Photo credit: fauxels
by Daniel Fink, MD, Chair, The Quiet Coalition
I spoke to HealthWatch USA on Oct. 16 about the National Institute of Occupational Safety and Health’s recommended exposure limit (REL), specifically that it needs to be revised down. Kevin Kavanaugh, the founder and board chair of HealthWatch, was kind enough to record and edit my presentation, which is available on YouTube.
My talk was based on a presentation at the Acoustical Society of America meeting in Nashville, Tennessee in December 2022, and a paper published in Proceedings of Meetings on Acoustics. In both the paper and the presentation, I point out that NIOSH’s 85 dBA* recommended exposure limit for occupational noise assumed workers experienced quiet when not at work, something that is no longer true. Additionally, noise exposure used to begin when an employee started working in a noisy occupation, but noise exposure now starts early in childhood and continues through adolescence, with ubiquitous use of personal listening devices for many hours every day.
More sensitive measures of auditory damage would find evidence of it much earlier in life, at a much higher prevalence. A true definition of normal hearing, a zero decibel hearing threshold level, would show much more auditory damage earlier. And, a comparison population to establish normal hearing, one not exposed to noise in everyday life, would show a greater difference between people with normal hearing and workers with hearing loss.
As those who follow our posts know, I generally avoid discussion of occupational noise issues. Why? Workers have the NIOSH recommended exposure limits and Occupational Safety and Health Administration’s permissible exposure limit to protect them, and the workers compensation system to pay for hearing health care if they develop occupational noise-induced hearing loss. The public has no such protections. The NIOSH standard is often wrongly cited as safe for the public. If that is lowered, I would hope that noise exposure recommendations for the public would also be lowered. To be specific, the NIOSH limit allows an 8% excess risk of hearing loss, a risk far too great for the public. The only evidence-based safe noise exposure level is a time-weighted average of 70 dB for 24 hours.
I’ve already thanked Kevin for the excellent job he did editing my presentation. I know this is a biased recommendation, but if you have a spare half an hour, please watch the video.
*A-weighting (expressed as dBA) adjusts unweighted sound measurements (measured in decibels, dB) to approximate the frequencies heard in human speech. The inability to understand speech is the compensable occupational injury, hence the use of A-weighting in occupational noise measurements and regulations.
