ACOEM updates distinguishing features of occupational hearing loss
Although it is irreversible, early detection can prevent the condition, according to the American College of Occupational and Environmental Medicine.
Workers with noise induced hearing loss may experience "significant morbidity," according to ACOEM, thus driving up workers' comp costs. Hearing loss can also impact worker communications and safety -- of themselves and their coworkers.
The ACOEM Task Force on Occupational Hearing Loss has revised its 2003 guidance statement based on the latest scientific knowledge. It outlines the role occupational and environmental medicine physicians can play to protect workers from unnecessary hearing loss.
Hearing loss is associated with depression, social isolation, and increased risk of accidents. "Workers with evidence of hearing loss require an individualized evaluation that takes into account both the need to communicate safely and effectively and the need for protection from additional damage due to noise," the statement says.
While a sudden change in hearing may result from a single exposure to a sudden burst of sound, NIHL builds up over time. The following are among the additional principal characteristics of occupational NIHL identified in the guidance statement:
- It increases most rapidly during the first 10 to 15 years of noise exposure. The rate of hearing loss then decelerates as the hearing threshold increases. The authors say that contrasts with age-related hearing loss, which accelerates over time.
- The first sign is a notching of the audiogram at the high frequencies of 3000, 4000 or 6000 hertz with recovery at 8000 Hz.
- Previously noise-exposed ears are not more sensitive to future noise exposure.
- The risk is believed to be low at exposures below 85 decibels but increases significantly as exposures rise above this level.
- Continuous noise exposure throughout the workday and over years is more damaging than interrupted exposure to noise, which permits the ear to have a rest period.
Factors other than workplace noise may impact hearing and should be considered, the statement says. For example, exposure to various chemicals should be evaluated, along with recreational noise exposure, genetic disorders, infectious diseases, certain medications, head injuries, neurologic disorders, and other medical issues.
The statement suggests physicians take a medical history to help determine whether factors other than work-related noise is contributing to hearing loss. Additionally, all previous audiograms for each patient should be reviewed.
"Making a diagnoses of NIHL is an important step in preventing further hearing loss in the affected worker and for identifying the potential for NIHL in coworkers," the statement says. "The OEM physician must work with management and other safety and health professionals to evaluate the workplace for noise exposure, educate the workers regarding the risk of noise exposure -- occupational and nonoccupational -- and reduce the potential for noise exposure."
Read more at the WorkersComp Forum homepage.
January 19, 2012
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