title: Committed effective dose determination in southern Brazilian cereal flours.
abstract: The health impact of radionuclide ingestion from foodstuffs was evaluated by the committed effective doses determined in eight commercial samples of South-Brazilian cereal flours (soy, wheat, cornmeal, cassava, rye, oat, barley and rice flours). The radioactivity traces of (228)Th, (228)Ra, (226)Ra, (40)K, (7)Be and (137)Cs were measured by gamma-ray spectrometry employing an HPGe detector of 66 % relative efficiency. The efficiency curve has taken into account the differences in densities and chemical composition between the matrix and the certified sample. The highest concentration levels of (228)Th and (40)K were 3.5±0.4 and 1469±17 Bq kg(-1) for soy flour, respectively, within the 95 % confidence level. The lower limit of detection for (137)Cs ranged from 0.04 to 0.4 Bq kg(-1). The highest committed effective dose was 0.36 μSv.y(-1) for (228)Ra in cassava flour (adults). All committed effective doses determined at the present work were lower than the International Atomic Energy Agency dose limit of 1 mSv.y(-1), to the public exposure.
authors.affiliation: Physics Department, Federal University of Southern Border, C.P. 253, P.O. Box 85770-000, Realeza, PR, Brazil. viviane.scheibel@uffs.edu.br
authors.forename: V
authors.initials: V
authors.lastname: Scheibel
authors.forename: C R
authors.initials: CR
authors.lastname: Appoloni
mesh_terms: D001417:Background Radiation; D001608:Beryllium / Q000032:analysis; D001938:Brazil; D002588:Cesium Radioisotopes / Q000032:analysis; D002523:Edible Grain; D005433:Flour; D005506:Food Contamination; D011197:Potassium Radioisotopes / Q000032:analysis; D011834:Radiation Monitoring / Q000379:methods*; D011868:Radioisotopes / Q000032:analysis; D011874:Radiometry / Q000379:methods*; D011883:Radium / Q000032:analysis; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D013051:Spectrometry, Gamma / Q000379:methods; D013910:Thorium / Q000032:analysis
chemical_list: D002588:Cesium Radioisotopes; D011197:Potassium Radioisotopes; D011868:Radioisotopes; D012990:Soil Pollutants, Radioactive; D013910:Thorium; D001608:Beryllium; D011883:Radium