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Know the West

Beware of orange clouds

  Earth-shattering explosions are a fact of life in northeast Wyoming's Powder River Basin. Each week millions of pounds of explosives are detonated as the basin's 17 open-pit mines rearrange thick layers of earth and extract the coal beneath. Sometimes blasting also creates clouds of nitrogen oxide gases.

Luann Borgialli was alarmed in January when one of the distinctive red-orange nitrogen oxide clouds from Arch Coal Inc." s Black Thunder Mine settled over her neighborhood in Wright, a cluster of homes and schools in this sparsely populated dry lake bed.

"Our kids were let off the school bus into that cloud," which lingered for an hour and a half, Borgialli says.

The orange color indicates a high concentration of nitrogen oxides, including nitrogen dioxide. When inhaled, nitrogen dioxide becomes nitric acid as it encounters moisture in the lungs. Exposure to the gas can cause respiratory problems, lung damage and even result in death.

While the coal industry agrees that nitrogen oxides are a problem, its representatives insist that the gases are difficult to predict and that risks to people are small.

Members of the grassroots citizens' group, Powder River Basin Resource Council, have appealed to the state for years, they say, only to be ignored. In February, however, the federal Office of Surface Mining issued a rare notice of violation to Cyprus Amax's Eagle Butte Mine north of Gillette. The company is appealing the agency's decision to the Department of Interior.

Since the federal crackdown, the mining industry in Wyoming has created a task force to consider ways of reducing its nitrogen dioxide emissions.

*Eric Whitney