FRIDAY, Dec. 17 (HealthDay News) -- The health of nonsmokers who
move into homes previously inhabited by smokers could be threatened
by tobacco toxins lodged in dust and on surfaces, a new study
This so-called "thirdhand smoke" was found on surfaces even
after the homes had been vacant for two months and cleaned and
repainted, said researchers reporting online Dec. 17 in
"We found that thirdhand smoke is trapped on surfaces like walls and ceilings and in household dust and carpets left over by previous residents," study author Georg Matt, a psychology professor at San Diego State University, said in a university news release. "The homes of smokers become reservoirs of tobacco smoke pollutants. When new nonsmoking tenants come in contact with polluted surfaces and inhale suspended microscopic dust, they are unknowingly exposed to tobacco smoke toxins."
The researchers say that thirdhand smoke includes smoking-linked
pollutants that linger on surfaces and dust and get re-emitted back
into the air or react to oxidants to become secondary toxins.
In the study, Matt's team examined the homes of 50 nonsmokers
and 100 smokers before and after they moved out. They measured
levels of nicotine on surfaces within the homes, in the air and on
participants' fingers. The team also collected urine samples from
nonsmoking residents after they moved into new homes and analyzed
them for traces of cotinine, a marker for tobacco smoke
The researchers found higher levels of tobacco-linked
contamination in dust and surfaces of homes formerly inhabited by
smokers versus nonsmoker homes. Levels of nicotine on fingers were
also higher among new residents of former smokers' homes, which
also correlated with levels of contaminants on surfaces and in
dust, and with urine cotinine levels.
The health outcomes of thirdhand smoke have not been assessed,
the researchers stressed, but they suspect that the residues could
pose special risks to babies and toddlers who tend to crawl on
floors or suck on items in the home.
The study echoes the findings of another report on
smoking-tainted living spaces published online Dec. 13 in
Pediatrics. That study, from the University of Rochester Medical Center, found that children living in nonsmoking apartments were exposed to smoke from neighbors' apartments that seeped through walls or traveled through building ventilation systems.
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