Investigation of aerosol pollution inside trams in Debrecen, Hungary

Abstract Fine (PMfine) and coarse (PMcoarse) particulate matter concentrations and elemental compositions were investigated inside trams during travelling in heating and non-heating seasons. New CAF and older KCSV tramcars were involved in the study. The results obtained for the trams were compared with the outside air quality measured at a nearby urban background site. The coarse (particles with aerodynamic diameter larger than 2.5 µm) and the fine (particles with aerodynamic diameter smaller than 2.5 µm) mass concentrations were determined by gravimetric method. The elemental analysis of the collected samples was carried out by particle induced X-ray emission (PIXE) method at the Institute for Nuclear Research, Hungarian Academy of Sciences (MTA-Atomki) Debrecen, Hungary. The mass concentrations inside the vehicles were 5–20 times higher than in the outdoor air. The elemental composition was similar inside the trams and outdoors in both size fractions. However, some elements (Cr, Zn, Cu) were enriched in the trams and could be derived from outdoor sources such as the re-suspended dust, the rail abrasion, the abrasion of the overhead wire. According to the results the new CAF tram type was less polluted than the old KCSV one.