Like many businesses, mining is an industry that involves the management of hazards and risks. While heavy and moving equipment is the obvious hazard that springs to mind when considering the large number of people on sites, the hazards of dust and noise are the two biggest health hazards that all miners face.
Prolonged exposure to unacceptably high levels of dust and noise can result in disabling, life changing conditions. To protect people’s health we need to make absolutely sure we have the right controls in place, including engineering and administrative controls, and that, if necessary, each individual is using the appropriate personal protective equipment (PPE) in the proper manner to bring exposure below the Occupational Exposure Limit (OEL).
Although there are many similarities in the way we manage health as opposed to safety, there is one very important difference. The impact of a safety failure is immediate, and serious injuries are graphic. Health impacts, on the other hand, are long term and less obvious, but the consequences can be just as disabling.
The effects of long term exposure to dust and noise do not show in people for many years afterwards. That time lag creates a very different reaction even if the ultimate impact is just as great – because there is no single, dramatic consequence, some people don’t believe it is something that they need to worry about now.
Damage that occurs now might not be apparent for 30 years, but we cannot wait for this to happen before we take action. Operating safely, sustainably and responsibly should be an integral part of your strategy as a business. All occupational illnesses are preventable, and two recently issued industry-leading standards reiterate the requirements that every site must implement in order to achieve this goal in respect of noise induced hearing loss, and occupational lung disease. As with safety, it is essential that senior managers take ownership of dust and noise as business risks. In the past, some might have taken the view that it was doctors who would sort out problems such as these. But the prevention of occupational disease is not a medical issue. It is essentially an engineering problem. Only the management of disease is a medical issue.
It is recognised that managing occupational health well is a key part of the way a good business operates. It’s a continuous process of improvement.
Legal requirements only take you so far. Most businesses need to go beyond legal compliance and health standards based on the contemporary science of human health.
The possible consequences of not managing health risks properly are:
• Long term disability and possible loss of life
• Loss of productivity
• Costly legal action
• Increased compensation costs
• Damage to brand reputation
• Risks to licence to operate
At work, people should not be exposed to noise levels above 85 dB(A). The noisy nature of mining means that individuals have the potential to be exposed to noise levels above that every day.
Noise is measured in decibels or dB(A) – and the decibel scale is deceptive: 88 decibels is not just a little louder than 85 decibels. Each three decibel increase in noise doubles the damage that it can do to hearing. So, 91 dB(A) is four times more damaging than 85 dB(A).
Looked at another way, for each three decibel increase in noise levels, allowable exposure time halves. Someone can work at 85 dB(A) for eight hours, but that person not wearing hearing protection should only work for four hours at 88 dB(A), or two hours at 91 dB(A). Some activities in mining have noise levels of 125 dB(A).
What is the effect of long term exposure to excessive noise? Ultimately deafness is possible, with all of the communication problems that can involve. It is constant background noise that does the damage. Your body adapts – like getting into a hot bath where the water burns to begin with, but you quickly get used to it.
The good news is that the damage stops as soon as the exposure ceases, but the bad news is that damage already done is not easily treated. This can include the extremely debilitating condition called tinnitus, which is a high pitched ringing noise in your head that never goes away.
The effects are not only physical. Impaired hearing can prevent a miner going underground as it is simply not safe if you can’t hear warnings or signals. Hearing damage can cost people their jobs.
Wherever possible noise should be eliminated at source. The first resort should be to engineer the noise out of the workplace. Invest in quieter equipment and create physical barriers that separate the worker from the noise. The second resort should be administrative controls. Workers’ exposure to noise should be minimised by, for example, rotating the work that they do. Providing personal protection against noise is an alternative to manage health risks. When it is not feasible to control the risks by engineering methods, personal protective equipment either on its own or in combination with other controls may be used to minimise personal exposure.
Mining is dusty, and while all respiratory hazards are potentially dangerous, some are more dangerous than others. It is those that you cannot see at all that are the most dangerous.
