title: Can default ICRP f1 values be applied to determine radiation dose from the intake of diet-incorporated thorium?
abstract: Data on the daily urinary excretion of thorium (Th) was obtained from 15 non-exposed adult German subjects. A radiochemical neutron activation analysis method was developed and standardised especially for this purpose. The daily urinary excretion of 232Th was found to be in the range 1.9-14.9 microBq d(-1) with a mean (+/-SD) value of 6.5 (+/-4.3) microBq d(-1). Using this excretion value and reported data on dietary intake of Th for a similar German population, the gastrointestinal absorption factor (f1 value) proposed by the International Commission on Radiological Protection (ICRP) was tested. Although the daily excretion of 232Th observed in the present study was comparable to some of the currently reported values in certain other countries, it was higher than the excretion value calculated by applying the biokinetic model of Th proposed by ICRP for the dietary intake values. The study showed that the default ICRP values of the f1 factor for diet-incorporated Th may not be applicable.
authors.affiliation: GSF-National Research Center for Environment and Health, Institute of Radiation Protection, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany. vera.hoellriegl@gsf.de
authors.forename: V
authors.initials: V
authors.lastname: Höllriegl
authors.forename: W B
authors.initials: WB
authors.lastname: Li
authors.forename: U
authors.initials: U
authors.lastname: Oeh
authors.forename: M
authors.initials: M
authors.lastname: Röhmuss
authors.forename: P
authors.initials: P
authors.lastname: Roth
mesh_terms: D000328:Adult; D000368:Aged; D001822:Body Burden; D004032:Diet; D005260:Female; D005507:Food Contamination, Radioactive / Q000032:analysis*; D005858:Germany; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D009502:Neutrons; D011336:Probability; D011829:Radiation Dosage; D011835:Radiation Protection / Q000592:standards*; D012737:Sex Factors; D013910:Thorium / Q000493:pharmacokinetics* / Q000652:urine; D013997:Time Factors; D014556:Urine
chemical_list: D013910:Thorium