Macon County is sitting on a hot bed of naturally occurring asbestos, according to a new report by the United States Geological Service. The asbestos deposits could potentially pose a risk to construction workers who find themselves drilling or crushing the rock in close quarters.

A survey of naturally occurring asbestos revealed Western North Carolina has 27 former asbestos mines — nearly half of the total 61 known asbestos mines in the Eastern United States. Georgia comes in second place with 17 mines. The same asbestos veins prevalent in Macon County run through North Georgia as well.

Brad Van Gosen, the geologist with USGS who compiled the asbestos survey, said he personally would not operate a jack hammer on a rock with an asbestos vein in it.

“It’s a dust issue: who is exposed to the dust and for how long,” Van Gosen said. “It’s an unknown. We thought we would tell people ‘here’s where asbestos does occur naturally’ and let them decide how to deal with it. I think it is a local decision.”

At least one county with high concentrations of natural asbestos has taken local measures. In 1987, the construction of an underground parking garage in Fairfax County, Va., hit a large vein of asbestos. Dust from the drilling and crushing covered the construction site and several air drill operators soon developed itchy, irritated skin.

Air monitoring revealed a direct link with their symptoms to the presence of asbestos in the air. The county passed an ordinance that has to be followed by all construction occurring in asbestos prone areas. (see related article)

The scientific community is not united, however, on whether asbestos can cause health effects for construction workers blasting, evacuating or crushing rock that contains it.

“That is a tough questions to answer,” said Gilles Allard, a geology professor at University of Georgia who has studied asbestos for several decades.

Allard said the primary threat comes from mining the actual asbestos instead of incidental disturbance.

“When you crush the rock to extract the asbestos, depending on the situation under which you work, you might create a dust and that dust has very fine needles of asbestos. Since it is very fine needles it can go into you lungs,” said Allard. “It is not dangerous until you crush it very fine.”

Dr. Stephen Yurkovich, a geology professor at Western North Carolina, said asbestos traces in WNC’s rock aren’t cause for panic.

“There are numerous housing developments sitting all over these deposits,” said Yurkovich, who has studied numerous geological formations containing asbestos. Yurkovich said the amount of asbestos present is negligible in many cases, with visible veins only an inch or two thick. The average bulldozing associated with most development would not crush the rock enough to unleash the fine dust.

In a search for a site to build a new elementary school a few years ago, Jackson County rejected their first choice after asbestos was found in the rock at the site, probably due more to the negative connotation associated with the word asbestos than any real health concern.

Before being identified as a carcinogen, asbestos seemed like a wonder material. When handled or crushed, asbestos readily separates into individual mineral fibers — long, thin, durable fibers with high tensile strength, flexibility, and resistance to heat, chemicals, and electricity

Asbestos is still used in break pads in cars and in firemen’s gloves and suits, said Allard. Allard said the fibrous quality of an asbestos vein makes it easily identifiable, even to an amateur.

“You cannot miss it. The ultramesic rock is nearly black and you will see a little vein that is paler grey and it will have little fibers in it,” Allard said.

The asbestos survey has been given to the Agency for Toxic Substances and Disease Registry, which will conduct a risk assessment and recommend precautions and regulations based on their findings.