We use the term ‘dust’ to cover a wide range of respiratory hazards that you breathe in. These include silica and rock dust, and also heavy metal fumes, radioactive materials such as radon, asbestos fibres, volatile organic compounds and particulates from diesel exhausts, solvents, sprays and chemicals.
In order to protect employees effectively, the starting point is knowing the composition of the dust at each site and the risks it represents. The most dangerous dust is invisible, and in order to find this hazard you have to look for it, using the proper equipment to measure it and the appropriate staff to interpret the findings.
A new respiratory protection standard implemented by one company requires each site to measure and monitor dust effectively. This means measuring in the right place at the right time, using the right skills and equipment and following the right processes.
Once you know what the problem is and its extent, then, as with noise, a hierarchy of controls needs to be put in place. This starts with introducing engineering controls, such as using water sprays to suppress dust, and local extraction ventilation to remove it. PPE is also important to reduce exposures.
One sustainable development commitment it’s possible for any operation to make it to is Zero Harm. This can be described as creating and instilling a company and industry culture that protects people from harm and improves their health and wellbeing.
Three principles support the achievement of this commitment:
• Zero mindset – that is, a belief that all injuries and occupational illnesses are preventable
• No repeats – that is that all necessary steps are taken to learn from incidents in order to prevent recurrence
• Ensure standards and rules are consistently applied throughout the company
Mandatory health standards that cover hearing conservation and respiratory protection should be adopted and aimed at helping you continually improve how you manage health risks across the company. These two standards require managers to understand the health hazards associated with dust and noise, and to emphasise that normal senses are not enough to assess what is happening.
The most dangerous dusts and respiratory hazards are invisible and high noise levels are hard to judge without proper measuring equipment. Physical measuring and monitoring are therefore of key importance.
The standards require managers to:
• Identify hazards
• Assess risks
• Put effective controls in place according to the hierarchy of controls
• Educate employees about the risks and the right PPE to use for each hazard and work environment
• Monitor feedback and adapt processes where necessary
Managers should be expected to make sufficient resources available and to engineer in controls as far as is reasonably possible, and to manage any residual risk in such a way as to protect the employee from harm.
Health risk management processes must also be fully embedded into every site. This means that education and training are essential so that workers understand why changes are being made.
Performance against these standards should be monitored through an ongoing self assessment process and audits to identify areas of strong performance and opportunities to improve, where additional support or focus might be required.
Isibonelo damps down dozer noise
To address issues such as dust and noise, you need management to provide commitment, engineering and resources. You also need employees to contribute to their own protection. This could involve them saying ‘No, I will not work in these conditions because I think they are dangerous’, but it could also mean closing doors in cabs or cabins, or reporting failures in ventilation systems.
This case study shows what is possible if a worker recognises the problem, and management provides the support to fix it. It also illustrates that substantial improvements in noise levels can be achieved with affordable investments, reinstating controls that had been allowed to deteriorate.
Dozer operators at Isibonelo Colliery, in South Africa, reported increasing noise levels in the cab of one of their machines, so the mine’s ventilation and occupational hygiene engineering officer, Mashile Moema, carried out a detailed survey which showed undesirably high levels of noise.
As the machine was not due to be replaced in the near future, Isibonelo’s engineering department provided solutions that – with relatively little effort – significantly reduced noise levels.
After years of wear and tear, the cab was bare of noise suppressing materials and flooring plates were not properly bolted down. The cab was therefore given a floor to ceiling makeover. All plates were securely bolted, floor and roof matting was installed and rubber seals on the doors and windows were replaced with new components.
As noise suppression is dependent on cabs being fully enclosed, even in the hottest weather, Isibonelo also equipped all of its surface mobile equipment with air conditioners to ensure that cabs remained cool and dust free during the summer months.
To protect employees’ health, the appropriate controls needed to be in place to prevent and minimise exposure. It’s also important to ensure that the controls are maintained and constantly monitored, or retrofitted as technology becomes available.
Encouraging employees to look for opportunities to improve their workplace conditions also contributed to increased efficiency of the controls, continuously improving the way Isibonelo managed dust and noise and the associated risks.
Published: 12th Mar 2013 in Health and Safety Middle East