In 1982, an EPA study found significant amounts of tremolite asbestos fibers in vermiculite ore from a mine owned by W.R. Grace outside Libby.
Tremolite is a rare, toxic form of asbestos that can cause cancer at very low exposure levels.
More than 200 deaths and hundreds of illnesses have since been blamed on asbestos exposure among Libby mineworkers and residents. Vermiculite from the W.R. Grace mine was turned into insulation, exposing factory workers and homeowners to asbestos as well. Last week, the EPA admitted that its officials filed away the 1982 report, halted plans for further studies and relied on company figures showing much lower levels of asbestos contamination. The EPA inspector general will begin the investigation today, based on the 1982 report, records of a 1983 Congressional hearing in which an EPA official downplayed the report s findings, and other materials. We want to know precisely what did happen.