Assessment of Levels of Natural Radioactivity in Sand Samples Collected from Ekalakala in Machakos County, Kenya
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Date
2020
Authors
Munyao, Lucia Nyiva
Ketui, Daniel Kipngetich
Otieno, Calford
Chege, Margaret Wairimu
Journal Title
Journal ISSN
Volume Title
Publisher
Hindawi
Abstract
Construction sand is naturally polluted with radionuclides of terrestrial origin. In this study, specific activities of 238U, 232+, and
40K in 30 sand samples collected along the Ekalakala River, Machakos County, Kenya, were measured using a high-purity
germanium c-ray spectrometer. +e specific activities ranged between 9.7 Bqkg−1 and 24.0 Bqkg−1, 11.5 Bqkg−1 and 26.2 Bqkg−1,
and 820 Bqkg−1 and 1850 Bqkg−1 for 238U, 232+, and 40K, respectively. While the mean specific activities for 238U and 232+were
less than half of the world average values of 33 Bqkg−1 and 45 Bqkg−1, respectively, the average specific activity of 40K was
significant since it was three times the global mean value of 420 Bqkg−1. A calculated absorbed radiation dose rate for the sand
varied between 46.8 nGyh−1 and 94.2 nGyh−1 with a mean of 68.5 ± 13.3 nGyh−1. +is is not significantly different from the world
average dose rate of 60 nGyh−1 for geological samples. +e AEDR and Hex had maximum values of 0.29 mSvy−1 and 0.52,
respectively, both within the recommended limits of radiation exposure for members of the general public. Based on these results,
the sand from Ekalakala River does not pose significant health implication to the sand harvesters as well as the inhabitants of the
houses constructed using this sand.
Description
A research article published in The Scientific World Journal
Keywords
Natural Radioactivity, Ekalakala, Machakos, Kenya
Citation
Munyao, L. N., Ketui, D. K., Otieno, C., & Chege, M. W. (2020). Assessment of Levels of Natural Radioactivity in Sand Samples Collected from Ekalakala in Machakos County, Kenya. The Scientific World Journal, 2020.