Mineral Hazards

The California Geological Survey provides maps, geologic information and advice, and monitors activity on minerals-related environmental and public health issues such as asbestos, mercury and radon.

The program has an ongoing effort to provide geologic information on natural asbestos occurrences in California to state and local government agencies and the public. The program also provides information about activities at historic mine sites related to mercury issues and has participated in detailed studies related to mercury in cooperation with other agencies and university research groups. In cooperation with the California Department of Public Health (CDPH), the program provides geologic information and advice related to radon occurrence in California, and has undertaken special projects to prepare county radon potential maps and to examine the relationships between geology and soils and indoor radon at elementary schools.

crysotile - asbestos specimen

Asbestos occurs naturally in certain geologic settings in California. Inhalation of asbestos fibers may cause cancer. Most commonly, asbestos occurrences are associated with serpentinite and partially serpentinized ultramafic rocks. Click here to read more on asbestos including reports, maps and guidelines for geologic investigations.

cinnabar specimen

Mercury was mined historically in California and widely used for gold recovery at mines until about 1970. Mercury from historic mercury mines or gold mines has entered a number of watersheds in California. In some watershed environments this mercury may enter the food chain and become a health hazard to animals and humans. Click here for more information about mercury

radon detectors

Radon gas is a naturally-occurring, radioactive gas that is invisible and odorless. It forms from the radioactive decay of small amounts of uranium and thorium naturally present in rocks and soils. The image shows different types of radon detectors. Click here for more information about radon​ including reports, maps, and the Radon Database for California.