Lung cancer researchers say they'll keep miners informed

Taconite fiber
This electron microscope photo shows a taconite fiber breaking up into smaller fibers in rat lung tissue. The state Health Department is conducting studies to see if taconite fibers can cause mesothelioma, a rare form of lung cancer which is usually associated with asbestos exposure.
Photo courtesy of Dr. Philip Cook, U.S. EPA

The task force studying a rare but deadly cancer among taconite miners on Minnesota's Iron Range offered an update on progress at a meeting Thursday.

Researchers say they want to meet often with mine workers and retirees -- some of whom have been bitterly critical of past attempts to explain the problem.

Fifty-nine men in northeastern Minnesota have died of mesothelioma, a cancer of the lining of the lung. It's not a big number, but it's twice the expected rate.

After years of complaints and several false starts, the legislature appropriated nearly $5 million to study the issue.

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The University of Minnesota School of Public Health is heading up the investigation. The university is working with the Health Department and the Natural Resources Research Institute in Duluth.

Among other resources, they'll be drawing on a database of 72,000 miners.

Some scientists are screening workers for lung problems; others are trying to figure out the best ways to protect workers from harmful dust. There's also a complicated effort to figure out just how much dust workers have been exposed to -- both in the past, and now.

Some of the former taconite workers at the meeting said that would present a huge challenge.

Roger Holmstrom put in 36 years at taconite mines. He told the researchers it's hard to pin down where the dust is coming from:

"A blast, or where the drills are drilling the taconite, or where the shovels are loading it into the trucks. There's dust all over. Plus when you get to the crusher you dump your load, there's dust there," said Holstrom.

This is the kind of input the scientists want. Gurumurthy Ramachandran is heading up the exposure part of the study. He'll be using current readings and data from earlier research, but he says there's lots of gaps in the historical data. To fill in the gaps, he'll create mathematical models.

"And in order to model them we need other types of information relating to the workplace conditions: what were the ventilation conditions for example, what types of respirator protection were the workers wearing," Ramachandran said.

He plans to interview not just workers, but safety officials, engineers, anyone who knows about taconite operations.

"They all have different pieces of the puzzle, and we hope to use all that information," explained Ramachandran.

He'll be looking at several types of dust: tiny particles that penetrate deep into the lung. Silica dust, that's implicated in other lung diseases. As well as the infamous fibers that have been the subject of debate for thirty years, since Judge Miles Lord forced Reserve Mining Company to stop dumping its waste rock in Lake Superior.

Scientists said the fibers in the rock were similar to asbestos, which causes mesothelioma. Mining companies say they're not asbestos; they're not even fibers. Ramachandran hopes to solve that vexing question.

"Fibers are defined by some people as different from the way fibers are defined by others," Ramachandran said. "So what we hope to do in the study is hopefully settle this question and look at all these components of taconite dust that various people have proposed as hypotheses for the health effects."

People across the Range have been calling the university to volunteer for the health screening part of the study, usually because they have a lung problem. Researcher Jeffrey Mandel says the team needs a random sample, to get clear results.

"If it isn't done on a random basis, it's more prone to being biased by the people who participate," Mandel said.

That's a basic rule of science. But the team is breaking another scientific principle. Normally researchers don't like to go public with their results until they've been reviewed by other scientists. In this case, Mandel says they want to share information as they go along. He says it's good that a small group of mine workers and retirees have been following the process.

"I think the main advantage in having a group like this is that you can use this group to get a message out and eliminate a lot of these rumors that can otherwise develop," Mandel said.

He's relying on people like Dave Trach, who heads a Steelworker retiree group. Trach said after the meeting he's feeling better about the issue than he has in a long time.

"I just think that the University of Minnesota is probably the A-Team, and that maybe they can really give us some answers, and that's what I'm hoping for: that we can find out what this is all about," Trach said.

It'll be about a year before any real results are known, and parts of the study won't be done for three years.