RESUMO
The aim of the study was to find out whether firefighters' professional exposure to the noise of sirens, motor water pumps and transportation by heavy vehicles causes biauricular hearing impairment. Furthermore, on the basis of the results the aim was to find out whether it is necessary to launch a hearing preservation program and additional health protection measures for this specific working population. The method of physical examination and audiometry was used. Thirty-four professional firefighters from Opatija and 30 workers of Rijeka Promet employed at the town parking lots underwent audiometry on a Sibelmed AC 50 device and then analyzed. The results of biauricular audiometry showed significant differences in hearing damage between the firefighters and Rijeka Promet employees at higher frequencies where hearing damage begins, i.e. at 4 kHz and 8 kHz (P < 0.05). The firefighters' maximal hearing loss of 30.58 +/- 24.66 dB for the right ear at 4 kHz and of 28.52 +/- 24.66 dB for the right ear at 8 kHz were higher than the hearing loss of the parking lot employees with maximal hearing loss of 17.00 +/- 13.10 dB at 4 kHz and of 16.33 +/- 13.89 dB at 8 kHz. The results of left ear audiometry were very close to those of right ear in both groups of subjects. The linear regression analysis yielded almost identical positive correlation between the time spent at the job and hearing damage, with correlation factor r = +.55 for the right and left ear at 4 kHz. The noise was measured at the Opatija Fire Station. Several measurements were performed: on the premises where firefighters are exposed to so-called communal noise, measurements at 2 m of the fire truck when sirens are sounded, noise measurements in driver's cab when sirens are sounded, and the noise made by motor water pump used in firefighting. Also, measurements were performed on the spot, i.e. at the working place of parking lot employees in the center of Rijeka where they stay most of the time, and on the street by the parking lot. It may be concluded that noise-induced hearing damage in firefighters is a major problem in this working population, their physical and mental condition being very good, which is to be expected of the groups of operatives on whom the lives of "ordinary" people often depend. Hearing damage is the only weak point of firefighters, although fairly mild to moderate at higher frequencies, so medical experts in cooperation with their chiefs should persuade them to wear hearing protection, which could be discomforting in firefighting operations. Firemen are employed mainly at a young age when their hearing is normal. A parallel may be drawn with the military. Professional soldiers who are physically perfectly fit, at periodical medical examinations are often assessed as "limited service" due to hearing damage, although their hearing was good when they started the career. Hearing in the young population is generally good, in Primorje-Gorski Kotar County the average hearing level is 10 dB at all routine frequencies on audiometry, so hearing damage is not among illnesses that might cause difficulties to young recruits. To conclude, to preserve good hearing in both young and experienced firefighters, the Hearing Preservation Program should be more strictly implemented in the Primorje-Gorski Kotar County.