For decades, miners who worked on Minnesota's Iron Range have wondered whether the dust they inhaled in the taconite mines had anything to do with the higher rates among them of a rare lung cancer called mesothelioma, as well as other respiratory diseases.
The answer came Monday from University of Minnesota researchers who have studied the health of Iron Range workers for the past six years.
Link to cancer found
Their conclusion: There is a link between the length of time a miner worked in the taconite industry and his or her risk of getting mesothelioma. Every year spent working in the industry increased the risk of contracting mesothelioma by 3 percent, and Iron Range mine workers contracted the disease at three times the rate of Minnesota's general population, MPR News reports.
Mesothelioma, a rare and deadly cancer of the lining of the lungs, has killed 80 former mine workers on the Iron Range.
What's not quite as clear is the exact cause of the illness – whether it's the tiny needle-shaped fibers called elongate mineral particles, or EMPs, which are found in the dust of crushed taconite iron ore; or whether it's fibers from commercial asbestos which was much more prevalent in the mines decades ago, according to MPR News.
Lawmakers approved nearly $5 million for the study after early findings in 2006 showed an unusually high number of the cancer among miners on the Range, according to WCCO. Researchers presented their final report at a community meeting in Hibbing on Monday afternoon.
Another somewhat surprising discovery is that the taconite workers also had higher than expected death rates from more common types of lung cancer and heart disease, when compared to the state's general population.
The higher heart disease rates could be linked to the inhaling of ultrafine dust particles in mines, principal investigator Jeffrey Mandel said, according to the Star Tribune, but the study was not meant to address that question specifically.
The report makes several recommendations, including one to consider requiring miners to wear protective equipment such as gas masks during certain circumstances.
Another recommends taking steps to encourage employees to reduce their risk factors for heart disease.
“The taconite industry continues to be committed to providing a safe working environment for our employees,” said a spokesman for the mining industries, Craig Pagel of the Iron Mining Association of Minnesota, according to the Star Tribune.
Mandel, the lead researcher, stressed that the mining industry in Minnesota, which employs several thousand people, is safe under most normal operating conditions. “But it is an inherently dusty industry. And it has risks.”
The 205-page final report is available below.
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