Research published ahead of print in Tobacco Control reports that levels of nicotine are much higher in smokers’ cars than levels found in public or private indoor places and in restaurants and bars that permit smoking.

Involuntary exposure to secondhand smoke accounts for thousands of cases of respiratory, cardiovascular, and cancer deaths every year in the US.

To deal with this problem, many countries have introduced smoke free regulations or legislation. However, most do not concern people who choose to smoke in their cars. The automobile is an environment that is increasingly being shared as a result of more carpooling between friends and work colleagues.

Researchers from the Johns Hopkins Bloomberg School of Public Health in Baltimore, USA, studied seventeen smokers and five non-smokers. They commuted to and from work for thirty minutes or longer.

They placed in the cars two passive airborne nicotine samplers for a 24 hour period. One was located at the front passenger seat headrest and one in the back seat behind the driver.

The researchers analyzed the 44 samplers gathered using gas chromatography. They found that air nicotine concentrations doubled (1.96 increase) per cigarette smoked.

Air nicotine concentrations in smokers’ motor vehicles were “strikingly higher” than non-detectable concentrations found in non-smokers’ cars.

Estimates indicated that nicotine concentrations were twice as strong in smokers’ cars as levels measured by other studies in public and private places. Also it was 40 to 50 percent higher than those in restaurants and bars that permit smoking.

The size of the vehicle and the use of ventilation made a difference to the results. However, opening the windows did not eliminate exposure to secondhand smoke.

People taking part in the study were also asked to complete a questionnaire. It included questions on their knowledge and outlook concerning the health risks of secondhand smoking and related regulations and legislation.

Every participant in the study (smokers and non-smokers) agreed that smoking in the car posed a health risk to passengers.

Among smokers, 53 percent said that being unable to smoke in the car would help them to quit smoking altogether. In addition, 93 percent of smokers agreed that motor vehicles should be smoke-free on a voluntary basis. Only 7% of smokers said vehicles should be smoke-free by regulation.

The researchers write in conclusion: “The high air nicotine concentrations measured in motor vehicles in this study support the urgent need for smoke-free education campaigns and legislative measures banning smoking in motor vehicles when passengers, especially children, are present.”

“Secondhand tobacco smoke concentrations in motor vehicles: a pilot study”
M R Jones, A Navas-Acien, J Yuan, P N Breysse
doi:10.1136/tc.2009.029942
Tobacco Control

Written by Stephanie Brunner (B.A.)