Evidence for a recent increase in delivery of atmospheric 210Pb to Oualidia lagoon, coastal Morocco

  • Abdelmourhit LaissaouiEmail author
  • N. Mejjad
  • N. Ziad
  • H. Ait Bouh
  • O. El Hammoumi
  • A. Benkdad
  • A. Fekri


Two sediment cores were collected from the Oualidia lagoon, on the Atlantic coast of Morocco, and analyzed for 210Pb and 137Cs activity by gamma spectrometry. The 210Pb profiles were characterized by high activity at specific depths in each core, which were attributed to substantial increases in atmospheric 210Pb 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 210Pb delivery and specifying the year when the increase began. Calculated 210Pb inventories (activity/area) and fluxes (activity/area/time) depend strongly on sedimentation rates and were much higher than mean values in similar coastal systems worldwide. We attempted to use 137Cs as a time marker to support the modified CRS chronologies for both cores. The 137Cs profiles, however, were affected by post-depositional cesium migration in the sediment which made it difficult to identify the 1963 atmospheric bomb-testing peak, especially in the core with low sedimentation rate. We conclude that the high activities of 210Pb detected at specific depths in the Oualidia lagoon sediment cores are a consequence of decay of radioactive 222Rn, which displayed periodic high concentrations in the overlying atmosphere.


210Pb flux Coastal sediment CRS dating model Oualidia lagoon 222Rn 



The authors acknowledge the use of sampling and laboratory equipment provided within the framework of the IAEA Technical Cooperation Project RAF7/015. The authors thank Prof. José María Abril from the University of Seville for his constructive comments on dating results.

Funding information

This work was supported by the International Atomic Energy Agency under the Contract Research Project CRP K41016: “Study of temporal trends of pollution in selected coastal areas by the application of isotopic and nuclear tools.


