Impact of Street Sweeping and Washing on the PM10 and PM2.5 Concentrations in Cracow (Poland)

Road traffic is one of the most important factors triggering an increase of suspended dust air pollution in urban areas, especially during the summer. This phenomenon is caused not only by emissions from vehicle combustion engines, but mainly by the formation of dust during road use (tire abrasion, and resuspension of accumulated dust). Sweeping and street washing are the main methods used to remove dust deposited on road surfaces. This article presents the effectiveness of the PM10 and PM2.5 reduction as a result of sweeping, and then intensive street washing in one of the most polluted cities in Europe (Cracow, Poland). The study was carried out in three locations: i) on one of the city's busiest streets; ii) the industrial zone; and iii) at a residential area. The combination of intensive sweeping and roadway cleaning led to the reduction of the suspended dust concentration by 14-20.4% PM10 and 20.8%-33.3% for PM2.5. The greatest impact of this activity was observed in the area where the vehicle traffic was the main source of air pollution. In other places, the obtained effect was reduced by meteorological conditions or emissions from industry.