Coal mining safety: Better but still perilous

NEW YORK (CNNMoney.com) -- As this week's explosion in a West Virginia mine proved, coal mining is still a very dangerous job. The mining accident in Upper Big Branch Mine killed 25, making it the worst coal mining disaster in 25 years.

But advances in coal mine safety have cut fatalities way down. Deaths have dropped from nearly 100 a year in the early 1990s to an average of about 30 a year now, according to statistics from the Mine Safety and Health Administration (MSHA), an agency of the U.S. Department of Labor.

The worst year for coal mining deaths was 1907, when 3,242 miners died, according to the MSHA. That year 362 men and boys died in a single explosion in a Monongah W.V. mine.

Newer, above ground mining methods like strip mining are less dangerous, but still risky. However, it's the underground miners at places like Upper Big Branch who are subject to a long list of calamities: cave-ins, floods, suffocations and poisonings from poor ventilation, and, most of all, explosions.

"Coal dust and methane have always been the big problems because of the explosions they cause," said Davitt McAteer, a former director of the MSHA.

Methane is a highly flammable gas that mining liberates from between the layers of coal, according to United Mine Workers spokesman Phil Smith. As the hard rock is stripped away, methane leaks out.

"You can hear it hissing," said McAteer.

And when too much methane gets trapped in an enclosed space like a mine it can explode -- as it did at Upper Big Branch -- and the results are dire. In a contained area like a mine, the explosion takes the path of least resistance, barrelling down the wide-open tunnels and other spaces where miners are at work.

But coal mining has gotten much safer over the years.

The carnage in the mines 100 or so years ago led to the creation of the U.S. Bureau of Mines in 1910, which is charged with investigating and improving mine safety.

Fatalities have dropped gradually since then. Also helping to cut deaths was the switch to surface mining from underground efforts.

According to the U.S. Energy Information Administration, more than twice as much coal is now produced by surface mining than from underground mining. Fifty years ago, underground mines accounted for three quarters of U.S. coal production.

Of course mine safety has improved thanks to better equipment, such as stronger ventilation systems for removing dust and gas. And changes in operating procedures have also reduced cut accident rates, according to McAteer.

He said that by simply not allowing more than one or two workers at a time to be near some of the most dangerous spots in a mine, fewer workers are put in harm's way.

But one procedure that worked against safety in the Upper Big Branch Mine was the mine's shift change protocol. To maintain efficiency, workers on the first shift stay in place working until the second shift workers arrive in the same spot to relieve them.

The blast was so devastating because it occurred during a shift change, when twice as many workers were on duty at once.

McAteer said that the industry's shift change procedures may very well be changed in the wake of Monday's tragedy.