2017–2020 trends of particulate matter PM10 concentrations in the cities of Suceava and Botoșani

: This study aims to analyze the trends and variability of PM10 concentrations at three monitoring sites in Suceava and Botoșani cities from 2017 to 2020. The results reveal a declining trend in PM10 concentrations at the urban background stations (SV1 and BT1), while the industrial site (SV2) indicated a slight increasing trend until 2019. The cold season recorded the highest daily PM10 concentrations, with peak values of 133.5 μg/m3, 114.9 μg/m3, and 91.8 μg/m3 at SV2, BT1, and SV1, respectively. Annual average PM10 concentrations d ecreased at SV1 and BT1, showing reductions of 6.7% and 19.7% in 2020 compared to 2017, respectively. The 90.4th percentile, with a threshold limit of 50 μg/m3, exceeded the limit during the 2018-2020 period at SV2. Pearson correlation analysis indicates a significant positive correlation between PM10 and NO2 (R = 0.66 in SV2) and CO (R = 0.69 in SV2, R = 0.54 in BT1) during the winter season. Additionally, a positive correlation was observed between PM10 and benzene in BT1, during both the warm season (R = 0.41) and the cold season (R = 0.66). These results provide insights into the spatiotemporal variability of PM10 and its relationship with other air pollutants.