Evaluation of Public Exposure to Gamma Radiation in Cotonou, Southern Benin

Gilles David Houndetoungan; Olatoundé Herbert Fachinan; Mahougnon Boniface Zinsou; Sonia Bignon Mahussi Gwladys Adjadohoun; Gibril Abogbo; Bonaventure Awede; Martial Zoungrana; Kuassi Marcellin Amoussou-Guenou

doi:10.15392/2319-0612.2025.2972

Authors

Dr Gilles David Houndetoungan Faculté des Sciences de la Santé, University of Abomey-Calavi , University of Abomey-Calavi https://orcid.org/0000-0003-0574-4386 (unauthenticated)
Dr Olatoundé Herbert Fachinan University of Parakou , University of Abomey-Calavi https://orcid.org/0009-0003-1833-3655 (unauthenticated)
Dr Mahougnon Boniface Zinsou École Polytechnique d’Abomey-Calavi, University of Abomey Calavi , University of Abomey-Calavi https://orcid.org/0009-0002-5514-9518 (unauthenticated)
Dr Sonia Mahussi Gwladys Adjadohoun Faculté des Sciences de la Santé, University of Abomey-Calavi , University of Abomey-Calavi https://orcid.org/0000-0002-2997-6918 (unauthenticated)
Dr Gibril Abogbo Faculté des Sciences de la Santé, University of Abomey-Calavi , University of Abomey-Calavi https://orcid.org/0009-0004-6844-6217 (unauthenticated)
Dr Bonaventure Awede Faculté des Sciences de la Santé, University of Abomey-Calavi , University of Abomey-Calavi https://orcid.org/0009-0003-6268-9376 (unauthenticated)
Dr Martial Zoungrana Joseph Ki-Zerbo University , University of Faso https://orcid.org/0000-0002-1637-2410 (unauthenticated)
Dr Kuassi Marcellin Amoussou-Guenou Faculté des Sciences de la Santé, University of Abomey-Calavi , University of Abomey-Calavi https://orcid.org/0009-0007-9342-5321 (unauthenticated)

DOI:

https://doi.org/10.15392/2319-0612.2025.2972

Keywords:

gamma radiation, georeferenced measurement, ambient dose equivalent rate, public radiation protection

Abstract

The objective of this study is to assess public exposure to natural background gamma radiation in Cotonou, southern Benin, in West Africa. This is a cross-sectional study with both descriptive and analytical aims, conducted from July to December 2024. The methodology involved continuous, georeferenced measurement of the ambient gamma dose rate at a height of one meter (1 m) above ground level using a spectrometer. The study sites included city streets and selected markets, including Dantokpa, an open-air market, and eight indoor markets. A total of 341,991 data points were recorded along the streets and 16,202 were recorded within the markets. The ambient gamma dose equivalent rate along the streets ranged from 4.67 to 136.84 nSv·h– 1, with an average of 25.11 ± 12.72 nSv·h– 1. The highest average rate was observed in District 5, which hosts a cement manufacturing plant. The average dose rates were 23.71 ± 12.90 nSv·h– 1 at the Dantokpa market and 69.72 ± 21.96 nSv·h– 1 in the indoor markets. In the latter, the dose rates were higher than those recorded in their respective districts. The estimated external annual effective doses were 0.04 ± 0.02 mSv for streets, 0.10 ± 0.06 mSv for Dantokpa, and 0.30 ± 0.09 mSv for indoor markets. These values remain below the worldwide average of 0.87 mSv, as recognized by the United Nations Scientific Committee on the Effects of Atomic Radiation for public exposure to natural radiation of terrestrial and cosmic origin. Overall, ambient gamma radiation exposure in Cotonou is low, though higher in enclosed market environments. These values may serve as baseline references for future studies in Cotonou and other African cities.

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