New York, Oct. 18 (Reuters): Exposure to second-hand tobacco smoke appears to increase asthma severity and might even influence the risk of hospital admission, according to a new report.

“Our study showed that second-hand tobacco smoke can be harmful for adults with asthma,” lead investigator Dr Mark D. Eisner said.

Eisner of the University of California, San Francisco, and colleagues note that most previous studies of asthma and passive smoking have relied on self-reported exposure.

In the present study, published in the journal Thorax, the researchers used nicotine badges to measure exposure. The badges trap ambient nicotine in a filter, and gas chromatography is subsequently used to evaluate the content. Hair was sampled for nicotine and its major metabolite cotinine to determine the levels of longer-term exposure.

The badges were used for seven days in 189 subjects.