A building material manufacturer, who in the past had manufactured an asbestos-containing product, asked us to investigate the history of construction and renovation activities at several colleges at which a former employee of the colleges claimed exposure to asbestos during the late 1960s through early 1980s.
We researched public and private records, and visited the sites. This allowed us to track the construction and renovation activities at these colleges during the relevant times, including the use of asbestos-containing materials. From this information we determined all materials associated with potential asbestos exposures to the former employee, and the magnitude of these potential exposures during the relevant time. In addition, a literature research was performed to estimate exposures experienced by the former employee during other employment. This data allowed a retrospective exposure study to be performed for exposures to asbestos experienced by the former worker during his occupational history. Cumulative exposure (dose) resulting from each employment was calculated. The portion of this cumulative exposure that could have resulted from the manufacturer’s product was determined. A literature search was also conducted to determine outdoor ambient airborne asbestos levels to which the former employee would have been exposed during his lifetime.
Our experience with asbestos-containing materials and the analysis described above allowed us to prepare a retrospective analysis of exposure to airborne asbestos experienced by the former worker. This analysis compared the former worker’s potential exposure related to the manufacturer’s product to exposure related to other products and to the ambient environment. Our analysis showed that the potential exposure associated with the manufacturer’s product was sufficiently below that resulting from the ambient environment that it contributed no increase in disease potential over that experienced by any individual living in the same locality. In addition, to put the risk from this exposure in context, it was compared to other everyday risks, such as driving an automobile, flying, or eating peanut butter.