  1. Abril, J. M. (2003). A new theoretical treatment of compaction and the advective-diffusive processes in sediments: a reviewed basis for radiometric dating models. Journal of Paleolimnology, 30, 363–370.CrossRefGoogle Scholar
  2. Abril, J. M., & Brunskill, G. J. (2014). Evidence that excess 210Pb flux varies with sediment accumulation rate and implications for dating recent sediments. Journal of Paleolimnology, 52, 121–137.CrossRefGoogle Scholar
  3. Abril, J. M., San Miguel, E. G., Ruiz-Canovas, C., Casas-Ruiz, M., & Bolívar, J. P. (2018). From floodplain to aquatic sediments: radiogeochronological fingerprints in a sediment core from the mining impacted Sancho reservoir (SW Spain). Science of the Total Environment, 631–632, 866–878.CrossRefGoogle Scholar
  4. Appleby, P. G. (2000). Radiometric dating of sediment records in European mountain lakes. Journal of Limnology, 59(Suppl. 1), 1–14.Google Scholar
  5. Audry, S., Schäfer, J., Blanc, G., & Jouanneau, J. M. (2004). Fifty-year sedimentary record of heavy metal pollution (Cd, Zn, Cu, Pb) in the lot river reservoirs (France). Environmental Pollution, 132, 413–426.CrossRefGoogle Scholar
  6. Baskaran, M. (2016). Progeny of radon (210Pb) as a tracer and chronometer in continents and aqueous systems. In Radon: a tracer for geological, geophysical and geochemical studies. Springer geochemistry. Cham: Springer.CrossRefGoogle Scholar
  7. Foster, I. D. L., Mighall, T. M., Proffitt, H., Walling, D. E., & Owens, P. N. (2006). Post-depositional 137Cs mobility in the sediments of three shallow coastal lagoons, SW England. Journal of Paleolimnology, 35, 881–895.CrossRefGoogle Scholar
  8. He, Q., & Walling, D. E. (1996). Interpreting particle size effects in the adsorption of 137Cs and unsupported 210Pb by mineral soils and sediments. Journal of Environmental Radioactivity, 30(2), 117–137.CrossRefGoogle Scholar
  9. Hilmi, K., Orbi, A., & Lakhdar Idrissi, J. (2009). Hydrodynamisme de la lagune de Oualidia (Maroc) durant l’été et l’automne 2005. Bulletins de l'Institut Scientifique de Rabat, 31, 29–34.Google Scholar
  10. Khater, A. E. M., & Ebaid, Y. Y. (2008). A simplified gamma-ray self-attenuation correction in bulk samples. Applied Radiation and Isotopes, 66(3), 407–413.CrossRefGoogle Scholar
  11. Kirchner, G. (2011). 210Pb as a tool for establishing sediment chronologies: examples of potentials and limitations of conventional dating models. Journal of Environmental Radioactivity, 102, 490–494.CrossRefGoogle Scholar
  12. Laissaoui, A., Mas, J. L., Hurtado, S., Ziad, N., Villa, M., & Benmansour, M. (2013). Radionuclide activities and metal concentrations in sediments of the Sebou estuary, NW Morocco, following a flooding event. Environmental Monitoring and Assessment, 185, 5019–5029.CrossRefGoogle Scholar
  13. Love, A., Esser, B., & Hunt, J. (2003). Reconstructing contaminant deposition in a San Francisco Bay Marina, California. Journal of Environmental Engineering, 129(7), 659–666.CrossRefGoogle Scholar
  14. Maanan, M., Ruiz-Fernandez, A. C., Maanan, M., Fattal, P., Zourarah, B., & Sahab, M. (2014). A long-term record of land use change impacts on sediments in Oualidia lagoon, Morocco. International Journal of Sediment Research, 29, 1–10.CrossRefGoogle Scholar
  15. Maanan, M., El Barjy, M., Hassou, N., Zidane, H., Zourarah, B., & Maanan, M. (2018). Origin and potential ecological risk assessment of trace elements in the watershed topsoil and coastal sediment of Oualidia lagoon, Morocco. Human and Ecological Risk Assessment, 24(3), 602–614.CrossRefGoogle Scholar
  16. Mejjad, N., Laissaoui, A., El-Hammoumi, O., Benmansour, M., Benbrahim, S., Bounouira, H., Benkdad, A., Bouthir, F. Z., Fekri, A., & Bounakhla, M. (2016). Sediment geochronology and geochemical behavior of major and rare earth elements in the Oualidia lagoon in the western Morocco. Journal of Radioanalytical and Nuclear Chemistry, 309(3), 1133–1143.CrossRefGoogle Scholar
  17. Omokheyeke, O., Sikoki, F. D., Laissaoui, A., Akpuluma, D., Onyagbodor, P., Benkdad A., Benmansour, M. (2014). Sediment geochronology and spatio-temporal and vertical distributions of radionuclides in the Upper Bonny Estuary (South Nigeria). Geochronometria, 41(4), 369–376.CrossRefGoogle Scholar
  18. Oughton, D. H., Børretzen, P., Salbu, B., & Tronstad, E. (1997). Mobilisation of 137Cs and 90Sr from sediments: potential sources to arctic waters. Science of the Total Environment, 202, 155–165.CrossRefGoogle Scholar
  19. Pham, M. K., Povinec, P. P., Nies, H., & Betti, M. (2013). Dry and wet deposition of 7Be, 210Pb and 137Cs in Monaco air during 1998-2010: Seasonal variations of deposition fluxes. Journal of Environmental Radioactivity, 120, 45–57.CrossRefGoogle Scholar
  20. Ramos-Lerate, I., Barrera, M., Ligero, R. A., & Casas-Ruiz, M. (1998). A new method for gamma-efficiency calibration of voluminal samples in cylindrical geometry. Journal of Environmental Radioactivity, 38(1), 47–57.CrossRefGoogle Scholar
  21. United Nations Scientific Committee on Effects of Atomic Radiation. 2000. Exposures from natural radiation sources, UNSCEAR Report, New York.Google Scholar
  22. Zourarah, B., Maanan, M., Carruesco, C., Aajjane, A., Mehdi, K., & Conceição Freitas, M. (2007). Fifty-year sedimentary record of heavy metal pollution in the lagoon of Oualidia (Moroccan Atlantic coast). Estuarine, Coastal and Shelf Science, 72(1–2), 359–369.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Centre National de l’Energie, des Sciences et des Techniques NucléairesRabatMorocco
  2. 2.Laboratoire de Géologie Appliquée, Géomatique et Environnement, Faculté des SciencesCasablancaMorocco
  3. 3.Ecole Nationale des Sciences AppliquéesUniversity Ibn TofailKenitraMorocco

Personalised recommendations