Investigation of Particulate Matter Pollutants in Parking Garages

Air pollution is getting more emphasis in recent research and legislations due to its impact on human health and overall environmental quality. Particulate matter (PM) is one of the most important ambient air pollutants involved in a number of adverse health effects. In the case of parking garages, there are high levels of mobile PM pollutants due to air pollution coming from operation of vehicles engines. This study presents indoor PM measurements performed at three different enclosed parking garages A, B and C in two cities of Belgium with varying vehicle intensity and varying layout. Garages A and B are located in the ground floor and basement respectively of different multi-storey buildings in Brussels, while Garage C is in the ground floor of a multi-storey building in Leuven. Garage A is equipped with natural ventilation, whereas B and C have a combined mechanical and natural ventilation. Parking capacity of the garages A, B and C is 50, 130 and 185 car spaces respectively. Particle mass concentrations, number concentrations and their size distributions were measured continuously using an Electrical Low Pressure Impactor Plus (ELPI+) instrument. The impactor has 14 stages in the range of 6 nm to 10 µm. Three sizes of particles including PM1, PM2.5 and PM10 were characterized under this study. The ELPI+ device was placed on a table at a height of 0.85 m from the floor. All samples were collected inside the garages for several hours during workdays for each measurement. The results indicated that the average particles mass concentrations in the garages ranged from 28 µg/Nm3 to 50 µg/Nm3 for PM1, 43 µg/Nm3 to 60 µg/Nm3 for PM2.5 and 58 µg/Nm3 to 90 µg/Nm3 for PM10 respectively. The number concentrations were in the range of 28e+03 particles/cm3 to 47e+03 particles/cm3. Two distinct particle sizes of coarse and fine modes were observed in the particle mass size distributions in all examined garages, while the observed number size distributions showed dominant quantities of fine particles.