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CGS Mineral Hazards: Indoor Radon Potential Zones

Published by California Department of Conservation | State of California | Metadata Last Checked: December 28, 2025 | Last Modified: 2016-07-12T00:00:00.000Z
This digital layer contains polygons (vector format) of portions of California designated as having high, moderate, low, or unknown potential for homes to exceed the U.S. EPA recommended radon action level of 4.0 picocuries per liter in indoor air. Only a portion of California is covered by the studies included in this dataset.

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