Air Pollution Characteristics during the 2022 Beijing Winter Olympics.

Using air pollution monitoring data from 31 January to 31 March 2022, we evaluated air quality trends in Beijing and Zhangjiakou before and after the 2022 Winter Olympics and compared them with the conditions during the same period in 2021. The objective was to define the air quality during the 2022 Winter Olympics. The results indicated that: (1) the average concentrations of PM, PM, NO, CO, and SO in Zhangjiakou during the 2022 Winter Olympics were 28.