Hearing status among Norwegian train drivers train conductors | ANMA – Associazione Nazionale del Medico Competente e d'Azienda

Occupational Medicine (Oxford Journals). Vol. 63, Iss. 8, December 2013

Hearing status among Norwegian train drivers and train conductors

A. Lie, M. Skogstad, T. S. Johnsen, B. Engdahl, K. Tambs

Riassunto

Background There is a general perception that train drivers and conductors may be at increased risk of developing noise-induced hearing loss.

Aims To study job-related hearing loss among train drivers and train conductors.

Methods Audiograms from train drivers and train conductors were obtained from the medical records of the occupational health service of the major Norwegian railway company. The results were compared with audiograms from an internal control group of railway workers and an external reference group of people not occupationally exposed to noise. The monaural hearing threshold level at 4kHz, the mean binaural value at 3, 4 and 6kHz and the prevalence of audiometric notches (≥25 dB at 4kHz) were used for comparison.

Results Audiograms were available for 1567 drivers, 1565 conductors, 4029 railway worker controls and 15 012 people not occupationally exposed to noise. No difference in hearing level or prevalence of audiometric notches was found between study groups after adjusting for age and gender.

Conclusions Norwegian train drivers and conductors have normal hearing threshold levels comparable with those in non-exposed groups.

Commento

I risultati del presente studio trasversale, svolto in Norvegia dai ricercatori del “National Institute of Occupational Health”, dell’“NSB Occupational Health Service” e del “National Institute of Public Health”, dimostrano che le audiometrie effettuate su personale ferroviario, con mansione di macchinista o conducente, sono sovrapponibili a quelle di un gruppo di controllo non esposto a rumore e rappresentativo della popolazione generale.

I risultati, ovviamente relativi alla condizioni lavorative presenti in Norvegia, sono in accordo con quanto rilevato alle indagini fonometriche effettuate nella medesima azienda, che mostravano livelli medi di esposizione di 70-80 dB(A) per i macchinisti e di 70-85 dB(A) per i conducenti, confermando l’assunto che livelli medi di esposizione giornaliera al rumore inferiori a 85 dB(A) non dovrebbero causare ipoacusie.

Keywords

noise-induced hearing loss, train conductors., train drivers

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