Renewed Concern Over Black Lung

"If you didn't have dust exposure, you wouldn't have the disease," said Vinicius Antao, a medical officer at the National Institute for Occupational Safety and Health (NIOSH), which carries out black lung studies. "There is not enough dust control."

In 1995, NIOSH recommended reducing the allowable level of coal mine dust from two milligrams to one milligram per cubic meter of air, but the recommendation was not adopted.

Bruce Watzman, vice president of safety and health for the National Mining Association, a national trade group, said industry officials were surprised by the NIOSH study.

"These results caught us off guard," he said. "We want to learn more about it."

He said the industry plans to use personal dust monitors -- devices each miner wears to immediately log dust levels -- once research is complete and the devices are commercially available. He said that development and testing of the devices, which will cost about $7,000 each, has taken "longer than anyone expected."

"We continue to work and explore new technology to reduce dust levels in the mines," Watzman said. "We have a twofold approach: the development of personal dust monitors and the refinement of existing tools to reduce dust exposure underground."

He said the group does not support lowering the legal dust limit.

Miners' advocates say that along with stricter limits, better enforcement is needed.

"It's one thing to have dust control measures in place, it's another to monitor them," said Mary Natkin, a law professor at Washington and Lee University in Lexington, Va., whose students help miners in black lung benefits cases. She said current dust control enforcement, which relies largely on companies' self-reporting, is like "putting the fox in charge of the henhouse."

There's no doubt that black lung has been drastically reduced since the Federal Coal Mine Health and Safety Act of 1969 established dust limits. Recent surveys indicate about a 3 percent overall rate of disease, compared with 10 percent or more in the 1960s. But with coal production increasing, mostly in smaller, nonunion mines, Robert Cohen, director of the black lung clinic in Chicago, worries about what the future will bring.

"Unfortunately, black lung disease is not likely to disappear. Rather, we're likely to see more cases if health and safety regulations are weakened or go unenforced," he said. "Unlike the Sago mine explosion, this will be the hidden disaster. These deaths won't hit the headlines and will take place quietly decades from now."