Passive smoking linked to hearing loss in teens…

A number of stories have hit the news recently claiming teenagers exposed to second hand smoke are twice as likely to suffer a hearing loss.  It is thought that passive smoking affects the blood supply to an area of the inner ear called the cochlear, causing a conductive hearing loss.

This study was conducted by researchers from New York University where it assessed 1500 US teenagers and found that those exposed to second-hand smoke had hearing loss for low-frequency sounds.

What were the basic results?
The researchers found that second-hand smoke exposure was associated with an increased rate of sensorineural hearing loss (SNHL) in one ear. They found that 7.5% of adolescents who were not exposed to smoke had SNHL, whereas 11.8% of adolescents exposed to second-hand smoke had SNHL for low-frequency sounds in one of their ears (pAdolescents exposed to second-hand smoke had an 83% increased risk of SNHL for low-frequency sounds compared to adolescents who were not exposed (95% confidence interval 1.08 to 3.41). There was no difference in the proportion of exposed or non-exposed adolescents who had SNHL for high-frequency sounds. Higher levels of cotinine in the blood among adolescents exposed to second-hand smoke were associated with the prevalence of low-frequency SNHL.
The researchers found that 82% of adolescents with SNHL did not recognise that they had hearing difficulties.

In conclusion, though this study suggests an association between exposure to second-hand smoke and the risk of losing hearing of low-frequency sounds, further studies would be needed to confirm this finding and whether this is a causal effect or not. Smoking and second-hand smoke are associated with numerous health risks, and avoiding exposure to smoke as much as possible is advised.