Monday, November 5, 2012

THE MIRACLE MINERAL


Over a century ago, American builders began using a remarkable mineral product.  Mined from a type of serpentine rock, it was natural, abundant and easy to produce, yet its unique properties made it almost limitlessly useful.  It was resistant to chemicals and intense heat. It was an excellent electrical and thermal insulator.  Out of its fibers, you could weave a cloth that wouldn’t burn.  You could even mix it with other materials to make them stronger and more fireproof. 

Over the course of the twentieth century, American industry--with the government’s blessing--found thousands of uses for this miraculous mineral.  Woven into a cloth, it was used to insulate electrical wires.  Mixed with a binder, it made a fireproof insulation for pipes and ducts.  Mixed with cement, it made a host of practically indestructible building materials such as corrugated siding, shingles, and flue pipe. Mixed with vinyl, it made an incredibly durable floor tile.  

Nor was its usefulness limited to construction. This same amazing mineral allowed the brakes on your car to survive blistering temperatures. Inside your home, you could find it in stoves, heaters, ovens, toasters, hair dryers, and ironing board covers--pretty much any product that had to resist high heat.  And if you happen to have an older example of any of these items--or perhaps an old furnace down in your basement--that miraculous mineral may still be there, silently doing its job.

The miraculous mineral is asbestos, a substance whose modern reputation is considerably more sinister than when it was found in countless industrial products.  Long-term occupational exposure to asbestos is now known to cause a number of terrible lung diseases, one more ghastly than the next.  The risk of exposure to the amounts of asbestos found in a typical older home is less clear, but on the premise of being better safe than sorry, asbestos is no longer manufactured in the United States.  Nevertheless, since it was used in thousands of long-lived domestic products, and because its peak period of use stretched from World War II well into the 1970s--in fact, the last U.S. asbestos mine closed only in 2002--its complete removal from the environment is a virtual impossibility.  

Millions of older American homes contain significant amounts of asbestos, found mostly in the form of insulation on steam pipes or heating ducts, in resilient floor tiles, acoustic ceiling tiles, and sprayed acoustic ceilings, and in asbestos-cement shingles, building panels and flue pipes.  Although removal was once widely considered the preferred remedy, today many authorities believe that the safest approach is to leave asbestos-containing building materials in place so long as they’re in good condition and not subject to disturbance. For the official policy in your own area, contact your local hazardous materials authority.

So it is that, after a century of vast commercial use, the miraculous mineral has now become the malevolent mineral.  If there’s a lesson here, perhaps it’s that sometimes, things that seem too good to be true--whether X-rays, atomic power, DDT or asbestos--are in fact exactly that. 

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