Haze Occurrence Caused by High Gas-to-Particle Conversion in Moisture Air under Low Pollutant Emission in a Megacity of China.

ABSTRACT: Haze occurred in Zhengzhou, a megacity in the northern China, with the PM_2.5 as high as 254 μg m^-3 on 25 December 2019, despite the emergency response measure of restriction on the emission of anthropogenic pollutants which was implemented on December 19 for suppressing local air pollution. Air pollutant concentrations, chemical compositions, and the origins of particulate matter with aerodynamic diameter smaller than 2.5 µm (PM_2.5) between 5-26 December were investigated to explore the reasons for the haze occurrence. Results show that the haze was caused by efficient SO₂-to-suflate and NO_x-to-nitrate conversions under high relative humidity (RH) condition. In comparison with the period before the restriction (5-18 December) when the

SUBMITTER: Ma Q 

PROVIDER: S-EPMC9179953 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature