Asbestos

Warning:
This information has not been verified as accurate for 2026.

Asbestos

Naturally occurring asbestos (a fibrous silicate material) is sometimes found in serpentine rock (a common rock in the El Dorado Hills area), especially near fault zones.


Serpentine rocks (2003, by the creators)
Figure 1. Serpentine rocks (2003, by the creators)

Asbestos can cause health problems if the fibers are inhaled. Some fibers can be retained in the lungs for long periods of time, and others can be dissolved in the body after inhalation. Health conditions caused by exposure to asbestos including chronic lung inflammation that can lead to cancer and asbestosis.

The greatest health dangers are to people who manufacture products containing asbestos, those regularly exposed to products containing asbestos, and those working or living where rocks containing asbestos are being moved around, broken down, or crushed.

The U.S. Agency for Toxic Substances (part of the Centers for Disease Control) reports that people exposed to low levels of asbestos have an increased risk of developing cancer, but the risk is usually small.

Among the many natural forms of asbestos are minerals called chrysotile and tremolite. Both can be dangerous, and tremolite is generally considered to be the more dangerous of the two.

Asbestos studies in El Dorado County (1998, 2000)

Occurrences of asbestos in western El Dorado County have been the subject of two studies by the California State Department of Conservation—one in 1998 and another in 2000.

In 1998, the California Air Resources Board did extensive measurements of the asbestos levels in various parts of El Dorado County, including El Dorado Hills. Of the 252 measurements done, 57 detected some asbestos. Air samples done along Silva Valley Parkway detected asbestos in 5 of the 35 samples. The estimated health risks from exposure to asbestos at this level were concluded to be very low.

The general conclusions of both these studies indicated that elevated levels of asbestos do not appear to be widespread except in areas where tremolite or chrysotile rock is common, and then only where extensive excavation or construction is taking place.

For more information

  • California Air Resources Board (ARB)

    Detailed results of the 1998 study.

  • California Office of Environmental Health Hazard Assessment

    Asbestos fact sheet.

  • California Department of Conservation

    Detailed results of the 2000 study.

  • El Dorado County Environmental Management Department

    Asbestos website page, which has links to additional sources of information.

  • U.S. Agency for Toxic Substances and Disease Registry (part of the U.S. Department of Health and Human Services)

    Fact sheet titled “Exposure to Asbestos in Sources Other than Insulation.”