Examination of particulate matter concentrations of the outdoor air of Miercurea Ciuc, Romania

Abstract This research aimed to measure particulate matter concentrations (PM1, PM2.5, PM4, PM10, and total suspended particles) at five locations in Miercurea Ciuc, while also monitoring road traffic intensity and meteorological parameters. Significant differences in particulate matter concentrations were observed across various points in the city. On weekdays, morning aerosol levels were notably higher than those in the afternoon, whereas weekend concentrations were generally lower and more stable throughout the day. Early morning measurements showed a strong correlation with peak traffic periods. During rainy conditions, PM10 levels returned to baseline values. In the city center, PM10 concentrations were typically higher (93.16% of the time) than those recorded by the Environmental Protection Agency, averaging 3.27 times greater than at the HR02 station.