MOUNTAIN IRON, Minn. (AP) — Taconite industry workers face an increased risk of contracting a rare form of lung cancer and the risk increases the longer they remain on the job, University of Minnesota researchers announced Friday, but said they can't say for certain if dust from the state's iron mining and processing operations causes it.
The researchers traveled to the Iron Range of northeastern Minnesota to announce the findings of their $4.9 million, five-year study into possible links between taconite dust and mesothelioma, a rare cancer of the lung lining caused by exposure to airborne asbestos fibers that has taken the lives of 82 taconite workers over the years.
Previously released research confirmed a 300 percent higher rate of mesothelioma on the Range than the general population in Minnesota.
"Our goal was to begin answering questions around how mining and taconite processing have impacted the health of Minnesotans. These studies have started to uncover those answers," John Finnegan, dean of the university's School of Public Health, said in a statement.
Asbestos fibers fall into a family of "elongated mineral particles" that are present within dust from taconite operations. Taconite, a low grade of iron ore, can contain asbestos. But the types of EMPs generated by iron mining had not previously been linked to an increased risk of mesothelioma.
"Researchers did identify a potential link between cumulative exposure to workplace EMPs and mesothelioma in taconite workers. However, the link is not felt to be certain," the researchers said in a statement. "As a result, the researchers cannot say with assuredness that dust from taconite operations causes mesothelioma. Further data analysis in this area will continue in the coming months."
Jeff Mandel, one of the principal researchers, said they know that the risk of contracting mesothelioma is higher among people who've worked longer in the industry. Unfortunately, he said, researchers have "minimal information" on their exposure to other sources of asbestos that they might have encountered outside of iron ore processing.
"It is something that we want to continue to look at, if at all possible," he said.
But he also said it's clear that the industry shouldn't wait for more answers.
"No matter how you look at it, this is dusty work, and it demands that workers and employers take responsibility to safeguard themselves," Mandel told the meeting where they present the study results.
The Taconite Workers Health Study found that death rates in the industry are also higher than state averages for more common kinds of lung cancer and for heart disease, which suggests that other health conditions are also at work — and lifestyle appears to be an important factor.
The death rates were higher than expected across the Range from all three diseases and were not concentrated in any particular location.
The study confirmed that air quality in Iron Range communities is better than in most parts of Minnesota in terms of particulates. It also found that occupational exposures to taconite dust are generally within safe limits. And it found that spouses of taconite workers aren't at any higher risk of contracting dust-related lung diseases than the general public.
"Although working in the taconite industry increases a person's lifetime risk of mesothelioma, the increase equates to a small risk of actually developing the disease. Mesothelioma is still a very rare disease," the statement said.