Radiological Assessment and Statistical Analysis of Natural Radionuclides Associated with Phosphate Ore Activities in the Southern Region of Togo

ORAL

Abstract

The increasing exploitation of phosphate in Togo raises concerns about potential radiological risks associated with mining activities. This study evaluated the activity concentrations of naturally occurring radionuclides (238U, 226Ra, 232Th, and 40K) in soils collected from the Dagbati phosphate mining site in southern Togo and assessed the related radiological health risks. Gamma-ray measurements were performed using a high-purity germanium (HPGe) detector. Elevated activity concentrations of 238U and 226Ra were observed, mainly due to the geological characteristics of the area.

Results showed that 73.33% of the samples exceeded the recommended limit for absorbed gamma dose rate. The mean annual effective dose equivalent was 0.68 mSv·year⁻¹, below the public exposure limit of 1 mSv·year⁻¹, although most individual samples exceeded reference values. Radiological hazard indices and excess lifetime cancer risk were also above recommended limits in more than 73% of samples. The radon mass exhalation rate was below the safety threshold, indicating low radon risk. However, elevated gamma radiation levels suggest potential long-term health risks for the local population.

*The authors wish to express their deep appreciation and gratitude to the IAEA for awarding the fellowship, without which this work would have been impossible; and the Director General of the National Radiation Protection Agency of Cameroon, Dr. Augustin SIMO for the laboratory support. The authors also appreciate the community of Hahotoé-Kpogamé for the understanding during sampling period. They also wish to thank Dr. Michel WARNAU, Programme Management Officer for IAEA to Togo for his understanding and availability to this work. We also wish to address special thanks to Col. MANZI Pidalatan, National Liaison Officer of Togo and project coordinator of IAEA TC Project Number: TOG/0/002 provided in granting access to the facilities to successfully complete this study.

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Publication: Hazou, E., Patchali, T.E., Konzou, E. et al. Radiological Assessment and Statistical Approaches of Natural Radionuclides in Soil Samples Related to Phosphate Ore Activities in the site of Dagbati, Southern Region of Togo. Water Air Soil Pollut 233, 237 (2022). https://doi.org/10.1007/s11270-022-05700-y
Hazou, E., Guembou Shouop, C.J., Nguelem Mekongtso, E.J. et al. Preliminary assessment of natural radioactivity and associated radiation hazards in a phosphate mining site in southern area of Togo. Radiat Detect Technol Methods 3, 16 (2019). https://doi.org/10.1007/s41605-018-0091-x
Hazou, E., Dzagli, M.M., Ndontchueng, M.M. et al. Assessment of radiation hazards related to phosphate ore processing around Kpémé plant in Togo: multivariate statistical approach. Int. J. Environ. Sci. Technol. 20, 307–320 (2023). https://doi.org/10.1007/s13762-022-04054-6

Presenters

  • Milohum Mikesokpo DZAGLI

    • Laboratoire LPMCS/ CERME University of Lomé

Authors

  • Milohum Mikesokpo DZAGLI

    • Laboratoire LPMCS/ CERME University of Lomé

  • Eyakifama Hazou

    • Laboratoire LPMCS, University of Lomé

  • Tchilabalo Essossimna Patchali

    • Department of Mechanical Engineering, University of Ibadan, Ibadan, Nigeria