Study confirms link between mesothelioma, taconiteMOUNTAIN IRON — After 14 years working in Northeastern Minnesota’s taconite industry, and an entire lifetime of living with people who did the same, Joanne Johnson of Silver Bay wanted to know if she was hearing things right.
By: John Lundy, Duluth News Tribune
MOUNTAIN IRON — After 14 years working in Northeastern Minnesota’s taconite industry, and an entire lifetime of living with people who did the same, Joanne Johnson of Silver Bay wanted to know if she was hearing things right.
“There is risk, but it’s very low?” Johnson asked a panel of researchers assembled Friday in Mountain Iron.
And after five years of delving into the question of a possible link between working in the taconite mining industry and developing a host of health issues, including the rare and fatal lung cancer mesothelioma, Dr. Jeff Mandel boiled that research down into a simple answer.
“That’s pretty well put,” Mandel, the lead investigator on the University of Minnesota’s Workers Health Study research team, told Johnson.
A full crowd filled the Mountain Iron Community Center on Friday afternoon to get their first real answers in the most comprehensive study of taconite workers’ health to date.
The study found an association between the length of time a worker spent working in the taconite industry and an increased risk of developing mesothelioma. But they also found that the dust containing the particles that cause lung problems is largely confined to the taconite mines — meaning little, if any, seems to filter into the surrounding communities — and today, mines have safety standards and procedures in place that largely protect workers, researchers said.
However, health hazards do remain, Mandel said.
“This is a dusty job,” Mandel said. “No matter how you look at it, it’s dusty work. You have to make sure you protect yourself.”
No smoking gun
The link between working in the taconite industry and unusually high rates of mesothelioma long had been suspected. But Mandel’s team still hasn’t found the smoking gun that explains the link.
At least 82 Iron Range residents have died in recent years from mesothelioma, which often doesn’t appear until 30 to 40 years after initial exposure to asbestos.
Previously, the research team confirmed the rate of mesothelioma on the Iron Range is almost three times higher than that of the general population in Minnesota.
What’s new in the results released Friday is the definite link to the taconite industry. Every year a worker spent in the industry increased the risk of mesothelioma by 3 percent, the researchers reported in a School of Public Health release.
But the “why” remains a mystery.
Researchers found little trace of traditional asbestos-size mineral fibers in their study. They’ve focused instead on shorter fibers called “elongated mineral particles” or EMPs. On Friday, they said they did find a “potential link” between cumulative exposure to workplace EMPs and mesothelioma in taconite works.
“However, the link is not felt to be certain,” the team reported.
That means they can’t say for sure that the dust from taconite operations causes mesothelioma. Mandel said researchers also still are looking for other possible sources of asbestos outside of the iron ore industry that may have affected the workers.
Taconite workers have higher-than-expected risks of all types of cancer and heart disease, the researchers said. That leads them to believe other factors, including lifestyles, may be at work.
Even with an increased risk, mesothelioma is still a rare disease, and the chances of contracting it are slim, the team noted.
While researchers found little to no levels of the studied dust particles in area communities, they found that certain jobs within the plants did have higher exposures to dust levels. The highest exposures came with workers in the agglomerators and the kiln discharge positions.
The researchers reported several bits of good news for the Iron Range:
“We’re hopeful that the results to date will allay fears that taconite dust has generated broad harm to the general public,” Mandel said in the School of Public Health release.
The University of Minnesota Medical School and the Natural Resources Research Institute at the University of Minnesota Duluth also participated in the study.
More info coming
Definitive answers as to why taconite miners kept developing high rates of mesothelioma and other lung and heart disease problems have been a long time coming.
The $4.9 million study was commissioned by the Minnesota Legislature in 2008. Friday’s meeting marked the beginning of the end of the study, Mandel said. He anticipated holding more public meetings throughout the rest of the year, as more results from the study became available.
“At the end of this process, we will have the final conclusions,” Mandel said.
The “buts” and “howevers” sprinkled through the researchers’ presentation Friday held a little worry for Johnson, who once worked for the Northshore Mining Co. in Silver Bay.
“I’m hearing positive things,” Johnson said as she listened to the researchers, “but those words trouble me.”
The audience sat quietly while the researchers presented their findings. The room was filled with a mixture of taconite workers and business professionals; a collection of husbands, wives, friends and union buddies. Some people wore suits, others wore union jackets. Nearly everyone held a notebook on their lap.
After the presentation came an opportunity to ask specific questions. Some wondered about how the study’s results would take into account mesothelioma’s long latency period. Others asked about asbestos-like fibers found in the area’s geological formations.
Edward Alto of Aurora worked in the now-closed LTV mine in Hoyt Lakes for 33 years. Alto said he has pleural abnormalities in his lungs, and wanted to know if those abnormalities could be considered “pre-cancerous tissue.”
“In general, the answer is no,” said Dr. Bruce Alexander, who presented the mortality and cancer incidence studies portion of the research. “Those are thought to be benign changes.”
Alto said he has several friends who worked in the mines who now have diseased lungs. And with the current interest in expanded non-ferrous mining in the area, Alto was mindful of the health of the next generation of miners.
“It should almost be a right-to-know issue,” Alto said.