Few studies have looked at the risks of breathing second-hand smoke outdoors, an activity increasingly capturing the attention of health officials. A recent study in Environmental Health Perspectives found that nonsmokers who visited outdoor restaurants and bars where smoking was allowed had elevated levels of tobacco-related chemicals in the body compared with people at a smoke-free control site.
In August and September 2010, 28 students from the University of Georgia spent three evenings in Athens, Ga., on patios outside a family restaurant and a bar where smoking was permitted, and at a nonsmoking open-air control site. The students, 18 women and 10 men, deliberately sat near smokers and one study participant counted the number of cigarettes lit every 10 minutes. Urine and saliva samples were collected before, immediately after and the morning after each three-hour visit.
Levels of salivary cotinine, a byproduct of nicotine, were significantly higher both immediately after and the morning after the restaurant and bar visits compared with the control-site visit. The greatest increase was recorded after the visit to the bar, where four times as many cigarettes were lit than at the restaurant. Urinary concentrations of NNAL, a chemical found in tobacco, were elevated immediately after the bar and restaurant visits and significantly elevated the next morning.