What is noise?
Noise is unwanted sound. Its intensity is measured in decibels (dB). The decibel scale is logarithmic, which means that a 3-decibel increase in sound represents a doubling of noise intensity. For example, a normal conversation takes place at approximately 65 dB, while a person shouting can reach 80 dB. Although the difference is only 15 dB, a shout is thirty times noisier. Intensity is not the only thing that determines the risks posed by noise, exposure time is also very important. To take this factor into account, average sound levels over time are used. Noise in the workplace is generally based on an eight-hour working day.
What possible problems are caused by noise?
Noise does not need to be intense for it to be harmful in the workplace. It can significantly contribute to increasing other risks already present, for instance:
– Noise can increase the risk of accidents owing to the inability to hear warning signals.
– Noise can cause exposure to certain chemical products by progressively increasing the risk of hearing loss.
–- Noise can cause work-related stress.
Exposure to excessive noise can cause a number of risks to workers’ health and safety. Hearing loss: excessive noise damages the cells in the inner ear and leads to hearing impairment. “In many countries, hearing loss caused by noise is the most relevant occupational disease.” It is estimated that the total number of people affected by hearing loss in Europe is greater than the population of France. Physiological effects: It has been proven that exposure to noise has a detrimental effect on the cardiovascular system. Work-related stress: work-related stress rarely has a single cause, and is generally the result of a number of different interacting risk factors. Noise in the workplace can be a source of stress, even at relatively low levels. Increased risk of injury: high levels of noise make verbal communication difficult and increase the likelihood of injury. Work-related stress (of which noise may be a factor) can aggravate this problem.
Who is at risk?
Any person exposed to noise is potentially at risk. Greater intensity of noise and prolonged exposure increase the risk of noise-related injury. In the manufacturing and mining industries, 40% of workers are exposed to significant noise levels for more than half of their working day. This proportion can reach 35% in the construction industry, while in other sectors, such as agriculture, transport and communications, it is about 20%. Noise is not a problem restricted to the manufacturing and other traditional industries. It is acknowledged to be a problem in the service sector, for example in education, health and food service.
– A study on noise in child day care centres found average noise levels higher than 85 dB.
– Drivers of articulated vehicles can be subjected to levels of 89 dB.
– Night club staff can be exposed to 100 dB.
– Noise on pig farms can reach 115 dB.
How can noise be reduced?
Business owners are legally responsible for protecting the health and safety of all their employees from any noise-related risks in the workplace and are obligated to:
– Conduct risk assessment; this can involve measuring noise levels, but should take into account all possible risks derived from noise (such as hearing loss and the effect of hearing on accidents).
– Set up a noise measuring programme, based on the risk evaluation, in order to eliminate sources of noise wherever possible.
– Control noise at its source.
– Reduce employee exposure through reorganisation of jobs and the workplace, including signage and restricting access to areas where workers are more likely to be exposed to noise levels higher than 85 dB.
– As a final resort, provide employees with personal protection equipment.
– Provide employees with information, advice and training on the risks they are exposed to, noise abatement operational procedures and methods for using noise protection.