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. Few realize the soil in their yard, school athletic field, or neighborhood park might be tainted with the mineral. The July 8 Science News magazine reported that U.S. Environmental Protection Agency data shows 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 activities kick up a “personal storm” of fibers that may be inhaled by adults and children, the magazine reported.

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

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

The rock-and-gravel industry has voiced objections and challenges to federal reports about the occurrence of asbestos-laden soils. Experts even disagree on what even constitutes asbestos, Science News found. Industry skeptics also say no formal study has established that people living over diffuse deposits of asbestos are acquiring potentially toxic doses.

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

Several new programs indicate the federal government takes outcroppings of naturally occurring asbestos seriously because of growing public-health concerns.

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

Topics Pollution