LEVELS OF NATURAL AND ANTHROPOGENIC RADIONUCLIDES IN SEDIMENTS OF SOME MOROCCAN COASTAL AREAS AND DOSE ASSESSMENT...

Area of Science:

• Environmental Science
• Radiochemistry
• Marine Ecology

Background:

• Coastal ecosystems are vital and susceptible to radionuclide contamination.
• Understanding radionuclide levels is crucial for assessing ecological risks.

Purpose of the Study:

• To quantify natural and anthropogenic radionuclides (40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th, 228Ra) in Moroccan coastal sediments.
• To assess radiological risks to biota using the ERICA tool.
• To establish baseline radioactivity levels in diverse Moroccan coastal environments.

Main Methods:

• Sediment samples collected from Moroccan estuaries and lagoons.
• Analysis of radionuclide concentrations using Gamma spectrometry.
• Radiological risk assessment performed with the ERICA tool to estimate dose rates to reference organisms.

Main Results:

• Highest radionuclide activity concentrations observed in Sidi Moussa Lagoon sediments, likely due to anthropogenic activities.
• Lowest levels found in Sebou estuary, possibly linked to a flooding event.
• 210Pb and 40K showed the most significant concentrations; 137Cs concentrations were lowest.
• World Wide Average concentrations of 226Ra and 40K were exceeded in specific lagoon sites.
• Total dose rates to biota were below the admissible limit (10 μGy h-1), indicating low radiological risk.

Conclusions:

• Moroccan coastal sediments exhibit varying radionuclide concentrations influenced by natural and anthropogenic factors.
• The ERICA tool confirmed that current radioactivity levels pose no significant radiological harm to aquatic organisms in the studied areas.
• Further monitoring is recommended, especially in areas with elevated concentrations like Sidi Moussa Lagoon.