2.8 Physical and psychological health hazards and risk control Flashcards
What does the ILO Code for Ambient Factors require with regards to exposure to noise?
The Code requires employers to:
• assess the risks to your employees from noise at work;
• take action to reduce the noise exposure that produces those risks;
• provide your employees with hearing protection if you cannot reduce the noise exposure enough by using other methods;
• make sure the legal limits on noise exposure are not exceeded;
• provide your employees with information, instruction and training; and
• carry out health surveillance where there is a risk to health.
What are the 2 main causes of damage to hearing?
- Long-term exposure: Regular but perhaps limited exposures to loud noise over a period of time creating a cumulative effect on hearing.
- Short-term exposure: A sudden traumatic exposure which causes damage where the effects are noticed immediately.
Define threshold shift, noise induced hearing loss and tinnitus.
Threshold shift
Sounds become muffled so that it is hard to tell similar-sounding words apart, or to pick out a voice in a crowd, and it is difficult to distinguish speech from background noise, indicating
that the level at which sounds can be clearly distinguished has reduced.
Noise-induced hearing loss
This occurs where the ear is unable to respond fully to sound within the speech range. The person does not necessarily lose the ability to hear sound, but is not able to distinguish the spoken word clearly even if it is presented with a raised voice.
Tinnitus
This is a subjective condition where ‘noises in the head’ or ‘ringing in the ear’ are the
descriptive symptoms. There are no observable external symptoms.
What are the main indicators that there is a noise problem in the workplace?
• Is the noise intrusive, like a busy street, a vacuum cleaner or a crowded restaurant for most of the working day?
• Do employees have to raise their voices to carry out a normal conversation when about two metres apart for at least part of the day?
• Do employees use noisy powered tools or machinery for more than half an hour each day?
• Is the work in a noisy industry, e.g. construction, demolition or road repair;
woodworking; plastics processing; engineering; textile manufacture; general fabrication; forging, pressing or stamping; paper or board making; canning or bottling; foundries?
• Are there noises due to impacts (such as hammering, drop forging, pneumatic impact
tools, etc.) or explosive sources such as cartridge operated tools or detonators, or guns?
What are the exposure limit and action values established in the EU relating to noise?
• The lower exposure action level: a daily or weekly personal exposure of 80dB(A) and a peak sound pressure of 135dB(C).
• The upper exposure action level: a daily or weekly personal exposure of 85dB(A) and a peak sound pressure of 137dB(C).
• The exposure limit level: a daily or weekly personal exposure of 87dB(A) and a peak
sound pressure of 140dB(C).
List some basic noise control measures.
- using quieter equipment; selection of equipment for one that produces less noise;
- reducing noise by technical means;
- replacing noisy components;
- maintaining equipment;
- isolating the workforce from the noisy activity using compartmentalisation;
- carrying out tasks at times when population of the area is low; and/or
- providing Personal Protective Equipment.
What are the main methods of noise control?
Enclosure
Surrounding the noisy equipment with noise insulating material.
Insulation
Imposing a barrier such as a brick wall between the noise source and the receivers will provide noise insulation.
Damping
Putting an elastic element, e.g. rubber mount, in the path of vibration can reduce the noise produced as it reduces the vibration transmitted by equipment to its surroundings
Lagging
The insulation of pipes and other fluid containers to reduce sound transmission.
Absorption
When noise passes through porous material, e.g. foam or wool, some of its energy is absorbed and less noise is returned to the environment.
Isolation of workers
The provision of sound-proofed workrooms or enclosures isolated from noisy environments.
Silencers
Normally fitted to engines which are exhausting gases to atmosphere. Silencers consist of absorbent material or baffles.
Personal hearing protection
Personal hearing protection should be used as a last resort
List some occupations with potential to noise exposure problems.
- Construction.
- Uniformed services.
- Entertainment.
- Manufacturing.
- Call centres.
What are the effects on the body in exposure to vibration?
Regular and frequent exposure to vibration is known to lead to permanent and debilitating health effects such as white finger, loss of sensation, pain, and numbness in the hand, arms, spine and joints. These effects are known as:
• Hand–arm vibration syndrome (HAVS).
• Whole body vibration (WBV).
What parts of the body can HAV cause damage to?
- Blood circulatory system (e.g. vibration white finger)
- Sensory nerves
- Muscles
- Bones
- Joints
What are the symptoms of HAV?
- tingling and numbness in the fingers;
- not being able to feel things properly;
- loss of strength in the hands; and/or
- fingers going white (blanching) and becoming red and painful on recovery
What is WBV caused by?
- poor design of controls, making it difficult for the driver to operate the machine / vehicle easily, twisting or stretching;
- incorrect adjustment by the driver of the seat, causing poor posture;
- sitting for long periods without being able to change position;
- poor driver posture; and/or
- repeated manual handling and lifting of loads by the driver.
What actions are employers required to take in terms of HAV and WBV?
• Assess the vibration risk to employees;
• Decide if likely exposure will exceed the daily exposure action value (EAV) and if so,
implement controls to reduce or eliminate risk so far as is reasonably practicable;
• Provide health surveillance to employees who are at risk;
• Decide if exposure will exceed the daily exposure limit value (ELV) and, if so, take
immediate action to reduce their exposure below the ELV; and
• Provide information and training to employees on health risks and the actions that are being taken to control those risks.
What measures can be taken to control risks from vibration?
- redesigning the job so that if possible vibration is eliminated;
- selection of the right equipment for the job and maintenance of it;
- scheduling work to avoid long periods of exposure and provide breaks;
- avoiding high levels and/or prolonged exposure for older employees, people with back problems, young people and pregnant women;
- provision of information and training to employees on health risks;
- PPE, especially clothing and gloves to keep hands warm; and
- health surveillance.
What health surveillance programme should be implemented where there are risks from vibration?
- implement a system for early reporting of back pain symptoms;
- review and analyse results to identify vulnerable individuals / groups;
- periodically complete a questionnaire checklist for employees at risk;
- refer those with problems to an occupational health service provider;
- consider the results to check if your risk controls are working; and
- make changes to the risk controls if necessary.