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Assessment of Natural Radioactivity Levels and Potential Radiological Risks of Common Building Materials Used in Bangladeshi Dwellings.

Asaduzzaman K, Mannan F, Khandaker MU, Farook MS, Elkezza A, Amin YB, Sharma S, Abu Kassim HB - PLoS ONE (2015)

Bottom Line: The radium equivalent activity values for all samples were found to be lower than the recommended limit for building materials of 370 Bq kg(-1), with the exception of the fly ash.For most samples, the values of the alpha index and the radiological hazard (external and internal) indices were found to be within the safe limit of 1.For all investigated materials, the values of the gamma index were found to be greater than 0.5 but less than 1, indicating that the gamma dose contribution from the studied building materials exceeds the exemption dose criterion of 0.3 mSv y(-1) but complies with the upper dose principle of 1 mSv y(-1).

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia; Bangladesh Atomic Energy Commission, Dhaka-1207, Bangladesh.

ABSTRACT
The concentrations of primordial radionuclides (226Ra, 232Th and 40K) in commonly used building materials (brick, cement and sand), the raw materials of cement and the by-products of coal-fired power plants (fly ash) collected from various manufacturers and suppliers in Bangladesh were determined via gamma-ray spectrometry using an HPGe detector. The results showed that the mean concentrations of 226Ra, 232Th and 40K in all studied samples slightly exceeded the typical world average values of 50 Bq kg(-1), 50 Bq kg(-1) and 500 Bq kg(-1), respectively. The activity concentrations (especially 226Ra) of fly-ash-containing cement in this study were found to be higher than those of fly-ash-free cement. To evaluate the potential radiological risk to individuals associated with these building materials, various radiological hazard indicators were calculated. The radium equivalent activity values for all samples were found to be lower than the recommended limit for building materials of 370 Bq kg(-1), with the exception of the fly ash. For most samples, the values of the alpha index and the radiological hazard (external and internal) indices were found to be within the safe limit of 1. The mean indoor absorbed dose rate was observed to be higher than the population-weighted world average of 84 nGy h(-1), and the corresponding annual effective dose for most samples fell below the recommended upper dose limit of 1 mSv y(-1). For all investigated materials, the values of the gamma index were found to be greater than 0.5 but less than 1, indicating that the gamma dose contribution from the studied building materials exceeds the exemption dose criterion of 0.3 mSv y(-1) but complies with the upper dose principle of 1 mSv y(-1).

No MeSH data available.


Dose contribution due to the content of 226Ra, 232Th and 40K in building materials to the inhabitants.
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pone.0140667.g001: Dose contribution due to the content of 226Ra, 232Th and 40K in building materials to the inhabitants.

Mentions: The lowest indoor absorbed dose rate (arithmetic mean ± standard deviation) of 152.0±16.6 nGy h–1 was obtained for the white sand samples, followed by the cement (153.7±12.0 nGy h–1), whereas the maximum value of 174.0±13.3 nGy h–1 was observed for the red sand samples, followed by the brick samples (170.0±16.8 nGy h–1). The mean indoor absorbed dose levels in the cement, brick and sand samples were found to fall within the typical worldwide range (20–200 nGy h–1) [9, 40], although they were approximately two times higher than the quoted population-weighted average value of 84 nGy h–1 [9, 40]. Meanwhile, the annual effective dose values in the cement, brick, white sand and red sand samples were found to be 0.75±0.06, 0.83±0.08, 0.75±0.08 and 0.85±0.07 mSv, respectively. These values are well below the maximum allowable dose equivalent limit of 1 mSv y–1 recommended by the ICRP (1990) [4, 6, 21, 22, 41]. Fig 1 shows the doses to inhabitants originating from the contents of 226Ra, 232Th and 40K in commonly used building materials. Among the investigated materials, red sand (27%) is the highest contributor to the annual indoor effective dose, followed by brick (26%), cement (24%) and white sand (23%). Among the radionuclides, 232Th is the predominant contributor to the dose in the indoor environment, with a contribution of approximately 42% of the total estimated dose, followed by 40K (37%) and 226Ra (21%).


