Some frequently asked questions about taconite fibers on Minnesota's North Shore.by Stephanie Hemphill, Minnesota Public Radio
Duluth, Minn. — Wasn't there a symposium that was supposed to answer questions about taconite fibers?
In March of 2003, the Minnesota Department of Health, Iron Range Resources, and other agencies sponsored a symposium, where researchers from around the world shared their work. The Health Department was hoping to use the information to establish a health-based standard for exposure to taconite fibers. But a report from the symposium has yet to be published. The symposium organizer, Dr. Robert Nolan of International Environmental Research Foundation, says he had trouble getting the papers peer-reviewed. Publication is expected sometime in the next year.
Why are these issues coming up now?
After the Reserve court ruling in 1979, the mine cleaned up its fiber emissions dramatically. There were fewer fibers in Silver Bay than in the comparison city of St. Paul. The Minnesota Pollution Control Agency stopped monitoring the air in St. Paul. Current mining section chief Ann Foss says officials at the agency back then have told her they never intended to stop monitoring permanently. But Northshore Mining says it has met the terms of its permit, and the comparison city requirement is outdated.
In 2005, Northshore Mining applied for a permit to reactivate a furnace it hadn't used for years. Under pressure from environmental groups, and in the absence of a health-based standard, the MPCA again sampled the air in St. Paul. Now St. Paul's air has fewer fibers than Silver Bay's air has, probably because asbestos has been phased out of so many uses, including brake linings.
The MPCA is urging Northshore to do more to capture "fugitive dust" from piles of ore. Northshore says it will work with the MPCA to try to determine the source of the fibers.
Meanwhile, in late May, two environmental groups filed notice that they intend to sue Northshore Mining for violating that court-ordered permit.
What are the relevant health standards?
Mine safety is regulated by the Mining Safety and Health Administration, part of the Department of Labor.
In 2001, MSHA came under scorching criticism for failing to detect the disastrous asbestos contamination at a vermiculite mine in Libby, Colorado. MSHA responded by proposing to reduce its permissible exposure limit for asbestos twenty-fold, to match the limit used at OSHA, and to use more advanced microscopes to detect asbestos. Those new rules are scheduled to go into effect in 2008. They apply to asbestos, and it isn't clear whether they apply to the fibers found in taconite on the east end of Minnesota's Iron Range.
The EPA says there is no known safe exposure to asbestos.
If the Minnesota Department of Health arrives at a standard for taconite fibers, it will be expressed in terms of increased risk for cancer in a population. Typically, if a substance is found to increase the risk of cancer by one in 100,000, a state or federal pollution control agency will impose an enforcement mechanism. By comparison, the Health Department says Minnesotans have about a one-in-two chance of getting cancer during their lifetime.