What do you rate as the most serious issue currently facing the mining industry in Australia? The state of global affairs, commodity prices or the emergence of disruptive technology, perhaps?

According to AusIMM Director Chris Davis, these issues pale into insignificance when compared to air management.

Mr Davis is part of a four-person team working to alert mining companies to the dangers of nano diesel particulate matter (nDPM) at minesites and provide some solutions to the problem, which he views as largely ignored in Australia.

The other members of the group are Emeritus Professor Ifan Odwyn Jones AO, Clinical Professor Bill Musk and Associate Professor Alison Reid.

Professor Jones was the head of the WA School of Mines in Kalgoorlie for a number of years, Professor Musk is one of Australia’s pre-eminent experts on asbestos and lung health, having researched it for around 35 years and Ms Reid is an associate professor in epidemiology and biostatistics at the School of Public Health at Curtin University.

Produced by diesel-powered vehicles, nDPM poses a significant risk to miners, according to Mr Davis, who said a class action law suit around the issue could send a potentially calamitous ripple through Australia’s mining industry.

According to research carried out by the group, diesel engines produce 100 million diesel nano particles per cubic centimetre of exhaust and, even with dilution from the environment, the average person inhales around 10,000 diesel nano particles with every breath in a shopping centre parking lot or next to a major road intersection.

In terms of size, nano particles are in the range 25 to 100 thousandths of a micron.

“A quick bit of maths means it is roughly 1.6 million nDPM a minute,” Mr Davis said.

“Those figures are for a normal person living and working outside of a minesite. When we did some readings inside an underground mine, we recorded one person inhaling around 1.2 million nano diesel particles per cubic centimetre in their breath. Even people sitting in the cab of a vehicle were inhaling 79,000 diesel nano particles per cubic centimetre.

“Mine operators have a duty of care to their workers, and by not taking this issue seriously they are putting the lives of their workers and, in fact, their workers’ families’ lives at serious risk.”

One of the reasons nDPM is such a big risk is it has the ability to break down cells in the body. As a result, there have been links to an increased level of lung and bladder cancer and DNA alteration, among other problems.

Mr Davis said nano particles acted as somewhat of a Trojan horse, as the particles did not conform to gravity, following the Brownian theory of motion and picking up various other particles as they moved around.

“Cells are like a little factory of sugars and protein which is held together by the solution pressure of the cell compared to their surroundings,” he said.

“Nano particles are small enough to be able to infiltrate the cells and change the solution pressure of the cell. If one gets in, that is manageable, but if 30 get in at once that’s when the damage can be caused. If you’re breathing in millions of these particles in every cubic centimetre of breath, it is easy to see how serious this issue is.”

Breath of fresh air needed

Despite the potential severity of the problem, Mr Davis said it was one that was not being taken seriously enough by a number of mine operators across Australia.

“At times I feel like we live in a different universe to the Northern Hemisphere,” he said.

“There has been a North American nano particle conference every year for the last 24 years, and in Zurich there has been a conference every year for the last 22 years, so that is 46 conference years, with each one producing at least 100 papers – last year there were 200 papers in Zurich. Of the 4500 to 5000 papers overall, I guarantee you not one says nDPM is good for your health.

“In Australia companies are waiting to be told what to do by the government, but since self-regulation was introduced the mine companies need to take the initiative and make more of an effort. Ignorance of the law is no excuse.”

Professor Musk said air quality in mining had been a major issue for as long as dust diseases had been recognised.

“As long as diseases in miners exist then more efforts need to be made to reduce the risks,” he said. “It is important to monitor the situation so protection can be provided for prevention.”

Mr Davis said the issue started when fresh air raises were withdrawn from underground mines in favour of using the main decline for ventilation.

“This means the same place you’re getting your fresh air from is where the trucks are driving, which is flooding that fresh air with nDPM,” he said.

“The deeper you go the worse it is, and that’s how every mine, just about, in Western Australia is ventilated.

“It’s a disgrace; it’s an abrogation of duty of care.”

Solution in sight?

A workable solution to the issue of nDPM has been hard to develop because monitoring of exposure to nDPM and the resultant health effects is difficult to measure, according to Professor Musk, who said investment in measurement was needed.

For Mr Davis there are four potential possibilities for mine operators to consider if they actively want to combat the issue.

“They have to either get better ventilation, better filtration, go all electric or close the mine down,” he said. “They cannot keep going on as they are – it is a seriously dangerous issue.

“Going all electric is all well and good, but to do so the battery technology needs to seriously improve. It is going to need something like graphene to get it to the levels where it will be sustainable and affordable to go all electric at a number of underground mines.”

Of the filtration options widely used, Mr Davis said these did not stand much of a chance against nDPM, but was confident a solution was possible.

“We have an axiom that says exhaust plus ventilation equals inhalation; if you put a catalytic converter into the engine and then apply a proper nDPM filter you can limit what comes out of the equipment to around 45,000 nDPM per cubic centimetre of exhaust,” he said. “Then if you have adequate ventilation this can dilute it down to 10,000 nDPM per cubic centimetre of breath, which is the same as the average person on the street.

“That’s all we’re asking for at this stage – allow the underground workers the same chance as someone who has never stepped foot in an underground mine, otherwise soon there will be a class action and its effect could be quite damaging and wide-ranging.”