These new cases bring the total to 52 on Minnesota's Iron Range. Health officials say that number is abnormally high for the population.
The challenge is to identify the cause of the disease -- a challenge complicated by the fact that it can be 40 or 50 years before mesothelioma symptoms present themselves.
The disease is traditionally associated with asbestos, and no studies have proven that it can be caused by other airborne particles such as those released in taconite production.
Mary Manning, the director of health promotion and chronic disease at the Minnesota Department of Health, says these new cases make it imperative to rule out other possible sources of mesothelioma.
"People are dying from mesothelioma because it shows they've been exposed to asbestos. And if there's any other cause, I think we need to find out what that is and get the answers that people need," Manning said.
That is exactly what the first of the new Department of Health studies hopes to do. The project is a followup to a 2003 study of Minnesota mine workers.
It will research possible places where workers who now have mesothelioma may have been exposed, either while working at the mine or in some other job during their lives. Officials hope the study will also answer questions about the possible dangers of taconite dust.
"Those fragments get into the air and there's been questions over the years about what the health effects associated with those mineral fragments are," Manning said.
John Linc Stine, director for environmental health at the Minnesota Department of Health, is studying the effects of breathing taconite dust on lab rats to determine a safe level for humans -- that is, how many fibers in how much air is a safe level of exposure. No such standard now exists. Stine says it's important to know what job each worker did when they contracted the disease.
"Whether it was related to mining activity, or whether it was involving changing the brake linings on mine trucks where there could be other fibers generated. So it's really trying to look at what activities were conducted in their jobs, and what parts of their jobs might have put them at risk for mesothelioma," Stine said.
Mine officials also want to know whether iron ore mining can be linked to mesothelioma. On the same day that the Department of Health announced its studies, Ohio-based Cleveland Cliffs announced it will do a study at its Northshore facility. Designed to work in conjunction with the state, the Cleveland Cliffs study will examine whether breathing taconite dust could be making its workers sick.
Mine spokesman Dana Byrne says it's in the company's best interest to find out whether mining causes mesothelioma.
"The whole idea is to come up with a study that's somewhat conclusive, and hopefully puts the issue to rest once and for all," Byrne said.
The company is currently planning an expansion at its Northshore mine. Byrne says that's a major part of what motivated company officials to launch the health study. He says they don't believe the taconite dust is dangerous.
"To get beyond this issue we feel we have to do this study. Not have to do it, want to do it. So that we can move forward with some of the plans we have at Northshore. So it's a question we'd like to have answered as well as the public."
State Pollution Control Agency and health officials are helping to design the Cleveland Cliffs study, which will focus on current and past Babbitt and Silver Bay employees.
In Duluth, Jackie Paaso says she welcomes the studies. She lost her husband, Floyd, to mesothelioma. He worked for 30 years as a sheet metal worker, until he got sick. Paaso says the family always suspected Floyd's cancer was caused by his work.
"He used to make a paste out of asbestos, when he would cover different things with his sheet metal work. It's been hidden, I think," Paaso said.
Paaso says she wishes these studies would've been done earlier. It may have prevented other families from losing loved ones. Floyd Paaso died from mesothelioma in February 2006. "To sit and watch somebody going downhill was very, very difficult," she said. "But we didn't live like it was the last day. We just kept living like we normally do or you wouldn't be able to do it."
The mesothelioma studies are expected to take up to three years and cost up to $1 million.