Used Cars for Sale by Smokers Polluted with Secondhand Smoke

Used cars sold by smokers are polluted with secondhand smoke and are offered at prices seven to nine percent below comparable nonsmoker cars, according to new research by San Diego State University.

The first study of secondhand smoke pollution in used cars for sale examined dust, surfaces and the air of 127 used cars for sale by nonsmokers and smokers. The study showed that cars offered for sale by smokers had significantly elevated levels of secondhand smoke in dust, on surfaces and in the air, as compared to nonsmoker cars with a smoking ban. The research was published in the journals Tobacco Induced Diseases and Nicotine & Tobacco Research this month.

"Cars with strong secondhand smoke odor showed nicotine surface contamination levels 30 times higher than cars free of the unpleasant odor," said Georg Matt, study co-author and a psychology professor at SDSU. "When smokers imposed in-car smoking bans, secondhand smoke levels in the air decreased, but dust and surface contamination levels remained elevated compared to nonsmoker cars."

Study researchers conducted telephone interviews with 1,642 private-party sellers in San Diego County. Research showed that 22 percent of used cars were advertised by smokers or had been smoked in during the previous year. Among nonsmokers, 94 percent did not allow smoking in their car during the past year. Only 33 percent of smokers had the same restrictions. Used nonsmoker cars were offered at a considerable premium above their Kelley Bluebook value, oftentimes greater than 11 percent, and above comparable smoker cars by seven to nine percent.

According to Matt, Kelley Bluebook and other used car pricing systems currently do not explicitly list tobacco use as a factor affecting the value of a used car. However, this system disregards a feature of an automobile to which at least some communities appear to have assigned a considerable monetary value.

"Secondhand smoke is a mixture of more than 4,000 chemicals, many of which are irritants, toxins, mutagens and carcinogens in humans," said Penelope Quintana, study co-author and professor in the SDSU Graduate School of Public Health. "When tobacco is smoked in the enclosed environments of passenger cars, air concentrations of tobacco smoke pollutants can become extremely high. Many of the pollutants attach to surfaces and accumulate in dust from where they can be released back into the air over days and weeks after smoking."

Some of these chemicals have an odor recognizable as the unpleasant smell of stale tobacco smoke. Secondhand smoke pollution in cars is difficult to remove because pollutants are trapped in upholstery, air ducts, ceiling liners, plastic surfaces and carpets that are difficult or expensive to clean or replace. Air fresheners disguise unpleasant odors, but do not remove secondhand smoke pollutants.

Since consumers prefer nonsmoker cars, nonsmokers are able to sell their cars for a premium as compared to smokers. According to Matt, buyers should always ask about the smoking status of the seller, drivers, and passengers of a used car. Nonsmoking sellers should advertise their car as smoke-free.

While these tactics may be helpful when buying a car from a private party, dealers often do not know the smoking status of the former owners of a car.

"To better protect nonsmoking consumers, smoke-free certifications for used cars may be needed," Matt said. "Until then, it is caveat emptor – buyer beware!"

Researchers from the Moores Cancer Center at the University of California San Diego also contributed to the study. Funding was provided by the California Tobacco Related Disease Research Program (TRDRP) and additional support was provided by the SDSU Center for Behavioral Epidemiology and Community Health.