Natural Deposits of Asbestos Found in at Least 20 States

Most people hear the word asbestos and think of home insulation, deteriorating ceiling tiles, or scuffed flooring. What few realize is that the soil in their yard, school athletic field, or neighborhood park might be tainted with the mineral. The July 8 Science News magazine now reports new Environmental Protection Agency data showing that where near-surface deposits of the mineral exist, substantial numbers of asbestos fibers can be lofted into the air by playing basketball, biking — even gardening. Such wholesome activities kick up a “personal storm” of fibers that may be inhaled by adults and children alike, the magazine finds.

EPA’s studies were conducted in California, where most counties have near-surface deposits of asbestos. In “Dirty Little Secret,” Janet Raloff recounts how one family built its dream home in the mid-1980s on a site underlain with tremolite, a very toxic form of asbestos. One of the homeowners recalls initially popping a huge vein of tremolite from the ground — one that was maybe 35 feet long. “I thought it was some old, ancient tree root,” he said. Raloff describes how the man industriously covered it up, only to have later nearby construction export asbestos-laden dust to his property. When their insurance company refused to pay for a clean-up, the man and his wife simply walked away from their seven-bedroom house — forever.

El Dorado County, the area where this couple lived in the Sierra foothills, has slowly been gaining regional notoriety for its naturally occurring asbestos. However, notes Raloff, “It’s really only the poster child for a problem that’s national in breadth.” Indeed, she found, such near-surface asbestos exists in at least 19 other states. The deposits are spotty, but many hundreds exist, she reports. Among the better known: an 11 square mile region in Fairfax County, Va., a suburb of the nation’s capital. The county’s Web site hosts maps that highlight affected areas, many of which have undergone heavy development in recent years.

The rock-and-gravel industry has voiced strong objections — even challenges — to federal reports about the occurrence of asbestos-laden soils. In fact, experts can strongly disagree on what even constitutes asbestos, Science News found. Industry skeptics also point out that no formal study has established that people living over diffuse deposits of asbestos in the United States are acquiring potentially toxic doses.

However, “Dirty Little Secret” reports several pieces of evidence that at least suggest risks to people living near deposits of those fibers in the Sierra foothills and elsewhere.

Science News also illustrates how unpopular a finding of natural asbestos outcroppings can be. For instance, she quotes one researcher who identified an open deposit of crocidolite — a highly toxic form of asbestos — along a New Jersey nature trail. As a public service, the scientist promptly alerted the local town’s mayor. The researcher had half expected a show of gratitude. Instead, he says, the mayor “went ballistic and basically chased me out of town.”

Several new programs indicate the federal government, by contrast, takes such outcroppings of naturally occurring asbestos quite seriously. Prompting these programs are growing public-health concerns about how big a threat such natural deposits of soil-laced asbestos might be.

The story may be viewed at: http://www.sciencenews.org/articles/20060708/bob9.asp