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Dig carefully, Fairfax. Area of asbestos-containing rock is expanding

By Michael Neibauer, http://www.bizjournals.com

fairfaxcountyWhen most people hear asbestos, they probably think of the toxic, fibrous mineral once commonly found in construction, insulation and fireproofing materials.

When Fairfax County builders hear asbestos, they may think deeper — as in two to three feet beneath their feet.

Roughly 10.5 square miles of the county, 2.5 percent of its total size, contain “problem soils” that may include naturally occurring asbestos, specifically actinolite and tremolite minerals. It is found along the Piney Branch Complex, a vein of bedrock locally known as greenstone for its green or blue-green hue.

And the area of problem soils is getting larger.

The Fairfax County Board of Supervisors has scheduled an Oct. 15 public hearing to consider an amendment to the 2011 county soils map that will increase the potential area of naturally occurring asbestos from 10.53 to 10.67 miles. It is a slight increase, based on field work by the Northern Virginia Soil and Water Conservation District, but it is one that all developers must be aware of, as it will affect how they proceed with construction projects. Read more

Researcher finds more asbestos-like fibers in Penokee Hills

By Danielle Kaeding, Wisconsin Public Radio

Penokeeoutcrop1More asbestos-like fibers have been discovered in rock samples from the Penokee Hills of Northwestern Wisconsin, where a company had proposed to build an open-pit iron mine.

According to a northern Wisconsin geoscientist, the greatest amounts of hazardous minerals are in the western part of the range, including the area that mining outfit Gogebic Taconite planned to develop before pulling out of the project earlier this year.

Northland College associate professor of geoscience Tom Fitz said there’s an approximately nine-mile stretch of the range with rock containing the long, slender “asbestiform” crystals. The crystals are a form of mineral known to be linked to mesothelioma, a rare type of lung cancer.

“In the stretch that’s in Wisconsin between the western part of the Penokee Range over to Ironwood, the area near Mellen, is the area that has the greatest potential to have the asbestiform variety,” Fitz said.

He said the asbestiform minerals show up in the Tyler Forks River and become abundant in some areas between there and southwest of Mellen.

Differences in geologic heat when the minerals were formed account for the variation in some parts of the range, Fitz explained. Not all so-called amphibole minerals are known to be hazardous, he said — just those that got hot enough to form into the long, slender asbestiform crystals.

“I don’t know exactly where the amphibole disappears in there, but it certainly decreases between Upson and Ironwood,” he said, cautioning that it could still be found in smaller veins across the entire range.

Fitz said more research is needed to determine what affect mining in the Penokee Hills could have on public health.

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