Environmental asbestos concentrations in the United States

Measurements were made of chrysotile concentrations in buildings with asbestos-lined return air plenums, in buildings with damaged asbestos surfacing material, in the houses of asbestos workers, and around buildings while asbestos-containing fireproofing material was being sprayed on steelwork. The data obtained demonstrate significant environmental contamination by asbestos: 43/89 air samples exceeded 50 ng/m3, although only 2/89 samples exceeded 1000 ng/m3. These findings should prompt appropriate control or remedial action.