Determination of Natural Radioactivity in the North East Beach Sands of Madagascar

Exploration and exploitation of radioactive ores (ilmenite, zircon and monazite) are considered as the main source of exposure to ionizing radiation of the population living in the coast of Analanjorofo Region (Fenerive-Est Districts, Rural municipality Ampasimbe Manantsatrana). Radioactivity measurements have been performed in this region. The distribution of natural radionuclide gamma-emitters (²³⁸U, ²³²Th and ⁴⁰K) and their respective annual effective dose rates have been determined for sand(s), water and air. The samples have been collected along and around the coast of the region. The radiation emitted from the natural radionuclide containing in the environmental samples has been determined by gamma spectrometry system and Radon meter (SARAD). Exposure dose rates at 1 m above the ground have been measured along the coast and in the villages around the exploitation sites. Dose rate measurements have been performed by Dosimeter Graetz X5DE, equipped of Geiger Muller Counter. Results have been compared with the reference values provided by IAEA (BSS 115) and UNSCEAR 2000.