Contamination from Libby mine found in two states
For more than 70 years, tons of asbestos-contaminated vermiculite was shipped by rail from a mine near Libby, Mont., to plants across the country that manufactured building insulation.
The Libby mine was shut down in 1990, and the area is today considered one of the deadliest Superfund sites in the country. More than 400 people in and around Libby have died of asbestos-related disease, and thousands more were sickened by air, soil and water contaminated by asbestos. An ongoing effort by the Environmental Protection Agency to cleanup the mine and nearby towns has so far cost $330 million.
But the mine’s legacy is also being played out hundreds of miles away, where health and safety officials are dealing with soil contaminated by vermiculite that originated in Libby.
In Albuquerque, federal contractors have begun removing soil at two sites where vermiculite insulation was once manufactured. The EPA estimates that there are some 5,000 cubic yards of contaminated soil at the former Silico Inc. plant. Soil removal is also underway at a smaller site used by the Southwest Vermiculite Co., which sold insulation under the brand names Zonalite and Texas Vermiculite.
According to the Albuquerque Journal, the projects raise concerns about the health of former plant workers, as well as the location of some 68,000 tons of asbestos-tainted vermiculite imported to New Mexico from the Libby mine between 1967 and 1988.
The Journal reports that local environmental-health officials plan to identify employees who worked at the plants and notify them about potential health risks. Mike McAteer, the EPA’s on-site coordinator, told the newspaper that plant employees who loaded and unloaded the vermiculite ore are at greatest risk for asbestos exposure.
“I have no doubt there would have been fiber getting kicked up during this loading operation,” McAteer said.
Meanwhile, the EPA has warned residents in North Little Rock, Ark., of possible asbestos contamination in their homes and at a city park. The agency is testing two locations, including an auto salvage yard that was once a vermiculite processing facility. The EPA’s Althea Foster told the station that the agency also found “some” contamination at Conley Park, reports THV Television in Arkansas. “We found some off site as well,” Foster said.
Vermiculite is a naturally occurring mineral composed of shiny flakes that expand when heated. The EPA says vermiculite from the Libby mine, which was contaminated by a nearby asbestos deposit, accounted for more 70 percent of the vermiculite sold in the U.S. from 1919 to 1990.
In 2003, the EPA published a study of asbestos levels in vermiculite attic insulation and the potential risk to homeowners. The agency studied insulation in six Vermont homes, taking air samples from the attic, the living space, and outside the houses. The study also analyzed samples of 10 different vermiculite insulation products.
Among the key findings:
- Disturbed vermiculite attic insulation can create a potential asbestos exposure risk to consumers;
- Bulk samples of vermiculite attic insulation that tested negative for asbestos contamination are not reliable for determining whether there are asbestos fibers elsewhere in the attic or whether a disturbance of the insulation would result in the release of asbestos fibers;
- Additional studies are needed to better understand any potential risks from asbestos contamination.
Current EPA guidelines warn homeowners that they should assume vermiculite insulation contains asbestos, and that any disturbance could potentially release asbestos fibers into the air. The agency recommends hiring a professional asbestos contractor for any renovation that would disturb vermiculite insulation in walls or the attic.