Title: Natural radioactivity measurements in drinking water and ingestion dose assessment: case of the uranium bearing region of Poli, Cameroon

Authors: Siaka Yvette Flore Tchuente; Yakum Ntaw Susan Younui; Serge Alain Djepang; Saïdou

Addresses: Nuclear Technology Section, Institute of Geological and Mining Research, Yaoundé, Cameroon ' Nuclear Technology Section, Institute of Geological and Mining Research, Yaoundé, Cameroon ' Nuclear Technology Section, Institute of Geological and Mining Research, Yaoundé, Cameroon ' Nuclear Technology Section, Institute of Geological and Mining Research, Yaoundé, Cameroon; Nuclear Physics Laboratory, University of Yaoundé I, Yaoundé, Cameroon

Abstract: This study aimed at measuring radioactivity in drinking water and to assess corresponding ingestion dose to the public and the uranium toxicity. Twenty samples were collected in the uranium bearing region of Poli, Cameroon. α- and γ-spectrometry were used for radioactivity measurements. The range of activity concentrations for each radionuclide is 0.7 ± 0.3-3.5 ± 0.5 mBq.l⁻¹ for ²³⁸U, 0.07 ± 0.03-2.1 ± 0.9 mBq.l⁻¹ for ²³⁵U, 0.6 ± 0.2-5.1 ± 0.6 mBq.l⁻¹ for ²³⁴U, 10 ± 1 mBq.l⁻¹ for ²²⁶Ra, 10 ± 2-16.8 ± 2.2 mBq.l⁻¹ for ²¹⁰Po. Ingestion dose due to intake of ²³⁸U, ²³⁵U, ²³⁴U, ²²⁶Ra and ²¹⁰Po in water was assessed for six age groups. The mean ingestion dose ranges from 8.8 μSv.yr⁻¹ for adult to 123 μSv.yr⁻¹ for infant, higher than the reference level of the committed effective dose (100 μSv.yr⁻¹) recommended by the World Health Organisation (WHO). The uranium mass ranges between 0.014 μg.l⁻¹ and 0.18 μg.l⁻¹, below the reference mass which is 30 μg.l⁻¹ showing that the uranium toxicity is low. ²³⁴U/²³⁸U isotopic ratio in water was observed with values near the equilibrium on 70% of collected samples and far from equilibrium reaching 3.09 in a borehole.

Keywords: water; uranium; radium; polonium; α-spectrometry; γ-spectrometry; ingestion dose; toxicity.

DOI: 10.1504/IJLR.2019.103330

International Journal of Low Radiation, 2019 Vol.11 No.2, pp.99 - 114

Received: 03 Apr 2018
Accepted: 14 Mar 2019
Published online: 04 Nov 2019 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article