Digital Mapping of Potential Mineral and Geochemical Hazards in California: Examples for Naturally Occurring Asbestos, Radon, and Highway Corridor Mapping Projects

Over the last two decades, the California Geological Survey (CGS) has increasingly received requests for environmental geology/mineralogy/geochemistry information from State and local agencies, consultants, industries, and the public. These requests have led to projects to identify and map potential mineral hazards such as naturally occurring asbestos, heavy metals, and radon. In these projects, digital mapping technology is used to compile, evaluate, and interpret data from a variety of sources and to develop associated products. The information and advice provided by the CGS are used by State and local government agencies and the public to protect the life and safety of California citizens, to protect the health of the environment, and to raise public awareness of these hazards. This paper discusses three different types of mineralhazard studies and the use of Geographic Information System (GIS) tools in their preparation. The complexity of these studies, both in geologic and GIS context, varies depending on the amount, type, and format of data involved as well as the intended use, audience, and format of the final products. These vary from relatively simple derivative maps based on geological information and intended for use by non-geologists to more complex maps and datasets combining data from varied sources and intended for multiple user groups with wide-ranging technical backgrounds. The reports accompanying all of these studies describe and document the study methodology, data sources, methods of analysis, interpretive conclusions, and limitations of the products. Digital Mapping of Potential Mineral and Geochemical Hazards in California: Examples for Naturally Occurring Asbestos, Radon, and Highway Corridor Mapping Projects