Environmental radiation levels in central Florida's phosphate mining district

Environmental levels of radionuclides and gamma radiation were measured in two communities located near active phosphate mining areas in Florida. Activated carbon canisters and alpha track detectors were used to measure indoor air levels of radon in approximately 100 private homes. Elevated levels of radon (> 4 picocuries per liter [pCi/L]) were detected in 8 of 27 homes in a community built on reclaimed land that had been previously mined. In a nearby community built on unmined land, elevated levels of radon were detected in 1 of 69 homes. All of the homes with elevated levels of radon were built on concrete slabs. Outdoor gamma radiation levels were significantly greater in the reclaimed area than in the unmined area. Air particulates collected from outdoor ambient air at three locations did not contain elevated levels of radionuclides.