Recently, at events for my book, I sometimes find myself describing the gas carbon monoxide as a favorite poison. "It's just so efficient," I'll joke. "And I like things that work."
In an academic sense, I do respectfully admire carbon monoxide's simplicity (a carbon atom + an oxygen atom) and the way such basic chemical addition creates something so deadly. But in light of last week's mining disaster in West Virginia (the subject of two previous posts on this blog), I want to acknowledge that poisonous efficiency is mostly a formula for tragedy.
If you followed the news reports on the fiery explosion at the Upper Big Branch mine, which left 29 miners dead, you'll discover that rescue efforts were continually hampered by lethal levels of carbon monoxide filling the tunnels and seeping out of bore holes. Carbon monoxide is a product of incomplete combustion.
If the flammable gas methane ignites in a mine, it tends to act as a fuse to highly explosive coal dust. In the resulting blast, the carbon-rich gases, dusts, and other materials burn. In the low-oxygen environment of the mine, they often burn incompletely, leaving residual carbon to attach to whatever oxygen is still jittering around underground. This scenario - burning carbon, low levels of oxygen - is perfect for brewing up carbon monoxide.
In fact, readings taken from bore holes drilled into Upper Big Branch after the explosion measured carbon monoxide (CO) levels at 14,000 parts per million. The safe level, according to safety standards, is 50 parts per million.
Carbon monoxide bonds much more strongly with proteins in the blood that carry oxygen throughout our bodies. It essentially muscles oxygen out of the way, saturating the blood stream, preventing oxygen from being distributed to cells.Â At high levels, the result is a dizzying kind of chemical suffocation - often in ten minutes or less.
Carbon monoxide isn't the only gas to build up in a mine after an explosion. Methane levels may rise as seams of coal are peeled open by the explosion. Levels of hydrogen can go up. Carbon dioxide may also increase and even the toxic gas hydrogen sulfide may begin to build up. But mostly, it's carbon monoxide.Â This toxic brew is is sometimes called "afterdamp" in the mining industry and by some accounts 75 percent of deaths after an explosion are due to this extremely lethal mixture.
Federal and state investigators announced Monday that they would begin a formal investigation into what precisely caused the explosion after the last nine bodies are retrieved from the mine. There's already speculation that the Massey company, which owns the mine, was careless with ventilation and allowed a risky build up of gases in Upper Big Branch.
They should be held entirely accountable if so - we know all this chemistry so well that such disasters are readily preventable. But let's acknowledge something else here. As I list the gases found in mines - seeping from seams, circulating in those underground tunnels - let's acknowledge that most of us wouldn't go down there on a good day.
So the conclusion here - in this last of my posts on the West Virginia mine disaster - is to pay tribute to the courage and determination of all those people who go underground every day, work in those never quite safe tunnels, and dig up the coal that we burn so freely for electricity around this country.
Our deepest sympathy to their families and our appreciation, always, for what they do.