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Radiological Air Sample Quarterly Composites

Published by California Department of Public Health | State of California | Metadata Last Checked: November 28, 2025 | Last Modified: 2025-11-07T05:02:24.564597
IMPORTANT: Please see the attached PDF for more context on this dataset. Per Health and Safety Code 114755 which mandates that "The department shall monitor radioactive materials in the environment", air sampling stations have been placed in or near major population centers with the potential for significant radiological activity. The data presented in this table are for quarterly aggregates of sampling media per site. Dose per quarter is reported in millirem Total Effective Dose Equivalent (TEDE); all other values are radiological activity concentrations reported in units of picoCuries per cubic meter. Any positive result less than the minimum detectable activity is attributable to statistical measurement noise, and results are reported even in the case of non-detection. Beryllium-7 and Potassium-40 are naturally occurring radionuclides. The other radionuclides in the dataset are fission products. Detection of Cesium-137 is not necessarily indicative of a new release because atmospheric nuclear weapons testing distributed significant amounts across the world that are still measurable.

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