Title: Study of grain size effect on radon exhalation rate using different detection methods and associated health risk assessment

Authors: Dalil Boumala; Abdelfettah Belafrites

Addresses: Département de Physique, Laboratoire de Physique de Rayonnement et Applications (LPRA), Université de Jijel, Ouled Aissa, Jijel, Algeria; Département de Génie de Procèdes, Faculté de Génie des Procédés, Université Constantine, Constantine, Algeria ' Département de Physique, Laboratoire de Physique de Rayonnement et Applications (LPRA), Université de Jijel, Ouled Aissa, Jijel, Algeria

Abstract: The effects of radon released from phosphate ore samples of different grain sizes on radon emanation and exhalation rates, annual effective dose and excess lifetime cancer risk and the associated health risk assessment were investigated. The activity concentrations of ²²⁶Ra and ²²²Rn were evaluated using a high purity germanium gamma-ray spectrometer, an AlphaGUARD ionisation chamber and nuclear track detector (NTD). Specific activities for different phosphate grain sizes ranging from 100 µm to 500 µm were obtained using the NTD. The ²²⁶Ra activity concentrations were found to be 500 ± 35 Bq kg⁻¹. The annual effective dose rate and excess lifetime cancer risk were calculated to be 0.032 mSv y⁻¹ and 0.12×10⁻³, respectively. The results were compared with those reported elsewhere and with UNSCEAR safety limits.

Keywords: phosphate ore; radon emanation; grain size effect; gamma-ray spectrometry; radiation risk.

DOI: 10.1504/IJNEST.2026.154191

International Journal of Nuclear Energy Science and Technology, 2026 Vol.18 No.3, pp.209 - 225

Received: 04 Sep 2024
Accepted: 20 Oct 2025
Published online: 16 Jun 2026 *

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