LAUSR

The results of a PM4 (airborne particles with an aerodynamic diameter less than 4 µm) study in Katowice and in the surrounding area in homes with and without environmental tobacco smoke (ETS) are presented. It was found that the average concentration of PM4 inside the homes with ETS was between 126 µg m−3 (in Jaworzno) and 208 µg m−3 (in Katowice)—significantly higher than in the homes without smokers (55–65 µg m−3). The mean of the indoor to outdoor ratios (I/O) for PM4 varied greatly, ranging from 0.6 in the apartments without smokers in Katowice to 5.2 in the homes with smokers in Jaworzno. The highly polluted by ETS indoor air causes children aged 14–15 living in these homes to inhale from 2.5 to 6.6 mg of PM4 more per day than their peers living in non-ETS homes. X-ray photoelectron spectroscopy (XPS) was used to determine the surface chemical composition of the studied indoor airborne particles. Carbon, including elemental carbon, and oxygen-containing species dominated the particulate surface, with traces of Si, N, S, Na, Al, Zn, and K present. The surface layer of PM4 from the homes with ETS contains significantly more carbon and less oxygen than the airborne particles collected in the homes without smokers, which can be explained by the high emission of carbon during tobacco smoking.