Minnesota health officials have discovered 21 new cases of mesothelioma in a group of 69,000 mine workers that have been monitored since the late 1990s. 80 cases of the rare lung cancer had previously been discovered the group of miners, bringing the total number of cases reported to 101.
Mesothelioma is caused by exposure to asbestos fibers. It's almost always fatal.
The workers monitored by MDH and the University of Minnesota were employed in the state's iron mining industry between the 1930s and 1982. All 101 cases occurred in miners who worked with multiple companies across the Iron Range, so the mesothelioma cases are not limited to one location or company.
These 21 new cases were not unexpected, but rather a matter of time.
"This form of cancer has an extremely long latency period," said Dr. Ed Ehlinger, Minnesota Commissioner of Health. "The interval between exposure to the agent that causes the cancer and the time when the cancer appears can be as long as 40 or 50 years, possibly even longer. We have always expected to see additional cases as time went by, in people who were exposed many years ago. We expect to see still more cases going forward."
Health officials are stressing that the spike mesothelioma cases in northeastern Minnesota is most likely an occupational health concern, and there is not any increased risk for the general public.