Does taconite dust lead to mesothelioma, a cancer of the lung’s lining? This was the main question that the Minnesota State Legislature charged University of Minnesota researchers with answering through a $4.9 million study called the Minnesota Taconite Workers Health Study nearly five years ago.
University researchers aim to determine whether exposure to particles in taconite dust released through mining in the Iron Range has caused the higher rates of mesothelioma identified there.
So far, they have found that for every year worked in the mines, a person’s risk for mesothelioma increased about 3 percent. But there’s more work to do, says lead researcher Jeffrey Mandel, M.D., M.P.H., of the School of Public Health.
“It’s an important project for the University, the state of Minnesota, and the communities up north,” says Mandel. “I knew it would be a complicated study to do, politically and scientifically, but this is a unique opportunity.”
The results of a report published in April were shared at a meeting with Iron Range workers and their families. The relationship between taconite dust and mesothelioma was being called an “association” rather than a “cause.”
“At this point in time, we’re not suggesting a cause,” Mandel says. “Workers are being told that the elevated rates of cancer seem to be related to the length of time that people worked in the industry.”
The University team now has a good understanding of the exposures to taconite dust in the mines, Mandel says. Most cases of mesothelioma they’re studying likely originated decades ago when the industry was new and fewer measures to protect workers’ health were taken, he says.
Due to updated safety precautions, such as better ventilation and improved engineering systems to process the ore, researchers believe that miners today aren’t more likely to develop cancer from their workplace than others.
Exposure to dust from taconite operations today is generally within acceptable limits, researchers say. In fact, they found that air quality in communities surrounding taconite mines is cleaner in terms of particulates than the air in Minneapolis.
Nonetheless, the numbers of people who develop mesothelioma and other types of lung cancer on the Iron Range are still higher than what’s expected in the general Minnesota population. Researchers are now conducting in-depth analyses to determine whether the taconite dust could be responsible for the heightened cancer rates.
“This is a time-consuming process, but we’re nearing the end of it,” says Mandel, adding that his team will be preparing a comprehensive report in the coming months. “As we finish the analyses, we’ll have enough information to say what is going on and what is driving these cases.”
- Grace Birnstengel