Second-hand smoke implicated for adolescent hearing loss

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Secondhand smoke linked
to teen hearing loss
Secondhand (SHS) smoke has received a significant amount of attention for harming health. Now a study shows adolescents exposed to SHS are at increased risk for hearing loss, in addition to other health issues that include respiratory ailments, behavior problems and low birth weight. 

The finding, published in the July issue of Archives of Otolaryngology–Head and Neck Surgery, one of the JAMA/Archives journals, cites statistics that 60 percent of children are exposed to secondhand smoke in the United States.

How second hand smoke leads to hearing loss in youth

The link is seen from recurrent ear infections, or otitis media. The chance of ear damage and sensorineural hearing loss (SNHL) increased with higher levels of exposure to secondhand smoke in adolescents studied.

The authors says hearing loss may occur from "suppression or modulation of the immune system" or from "impairment of the respiratory mucociliary apparatus" that would normally act as a defense against bacteria and infection. Without defenses, bacteria can more easily adhere to structures in the ear. 

The study

The finding was extracted from data that was part of the National Health and Nutrition Examination Survey from 2005 to 2006. Researcher Anil K. Lalwani, M.D., and colleagues from NYU Langone Medical Center in New York City examined hearing loss risk factors among 1,533 individuals from 12 years to 19 years of age who were part of the study.

The study showed teens exposed to secondhand smoke were more likely to experience hearing loss affecting low and high frequencies.

Levels of cotinine, a byproduct of nicotine, correlated with higher rates of hearing loss and were measured in the bloodstream.

The study authors concluded:

"Adolescents who are exposed to SHS may need to be more closely monitored for hearing loss. In addition, they should be educated about risk factors for hearing loss, such as recreational or occupational noise exposure and SHS."

The authors note the finding that secondhand smoke leads to more ear infections and hearing loss in adolescents has public health implications. Loss of hearing can have a negative impact on normal childhood growth and development.

The study is believed to be the first to link hearing loss in adolescents to secondhand smoke exposure in the U.S.  If further studies support the finding, the authors say exposure to secondhand smoke might be considered a risk factor that would prompt screening for hearing loss in teens.

Arch Otolaryngol Head Neck Surg. 2011;137:655-662.