Although the toxicity values presented in these toxicity profiles were correct at the time they were produced, these values are subject to change. Users should always refer to the Toxicity Value Database for the currect toxicity values. Managed by Lockheed Martin Energy Systems, Inc., for the U.S. Department of Energy under Contract No. Asbestos fibers are chemically inert, or nearly so.
Asbestos fibers can enter the body after inhalation or oral exposures.
Some ingested asbestos fibers penetrate the gastric mucosa, and a small percentage of the fibers are distributed to other tissues. The main clinical symptom is shortness of breath, often accompanied by rales and cough. Because asbestos fibers are resistant to breakdown in the lungs, the inflammatory response triggered by the fibers is ongoing, even after exposure has ceased. The evidence for carcinogenicity in orally exposed animals is also equivocal. For lung cancer, the magnitude of the carcinogenic risk appears to be a function of a number of factors, including the level and duration of exposure, the time since exposure occurred, the age at which exposure occurred, the smoking history of the exposed person, and the type and size distribution of asbestos fibers.