Do hearing threshold levels in workers of the furniture industry reflect their exposure to noise?

摘要

Background: The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposureto noise and the presence of additional risk factors of noise-induced hearing loss (NIHL). Material and Methods: Noisemeasurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers,aged 20–57 years, directly employed in the manufacture of furniture. The actual workers’ hearing threshold levels (HTLs)were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. Results: Workers under study were exposed to noise at daily noise exposure levels of 82.7–94.8 dB (mean: 90.9 dB) for a periodof 3–14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, highfrequency notches were found in 11% of audiograms. The actual workers’ HTLs at 3000–6000 Hz were similar to those predictedusing PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher( 78 mm Hg) and lower (≤ 78 mm Hg) diastolic blood pressure, smokers and non-smokers, and those working with organic solvents.Hearing loss was more evident in subjects affected by the additional risk factors specified above. Conclusions: The resultsconfirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated bloodpressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programsfor workers. Med Pr 2016;67(3):337–351