According to EU figures, about 40% of the population in the EU countries is exposed to road traffic noise at levels exceeding 55 dB(A), and 20% is exposed to levels exceeding 65 dB(A) during daytime. More than 30% is exposed to levels exceeding 55 dB(A) during night-time. Excessive exposure to noise has a significant negative impact on human health.
Noise, as described in the Oxford English Dictionary, is undesired, unpleasant and loud.
Noise in the workplace can be dangerous and lead to devastating consequences. Often workers experience sleep issues due to high noise levels for a long period of time. Apart from causing hearing problems, noise can affect your performance at work including lack of attention and concentration in terms of reading or producing content. In addition, noise can be the cause of accidents due to interference in communication, misunderstanding of oral instructions and coverage of sounds of eminent danger.
Noise levels still regularly exceed limit values in many sectors, such as agriculture, construction, engineering, foods and drinks industry, woodworking, foundries or entertainment. In 2000, 29% of workers in the EU report being exposed to high-level noise at least one quarter of the time and 11% all the time.
According to European and national sources you are at a higher risk if you have a full time, non-permanent contract or are a younger worker, as you are more likely to be affected by loud noises. They suggest that these two groups of people receive less information regarding health and safety issues, less training and less formal supervision and control in the workplace. This should not be happening within your workplace and employers should be encouraged to ensure everyone has the same information, training and supervision.
Sound is a form of energy. This energy is transmitted through the air as pressure waves. The ear then detects these pressure waves and they are perceived as a sound, or noise. When sound waves enter the outer ear, the vibrations impact the ear drum and are transmitted to the middle and inner ears. The middle ear has three small bones inside and they amplify and transmit the vibrations generated by the sound to the inner ear. The inner ear contains a snail like structure called the cochlea, which is filled with fluid and lined with tiny hairs. These hairs are microscopic and move with the vibrations, and convert the sound waves into nerve impulses. The result is that the sound is heard. Constant exposure to loud noise can destroy these hair cells, which will then cause hearing loss. The hair cells will not grow back and hearing will not be restored, leaving permanent hearing loss.
A decibel is a logarithmic measure of the ratio between numbers and is measured on a logarithmic scale, which means that small changes in the number of decibels results in a huge change in the amount of noise, and the potential damage to a person’s hearing.
The loudness of the noise is measured in units of sound pressure levels. These are known as decibels and are abbreviated to dB. A-weighting is a measurement scale that approximates the “loudness” of tones, and is normally used to evaluate environmental noise. This is measured as dB (A).
Noise can cause a number of negative health effects including:
- Temporary hearing loss from short-term exposure to high noise levels, with normal hearing returning after a period of rest
- Permanent hearing loss after prolonged exposure to high noise levels
- Tinnitus — a ringing or buzzing in the ears or head
- Increased blood pressure and stress
- Inability to sleep, fatigue and other sleep problems
- a sense of isolation and interference with general workplace communications
- Inability to hear warnings of imminent safety hazards due to excessive noise.
Noise sources, their Db level and health effects are presented below:
The technical angles
There are many terms within health and safety, such as directives, regulations, legislations, codes of practice and standards. A directive is binding in its entirety and obliges member states to transpose it into national law within set deadlines. A directive enters into force once it is published in the official journal of the EU.
The directive that has been set for noise at work in Europe is the 1986 EEC Directive of Occupational Noise Exposure. This exists to provide protection to all workers from harm caused by exposure to noise. It was originally the 1986 EE Directive, which was altered in 2002 as it was decided by the European Union that a new directive would be released covering the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents like vibration. According to the new PPE Regulation (EU) 2016/425,noise has moved to category III – Very serious consequences, exclusive list, in terms of personal protective equipment requirements.
There are many health problems that can develop due to noise at work. Acoustic trauma or acoustic shock is caused by short bursts of extremely loud noises.
Tinnitus is caused by exposure to excessive noise, which can be caused by using machinery including chain saws, or even from music at a concert if you are working in the entertainment sector. This condition is a constant ringing and buzzing in your ears and occurs when the hairs within the ears are destroyed due to loud noise over long periods of time. Once the hairs within the ears are destroyed they will not be repaired, causing a lifetime of unpleasant constant noises in the ears.
Temporary hearing loss is known as a temporary threshold shift, which may occur immediately after exposure to a high level of noise. This could be recovered after spending time in a quiet place. Over time, this will result in permanent hearing damage.
There is also evidence of several non-auditory health effects associated with medium levels of noise. This includes voice problems, stress, cardiovascular diseases and neurological issues. Noise below the levels usually associated with hearing damage can cause regular and predictable changes in the body. Even ‘ear safe’ sound levels can lead to these health effects if they chronically interfere with recreational activities such as sleep and relaxation; if they disturb communication and speech intelligibility; or if they interfere with mental tasks that require a high degree of attention and concentration.
Due to the high risk nature of noise, employers are required to control risks at the source of noise and eliminate or reduce them. Personal hearing protection is not to be used as the only source of protection – prevention control measures must be in place to control or reduce the risk of noise. The use of controls within the workplace should aim to reduce the hazardous exposures, so the risk to loss of hearing is eliminated or reduced. Administration controls and training can alter the way work is done including the timing of work, policies and other rules.
All hearing protection should come with a SNR, or single number rating. This number provides the simple estimate of protection and it will give the wearer an approximate protection of 38dB. Protection will only be provided if the PPE is working correctly, so provide training to employees on how and when to wear protection to ensure it is effective.
Hearing protection may be used for people who are already suffering with hearing damage but is not the only source of protection against noise. Procedures could also be implemented within the workplace to reduce or illuminate the hazards, including health surveillance and regular noise assessments. Noise at work remains a significant hazard at work and it should be addressed by employers as such in order to ensure all necessary measures are carried out within their business.