Potential Radiological Impact of Airborne Releases and Direct Gamma Radiation to Individuals Living Near Inactive Uranium Mill Tailings Piles.
The estimated potential annual dose from radioactive radon decay products to individuals in dwellings in the vicinity of an average inactive pile is approximtely 8 rem to the tacheobronchial region of the lungs at about 50 meters from the pile, 0.3 rem at 1 kilometer, and 0.1 rem at about 2.2 kilometers. The corresponding doses to the pulmonary region of the lungs from airborne uranium thorium-230, and radium-226 are estimated to be about one-third as large within 1 kilometer of the pile. Gamma exposure rates on the tailings are up to 1 mR/hr. Estimated exposure rates are in reasonable agreement with the limited data from field measurements. Should an individual be exposed continuouly to a dose equivalent of 8 rem/yr to the tracheobronchial region of the lung, it would require 100 years of exposure to double his risk of bronchial cancer. Also, this level of exposure is considered equivalent to 0.5 Working Level Months per year. Average individuals exposed over a lifetime to a dose equivalent of 0.3 rem/yr and 0.1 rem/yr would increase their risk of bronchial cancer by about 3 percent and 1 percent respectively.
|Uranium; Gamma rays; Health physics; Radiation dosage; Radioactivity; Mills; Populations; Exposure; Radon isotopes; Public health; Risk; Pulmonary neoplasms|
|Office of Air and Radiation|
|No suboffice specified|
|Office of Radiation Programs|
|Swift, Jerry J.; Hardin, James M.; Calley, Harry W.|