Children who are exposed to secondhand smoke have a higher risk of suffering from low- and high-frequency hearing loss during their teens, researchers from NYU Langone Medical Center in New York City reported in Archives of Otolaryngology-Head and Neck Surgery. The authors added that they found that over 80% of the adolescents who had hearing loss were unaware of it.

As background information to the article, the researchers explained that about 60% of children in the USA are exposed to some kind of secondhand smoke. Secondhand smoke (SHS) exposure raises the risk of being born with a low birth weight (if the pregnant mother smoked), as well as ear and respiratory infections, and behavioral problems.

The scientists added:

"Secondhand smoke may also have the potential to have an impact on auditory development, leading to sensorineural hearing loss (SNHL)."

Dr. Anil K. Lalwani, M.D. and team set out to determine what risk factors might be linked to sensorineural hearing loss, including second hand smoke exposure, among teenagers. They gathered details on 1,533 adolescents aged from 12 to 19 years who had taken part in the National Health and Nurtition Examination Survey, 2005-2006.

They were all interviewed regarding their exposure to SHS, whether they had a hearing impairment, health status, and family medical history. They also had a medical checkup which included a hearing test as well as a blood test for cotinine (a nicotine-exposure by-product).

They found that that the adolescents who had been exposed to SHS had higher rates of high- and low-frequency hearing loss. Degrees of hearing loss correlated closely with their levels of blood cotinine. Four-fifths of those who had some hearing loss did not know.

An individual who suffers hearing loss early in life risks having problems with functioning and development, the researchers warned. They added that their findings have "significant implications for public health in the United States."

Unless there are known risk factors, the majority of adolescents in the USA are not screened for hearing loss.

If further studies can confirm the findings of this one, perhaps SHS should be considered as a hearing loss risk factor, the scientists suggested.

The authors concluded:

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

"Secondhand Smoke and Sensorineural Hearing Loss in Adolescents"
Anil K. Lalwani, MD; Ying-Hua Liu, MD, PhD; Michael Weitzman, MD
Arch Otolaryngol Head Neck Surg. 2011;137(7):655-662. doi:10.1001/archoto.2011.109