Exposure to tobacco smoke leads to hearing loss, even in nonsmokers, according to a Nov. 16 BBC News report.

In a recent study by University of Miami and Florida International University investigators, 3,307 nonsmokers (both former smokers and those who never smoked) underwent hearing tests and blood screens for cotinine, a metabolite produced by the body in response to nicotine.

Results revealed that participants exposed to environmental tobacco smoke had significantly poorer hearing-test results.

In fact, passive smoking reduced the ability to hear across all frequencies by roughly one-third.

Dr. David Fabry, former chief of audiology at the University of Miami Miller School of Medicine and lead author of the study, said the degree of exposure necessary to affect hearing remains unclear.

“We really do not know exactly how much smoke you need to be exposed to in order to be at increased risk. But we do know that the threshold for damage is very low.”

One thing is certain, according to Dr. Ralph Holme, head of biomedical research at London's Royal National Institute for Deaf People. “Hearing loss can often be very frustrating and lead to social isolation.

“Before you next light up a cigarette, consider how it could impact not only on your own long-term hearing but your friends' and relatives', too.”

The study was published online Nov. 15 in the journal Tobacco Control.