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Naturally occurring radionuclides and Cs were measured in a sediment core and surface deposit collected from the bed channel of the Oualidia Lagoon located in the western Morocco. Major and rare earth elements (REE) profiles were determined by instrumental NAA technique. Pb and Cs were used to establish the sedimentation chronology over the last decades by using conventional models. Pb displayed relatively higher concentrations and rate of supply to the sediment than typical levels found in other coastal areas in Morocco. REE ratios and Ce anomalies showed that the direct incorporation of particles from seawater to the bed sediment is the most important, followed by the terrigenous component. [ABSTRACT FROM AUTHOR]

This study presents metal concentrations (Fe, Mg, Mn, Co, Cu, Zn, Pb, As, Sr and V) and radionuclide activities (K, Cs, Pb, Ra, Ac, Th and Pb) in surface deposits and a sediment core from the Sebou Estuary, Northwest Morocco. Samples were collected in April 2009, about 2 months after a flooding event, and analysed using a well-type coaxial gamma-ray detector and inductively coupled plasma-quadrupole mass spectrometry. Activities of radionuclides and concentrations of almost all elements in surface samples displayed only moderate spatial variation, suggesting homogenous deposition of eroded local soil in response to intense precipitation. Excess Pb displayed relatively constant activity throughout the sediment core, preventing dating and precluding determination of the historical accumulation rates of pollutants at the core site. Some elements showed non-systematic trends with depth and displayed local maxima and minima. Other elements presented relatively systematic concentration trends or relatively constant levels with discrete maxima and/or minima. Except for Mn, Sr and Cr, all metal concentrations in sediment were below levels typical of polluted systems, suggesting little human impact or losses of metals from sediment particles. [ABSTRACT FROM AUTHOR]

In forensic contexts, time since death assessment in human skeletal remains is crucial for identification, and both accuracy and reliability are required. In this paper, we present the possibilities and constraints of the use of Pb in dating skeletonized human bones in Morocco. The method was tested on recent as well as archaeological bones of known dates of death. A calibration curve was obtained from the available data in the scientific literature. The Pb initial activity was introduced as an increasing lineal function with time. The Pb dating approach gives promising results only for recent bones. On the contrary, for archaeological bones, the technique has erroneously led to post-mortem intervals in the range of recent bones which constitute a serious limitation of the method. On the other hand, uranium isotopes content in bones is suggested in this work as a possible indicator in placing a studied bone within either a forensic or archaeological context. [ABSTRACT FROM AUTHOR]

new certified reference material (CRM) for radionuclides in sea water from the Irish sea (IAEA-443) is described and the results of the certification process are presented. Ten radionuclides (H, K, Sr, Cs, U, U, U, Pu, Pu and Am) have been certified, and information values on massic activities with 95% confidence intervals are given for four radionuclides (Th, Th, Pu and Pu). Results for less frequently reported radionuclides (Tc, Th, Np and Pu) are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in water samples, for the development and validation of analytical methods and for training purposes. The material is available in 5 L units from IAEA (). [ABSTRACT FROM AUTHOR]

A new Reference Material (RM) for radionuclides in mussel ( Mytilus galloprovincialis) from the Mediterranean Sea (IAEA-437) is described and the results of the certification process are presented. Four radionuclides (40K, 234U, 238U, and 239+240Pu) have been certified, and information values on massic activities with 95% confidence intervals are given for nine radionuclides (137Cs, 210Pb(210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, and 241Am). Results for less frequently reported radionuclides (90Sr, 129I, 238Pu, 239Pu, and 240Pu) are also reported. The RM can be used for quality assurance/quality control of the analysis of radionuclides in mussel samples, for the development and validation of analytical methods and for training purposes. The material is available in 200 g units. [ABSTRACT FROM AUTHOR]

The uranium and thorium contents were evaluated in the 100–400 µm granulometric fraction of different sedimentary phosphate samples by using a method based on determining the mean critical angles of etching of the CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) for detecting α-particles emitted by the nuclei of the uranium-238 and thorium-232 series. Data obtained were compared with the results of γ-ray spectrometry measurements performed on the same samples. The influence of the calcination and water washing treatments as well as the lithology and stratigraphy on the uranium concentration of the phosphate samples was investigated. [ABSTRACT FROM AUTHOR]

An improved and rapid method is described for the determination of 90Sr in environmental samples, through the separation of the daughter 90Y at equilibrium. The procedure is based on the HDEHP solvent extraction in combination with liquid scintillation spectrometry (LSS). A low background QuantulusÔ has been optimized for low level counting of Cerenkov radiation emitted by the hard b-emitter 90Y. The counting efficiency was 60% and the background 0.53 cpm. The reliability and reproducibility of the method have been checked using IAEA reference materials. The chemical recovery for 90Y extraction ranges from 83 to 90%. [ABSTRACT FROM AUTHOR]