This study investigated the level of natural radioactivity and radiological risks of 40 different ceramic tiles through gamma-ray spectroscopy using a high-purity germanium detector. The calculated activity concentrat...This study investigated the level of natural radioactivity and radiological risks of 40 different ceramic tiles through gamma-ray spectroscopy using a high-purity germanium detector. The calculated activity concentrations were evaluated to determine their potential radiological risks to human health. Furthermore, the activity concentrations were subjected to the RESRAD-BUILD computer code to assess the effect of ventilation rate, dweller position, and room size and direction on the total effective dose(TED). The simulated TED received by a receptor when changing the ventilation rate in a room ranged from0.26 ± 0.01 to 0.61 ± 0.01 mSv/y; however,the percentage variations in the TED due to dweller position and room size are 34, 31,and 35% and 33, 27, and 40% for the x-,y-,and z-directions, respectively. The overall TED received by the dweller based on room size and direction is 0.75 mSv/y. The calculated radiological risk parameters were all below the recommended maximum limit. However, the TED received by the dweller is significantly affected by the directions of the measurement, position,room size,and ventilation. Therefore,estimating the TED from one direction would underestimate the total dose received by the dweller.展开更多
In this study, the activity concentrations of ^(226)Ra,^(232)Th,^(222)Rn, and ^(40)K, emanation fractions(P),equilibrium equivalent concentration(EEC), and mass exhalation rates(E_m) of radon released from building ma...In this study, the activity concentrations of ^(226)Ra,^(232)Th,^(222)Rn, and ^(40)K, emanation fractions(P),equilibrium equivalent concentration(EEC), and mass exhalation rates(E_m) of radon released from building materials used in Malaysia were studied using gamma-ray spectrometer with HPGe detector. Radiological parameters[activity concentration index(ACI), indoor air-absorbed dose rate(D_(in)), annual effective dose(AED_(in)) from external and internal(E_(Rn)), soft tissues(H_(ST)) and lung(H_L), and effective dose equivalent(H_(eff))] were estimated to evaluate radiological hazards due to the use of these building materials: sand, cement, gravel, bricks, tiles, fly ash, white cement, and ceramic raw materials. The measured P, EEC,and E_m vary from 10 to 30%, 0.9 to 22 Bq m^(-3), and 33 to 674 mBq h^(-1) kg^(-1), respectively, while the calculated ACI and AED_(in) vary from 0.1 ± 0.01 to 2.1 ± 0.1 and 0.1 ± 0.01 to 2.4 ± 0.6 mSv y^(-1), respectively. On the other hand, the internal annual effective dose ranges from 0.1 to 1.4 mSv y^(-1). The estimated radiological risk parameters were below the recommended maximum values, and radiological hazards associated with building materials under investigation are therefore negligible.展开更多
基金supported by the Universiti Kebangsaan Malaysia(UKM)under Grant Number GGPM-2017-084
文摘This study investigated the level of natural radioactivity and radiological risks of 40 different ceramic tiles through gamma-ray spectroscopy using a high-purity germanium detector. The calculated activity concentrations were evaluated to determine their potential radiological risks to human health. Furthermore, the activity concentrations were subjected to the RESRAD-BUILD computer code to assess the effect of ventilation rate, dweller position, and room size and direction on the total effective dose(TED). The simulated TED received by a receptor when changing the ventilation rate in a room ranged from0.26 ± 0.01 to 0.61 ± 0.01 mSv/y; however,the percentage variations in the TED due to dweller position and room size are 34, 31,and 35% and 33, 27, and 40% for the x-,y-,and z-directions, respectively. The overall TED received by the dweller based on room size and direction is 0.75 mSv/y. The calculated radiological risk parameters were all below the recommended maximum limit. However, the TED received by the dweller is significantly affected by the directions of the measurement, position,room size,and ventilation. Therefore,estimating the TED from one direction would underestimate the total dose received by the dweller.
基金supported by Universiti Kebangsaan Malaysia and Lynas Advanced Material Plant under Grant Numbers GGPM-2017-084 and ST-2017-012,respectively
文摘In this study, the activity concentrations of ^(226)Ra,^(232)Th,^(222)Rn, and ^(40)K, emanation fractions(P),equilibrium equivalent concentration(EEC), and mass exhalation rates(E_m) of radon released from building materials used in Malaysia were studied using gamma-ray spectrometer with HPGe detector. Radiological parameters[activity concentration index(ACI), indoor air-absorbed dose rate(D_(in)), annual effective dose(AED_(in)) from external and internal(E_(Rn)), soft tissues(H_(ST)) and lung(H_L), and effective dose equivalent(H_(eff))] were estimated to evaluate radiological hazards due to the use of these building materials: sand, cement, gravel, bricks, tiles, fly ash, white cement, and ceramic raw materials. The measured P, EEC,and E_m vary from 10 to 30%, 0.9 to 22 Bq m^(-3), and 33 to 674 mBq h^(-1) kg^(-1), respectively, while the calculated ACI and AED_(in) vary from 0.1 ± 0.01 to 2.1 ± 0.1 and 0.1 ± 0.01 to 2.4 ± 0.6 mSv y^(-1), respectively. On the other hand, the internal annual effective dose ranges from 0.1 to 1.4 mSv y^(-1). The estimated radiological risk parameters were below the recommended maximum values, and radiological hazards associated with building materials under investigation are therefore negligible.
