The presence of asbestos-contaminated vermiculite attic insulation or other asbestos-containing materials in homes and the potential for living space contamination.

Asbestos-contaminated vermiculite attic insulation (VAI) produced from a mine near Libby, Montana, may be present in millions of homes along with other commercial asbestos-containing materials (ACM). The primary goal of the research described here was to develop and test procedures that would allow for the safe and effective weatherization of low-income homes with asbestos. The presence of asbestos insulation was confirmed by bulk sampling of the suspect asbestos material. The homes were then tested for the presence of asbestos fibers in the living spaces. All 40 homes containing VAI revealed the presence of amphibole asbestos in bulk samples. Asbestos (primarily chrysotile) was confirmed in bulk samples of ACM collected from 18 homes. Amphibole asbestos was detected in the living space of 12 (26%) homes, while chrysotile asbestos was detected in the living space of 45 (98%) homes. These results suggest that asbestos sources in homes can contribute to living space contamination.