a certain distance was always implemented. The necessity of taking the similar or even same measures everywhere is suspect. The 7th Military World Games (MWG) was held in an inland city-Wuhan, and the air pollution control regions within a cycle of diameter as 400 km, which give a good opportunity to address this problem. Compared to the air pollution control period (10/08 − 10/28) in 2019 with those from 2015 to 2018, CO, NO₂, PM₁₀, PM_2.5, and SO₂ showed negative anomalies of 0.13 ± 0.09 mg m^− 3, 10.8 ± 3.34 µg m^− 3, 39.3 ± 5.98 µg m^− 3, 18.0 ± 3.17 µg m^− 3, and 4.30 ± 2.66 µg m^− 3, respectively, while O₃ showed positive anomalies (9.84 ± 4.06 µg m^− 3) in the core control area (Wuhan). Using the weather normalized technique, the contributions of emissions and meteorology to anomalies of air pollutants were quantified, i.e., emission variations contributed to 52.7% of PM_2.5 anomalies in Wuhan. The reduced mass concentrations of elemental carbon (0.49 µg m^− 3) and trace elements (0.88 µg m^− 3), as well as the reductions from biomass burning (4.15 µg m^− 3), vehicle emissions (2.75 µg m^− 3), and coal combustion (1.03 µg m^− 3) all verified the effectiveness and necessity of pollution control for local primary particles. While the elevated nitrate (6.14 µg m^− 3) and sulfate (2.23 µg m^− 3) concentrations during the MWG period highlighted the enhanced secondary formation when the air mass transported mainly from the north, northeastern and western regions of Wuhan, within a cycle of diameter of 300 km. The pollution control at the south regions of Wuhan is not necessary here. This study suggested that during a mega-event, the primary emission reduction of particles from local biomass burning, vehicle emission, fugitive dust as well as the NO₂ and NH₃ reduction from the unwind regions within a certain distance should be emphasized, which can save costs and human efforts effectively.