In-situ assessment of natural terrestrial-radioactivity from Uranium-238 (238U), Thorium-232 (232Th) and Potassium-40 (40K) in coastal urban-environment and its possible health implications
E. S. Joel, Maxwell Omeje, Olukunle C. Olawole, Gideon Adewale Adeyemi, Akinwumi Akinpelu, Zaidi Embong, M. A. Saeed
Abstract
Abstract The risk of natural terrestrial radioactivity on human health is often underestimated, and environmental safety awareness is necessary. Hence, this study aims to assess natural sources of gamma radiation emitter in coastal urban-environment using the radiometric technique. The dosage of gamma radiation from a parent radionuclide such as Uranium-238 ( 238 U), Thorium-232 ( 232 Th) and Potassium-40 ( 40 K) and were measured using portable gamma spectroscopy. The result showed that the measured value of 238 U activity was between 10.81 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 0.69 and 46.31 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 1.43 Bqkg −1 . The mean value was estimated to be 35.44 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 0.97 Bqkg −1 which is slightly higher than the world average. Meanwhile, 232 Th activity ranges from 28.42 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 1.12 to 69.43 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 1.76 Bqkg −1 with the calculated mean value of 92.57 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 1.17 Bqkg −1 while 40 K activity ranged between 31.30 ± 1.32 and 328.65 ± 2.32 Bqkg −1 with the estimated mean 137.59 $$\pm$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>±</mml:mo> </mml:math> 2.42 Bqkg −1 . Radiological parameters such as radium equivalent (R eq ), internal hazard (H int ) and external hazard (H ext ) assessment were in the range of 66.00 Bqkg −1 to 141.76 Bqkg −1 , 0.232 to 0.452 and 0.178 to 0.383, respectively. The measured values of gamma dose-rates ranged between 54.283 ± 0.78 and 117.531 ± 1.14 nGyh −1 with the calculated mean value of 84.770 ± 0.97 nGyh −1 .