title: An evaluation of the external radiation exposure dosimetry and calculation of maximum permissible concentration values for airborne materials containing 18F, 15O, 13N, 11C and 133Xe.
abstract: To better understand the dose equivalent (D.E.) rates produced by airborne releases of gaseous positron-emitting radionuclides under various conditions of cloud size, a study of the external radiation exposure dosimetry of these radionuclides, as well as negatron, gamma and x-ray emitting 133Xe, was undertaken. This included a calculation of the contributions to D.E. as a function of cloud radii, at tissue depths of 0.07 mm (skin), 3 mm (lens of eye) and 10 mm (whole body) from both the particulate and photon radiations emitted by these radionuclides. Estimates of maximum permissible concentration (MPC) values were also calculated based on the calculated D.E. rates and current regulations for personnel radiation protection (CFR84). Three continuous air monitors, designed for use with 133Xe, were evaluated for applications in monitoring air concentrations of the selected positron emitters. The results indicate that for a given radionuclide and for a cloud greater than a certain radius, personnel radiation dosimeters must respond acceptably to only the photon radiations emitted by the radionuclide to provide acceptable personnel dosimetry. For clouds under that radius, personnel radiation dosimeters must also respond acceptably to the positron or negatron radiations to provide acceptable personnel dosimetry. It was found that two out of the three air concentration monitors may be useful for monitoring air concentrations of the selected positron emitters.
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D002250:Carbon Radioisotopes / Q000032:analysis; D005461:Fluorine / Q000032:analysis; D006801:Humans; D008452:Maximum Allowable Concentration; D009590:Nitrogen Radioisotopes / Q000032:analysis; D010104:Oxygen Radioisotopes / Q000032:analysis; D011834:Radiation Monitoring / Q000295:instrumentation; D011868:Radioisotopes / Q000032:analysis*; D011874:Radiometry / Q000379:methods; D014980:Xenon Radioisotopes / Q000032:analysis
chemical_list: D000393:Air Pollutants; D000396:Air Pollutants, Radioactive; D002250:Carbon Radioisotopes; D009590:Nitrogen Radioisotopes; D010104:Oxygen Radioisotopes; D011868:Radioisotopes; D014980:Xenon Radioisotopes; D005461:Fluorine