title: Natural radioactivity in phosphates, phosphogypsum and natural waters in Morocco.
abstract: The contents of natural radionuclides (uranium, actinium and thorium series) were measured in sedimentary phosphate rock samples using high-resolution gamma spectrometry. Data obtained for uranium content (ppm) were compared with the results obtained by a method based on the measurements using solid-state nuclear track detectors (SSNTD) in the same samples. The potential leaching of radionuclides from sedimentary phosphate rock during the industrial production of the phosphoric acid was studied. The process of leaching of the radioisotopes from phosphogypsum was discussed. A method for the direct alpha counting of 226Ra thin source, elaborated by the deposition of Ra from aqueous solutions on manganese oxides film deposited on polyvinyl support, have been developed and applied for the determination of 226Ra in natural water samples. The results show that only the water sample from the mine area reveals the presence of 226Ra at a level of about 0.2 Bq l-1.
authors.affiliation: Laboratoire de Radiochimie, Université Hassan II-Mohammedia, Faculté des Sciences Ben M'Sik, Département de Physique, Sidi Othmane, Casablanca, BP 7955, Morocco.
authors.forename: M
authors.initials: M
authors.lastname: Azouazi
authors.forename: Y
authors.initials: Y
authors.lastname: Ouahidi
authors.forename: S
authors.initials: S
authors.lastname: Fakhi
authors.forename: Y
authors.initials: Y
authors.lastname: Andres
authors.forename: J C
authors.initials: JC
authors.lastname: Abbe
authors.forename: M
authors.initials: M
authors.lastname: Benmansour
mesh_terms: D000186:Actinium / Q000032:analysis; D000512:Alpha Particles; D001031:Apatites / Q000032:analysis; D001417:Background Radiation; D002133:Calcium Sulfate / Q000737:chemistry*; D005308:Fertilizers; D005618:Fresh Water / Q000737:chemistry; D006207:Half-Life; D007854:Lead / Q000032:analysis; D008906:Mining; D009018:Morocco; D016273:Occupational Exposure; D010710:Phosphates / Q000737:chemistry*; D010756:Phosphoric Acids / Q000138:chemical synthesis; D010758:Phosphorus / Q000737:chemistry*; D011883:Radium / Q000032:analysis; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma; D013057:Spectrum Analysis; D013910:Thorium / Q000032:analysis; D014501:Uranium / Q000032:analysis; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D001031:Apatites; D005308:Fertilizers; D010710:Phosphates; D010756:Phosphoric Acids; D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive; C077769:phosphogypsum; D010758:Phosphorus; D007854:Lead; D014501:Uranium; D013910:Thorium; C030242:phosphoric acid; D000186:Actinium; D011883:Radium; D002133:Calcium Sulfate