You are here:
ASBESTOS AND RELATED DURABLE FIBERS: TOO UBIQUITOUS, TOO PERSISTENT, TOO COMPLEX TO PUT HEALTH RISKS TO REST?
Citation:
Cook, P. M. ASBESTOS AND RELATED DURABLE FIBERS: TOO UBIQUITOUS, TOO PERSISTENT, TOO COMPLEX TO PUT HEALTH RISKS TO REST? Presented at Minnesota Society of Toxicology, Duluth, MN, October 29, 2003.
Description:
Asbestos was used for centuries before its health risks become publicly known. Health concerns for non-occupational exposures rose at EPA's inception and these concerns quickly expanded to include risks from inhalation and ingestion of durable mineral and synthetic fibers that were similar but not identical to fibers in commercial asbestos dusts. Examples of these "asbestos-like fibers" include chrysotile or zeolite fibers from disturbed soils; amphibole fibers from mining metamorphosed iron formations, vermiculite, or talc; and synthetic fibers of glass, silicon carbide, or alumina. Today the incidence os asbestos disease in the general population is unabated despite efforts for several decades to reduce exposures. Most of the uncertainties articulated in the 1970s, concerning the relative potencies of different fibers, are still unresolved today, especially for assessing risks to environmentally exposed populations. As with persistent bioaccumulative chemical toxicants, analytical options are often controversial with cost minimization a contributing factor. There is need to insure that interpretations of epidemiological data which are primarily from past occupational exposures with very uncertain characterizations, are consistent with advances in knowledge of the biological mechanisms of action, animal toxicity data, and inclusive, rather than exclusive, dose measurements. In this regard, a tissue fiber dose based, variable relative fiber potency, cumulative risk model for assessing health risks associated with inhalation exposures is proposed for further development and application.