Assessment of Natural Radioactivity Levels and Potential Radiological Risks of Common Building Materials Used in Bangladeshi Dwellings.

Asaduzzaman K, Mannan F, Khandaker MU, Farook MS, Elkezza A, Amin YB, Sharma S, Abu Kassim HB - PLoS ONE (2015)

Dose contribution due to the content of 226Ra, 232Th and 40K in building materials to the inhabitants.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608819&req=5

pone.0140667.g001: Dose contribution due to the content of 226Ra, 232Th and 40K in building materials to the inhabitants.
Mentions: The lowest indoor absorbed dose rate (arithmetic mean ± standard deviation) of 152.0±16.6 nGy h–1 was obtained for the white sand samples, followed by the cement (153.7±12.0 nGy h–1), whereas the maximum value of 174.0±13.3 nGy h–1 was observed for the red sand samples, followed by the brick samples (170.0±16.8 nGy h–1). The mean indoor absorbed dose levels in the cement, brick and sand samples were found to fall within the typical worldwide range (20–200 nGy h–1) [9, 40], although they were approximately two times higher than the quoted population-weighted average value of 84 nGy h–1 [9, 40]. Meanwhile, the annual effective dose values in the cement, brick, white sand and red sand samples were found to be 0.75±0.06, 0.83±0.08, 0.75±0.08 and 0.85±0.07 mSv, respectively. These values are well below the maximum allowable dose equivalent limit of 1 mSv y–1 recommended by the ICRP (1990) [4, 6, 21, 22, 41]. Fig 1 shows the doses to inhabitants originating from the contents of 226Ra, 232Th and 40K in commonly used building materials. Among the investigated materials, red sand (27%) is the highest contributor to the annual indoor effective dose, followed by brick (26%), cement (24%) and white sand (23%). Among the radionuclides, 232Th is the predominant contributor to the dose in the indoor environment, with a contribution of approximately 42% of the total estimated dose, followed by 40K (37%) and 226Ra (21%).

Bottom Line: The radium equivalent activity values for all samples were found to be lower than the recommended limit for building materials of 370 Bq kg(-1), with the exception of the fly ash.For most samples, the values of the alpha index and the radiological hazard (external and internal) indices were found to be within the safe limit of 1.For all investigated materials, the values of the gamma index were found to be greater than 0.5 but less than 1, indicating that the gamma dose contribution from the studied building materials exceeds the exemption dose criterion of 0.3 mSv y(-1) but complies with the upper dose principle of 1 mSv y(-1).

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia; Bangladesh Atomic Energy Commission, Dhaka-1207, Bangladesh.

ABSTRACT
The concentrations of primordial radionuclides (226Ra, 232Th and 40K) in commonly used building materials (brick, cement and sand), the raw materials of cement and the by-products of coal-fired power plants (fly ash) collected from various manufacturers and suppliers in Bangladesh were determined via gamma-ray spectrometry using an HPGe detector. The results showed that the mean concentrations of 226Ra, 232Th and 40K in all studied samples slightly exceeded the typical world average values of 50 Bq kg(-1), 50 Bq kg(-1) and 500 Bq kg(-1), respectively. The activity concentrations (especially 226Ra) of fly-ash-containing cement in this study were found to be higher than those of fly-ash-free cement. To evaluate the potential radiological risk to individuals associated with these building materials, various radiological hazard indicators were calculated. The radium equivalent activity values for all samples were found to be lower than the recommended limit for building materials of 370 Bq kg(-1), with the exception of the fly ash. For most samples, the values of the alpha index and the radiological hazard (external and internal) indices were found to be within the safe limit of 1. The mean indoor absorbed dose rate was observed to be higher than the population-weighted world average of 84 nGy h(-1), and the corresponding annual effective dose for most samples fell below the recommended upper dose limit of 1 mSv y(-1). For all investigated materials, the values of the gamma index were found to be greater than 0.5 but less than 1, indicating that the gamma dose contribution from the studied building materials exceeds the exemption dose criterion of 0.3 mSv y(-1) but complies with the upper dose principle of 1 mSv y(-1).

No MeSH data available.