Gamma Ray Spectrometric Analysis of Sand Samples from Selected Beaches along Kenyan Coastline.

Willis Otieno Gor Odongo,Jacek Karwowski,Margaret Wairimu Chege,Nadir Hashim

doi:10.1155/2021/6621645

Willis Otieno Gor Odongo, Jacek Karwowski + Show 2 more

Open Access

https://doi.org/10.1155/2021/6621645

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Journal: TheScientificWorldJournal	Publication Date: Feb 23, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: Kisii University, Kenyatta University

Abstract

In this study, the activity concentration levels of 238U, 232Th, and 40K in sand samples collected from Shanzu, Nyali, Kenyatta, Tiwi, Shelly, and Diani beaches selected along the Kenyan coastline were determined using a gamma ray spectrometer with a NaI(Tl) detector. The average activity concentrations of 238U, 232Th, and 40K in sand samples were analyzed as 87 ± 4, 98 ± 4, and 1254 ± 62 Bq/kg, respectively. Also, radium equivalent (Raeq) activity and internal (Hin) and external (Hex) hazard index were calculated to assess the radiological hazards associated with the use of sand samples as building materials. The average values of Raeq, Hin, and Hex were found as 327 ± 16 Bq/kg, 0.98, and 0.72, respectively. The average values of outdoor and indoor annual effective dose rates were estimated as of 0.23 and 0.63 mSv/y, respectively, which are below maximum recommended limit of 1 mSv/y. Generally, these results indicate no significant radiological health hazards for the studied beaches.

Highlights

IntroductionRadioactivity levels from natural radionuclides on Kenyan beaches are not known despite the fact that there is a need to determine the reference levels more so for areas with higher risk of radioactive materials exposure [8]
Natural radionuclides originated from nucleo-synthesis process. Radionuclides such as 40K, 238U, and 232 which have half-lives comparable to the age of the Earth are to date present in geological materials. ey occur in varying amounts in rock and soil as characterized by geology of a place [1]. ey contribute the largest fraction of natural radiation exposure to the general public [2]
People spend time relaxing and sunbathing on these beaches oblivious of the possible danger of exposure to naturally occurring radiation. e beach sand is used for construction of houses by the coastal communities and the need for the determination of risks associated with the radiation exposure from such houses

Summary

Introduction

Radioactivity levels from natural radionuclides on Kenyan beaches are not known despite the fact that there is a need to determine the reference levels more so for areas with higher risk of radioactive materials exposure [8]. Beach sands may be exposed to these radioactive materials through wave action to traces of oil spillages and dumped radioactive wastes in the Indian Ocean waters, all of which have high association with these radionuclides. E beach sand is used for construction of houses by the coastal communities and the need for the determination of risks associated with the radiation exposure from such houses. E coastline is divided with respect to the city into two zones: south coast and north coast. Most south coast beaches are e Scientific World Journal of sheltered type with relatively coarse sand grains compared to the ones on the north coast which are majorly exposed type with more fine-grained sand particles [9]

Materials and Methods

Experimental Techniques

Radiation Hazard Indices

Absorbed Dose Rates

Results and Discussion