The University is investigating a possible link between taconite fibers in northern Minnesota and lung cancer.
For silica and asbestos, the health dangers are certain and often deadly, but monitoring and reduction of the particles remains inadequate, some say.
As the winter chill hits Minnesota’s Iron Range, the windows and doors of the taconite mining facilities have begun to close.
But in keeping out the cold, the companies may be keeping in a deadlier hazard: dust.