Dynamic Changes and Impact on Premature Mortality of Air Pollution in Beijing Before, During, and After the COVID-19 Restrictions

Air pollution is a major threat to human health. The restriction policies adopted in response to the spread of COVID-19 had a significant effect on air pollution. In this paper, we studied the changes in air pollution in Beijing from 2019 to 2023 and the associated impact on premature mortality. PM_2.5, NO₂, SO₂, and CO concentrations have continued to decrease since the COVID-19 outbreak. Notably, the decrease in “Traffic” stations in 2020 exceeded that of “Urban” and “Rural” stations. This reflects the significant suppression of anthropogenic emissions, especially traffic emissions, in Beijing during the COVID-19 lockdown period. When the lockdown was eased in 2023, the concentrations of PM_2.5, PM₁₀, and NO₂ increased to varying degrees (approximately 10%–40%). The AQI reflects the same characteristics, with continuous improvement from 2019 to 2022 and deterioration in 2023. In summer, the AQI was affected mainly by the lockdown policy, whereas in winter, the effects of the policy were superimposed by atmospheric conditions. The AirQ+ results show that the COVID-19 restrictions significantly reduced the attributable fraction of deaths due to air pollution. However, PM₁₀, NO₂, and O₃ still pose considerable threats to the respiratory and circulatory systems of Beijing residents. Even if the concentration of pollutants decreases, the estimated number of deaths may still increase in the context of the continued increase in the population at risk; thus, it is necessary for local authorities to focus on controlling air pollution.