Recent pollution records in Sidi Moussa coastal lagoon (western Morocco) inferred from sediment radiometric dating.

The Sidi Moussa lagoon, located in western coastal Morocco and ranked as a wetland of biological and ecological importance (Ramsar site), is contaminated due to its proximity to the industrial phosphate plants and other anthropogenic activities around it. This study was carried out to assess the current environmental state of the lagoon as well as historical inputs of pollutants over several decades. Three sediment cores were collected and analyzed for the determination radionuclide activities (Pb, Ra, U and Cs) by gamma spectrometry and element concentrations by Inductively Coupled Plasma - Mass Spectrometry.

Assessment of soil erosion rates in a Mediterranean cultivated and uncultivated soils using fallout 137Cs.

Fallout radionuclides, such as Cs, have been recognized as a valuable means for studying soil erosion processes. In this study, the Cs technique was used to assess soil erosion magnitude and to investigate the effectiveness of terrace cultivations in the High Atlas of Morocco, particularly, the Ourika watershed. Cs depth distribution profiles were established along slope gradients associated with land use considering cereal crop, arboriculture and native forests.

Evidence for a recent increase in delivery of atmospheric Pb to Oualidia lagoon, coastal Morocco.

Two sediment cores were collected from the Oualidia lagoon, on the Atlantic coast of Morocco, and analyzed for Pb and Cs activity by gamma spectrometry. The Pb profiles were characterized by high activity at specific depths in each core, which were attributed to substantial increases in atmospheric Pb input to the sediment. A modified CRS model was applied to develop age-depth relations (chronologies) for the cores and calculate sediment accumulation rates, taking into account changing unsupported Pb delivery and specifying the year when the increase began.

Geochemical, radiometric, and environmental approaches for the assessment of the intensity and chronology of metal contamination in the sediment cores from Oualidia lagoon (Morocco).

The present study evaluates the distribution of metals over the last 100 years in the Oualidia lagoon by examining their concentrations in the sediment cores. The samples were analyzed by instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Activities of Pb, Ra, and Cs were determined by gamma-ray spectrometry for establishing the age-depth relationships throughout the sediment cores by applying conventional models.

Assessment of soil erosion and deposition rates in a Moroccan agricultural field using fallout 137Cs and 210Pbex.

In Morocco land degradation - mainly caused by soil erosion - is one of the most serious agroenvironmental threats encountered. However, only limited data are available on the actual magnitude of soil erosion. The study site investigated was an agricultural field located in Marchouch (6°42' W, 33° 47' N) at 68 km south east from Rabat.

Trace metals and radionuclides in macroalgae from Moroccan coastal waters.

Macroalgae species Codium sp, Bangia atropurpurea, Membranoptera alata, Plocamium cartilagineum, Dictyota dichotoma, Fucus spiralis and Stypocaulon scoparia were collected from seven stations along the north coast of Morocco. Samples were analysed to determine activities of naturally occurring radionuclides ((210)Pb, U isotopes and (40)K) and concentrations of metals (Zn, Fe, Co, Cu, Ni, Mn, Pb, Cd, As and Cr) using radiometric and ICP-OES techniques, respectively. Metal concentrations were within ranges reported in the scientific literature, and concentrations of bio-essential elements were in the order Mn>Fe> Zn>Cu in all samples.

Partitioning of radiostrontium in marine aqueous suspensions: laboratory experiments and modeling studies.

Quantitative information on the adsorption/desorption of radionuclides by suspended loads is important in the study of their environmental behavior. In this paper, controlled laboratory experiments were directed at studying the kinetic transfer and final distribution of radiostrontium in aqueous suspensions using 85Sr as tracer. The results showed that the uptake of 85Sr in seawater can be properly described by one reversible-reaction model.