When smokers move out and non-smokers move in: residential thirdhand smoke pollution and exposure.

BACKGROUND: This study examined whether thirdhand smoke (THS) persists in smokers' homes after they move out and non-smokers move in, and whether new non-smoking residents are exposed to THS in these homes. METHODS: The homes of 100 smokers and 50 non-smokers were visited before the residents moved out. Dust, surfaces, air and participants' fingers were measured for nicotine and children's urine samples were analysed for cotinine. The new residents who moved into these homes were recruited if they were non-smokers. Dust, surfaces, air and new residents' fingers were examined for nicotine in 25 former smoker and 16 former non-smoker homes. A urine sample was collected from the youngest resident. RESULTS: Smoker homes' dust, surface and air nicotine levels decreased after the change of occupancy (p<0.001); however dust and surfaces showed higher contamination levels in former smoker homes than former non-smoker homes (p<0.05). Non-smoking participants' finger nicotine was higher in former smoker homes compared to former non-smoker homes (p<0.05). Finger nicotine levels among non-smokers living in former smoker homes were significantly correlated with dust and surface nicotine and urine cotinine. CONCLUSIONS: These findings indicate that THS accumulates in smokers' homes and persists when smokers move out even after homes remain vacant for 2 months and are cleaned and prepared for new residents. When non-smokers move into homes formerly occupied by smokers, they encounter indoor environments with THS polluted surfaces and dust. Results suggest that non-smokers living in former smoker homes are exposed to THS in dust and on surfaces.

Residual tobacco smoke pollution in used cars for sale: air, dust, and surfaces.

Regular tobacco use in the enclosed environment of a car raises concerns about longer-term contamination of a car's microenvironment with residual secondhand smoke pollutants. This study (a) developed and compared methods to measure residual contamination of cars with secondhand smoke, (b) examined whether cars of smokers and nonsmokers were contaminated by secondhand smoke, and (c) how smoking behavior and restrictions affected contamination levels. Surface wipe, dust, and air samples were collected in used cars sold by nonsmokers (n = 20) and smokers (n = 87) and analyzed for nicotine. Sellers were interviewed about smoking behavior and restrictions, and car interiors were inspected for signs of tobacco use. Cars of smokers who smoked in their vehicles showed significantly elevated levels of nicotine (p < .001) in dust, on surfaces, and in the air compared with nonsmoker cars with smoking ban. When smokers imposed car smoking bans, air nicotine levels were significantly lower (p < .01), but dust and surface contamination levels remained at similar levels. Smoking more cigarettes in the car and overall higher smoking rate of the seller were significantly associated with higher secondhand smoke contamination of the car (p < .001). Use of a cutpoint for nicotine levels from surface wipe samples correctly identified 82% of smoker cars without smoking bans, 75% of smoker cars with bans, and 100% of nonsmoker cars. Surface nicotine levels provide a relatively inexpensive and accurate method to identify cars and other indoor environments contaminated with residual secondhand smoke. Disclosure requirements and smoke-free certifications could help protect nonsmoking buyers of used cars.