FRANKFORT. Ky. (AP) - Hourly workers in one of the nation's most hazardous occupations, underground mining, would face mandatory drug testing under a proposal that's been in the works for more than two years.

The move by the U.S. Mine Safety and Health Administration is in reaction to concerns initially raised by coal operators in Appalachia, a region that has struggled with what officials describe as an epidemic of prescription drug abuse.

"Mining under the best of circumstances can be dangerous, and the use of alcohol and illegal substances creates additional, unnecessary hazards," federal mine safety chief Richard E. Stickler said in a written statement. "If one miner is abusing substances, everyone's safety is put at risk."

Lawmakers in Kentucky instituted a similar requirement two years ago in response to deadly accidents at mines where investigators found drugs.

One miner was killed and another critically injured at an underground operation in 2003 in Floyd County where a witness reported seeing miners snorting crushed painkillers. And the widow of a miner killed in an accident at a separate location in Harlan County in 2005 said in a lawsuit filed last year that drug abuse was so rampant that the miners referred to the company's bathhouse as "the crack house."

While other parts of the country wrestle with methamphetamine cocaine and heroin, the Appalachian region has been a hotbed for abuse of prescription pills, like the painkiller OxyContin, that are either crushed and snorted or mixed with liquid and injected intravenously.