Exposure to noise at work can be potentially hazardous. Dr Muiris Houston reports.
It is estimated that between 1 and 4 per cent of the working population of industrialised countries is exposed to potentially hazardous noise levels. Many modern industries by their very nature are noisy environments.
As a general rule, if it is difficult to carry out a normal conversation at a distance of two metres, the noise level may well be 85 decibels or higher and should be investigated in case it poses a danger to your health.
Noise levels can be measured by special apparatus designed to measure its loudness in decibels.
Any sample measurement must be representative of daily personal exposure. It is widely accepted that noise exposure above 90 decibels can lead to hearing loss over time.
It is therefore advisable that to prevent noise-induced hearing loss, workers should be protected if they are exposed to noise levels above 80 decibels. This level is set to become a legal threshold when a 2003 European directive is implemented in 2005.
Current legislation requires workers in environments where noise levels are above 85 decibels to be provided with ear protectors and that they should have access to hearing checks. The legislation also sets an absolute ceiling limit for short-term unprotected exposure.
There are a number of ways in which noise can be controlled. These include a review of machines in use and developing noise-reduction features to reduce vibration and noise.
The emphasis must be on the conservation of workers' hearing and the first step should always be to reduce exposure to noise by the application of engineering and acoustic noise control techniques.
The acoustic treatment of walls may also help reduce noise exposure in the workplace as will the provision of acoustic enclosures of noisy machinery.
The 1990 Noise Regulations compel employers to carry out an assessment to establish the level of noise to which their workers are exposed. If the level of noise is greater than 85 decibels, then suitable and adequate ear protection must be provided. Adequate protection means that the type of protection should be matched to the job and the worker. And, most importantly, the worker must wear it.
Where employees are exposed to noise levels above 85 decibels, an employer is required to preserve workers' hearing. The objective of a hearing conservation programme is to establish a baseline of a worker's hearing, to identify individuals who may have a sensitivity to noise, to detect any deterioration in a worker's hearing and to identify those who require referral to a specialist for treatment.