Chemicals and Hearing Loss: A Connection

What to know

Top takeaway: Chemicals that can damage hearing are common in the workplace. Every industry and many occupations have the potential risk of exposure. Awareness, monitoring, and safe chemical handling can protect hearing.
By: Elizabeth A. Masterson, PhD, CPH and Amy Mobley, MEn
Worker spray painting a car part.

Summary

Chemical use is common in many occupations. Some chemicals are harmful to hearing, especially when loud noise is also a concern. NIOSH researchers studied how many workers are exposed to chemicals that damage hearing and identified the industries and occupations with the most risk.

Some chemicals can hurt your ears

Chemicals that can damage hearing are called ototoxic chemicals. Ototoxic chemicals can cause hearing loss and/or make the ear more vulnerable to loud noise. Exposure to both loud noise and chemicals can lead to much greater hearing loss than exposure to either alone.

Which chemicals are ototoxic?

Ototoxic chemical groups include, but are not limited to, solvents, heavy metals, nitriles, pharmaceuticals, and asphyxiants.

Examples include:

  • Cancer-fighting drugs
  • Engine exhaust and lead
  • Industrial cleaners and glues
  • Organic cyanides and tin compounds
  • Paints, lacquers, and thinners
  • Pesticides
  • Tobacco smoke

This is not a complete list - other chemicals are suspected of being ototoxic. More research could confirm additional chemicals that may harm hearing.

Millions exposed to ototoxic chemicals

NIOSH researchers found that about 22 million workers are exposed to ototoxic chemicals each year, which is about 13% of civilian workers. Every industry and many occupations have the potential risk of ototoxic chemical exposure.

Industries with the highest percentage of workers exposed to ototoxic chemicals are:

  • Mining (49%)
  • Combined Mining and Oil and Gas Extraction (OGE) (44%)
  • Construction (30%)
  • Agriculture, Forestry, Fishing and Hunting (AFFH) (29%)
  • Transportation (24%)
  • Manufacturing (24%)

Occupations with the highest percentage of workers exposed to ototoxic chemicals are:

  • Installation, Maintenance, and Repair (43%)
  • Farming, Fishing, and Forestry (39%)
  • Construction and Extraction (35%)
  • Production (30%)
  • Protective Service (26%)
  • Transportation and Material Moving (23%)

Work-related hearing loss is preventable

Once someone loses hearing, they cannot regain it, so prevention is critical.

First, notice when it's loud or when using a chemical that may be harmful.

Second, remove or decrease the exposure:

  1. Eliminate the noise or change the process that requires the use of an ototoxic chemical.
  2. If that is not possible, substitute a quieter piece of equipment or use a non-toxic chemical.
  3. Use engineering controls to block or enclose the noise source or increase ventilation.
  4. Ensure all tools and equipment are well-oiled and maintained.
  5. Adjust worker schedules to reduce the number of people exposed and how long they are exposed.
  6. Make sure all workers correctly and consistently wear personal protective equipment (PPE). PPE could include hearing protection, long sleeves, gloves, aprons, eye protection, and respirators.

Special attention for combined exposures

Each year, about 12 million workers are exposed to both loud noise and ototoxic chemicals, which is about 7% of workers. The combined exposures for these workers put them at greater risk for hearing loss. Employers are highly encouraged to carefully monitor these workers.

Author Information

Elizabeth A. Masterson, PhD, CPH, is a Co-Coordinator for the NIOSH Hearing Loss Prevention Cross-Sector Research Program and Research Epidemiologist in the NIOSH Division of Field Studies and Engineering.

Amy Mobley, MEn, is a Health Communication Specialist in the NIOSH Division of Field Studies and Engineering.

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Content Source:
National Institute for Occupational Safety and Health