Combined effect of environmental factors on hearing loss of young people

Living in big cities exposes the population to upper noise levels than just a few years ago. The acoustic environment of daily life and social activities may not be considered as significantly ototoxic, according to phonometric investigations carried out in Italian urban centers. Little information is available about chronic effects on hearing of others factors as Whole body vibration (WBV), ototoxic substances (solvents, carbon monoxide, hydrogen cyanide), smoke habit. Occupational deafness may be caused or aggravated by the additive effects of several environmental factors, especially vibration. It is hypothesized that WBV impairs cochlear function. Researchers discuss on the ability of some chemicals present in both occupational settings and ambient environments to potentiate noise induced hearing loss. Some data indicate that toxic solvents in car paints act in synergism with moderate noise exposure, damaging the cochlear hair cells. Other studies underline an additive interaction at high frequencies (mostly at 8000 Hz) between smoking and noise. Regarding the occupational exposure to noise, we underline that TLVs couldn't protect all workers from the harmful effects of noise because of individual susceptibility; so TLVs cannot be considered as an absolute cut-off between safety and danger levels. This issue is even more complex in apprentices and youngest workers; in addition, there are no reference values for these kinds of population in Italy. The aims of our research are: identification of reference levels for auditory function in the youth ages, evaluation in a large population of young apprentices the incidence of early changes in the auditory function considering the additive effects of several environmental factors (vibration, chemical exposure, smoke habit) In this study were included more than 300 subjects. In detail, we observed a significant influence of age, level of education, smoke habit, moped use.