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'How clean is clean?' still the question for EPA

| March 14, 2007 12:00 AM

By BRENT SHRUM Western News Editor

More than seven years after arriving in Libby to investigate reports of contamination left behind by decades of vermiculite mining, the Environmental Protection Agency is ramping up research efforts aimed at a host of still-unanswered questions about Libby asbestos.

"How clean is clean?" is one of the central questions that the agency has been asking since starting the Libby cleanup, said local EPA team leader Paul Peronard at a community meeting last Wednesday at the Memorial Center.

Peronard and other EPA representatives provided an overview of ongoing research and an update of the status of the cleanup. The EPA's Office of Inspector General issued a report in December that was critical of the agency's failure to provide a risk assessment for Libby asbestos and called for an increased focus on scientific studies.

Peronard stressed that research will not cut into funding for cleanup, which is expected to remain at current levels of $17-20 million per year. At least three or four seasons of cleanup remain, Peronard said.

How long the cleanup takes may depend in part on findings of studies directed at determining if past cleanups have been sufficient. New sampling and analytical methods are being tested, with one focus being on the way the agency tests for asbestos contamination in soil.

In some places where soil samples came back "non-detect," new air samples taken while simulating typical outdoor activities have shown the presence of asbestos fibers, Peronard said.

Peronard acknowledged the controversy surrounding the agency's decision to leave asbestos-contaminated vermiculite insulation behind in some difficult to access locations, like inside walls. To deal with potential exposures years in the future, the EPA is piloting a permanent position for a specialist who would provide assistance in such cases. Local project manager Mike Cirian is currently filling the position and developing the job description and cost estimates as he goes along.

Because existing guidelines for asbestos exposure were developed using chrysotile asbestos - the type used in commercial applications and different from Libby asbestos in chemical makeup and structure - a primary focus of EPA research is to develop a risk model specifically for Libby asbestos.

"It's fairly outdated," Peronard said of the current model. "We don't think it's appropriate."

Studies are looking at better ways to correlate the amount of asbestos in the air with the amount in dust, and the amount that may be breathed into the lungs with the amount in the air. Scientists are also looking at how the asbestos behaves inside the body, including its influence on non-respiratory ailments like autoimmune diseases. Researchers are looking for genetic markers that could provide early warning signs for asbestos-related disease.

Ultimately, the health studies are hoped to provide information that will lead to the development of mathematical models that link exposure levels with health risks.

In addition to the ongoing removal of vermiculite from Libby-area homes and yards, plans are moving ahead for a similar cleanup in Troy. An investigation similar to what was done in Libby will start this spring and is expected to take two seasons. Cleanup actions will depend on the findings of the investigation.

"It's premature to talk about what we're going to do until we see what the data shows," Peronard said.

The agency is also taking a closer look at completed cleanup operations at former vermiculite processing sites, with a record of decision expected in 2008 or 2009, and at the vermiculite mine itself.

The mine has been closed since 1990, and the road leading to it from Highway 37 - Rainy Creek Road - has been closed since early 2000. It's not yet known just how far contamination spreads away from the mine, Peronard said. The EPA plans to begin its evaluation this year and hopes for a decision in 2010 or 2011.