We have addressed potential contamination of PM(2.5) filter samples by nicotine from cigarette smoke. We collected two nicotine samples - one nicotine sampling filter was placed inline after the collection of PM(2.5) and the other stood alone. The overall correlation between the two nicotine filter levels was 0.99. The nicotine collected on the "stand-alone" filter was slightly greater than that on the "in-line" filter (mean difference = 1.10 mug/m(3)), but the difference was statistically significant only when PM(2.5) was low (</= 50 mug/m(3)). It is therefore important to account for personal and secondhand smoke exposure while assessing occupational and environmental PM.
Keywords: Nicotine; cigarette smoke; contamination; particulate matter; sampling filter; secondhand smoke exposure.