Impact of the size of settlement units, Covid-19 pandemic, and the ongoing war in Ukraine on air quality in Poland

The concentrations of air pollutants, PM₁₀, SO₂, NO₂, NO_x, and C₆H₆ were analysed in 30 settlement units (10 in each category: cities, towns, and rural areas) in the 2017–2022 in Poland (Central-Eastern Europe). The concentrations of air pollutants were related to the spatial distributions of the settlement units, air temperature, and geopolitical events (the Covid-19 pandemic and war in Ukraine). The described multi-criteria analysis is an innovative approach to the area-based assessment of air quality changes in the country. Spatial analysis showed high concentrations of pollutants mainly in the central-southern and eastern-southern parts of the country in areas with a highly urbanized and industrialized areas. The cities and towns were found to have similar air pollutant concentrations. Better air quality was observed in the sparsely populated northern part of the country. Rural areas had on average 30 % better air quality than cities. A high negative correlation was found between the average air temperature and the concentrations of all the analysed pollutants. The highest concentrations of pollutants were observed in the winter (heating) periods. Overall, in the 6-year period there was a decrease in the level of air pollution year-on-year throughout the country. The lockdown in 2020 also caused a reduction in pollutant concentration. However, the outbreak of war in 2022 contributed to an area increase in pollutant concentrations.