Teenagers could suffer hearing loss because of passive smoking, according to new research.
Inhaling other people’s tobacco smoke almost doubled the risk of impaired hearing among adolescents, it was claimed.
The levels of damage were mild but could be enough to stop them hearing properly in class and leave them branded ‘troublemakers’.
‘It’s the type of hearing loss that usually tends to occur as one gets older, or among children born with congenital deafness,’ said researcher Prof Michael Weitzman, from the New York University School of Medicine.
The loss of hearing may be explained by toxic tobacco chemicals damaging the ear’s delicate blood supply, the scientists believe. Even mild hearing loss could have ‘subtle yet serious’ consequences, said Prof Weitzman.
More than 1,500 youngsters aged 12 to 19 were studied for the research. Participants were seen at their homes and given extensive hearing tests.
Their blood was also analysed for traces of cotinine, a chemical produced from nicotine in the body. They were then assessed for their ability to hear different frequencies of sound.
In every test, those exposed to smoke performed worse than those living in non-smoking environments. They were especially impaired in the mid-to-high frequency range important for understanding speech.
Overall, the researchers concluded passive smoking was ‘independently associated with an almost two-fold increase in the risk of hearing loss’. More than 80 per cent of the affected teenagers were not aware of any problem, said the scientists.