In worrying news for an industry that relies on diesel fuel, a new report from the World Health Organization says diesel fumes cause cancer.
A new ruling from the WHO may make diesel exhaust as dangerous a public threat as second hand smoke, AP reports.
While the risk of cancer is fairly small a science panel said raising the status of diesel fumes to carcinogen from a 'probable carcinogen' was an important move.
This may have major repercussions throughout the mining industry, where workers are constantly exposed to high levels of diesel fumes, particularly underground miners.
It's on the same order of magnitude as passive smoking," Kurt Straif, director of the International Agency for Research on Cancer (IARC), said.
"This could be another big push for countries to clean up exhaust from diesel engines."
This new classification comes after a week of discussions by the IARC in Lyons, France and is the first time the status of diesel exhaust has changed in more than 20 years.
In 1989 it was labelled as a 'probable carcinogen', but with this new ruling it moves the fumes into the same category as asbestos and ultraviolet radiation.
However in the ruling these studies did not take into account the new lower emission diesel engines and the filters currently in place.
"We don't have enough evidence to say these new engines are zero risk, but they are certainly lower risk than before," the US EPA stated.
One of the major focus areas for the recent study was research carried out in the US on the mining industry.
It monitored more than 12 000 miners over seventy years, and found that miners exposed to high levels of diesel fumes had a higher chance of contracting lung cancer.
The diesel fuel industry rejected the study, stating that it wasn't accurate as researchers had unreliable data on early exposure levels.
Diesel engine technology has recently focused heavily on cutting particle matter and fumes from the engines, as US and European standards increase and filtration technology improves.