Silver Bay taconite plant wants old asbestos rule clarified

There’s a new dust-up in a decades-old dispute over asbestos releases from a Silver Bay taconite plant. Attorneys for Northshore Mining asked a federal judge in St. Paul on Thursday to either overturn or clarify a unique rule meant to protect communities around Lake Superior from airborne asbestos particles.

Northshore Mining crushes up taconite pellets and separates the metallic iron using huge magnets. The taconite comes by rail from a mine 50 miles away near Babbitt, Minn. Unlike other taconite mines in Minnesota, the material taken from this particular site also contains some asbestos. When the taconite is processed, the dust it creates is contaminated with asbestos fibers.

Asbestos is a carcinogen that is known to cause breathing disorders, lung cancer and mesothelioma, a rare but particularly lethal cancer type.

State and federal regulators, along with environmental groups, say lifting the rule could put Minnesota and Wisconsin communities along Lake Superior at a greater risk for these asbestos-related diseases.

“This court should decline Northshore’s invitation to put Lake Superior residents at a higher risk of deadly disease than is faced by other Minnesotans,” said Kevin Reuther, a lawyer for the Minnesota Center for Environmental Advocacy, in a brief to the court.

A lawsuit over the plant’s asbestos releases stretched out for years during the 1970s and eventually led to a federal appeals court coming up with an unconventional solution. It was widely accepted then as it is today that asbestos is harmful to human health. But experts testifying during the trial couldn’t say how much exposure was needed to pose a significant health risk.

“If I knew more about that human carcinogen, if I knew what a safe level was in the air,” Dr. Arnold Brown of the Mayo Clinic back then told the court, “then I could draw some firm conclusions and advise you in precise terms. That information is not available to me and I submit, sir, it’s not available to anyone else.”

Stuck without a scientific benchmark to go on, the 8th U.S. Circuit Court of Appeals arrived at what’s become known as the control-city standard. The logic was that residents in Silver Bay don’t deserve to be exposed to any more asbestos than residents of other cities. It suggested St. Paul as a “control” city, and said the mining company needed to reduce its asbestos releases so that Silver Bay’s air contains no more asbestos fibers than the stuff people breathe in St. Paul.

The amount of airborne asbestos in Silver Bay has dropped by about tenfold since the court decision, which can be attributed to new technologies installed at the plant and periods of inactivity. What state officials found in recent testing, however, is that the amount of airborne asbestos in St. Paul has fallen slightly more than in Silver Bay.

The Minnesota Pollution Control Agency (MPCA) sent Northshore Mining a letter last spring notifying it of the new data and raising the possibility of enforcement actions against the plant. The company then filed a motion in federal court asking it to clarify the rule. The company argues that a one-time study of airborne asbestos in St. Paul was meant to set a temporary standard until scientists concluded what exposure is needed to be considered a significant public health risk.

The problem is: 30 years later there’s still a lack of conclusive data about how much asbestos exposure is needed to cause health concerns. The MPCA is working with the U.S. Environmental Protection Agency to reach a science-based standard, but they don’t expect to have one for at least a couple more years. Until then, Northshore Mining says it’s unfair and arbitrary to expect it to meet a goal that’s a moving target.

“It’s irrational,” said Geoffrey Barnes, a lawyer for Northshore Mining. “No one can predict what it will be.”

A plank of lawyers from the Minnesota and Wisconsin attorney generals’ offices, as well the U.S. Justice Department and several environmental groups, lined up to oppose changing the rule. They argued the company is trying to avoid enforcement actions and free itself to increase asbestos releases.

“Northshore Mining seeks an order from this court that would, in effect, allow the company to pollute the air on Lake Superior’s North Shore with unlimited amounts of asbestos fibers,” Reuther said.

There’s growing evidence about the risk of asbestos fiber in taconite dust, Reuther said, and now isn’t the time to loosen standards for its regulation. Nearly 60 iron ore miners have been diagnosed with mesothelioma in northeastern Minnesota. Since 1988, 145 cases have been reported across the region, about three times the statewide rate, Reuther said. The U.S. Mine Safety and Health Administration is also considering tightening its regulations on asbestos exposure to workers.

The state resumed measuring asbestos levels in St. Paul and Silver Bay in March 2006, the first time the tests were conducted since the original batch more than 25 years earlier. Barnes said that long gap suggests the standard was never meant to be continually updated, otherwise the state would have tested more frequently. Carla Heyl, assistant attorney general for environmental protection, said the gap in testing was due to funding problems that caused the MPCA to neglect sampling.

The plant’s asbestos releases have potentially far-reaching health impacts — an assistant Wisconsin attorney general attended the hearing to raise concerns on behalf of communities on the south shore of Lake Superior where the particles could drift. But measuring the effect is difficult in part because of the amount of time it takes for mesothelioma to develop, two to four decades after asbestos exposure in some cases.