Friday, July 29, 2011

Secondhand smoke, hearing loss linked

Compared to teens with non-smoking parents, adolescents who are exposed to secondhand smoke are two times more likely to develop levels of hearing loss in the long run.

New York University School of Medicine researchers studied any possible relationship between exposure to tobacco smoke at home and the risk of developing hearing loss in 11,533 US teenagers.

The teens with higher blood levels of cotinine, a metabolite of nicotine, were more likely to have sensorineural hearing loss -- a condition most often caused by problems with the cochlea, the snail-shaped hearing organ in the inner ear.

About 12 percent of the exposed kids had mild to severe hearing loss in one ear, compared to less than eight percent of kids without smoke exposure, according to the findings published in the Archives of Otolaryngology -- Head and Neck Surgery.

"More than half of all children in the U.S. are exposed to secondhand smoke, so our finding that it can lead to hearing loss in teenagers has huge public health implications," said study co-author Anil Lalwani.

Researchers believe children may need to be screened more regularly for hearing problems because more than 80 percent of the affected teens in the study were not aware of having any hearing problems.

Further studies are needed to determine how exactly exposure to tobacco smoke causes hearing difficulties, the scientists added.