Industrial Deafness: Is your job making you deaf?
An estimated 1 million Australian employees (almost 12% of the workforce) may be exposed to dangerous levels of noise at work, which over time can lead to hearing loss and impairment.
Occupational noise is also associated with tinnitus, cardiovascular disease, hypertension, depression, fatigue, decreased production output and performance, increased stress, increased absenteeism, and increased risk of workplace injuries and accidents.
Despite these alarming statistics and the fact that there is an entire workers’ compensation claim category dedicated to the issue, ‘industrial deafness’ or occupational noise-induced hearing loss (ONIHL) has low prominence as a workplace health and safety issue, even amongst those most at risk. There seems to be too many employers, managers, and workers who believe that noise control is too expensive, too difficult, or simply not worth worrying about.
• Exposure to loud noise is the most common preventable cause of hearing loss and impairment.
• Occupational noise accounts for about 10% of all adult-onset hearing loss.
• The effects of age and noise exposure are additive so that excessive noise exposure may cause hearing loss in middle age that would not otherwise occur until old age.
• Hearing loss is more prevalent in men than women due to the higher exposure of males to workplace noise (although the gap reduces as people get older).
• 46% of workers provided with personal hearing protection devices (PHPs) do not wear them at least most of the time while working in loud noise and 31% never wear them.
• About 50% of workers provided with PHPs at least sometimes remove them while working in loud noise.
Who is most at risk of Occupational Noise-Induced Hearing Loss?
Damage to hearing can occur from exposure to very loud noise for a short time, or prolonged exposure to moderate noise levels. Risk of hearing impairment in the workplace may also occur through exposure to occupational ototoxins (including solvents, fuels, metals, fertilisers, herbicides and pharmaceuticals), with hearing loss being more likely if a person is exposed to a combination of substances and noise.
The sectors most affected by ONIHL are the manufacturing, construction, transport and storage industries, with the highest incidence rates in mining, construction, and electricity, gas and water supply.
The agricultural sector also reports high levels of hearing loss, particularly amongst farmers, as does the entertainment/nightlife industry and the military.
Here is a closer look at 4 of the most at-risk industry sectors:
The loud machinery, compressed air, and reverberation of manufactured goods all combine to make hearing loss the most common occupational illness in the manufacturing industry. The majority of hearing loss occurs within the first 10-15 years of employment in manufacturing, and since noise related hearing loss is gradual, the damage isn’t noticed until it’s too late. Many companies do provide PHPs, but some workers choose not to wear them or only wear them sporadically.
The tools used in the construction industry tend to be well over the recommended limit of 85 decibels (dB), with equipment such as the hammer drill sometimes reaching levels as high as 115 dB. Due to the overall lack of hearing protection governance, the large number of contract employees, and the seasonal nature of employees, the construction industry in particular has had trouble putting any meaningful hearing conservation practices into place.
In the agricultural industry daily exposure to harmful noise starts at a young age, with the sounds of livestock, chainsaws, and other noisy equipment, the operation of noisy workshop equipment or firearms, and driving tractors and other vehicles that don’t have an enclosed cabin over a sustained period. While education programs have been conducted to improve hearing protection for farm workers, the 2009 Rural Noise Injury Program assessment found that only 1/3 of farmers reported adoption of higher order noise reduction strategies, such as upgrading to quieter equipment, and that farmers aged 35-44 years had significantly worse hearing in their left ears (i.e., the ear closest to the tractor engine when the farmer is turned around watching behind him).
Employees in the entertainment or nightlife sector including DJs, musicians, bartenders, and wait and security staff, are regularly exposed to noise far in excess of the recommended levels. Exposure to thumping bass and live music night after night ⎯ often at levels reaching over 100 dB ⎯ can wreak havoc on hearing, causing noise induced hearing loss and tinnitus. Further, most nightclubs regularly exceed the level at which employers are required to provide hearing protection for their employees and yet very rarely are PHPs provided or worn in this industry.
So how can employers lower the ONIHL risk in the workplace?
The preferred solution to excessive noise exposure is to completely eliminate the source of the loud noise. When this is not possible or practical, the legal requirement is to minimise exposure through a hierarchy of controls:
• Substitute the noise source with quieter machinery or processes
• Isolate the noise source from workers
• Apply engineering solutions (e.g. fit mufflers, redesign the noise source, install noise guards or enclosures/soundproof the workplace)
• Apply administrative solutions (e.g. schedule noisy work for when fewest workers are present, provide signs and quiet areas for breaks), and when none of the above are reasonably practicable
• Provide high grade PHPs that enhance sounds workers want/need to hear while blocking harmful decibels levels.
Hearing loss is permanent. Therefore, workers as well as operations, factory and OH&S managers must be proactive and take the necessary actions to limit the risk of workplace noise-induced hearing loss.