Assessment of Natural Radioactivity in Phosphogypsum Generated in Senegal: A Radiological Investigation

Abstract

The concentrations of radioisotopes (²³⁸U, ²³⁴U, ²³⁵U, ²¹⁰Po, ²³²Th, ⁴⁰K, and ²²⁶Ra) in naturally occurring radionuclide materials were determined through gamma and alpha spectrometry. The average activities of ²²⁶Ra, ²³²Th, and ⁴⁰K were matched with literature data from various countries. The radium equivalent value derived is 532.3 Bq kg⁻¹, which exceeds the recommended limit of 370 Bq kg⁻¹ for building materials without restrictions by 43.86%. The mean absorbed dose rate is 245.3 nGy h⁻¹, significantly superior than 57 nGy h⁻¹ reference value. The global annual effective dose, resulting from external radiation exposure and dust inhalation, is 0.3 mSv y⁻¹, below the 1 mSv y⁻¹ limit approved by the International Commission on Radiological Protection for public exposure.