Effects of tobacco smoke exposure during childhood


© Gabriella Fabbri- Sxc

Tobacco control policies have gradually been implemented in many countries worldwide and may include package warnings, smoke-free public areas, and taxation. Smoking in the home is however outside the scope of government intervention, and can be associated with significant environmental exposure to tobacco smoke.

A large number of health hazards related to passive smoking in childhood have been documented. A team of researchers from the Santa Casa Hospital and School of Medical Sciences in São Paulo, Brazil, recently published results of a study aimed at evaluating the effect of smoke exposure during childhood on cochlear physiology, through measurement of transient evoked otoacoustic emissions (TEOAE) response levels. Otoacoustic emissions (OAE) were used as an early detection marker for cochlear auditory dysfunction.

The team studied data from 145 children with normal hearing aged 8 to 10 years, divided into two groups: a control group of 85 children not exposed to tobacco smoke, and a smoke exposure group of 60 children. Levels of cotinine, the main urinary metabolite of nicotine, were used to allocate subjects to one of the two groups.

TEOAE levels were measured in dB and registered for the right and left ears. Assessment of TEOAE on both ears in tobacco-exposure subjects showed lower response levels and signal-noise response levels when compared to the control group. A mean loss of 2.1 dB SPL in smoke-exposed children was found and, according to the authors, these results have major implications for damage to the cochlear structures, and indicate possible hearing loss and impaired development of hearing abilities.

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Source: Durante AS, et al. Tobacco Smoke Exposure during Childhood: Effect on Cochlear Physiology. International journal of environmental research and public health. 2013 Oct 24; 10(11):5257-65.