The mining guidelines are clear when it comes to exposure standards for respirable hazards such as dust or silica, but limits for mould are a bit more complicated.
Mould is common in everyday life, found in leftovers at the back of the fridge, in the grout of a share-house shower, and even floating in the air we breathe. Just as mould can easily be found around the house, it can also be seen (or unseen) at mine sites across Australia.
Anywhere there is moisture, there is the potential for mould. Many types of mould are harmless, but there are also toxic species that make vigilance from mining companies especially important.
The Australian Institute for Occupational Hygienists (AIOH) is working to draw more attention to the challenges of mould on mine sites and what companies can do to limit exposure to workers. AIOH certified occupational hygienist Ash Boss-Handley said that because there are no official exposure limits for mould, it’s up to experts to determine the level of risk.
“We really rely on our professional judgement to determine acceptable levels based on a range of factors,” Boss-Handley told Safe to Work.
“Mould is everywhere, spores are invisible in the air, in soil and on surfaces, but if you can see mould growing indoors, that’s a pretty good indication there’s a problem.”
According to Boss-Handley, moisture and ventilation represent perhaps the two biggest factors that will affect the prevalence of mould in mines.
Mould growth in fly-in, fly-out (FIFO) camps can be common if there are leaks, ineffective ventilation or standing water around amenities.
Dust can also be a significant culprit, as mould binds to particles in the air which are then inhaled, making ventilation and dust suppression efforts crucial.
Exposure to mould can cause lung irritation, wheezing, coughing and shortness of breath, with a small number of mould species causing more serious issues.
A common type of mould is Aspergillus, a genus that covers about 200 different species. A small number of those species cause a disease called Aspergillosis, which occurs when the mould enters the lungs and causes significant health issues like a reduction in lung function.
“It’s cases like that where people can get quite frightened, because they might assume any spore of mould is going to cause these issues,” Boss-Handley said.
“But the reality is there’s a huge proportion of mould that is more or less benign and just kind of exist naturally in the air or in soil.
“Our objective is always to just eliminate excess mould as much as possible. If we know there is an issue where visible mould growth is identified, it’s important to get rid of that mould irrespective of whether we think it is a toxic variety.”
How can mining companies keep mould to a minimum?
The risk is well known, meaning most Australian miners have controls in place to reduce the likelihood of excessive growth. Workers will generally already be wearing personal protective equipment (PPE) like respirators that will serve to protect them from stray spores, and most mines will monitor their ventilation systems diligently to ensure fresh air is provided to work areas.
When it comes to removing mould, Boss-Handley emphasised it doesn’t need to be a complicated operation.
“If you see mould, remove it as soon as you can,” she said. “If you notice mould on something non-porous, simply wiping it away with a damp cloth may suffice, there’s no need to use harsh chemicals, which may compound respiratory issues.
“If there is visible mould on a porous surface such as clothing or cardboard, it will have already taken root in the pores of the material, meaning the best course of action is to dispose of it.”
If there is concern of excessive mould growth in an area, Boss-Handley recommends calling in a professional.
“As occupational hygienists, we can use our experience, expertise and professional equipment to attend a site and assess the affected area,” she said.
“That way, we are able to determine the larger systems that might be at play in allowing mould to grow and give recommendations on how to prevent future growth.”
On a mine site, like in all environments, there are countless mould spores present completely invisible to the naked eye, most of which will not lead to mould growth or cause illness.
If mine sites uphold the controls they have in place to tackle mould and keep a watchful eye, Boss-Handley said there should be little cause for alarm.
“Reducing moisture sources and maintaining airflow are the keyways mould growth can be kept to a minimum,” she said.
“Ensuring miners are safe from the respiratory effects can be straightforward as long as workers and mining companies collaborate to remove mould as soon as possible.”
This feature also appears in the March–April issue of Safe to Work.