Diesel exhaust could be causing fatal lung cancer in underground miners at a rate up to 38 times the accepted occupational risk, according to a new study.

Key points: There is no national occupational standard for exposure to diesel emissions

There is no national occupational standard for exposure to diesel emissions Researchers are calling for exposure limits to diesel to be lowered

Researchers are calling for exposure limits to diesel to be lowered Diesel exhaust is the second most common cause of cancer after UV exposure

It shows underground production workers, including diesel loader operators and shotcreters, face the highest risk — and researchers are calling for strict controls to limit their exposure.

The study, published in Occupational and Environmental Medicine, marks the first phase of a landmark investigation sponsored by the National Health and Medical Research Council.

Using Department of Mines and Petroleum data from 2003 to 2015 and other studies, it modelled the average levels of exposure among employees in a range of occupations on Western Australian mine sites.

It then estimated the number of lung cancer deaths caused by those levels with stark results.

"If somebody were to be exposed as an underground miner, we saw that that person would be exposed to on average 44 micrograms per cubic metre (ug/m3)," lead investigator Dr Susan Peters from the University of Western Australia told the ABC.

"If that would occur for 45 years and you would compare their risks … to the general population, that would have resulted in 38 extra lung cancer cases among males."

Above-ground mine workers were found to face lower levels of risk, with an average exposure of 14 ug/m3 over 45 years causing about 5.5 lung cancer deaths per 1,000 workers.

Exposure limits 'should be lower'

Following years of research, the International Agency for Research on Cancer formally classified diesel exhaust as a carcinogen in 2012.

There is still no national occupational standard for exposure to diesel emissions but the Australian Institute for Occupational Hygienists recommends an average exposure limit of 100 ug/m3 over eight hours.

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The study found that the average exposure rates modelled for WA mines were well below that limit, peaking at about 59 ug/m3 for an underground miner over 12 hours.

But since it also found the estimated rates of lung cancer deaths were higher than generally accepted as an occupational risk, the researchers recommended a reduction in the limit.

"You don't want anyone to get lung cancer but generally what we can accept as a risk is one in 1,000 workers, so you can image that 38 workers in 1,000 is way too high," Dr Peters said.

"So that's why I refer to the fact that the exposure limit should be much, much lower than 100 ug/m3."

Few other countries have set an exposure limit for diesel exhaust, and those that have, such as the US and Germany, generally recommend a higher limit than the AIOH.

But there has been growing calls for a reduction in those guidelines. In December last year the Finnish Institute of Occupational Health announced it was recommending an underground limit of 20 ug/m3.

There are also calls for diesel machinery to be replaced with emissions-free electric equipment.

Second most common cause of workplace cancer

Last month, the Cancer Council released new estimates that 130 Australian workers would contract lung cancer caused by diesel fumes each year.

About 1.2 million Australians are believed to be exposed at work each year, and diesel exhaust is now the second most common cause of cancer in the workplace after UV exposure.

Anyone exposed to diesel exhaust on a regular basis — even truck drivers — could face a higher cancer risk. ( Supplied: BHP Billiton )

The council's cancer smart manager Melissa Ledger said workers in a wide range of occupations were at risk.

"Underground miners is one of those occupations … but also anyone really exposed on a regular basis," she said.

"It could be truck, bus or train drivers, it could be farmers who have diesel equipment."

The council said awareness of the dangers of diesel fumes was quite low when compared to other cancer-causing agents such as asbestos.

"Not a lot of work has been done around providing education opportunities or awareness for workers in those areas around diesel exposure," Ms Ledger said.

Diesel exposure a 'sleeping giant'

In 2013, the WA Department of Mines and Petroleum issued guidelines on the management of diesel emissions, calling on the industry to conduct regular sampling, implement controls and develop an emissions management plan.

But the guideline also noted "some sites have not effectively controlled emissions" to below the AIOH guideline of 100 ug/m3.

A sampling program of 29 mine sites conducted by the department that same year found 10 of the sites exceeded the accepted exposure standard.

The highest reading recorded was 1,100 ug/m3, 11 times the accepted standard.

The 10 mine sites were never identified until their names were tabled in the WA Parliament last night at the request of Greens MLC Robin Chapple.

Among those still operating are the Cliffs Nickel mine, the Jaguar copper and zinc mine, and Sunrise Dam outside of Laverton.

More recently, the DMP has advised that its Mines Safety Inspectorate has issued 19 notices for ventilation safety issues in the past six months.

Mr Chapple said the issue of diesel emissions exposure among miners was a "sleeping giant" just waiting to be addressed.

"In South Africa now there are very few miners that allow diesel machines underground and a lot of other countries are starting to do the right thing," he told the ABC.