Multiple Modes of Action of Asbestos and Related Mineral Fibers

“Asbestos” is a generic term that encompasses multiple fiber types but may mean different things, depending on the scientific discipline. This lack of consistency among asbestos research communities can lead to a disconnect when comparing studies in asbestos research. Differences in the interpretation of asbestos definitions between disciplines lead to discrepancies in the results and their interpretations from the research analyzed. A comparison of the health and environmental impacts of various asbestos fibers is not possible without consistency in how these fibers are defined. A grasp of these issues is important to fully understand the state of the science of asbestos research. A respirable environmental dust like asbestos may work through more than one mode of action (MOA), with multiple MOAs for various health outcomes following exposure to the same particulate (e.g., interstitial fibrosis versus lung cancer versus mesothelioma). A mode of action encompasses a sequence of key events and processes that begin with the interaction between fibers and cells that may result in both cancer and complex noncancer health effects. The complexities of fiber toxicity make it difficult to define one MOA for asbestos in general. Further, the potential overlap of multiple MOAs makes it feasible to assume