title: Lung counting: summing techniques to reduce the MDA.
abstract: The new dose limits recently adopted in Canada (and elsewhere in the world) have made it more difficult to detect some radionuclides by in vivo counting at the average dose limit of 20 mSv. This is particularly true for natural uranium. Two techniques have been developed by the Human Monitoring Laboratory to reduce the Minimum Detectable Activity (MDA) for the lung counting of this nuclide. The first technique, developed in collaboration with Cameco, is to either sum sequential counts of an individual or to sum spectra of a group of workers similarly occupationally exposed. This technique offers a reduction in the MDA of up to a factor of three. The second technique, developed in collaboration with CNEN, involves the summing of photopeaks within an individual spectrum and offers a reduction in the MDA of up to a factor of two.
authors.affiliation: Human Monitoring Laboratory, Radiation Protection Bureau, 775 Brookfield Road, PL6302D1, Ottawa, Ontario K1A 1C1, Canada. Gary_H_Kramer@hc-sc.gc.ca
authors.forename: Gary H
authors.initials: GH
authors.lastname: Kramer
authors.forename: Barry M
authors.initials: BM
authors.lastname: Hauck
authors.forename: Steve A
authors.initials: SA
authors.lastname: Allen
authors.forename: Bernardo M
authors.initials: BM
authors.lastname: Dantas
authors.forename: Ana Letícia A
authors.initials: AL
authors.lastname: Dantas
authors.forename: Adelaide M G F
authors.initials: AM
authors.lastname: Azeredo
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis* / Q000493:pharmacokinetics*; D001822:Body Burden; D002170:Canada; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D008452:Maximum Allowable Concentration; D008875:Middle Aged; D008954:Models, Biological; D016273:Occupational Exposure / Q000032:analysis*; D011786:Quality Control; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D020711:Threshold Limit Values; D014501:Uranium / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D014501:Uranium