What is asbestos exposure and why is asbestos exposure a concern?

Ultramafic or serpentine rock, which often contains asbestos, has been used in surfacing applications subject to pedestrian, vehicular, and recreational use. Activity in areas with asbestos-containing rock or soil may create dust emissions containing asbestos fibers. Asbestos exposure primarily results from breathing in asbestos fibers, and less commonly from ingesting asbestos fibers. Asbestos fibers are too small to be seen by the naked eye. All types of asbestiform minerals are considered hazardous with no safe exposure level established for non-occupational exposures. 

While exposure to low levels of asbestos for short periods of time is thought to pose minimal risk, asbestos fibers can penetrate body tissues and remain in lung or abdominal areas for a long time. Asbestosis is widespread scarring of lung tissue caused by breathing air contaminated with asbestos dust or fibers. Asbestos inhalation also can cause the two layers of membrane covering the lungs (the pleura) to thicken. The more a person is exposed to asbestos fibers, the greater the risk of developing asbestos-related diseases including lung cancer and rarely, mesothelioma - a rare cancer, mostly caused by asbestos, which may affect the pleura or peritoneum. The illnesses caused by asbestos may not be noticed for twenty years or more, with mesotheliomas usually developing 30 to 40 years after exposure. (Merck Manual of Medical Information, 1997, page 182)

Additional Information

For further information, visit the Health Effects of Asbestos website.

Show All Answers

1. Where are NOA deposits, or rock formations that may contain NOA, located in Placer County?
2. Considering the findings of the EPA and the ATSDR activity-based air monitoring in El Dorado Hills in El Dorado County, will similar monitoring be conducted by the District?
3. What is being done to minimize the disturbance of NOA deposits, or rock formations that may contain NOA, in Placer County?
4. What is asbestos exposure and why is asbestos exposure a concern?
5. What can I do to reduce my exposure and that of my family to NOA fibers?