Does Second-Hand Smoke Cause Hearing Loss?

For a couple of decades now, health researchers have said exposure to second-hand smoke can raise the risk of cancer and heart disease. Now a new study says there is yet another risk – hearing loss.

“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 Anil Lalwani, MD, a professor at NYU School of Medicine, who led the research. “We need to evaluate how we deal with smoking in public places and at home, as well as how often and when we screen children for hearing loss.”

According to the American Cancer Society, living with a smoker raises the risk of dying from heart disease and lung cancer, and in children exposure to smoke exacerbates the severity of asthma attacks and causes more than 750,000 middle ear infections.

More than 1,500 teenagers aged 12 to 19 participated in the nationwide study. They were selected from the 2005-2006 National Health and Nutrition Examination Survey, which collects health information from children and adults around the United States. The teenagers were initially evaluated in their homes and then were given extensive hearing tests and blood tests for the chemical cotinine, a metabolite of nicotine, at a medical center.

Sensorineural hearing loss

The teens exposed to secondhand smoke were more likely to have “sensorineural” hearing loss, which is most often caused by problems with the cochlea, the snail-shaped hearing organ of the inner ear.

“It’s the type of hearing loss that usually tends to occur as one gets older, or among children born with congenital deafness,” said co-author Michael Weitzman, MD, professor of pediatrics and psychiatry at NYU School of Medicine.

The study found that teenagers exposed to smoke performed worse across every sound frequency tested, especially mid-to-high frequencies important for understanding speech. In addition, teenagers with higher cotinine levels, indicating greater exposure, were more likely to have one-sided–or unilateral–low-frequency hearing loss.

Overall, the researchers conclude that their findings indicate that “tobacco smoke is independently associated with an almost 2-fold increase in the risk of hearing loss among adolescents.”