Assessing the spatio-temporal impact of the COVID-19 pandemic lockdown on air quality in Jiangsu province, China

The Chinese government has implemented severe restrictions and lockdown (LD) measures in response to the COVID-19 pandemic. This kind of environment offers a terrific opportunity to work in this area. The current study sought to evaluate the COVID-19 lockdown’s spatiotemporal impact on Jiangsu Province, China’s air quality. We examined the data gathered from 72 monitoring stations for each of the six air pollutant factors: PM₁₀, SO₂, PM_2.5, CO, NO₂, and O₃ from 2017 to 2021. Our findings indicate that air pollution concentrations abruptly decreased as a result of the COVID-19 lockdown. During the active-LD period, SO₂, NO₂, PM₁₀, PM_2.5 and CO concentrations declined by − 17.85%, − 38.07%, − 29.52%, − 30.33%, and − 19.05%, respectively, while O₃ concentrations significantly increased by 58.62%, because of a combination of decreased emissions of NOx and VOCs, and variations in the weather. In contrast to the historical data (2017–19), O₃ levels increased by 3.53%, while SO₂, NO₂, PM₁₀, PM_2.5, and CO reductions were − 50.11%, − 34.95%, − 36.51%, − 33.16%, and − 23.60%, respectively. Among the selected pollutants, PM₁₀, PM_2.5, NO₂, and CO all exhibited increasing tendencies, while SO₂ and O₃ concentration levels reduced in 2021. According to the correlation analysis, Jiangsu’s active-LD phase observed a considerable relationship between SO₂, PM_2.5, NO₂, PM₁₀, and CO. The findings suggest that the COVID-19 lockdown measures had a significant influence on both raising and declining air pollution levels. These findings illuminate a new light and are helpful for the scientific community and local authorities to create strategies to protect the environment.