The Minnesota Health Department suppressed research about additional deadly cancers among Iron Range miners for a year, even though a top government scientist warned that the findings raised significant new health issues.

The department discovered in March 2006 that a rare, asbestos-related cancer had stricken 35 more miners than the 17 previously known. All of the miners have died. The state didn't release the new information until March of this year, a decision that some health experts are now criticizing.

The findings sparked renewed concern about taconite dust and lung cancer among the 4,000 workers in the state's iron ore industry.

Health Department documents obtained by the Star Tribune show that officials had planned last year to disclose the information to mining unions, businesses, federal regulators and others. But state Health Commissioner Dianne Mandernach rejected those plans last fall.

Documents also show that the department feared that public disclosure of the findings would create controversy.

In an interview Wednesday, Mandernach defended the yearlong delay, saying the department had needed time to plan new studies of mining and disease.

The cancer, called mesothelioma, is deadly. It strikes the lung lining and develops decades after exposure to asbestos fibers.

Mandernach said that releasing the findings without having a plan for further studies could "excite and cause tremendous concern before you have all of your ducks in a row."

But public-health experts and others said the department shouldn't have waited.

"Whether or not they had a plan in place is neither here nor there," said Dr. Ian Greaves, an associate professor of environmental health at the University of Minnesota who is an expert in lung diseases.

"They're a public agency that serves the public, and I think it's overreaching to think they should take an attitude that they know best. ... This sounds very paternalistic in some ways."

Yearlong delay is unusual

For decades, mine dust has been a concern because some taconite fibers are chemically identical to asbestos. Mine operations also used commercial asbestos on such things as pipes and boilers, creating another source of exposure.

In 2003, Health Department researchers found that 17 miners had developed mesothelioma between 1988 and 1996, and that commercial asbestos, not taconite dust, was a more likely culprit. Some critics said the Health Department didn't look hard enough at mine dust.

That contentious history is reflected in department e-mails, memos and notes released under the state public-records law. They show that officials worried about public reaction to the latest research, which covered 1997 to 2005.

"Many will believe that they confirm the health hazards of the miners that have long been feared and predicted," said a March 2006 talking-points memo by Dr. Alan Bender, who heads the environmental epidemiology section that conducted the research.

Another briefing paper, prepared last year for the commissioner, said: "Release of the findings is likely to generate demands that the government do more to protect workers."

Bender, who has long advocated more research into occupational hazards, urged at the time that the findings be released.

For years, the Health Department has regularly released public-health research. Officials could not cite another case in which findings were withheld for a year.

New study released quickly

Just this month, the department quickly released another study based on the same cancer-tracking registry used in the Iron Range research. That study found no cancer clusters in Washington and Dakota counties, where groundwater pollution is a growing concern. The findings were made public shortly after the work was done.

State Rep. Denny McNamara serves on a committee that reviewed the Iron Range findings in April. He said he didn't know the release of the mesothelioma research had been delayed a year until a reporter called him. He said the Legislature should have been told earlier.

"I know in the Dakota County one, we pushed for that in a very expedited manner," said McNamara, R-Hastings. "I wouldn't want them to do anything different in the same situation, no matter what geographic area."

Fear of information leaks

Internal documents show that the Health Department drafted a news release in June 2006 about the 35 additional cases of mesothelioma, but planned to release it only if word of the findings leaked out.

The documents reveal that department officials were so concerned about a possible leak that they excluded two prominent University of Minnesota researchers from scientific consultation because they had been critical of the Health Department in the past.

The two scientists are Greaves, the lung-disease expert, and Prof. William Toscano, head of the division of environmental health sciences in the School of Public Health. In interviews, the scientists said they had never leaked anything. They expressed fresh criticism of the department's actions.

"People need to know this," Toscano said of the mine- disease findings. "I can't imagine people not wanting to know this information."

That's also the view of the United Steelworkers, which represents many miners. "It is a basic right to know what the government knows about exposures and problems that can affect your health," said Mike Wright, the union's director of health, safety and environment.

State officials also withheld the findings from the federal Mine Health and Safety Administration, which last year was considering stricter limits on asbestos dust in mines. The rule revision languished after a West Virginia mine explosion last year refocused the agency's efforts toward coal-mine safety.

The federal safety group declined to comment on the Health Department's action, but said the agency welcomes the opportunity to review new research "that may assist us in our efforts to draft
a more comprehensive asbestos regulation."

Federal regulators have repeatedly detected elevated asbestos since 2003 in the Northshore Mining Co. plant in Silver Bay, Minn.

In January, the company talked with state officials about a new miner health study, which the company would pay for. Yet no one told company officials about the additional mesothelioma cases even then, said Dana Byrne, vice president-public affairs for Northshore's parent company, Cleveland-Cliffs Inc.

The Northshore study is in addition to the state's plan to study dust exposure in Iron Range miners who developed mesothelioma and those who didn't. In another state study, researchers plan to compare cancer risks of different types of mineral fibers based on animal testing. The department hopes to pay for the research out of existing budgets and by seeking a federal grant.

Plans for both studies were prominently noted in the Health Department's March announcement. The 35 new cancer cases were mentioned - but not until the fifth paragraph.