Air Date: Week of January 6, 2006

Why the worst mining accidents seem to always happen around the holidays.

Transcript

YOUNG: It’s Living on Earth. I’m Jeff Young, and coming up: Cracking down on one of the last sources of unregulated pollution: America's busy seaports. First this Note on Emerging Science from Rachel Gotbaum.

[SCIENCE NOTE THEME]

GOTBAUM: Winter is the most dangerous time for mine workers. That’s because explosions like the one that recently killed 12 miners and critically injured another in West Virginia are more likely to occur in cold weather.

Cold weather lowers the barometric pressure, and the lower pressure enables an odorless, colorless but highly flammable gas called methane to seep out of the mine rock and accumulate. Colder weather also brings dryer air which dries out the coal dust in the mine and makes it more explosive. In the winter months, to offset the accumulating methane, mine workers often turn up the ventilation system to disperse the gas from the mine shaft. But that ventilation system also keeps the coal dust from getting moisture and increases the explosive hazard.

So even a spark resulting from something as seemingly innocuous as static electricity can cause an explosion in a mine under winter conditions.

That’s this week’s Note on Emerging Science. I’m Rachel Gotbaum.