Temporal evolution of PM(2.5), PM(10), and total suspended particles (TSP) in the Ciuc basin (Transylvania) with specific microclimate condition from 2010 to 2019

Modern societies are characterized by increased air pollution, and particulate matter (PM) is one of the most significant air pollutants and is a major environmental health problem. Therefore, long- and short-term exposure via inhalation, ingestion, and dermal absorption of particulate matter may cause series health issues, such as cardio pulmonary and lung cancer disease. Air pollutants accumulation is significantly higher in closed regions or basins characterized by strong thermal inversions, especially during the cold period such in case of the Ciuc basin. The aim of this study was to carry out the time series analysis of PM(2.5), PM(10) and TSP in the Ciuc basin for the period 2010–2019, in order to decipher the main characteristics of air pollution in this region. The data obtained were analyzed on a daily, monthly and annual basis by different statistical methods. The average monthly concentration of TSP (60.03 µg m(−3)), PM(10) (19.21 µg m(−3)) and PM(2.5) (14.73 µg m(−3)) particulate matter in the studied regions varied between 29.84–134.79 µg m(−3), 4.38–63.51 µg m(−3) and 4.01–54.41 µg m(−3), respectively. Regarding the ratio of PM(2.5) and PM(10) in the total particulate matter (TPM) was 0.25 and 0.33. Due to meteorological factors and emission fluctuations, particulate matter exhibits high seasonal variations, therefore the highest concentrations were recorded during the cold period, while the lowest values were observed in summer. The percentage of PM(10) exceedances (50 µg m(−3)) represents 24.8% in winter, meanwhile in autumn and spring a significantly lower exceedances percentage was observed, 2.6% and 1.7%, respectively. The correlation analysis revealed that the correlation level of the studied pollutants varied between 0.73–0.78.