Case 8: The Fallacy of Changing Asbestos Fiber Measurement Criteria for Risk Assessment Purposes

Standard methods for asbestos fiber counting have been in use for many years, and have been used in epidemiologic studies which have been the basis for regulatory standards. The underlying concept is of estimating the dose-response relationship between asbestos exposure and health outcome (such as asbestosis). Different outcomes may have different dose-response relationships. For example, low dose exposures to asbestos present very little risk for development of asbestosis, but may confer a significant risk for development of mesothelioma many decades later.

Consequently, recent and ongoing attempts to change the criteria for asbestos fiber counting in environmental/occupational sampling MUST BE VIEWED WITH GREAT CAUTION, as the initial tendency is to take the new measurement method and 'plug in' the resulting asbestos fiber concentrations into the established risk-estimation formulas. THERE IS A DANGEROUS FALLACY OPERATING IF THIS IS ALLOWED TO HAPPEN, as I have tried to explain in the following presentation: