Radiological Risk Assessment For The Population Of Antsiranana Ii District, Madagascar, Due To External Exposure To Natural Radioactivity In Soil

Astellinah Née Stevenah TSILAILAY, Zafizara DONNE, Rodel Justola TSIAFITAKA, Asivelo Fanantenansoa SOLONJARA, Augustin RAZAFINDRAPATA, Frédéric ASIMANANA

Abstract


The assessment of public exposure to natural radiation sources is a fundamental component of public health protection. This study evaluates the radiological hazards associated with soils in the Antsiranana II district, Madagascar, a region where the population has significant daily contact with soil for agriculture and as a building material. Activity concentrations of ⁴⁰K, ²³⁸U, and ²³²Th in 23 soil samples were used to calculate key radiological risk parameters. The radium equivalent activity (Raeq) ranged from 87 to 196 Bq.kg⁻¹, with a mean of 147 Bq.kg⁻¹, a value well below the international safety limit of 370 Bq.kg⁻¹ for building materials. The absorbed gamma dose rate in air (Da) was calculated to have a mean of 67 ± 14 nGy.h⁻¹, which is slightly above the world average of 57 nGy.h⁻¹. Consequently, the mean annual effective dose (AED) received by the population from external exposure to soil was estimated at 0.21 ± 0.04 mSv.h⁻¹, significantly lower than the 1 mSv.h⁻¹ public dose limit recommended by the ICRP. The associated lifetime excess cancer risk was also found to be negligible. Despite the observed geological enrichment in uranium and thorium, this study concludes that the overall radiological risk to the population from external terrestrial radiation in the district is low and does not pose a significant public health threat.

Keywords


Radiological Risk; Annual Effective Dose; Radium Equivalent; Soil Radioactivity; Public Health; Radioprotection; Madagascar.

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DOI: http://dx.doi.org/10.52155/ijpsat.v59.1.8640

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