Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak

Terrestrial gamma radiation (TGR) is one of the contributors for ionizing radiation exposure to society. In this study, the baseline TGR dose rate measurement and radiological health risk assessment of west Sarawak were made. The study area covers 5 divisions; Kuching, Samarahan, Serian, Sri Aman an...

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Main Author:	Izham, Azril
Format:	Thesis
Language:	English
Published:	2020
Subjects:	QC Physics
Online Access:	http://eprints.utm.my/id/eprint/102084/1/AzrilIzhamMFS2020.pdf
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spelling	my-utm-ep.1020842023-08-05T02:28:26Z Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak 2020 Izham, Azril QC Physics Terrestrial gamma radiation (TGR) is one of the contributors for ionizing radiation exposure to society. In this study, the baseline TGR dose rate measurement and radiological health risk assessment of west Sarawak were made. The study area covers 5 divisions; Kuching, Samarahan, Serian, Sri Aman and Betong, for a total area of 20,259.2 km2 using random sampling method as data point selection. The outdoor measurements were performed at approximately 1 meter above ground level, avoiding human infrastructures, using Ludlum 19 micro R meter NaI(Tl) scintillation detector. Twenty-nine soil samples were taken across the 5 divisions covering combinations of 9 geological backgrounds and 7 soil types. A hyper-pure Germanium spectrometer was then used to detect the samples‘ 238U, 232Th, and 40K radionuclides concentrations producing a correction factor Cf = 0.544 from linear fitting of y = 0.544x + 8.13. Excluding 2 outliers, a total of 239 data were corrected with Cf producing a mean of 47 ± 1 nGy h-1, with a range between 5 nGy h-1 – 103 nGy h-1. A multiple regression analysis was conducted between geologicallyrespective mean dose and soil types-respective mean dose against TGR dose rate, generating DG,S = 0.847Dg + 0.637Ds – 22.313 prediction model with a normalized beta equation of DG,S = 0.605Dg + 0.395Ds. The model showed 100% acceptance of sign test null hypothesis when used against TGR dose rate readings. Calculations of radiological health risk assessment produce annual effective dose equivalent of AEDE = 0.058 mSv year-1, radium equivalent dose Raeq = 140.52 Bq kg-1 and external hazard index Hex = 0.4. An isodose map was generated using kriging spatial analysis in ArcGIS 10.3 software. 2020 Thesis http://eprints.utm.my/id/eprint/102084/ http://eprints.utm.my/id/eprint/102084/1/AzrilIzhamMFS2020.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:146163 masters Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QC Physics
spellingShingle	QC Physics Izham, Azril Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak
description	Terrestrial gamma radiation (TGR) is one of the contributors for ionizing radiation exposure to society. In this study, the baseline TGR dose rate measurement and radiological health risk assessment of west Sarawak were made. The study area covers 5 divisions; Kuching, Samarahan, Serian, Sri Aman and Betong, for a total area of 20,259.2 km2 using random sampling method as data point selection. The outdoor measurements were performed at approximately 1 meter above ground level, avoiding human infrastructures, using Ludlum 19 micro R meter NaI(Tl) scintillation detector. Twenty-nine soil samples were taken across the 5 divisions covering combinations of 9 geological backgrounds and 7 soil types. A hyper-pure Germanium spectrometer was then used to detect the samples‘ 238U, 232Th, and 40K radionuclides concentrations producing a correction factor Cf = 0.544 from linear fitting of y = 0.544x + 8.13. Excluding 2 outliers, a total of 239 data were corrected with Cf producing a mean of 47 ± 1 nGy h-1, with a range between 5 nGy h-1 – 103 nGy h-1. A multiple regression analysis was conducted between geologicallyrespective mean dose and soil types-respective mean dose against TGR dose rate, generating DG,S = 0.847Dg + 0.637Ds – 22.313 prediction model with a normalized beta equation of DG,S = 0.605Dg + 0.395Ds. The model showed 100% acceptance of sign test null hypothesis when used against TGR dose rate readings. Calculations of radiological health risk assessment produce annual effective dose equivalent of AEDE = 0.058 mSv year-1, radium equivalent dose Raeq = 140.52 Bq kg-1 and external hazard index Hex = 0.4. An isodose map was generated using kriging spatial analysis in ArcGIS 10.3 software.
format	Thesis
qualification_level	Master's degree
author	Izham, Azril
author_facet	Izham, Azril
author_sort	Izham, Azril
title	Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak
title_short	Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak
title_full	Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak
title_fullStr	Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak
title_full_unstemmed	Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak
title_sort	terrestrial gamma radiation dose rate and radiological health risk assessment of western region of sarawak
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2020
url	http://eprints.utm.my/id/eprint/102084/1/AzrilIzhamMFS2020.pdf
_version_	1776100841945563136

Terrestrial gamma radiation dose rate and radiological health risk assessment of western region of Sarawak

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