Impact of wind speed and apartment ventilation on indoor concentrations of PM10 and PM2.5 in Kraków, Poland

Abstract

In the period 2013–2015, PM2.5 and PM10 outdoor and indoor concentrations were measured on 23 days in cold half-year periods, in Kraków, Poland. Air pollution is still a serious health hazard for the inhabitants as Kraków is located in a concave landform and smog episodes occur often in the city during the heating periods, due to poor natural ventilation and frequent air temperature inversions. The PM10 and PM2.5 concentrations were studied for very good and very poor weather conditions concerning air pollution. Each subgroup was further divided into cases when the apartments’ windows were kept open or closed. Daily courses of PM10 and PM2.5 concentrations were very dynamic. Weather pattern, in particular wind speed and atmospheric stability, largely determined the concentrations of PM10 in ambient air. The share of PM2.5 in PM10 indoor concentrations reached around 70% for both types of weather conditions. The share of indoor PM10 and PM2.5 mean concentrations in the outdoor values was higher during good than during poor weather conditions by about 10%.