Assessment of the proposed draft American national standard method for evaluating the effectiveness of hearing conservation programs.
Adera-T; Donahue-AM; Malit-BD; Gaydos-JC
J Occup Med 1993 Jun; 35(6):568-573
The validity of the Draft American National Standard (DANS) method was examined for its capability to evaluate hearing conservation programs. A standard epidemiological method was used for comparison. The study subjects were drawn from 2317 utility company employees who were enrolled in the Hearing Conservation Program (HCP) from 1979 through 1989. The criterion for entry to the HCP was exposure to a noise level of over 85 decibels-A (dBA) as an 8 hour time weighted average (TWA). The reference population included 105 tobacco company employees who had TWA noise exposures of about 87dBA, reportedly wore personal protective devices consistently, and were followed from 1972 through 1984. The DANS method rated the HCP of the study population as acceptable (the choices being acceptable, marginal, or unacceptable) while the results of the epidemiologic method of evaluation found a 130% increased risk of hearing loss. The DANS method appeared to systematically exclude workers at high risk of hearing loss from the analyses, which could result in an underestimation of the adverse effect of industrial noise exposure on hearing loss, giving a spurious impression of program effectiveness. The findings question the applicability of the proposed DANS method for evaluating HCPs designed to protect all workers from industrial noise induced hearing loss.
JOCMA7; NIOSH-Author; Occupational-health-programs; Industrial-health-programs; Industrial-safety-programs; Noise-exposure; Hearing-impairment; Hearing-disorders; Hearing-acuity
Journal of Occupational Medicine