[Hearing loss in workers in the ceramics industry: a profile of the damage assessed by a longitudinal study].

Over the period 1980-1990, 2024 workers in ceramic plants in the Emilia-Romagna region, Italy were evaluated for exposure to noise and hearing loss. Data collected by the National Health Service Local of Occupational and Preventive Medicine Units were used. In a relatively young population (34.8 years mean age, 8.98 years s.d.) exposed for not too long to > 90 dBA noise levels (87.2 for less than 4 years) a statistically significant effect of exposure was found only on the audiometric frequency of 6 kHz (95% confidence interval for mean hearing loss for 1 year exposure to > 90 dBA: 0.05-0.72 dB). An initial isolated loss at the audiometric frequency of 6 kHz was found to be significantly associated with (was a prognostic indicator of) a subsequent impairment at 4 kHz.