The Masabi Iron Range in Minnesota has been a primary source of iron ore in the U.S. for many decades. There are large deposits of taconite ore in the region, a form of silicate rock that contains twenty to thirty percent iron. The iron ore mines in this country have been tapped out for fifty years, which has made the extensive processing required to extract iron from taconite a feasible expense.
Over the past ten years clear evidence has developed of a high level of mesothelioma occurrence among the Masabi taconite miners. Mesothelioma is a highly aggressive form of cancer for which the only known cause is asbestos. Its most common form, pleural mesothelioma, develops in the outer lining of the lungs which has caused it to be called asbestos lung cancer.
A 2003 study of mesothelioma development among the Minnesota taconite miners concluded that of the 17 cases studied, 13 were probably the result of asbestos exposure. Since then, however, thirty five additional cases have been diagnosed among the miners and their families. The disease is extremely rare, with three thousand cases diagnosed annually in the U.S. so the level of occurrence among Minnesota’s taconite miners is exceptionally high.
The Minnesota State Legislature committed several million dollars to a renewed effort to study the possible relationship of taconite and taconite mine dust to mesothelioma development. The University of Minnesota is conducting the study and seeking volunteers among miners, retired miners and their spouses to conduct in-depth health studies seeking symptoms of mesothelioma, a disease which can have a latency period of up to forty years.
They would like to interview 1200 miners and 800 spouses. In addition, they will review 20,000 death certificates for taconite workers, seeking further evidence that taconite exposure is linked to mesothelioma and other lung diseases. The Duluth News Tribune quotes University of Minnesota health expert Dr. Jeff Mandel as saying, “Certainly, there is a suspicion it is. We wouldn’t be up here if we didn’t think there was a pretty good chance at a link.”
If Dr. Mandel’s suspicions are accurate, taconite would be only the second proven cause for mesothelioma – a disease that has been associated solely with asbestos for nearly a century.
