Second-hand smoke pollutants found outside bars, restaurants

Smoking bans in restaurants and bars that drive smokers outside may lead to a haze of hazardous pollutants where people congregate to light up, researchers say.

"You can have 40 to 50 smokers in a small area, which translates to fairly aggressive exposures to second-hand smoke, even if it's outside," said study author Luke Naeher ofthe University of Georgia College of Public Health

"We want to know what those exposures are and, if it's unhealthy, we want to tell policy makers who are making decisions about these regulations."

Naeher and his colleagues measured particles fromsecond-hand smoke over four weekends in a couple of restaurants, bars and a no-smoking zone in Athens, Ga., a college town where thousands of students light up cigarettes while standing shoulder to shoulder.

Researchers measured carbon monoxide and small particles called PM2.5 that penetrate deep in the lung every 30 seconds.

Since both pollutants are also found in car exhaust, the team also counted the number of cars, smokers and non-smokers who passed by every five minutes.

An increase in pollutants was linked with an increase in the number of smokers, but not traffic, the researchers reported Tuesday at the American Thoracic Society's international conference in San Francisco.

To learn more about how much second-hand smoke people are exposed to outside bars and restaurants, a follow-up study is underway. Researchers will collect samples of urine and saliva from smokers to look for chemicals that are specific to cigarette smoke.