Road traffic effects in size-segregated ambient particle-bound PAHs

Polycyclic aromatic hydrocarbons (PAHs) in 13 size fractions of ambient particulate matter (PM) were investigated at three sites in Katowice, Poland. PM was sampled with two of the same type 13- stage low-pressure impactors (DEKATI). One of them was used first at a motorway shoulder in the spring of 2012, and then, in the summer, at a busy crossroads. The second impactor was used in parallel with the first one at an urban background site in both the seasons. The PAH contents in PM were determined by means of gas chromatography (Perkin Elmer). The ambient concentrations of PAHs from particular PM fractions at the urban background site differed insignificantly from those at the two traffic sites. Although the concentrations of PAHs and total PAHs (ΣPAH) for some PM size fractions were higher at the urban background site, the significant influence of traffic emissions on the mass size distributions and concentrations of PAHs in Katowice was proved. For example, the traffic effects can be seen in the shares of the PM1-bound ΣPAH and some PM1- bound PAHs in the concentrations of PM-bound ΣPAH and these PAHs, visibly higher at the motorway and crossroads. Also, the mass size distributions of some PM-bound PAHs reflect the traffic influence on the ambient PAH concentrations within the whole city in summer. As the traffic emissions cause high concentrations of PM-bound BaP and BaA, these two PAHs probably pose the main health risk related with ambient PAH inhalation in non-heating periods in Katowice.