Airborne Concentrations of Asbestos‐in‐air in Buildings and Exposure of Occupants: Risk and Regulatory Implications

Concern for the health risk of occupants in buildings containing asbestos fireproofing, acoustic materials or lagging, among other products, has led to several investigations of airborne asbestos concentrations in buildings and exposure assessments of occupants and maintenance personnel. The purpose of this paper is to summarize these results, to place in perspective exposure to occupants and maintenance personnel, and to estimate risks based on these exposures. Regulatory implications of these results are discussed. It is concluded that asbestos‐in‐air measurements carried out with the most appropriate methods in buildings with damaged or undamaged asbestos‐containing materials consistently show extremely low concentrations comparable to those measured outdoors for fibers greater than 5 μm in length. Risks to occupants in such buildings are correspondingly very low. Potential exposures are higher to those performing building maintenance procedures that may disturb the asbestos‐containing materials. Operations and maintenance procedures are effective in protecting maintenance personnel through engineering controls, work practices and personal protective devices, which are used to a greater or lesser extent depending on the specific activity.