Noise Health. 2014 Sep-Oct;16(72):270-8. doi: 10.4103/1463-1741.140503.
This study was conducted to evaluate noise exposures and the contributions of occupational and nonoccupational activities among three groups of Swedish workers (office workers, day care workers, and military flight technicians), and to evaluate risk factors for elevated hearing threshold levels. Forty-five subjects were recruited across the three groups. Each subject completed a risk factor questionnaire along with Békésy audiometry at frequencies between 125 and 8000 Hz. Subjects also wore a noise dosimeter continuously for 1 week, and documented their occupational and nonoccupational activities using a time-activity log. Subjects in all groups completed >7400 h of dosimetry, and had weekly exposures between 76 and 81 dBA. Day care workers had the highest daily exposures, and flight technicians had the highest weekly exposures. Most daily and weekly exposures exceeded the 70 dBA exposure limit recommended for prevention of any hearing loss. Subjects’ perceptions of their exposures generally agreed well with measured noise levels. Among office workers, exposures were predominately nonoccupational, while among flight technicians nonoccupational and occupational activities contributed roughly equally, and among day care workers occupational exposures were dominant. Extreme exposures and cumulative noise exposure were associated with an increased risk of hearing threshold levels >10 dB hearing level. Effective hearing loss prevention programs may be needed in occupations not historically considered to be at high risk of noise-induced hearing loss (e.g., day care workers). Prevention efforts need to address nonoccupational exposures as well as occupational exposures, as nonoccupational activities may present the dominant risk of noise-induced hearing loss for some workers.