Occupational exposure to noise and hearing thresholds among civilian aircraft maintenance workers

Abstract

High noise exposure is anticipated to be present in the aircraft maintenance operations in civil aviation sector. The objective of the present study is the assessment of noise exposure and hearing threshold of the aircraft maintenance workers in this sector. Noise levels were measured in the aircraft hangers and in the workshops at a main international airport in Saudi Arabia. Two hundred aircraft maintenance workers were subjected to pure tone audiometry. The average Leq,8h at most of the aircraft maintenance operations was considerably high and most of the workers (89.5%) were exposed to noise levels ≥85 dBA. Frequency analysis of sound pressure levels revealed that the contribution of the octave bands 1, 2 and 4 kHz to the overall noise level was high. The audiograms of the examined workers showed significant hearing impairment as compared to non-noise-exposed Saudi employees. Although the observed excessive noise levels can cause hearing loss, the effect among the studied aircraft maintenance workers was mild. This might be attributed to the usage of hearing protection devices, the intermittent nature of the workers' exposure to noise and job rotation. Statistical analysis revealed significant association of both age and usage of hearing protectors with hearing loss. The effect of exposure duration on hearing loss was also detected. Relevance to industryUnlike military aircraft maintenance workers, exposure of civilian workers to noise is not sufficiently addressed. The data presented in this study may be used to set appropriate measures for hearing protection among those workers.