1
|
Montes ML, Errico LA, Mercader RC, Taylor MA. Review and statistical analysis of activity values reported for coastal sands worldwide. CHEMOSPHERE 2024; 364:143201. [PMID: 39214408 DOI: 10.1016/j.chemosphere.2024.143201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 08/26/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
The activity of natural radionuclides is unevenly distributed across the Earth's crust, with certain areas exhibiting significantly higher levels than others, known as High Background Radiation Areas (HBRAs). This study presents a statistical analysis of reported activity values for coastal sands globally. Through this statistical analysis, costal sands were classified into four categories based on their activity levels, providing a standardized framework to compare the natural radioactivity of these sands. This classification is a valuable tool for identifying populations exposed to different radiation levels, which is essential for the study of stochastic effects. The study proposes thresholds to define HBRAs as regions with activity values exceeding 203 Bq/kg for 238U, 517 Bq/kg for 232Th, or 960 Bq/kg for 40K. Regions with lower values are classified as NonHBRAs. Further subdivision of these categories resulted in four distinct regions: NonHBRA-, NonHBRA+, HBRA-, and HBRA+. The activity values for these subdivisions are 92 Bq/kg and 2,903 Bq/kg for 238U, 94 Bq/kg and 7,230 Bq/kg for 232Th, and 901 Bq/kg and 2,298 Bq/kg for 40K. By calculating the external dose rates from the reported activity data, a threshold of 357 nGy/h was identified as the dose boundary separating NonHBRAs from HBRAs. The values for the subdivisions resulted 101 nGy/h and 3,867 nGy/h. The study also explores the content of these natural radionuclides in relation to their bearing minerals and discusses correlations between the reported activity values and the characteristics of the sands. Additionally, the activity of the anthropogenic radionuclide 137Cs (reported values ranging from the detection limit to 63 Bq/kg) is examined.
Collapse
Affiliation(s)
- M L Montes
- IFLP- CONICET- CCT La Plata, CC 67, 115 & 49, 1900, La Plata, Argentina; Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina.
| | - L A Errico
- IFLP- CONICET- CCT La Plata, CC 67, 115 & 49, 1900, La Plata, Argentina; Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina; UNNOBA, Argentina
| | - R C Mercader
- IFLP- CONICET- CCT La Plata, CC 67, 115 & 49, 1900, La Plata, Argentina; Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina
| | - M A Taylor
- IFLP- CONICET- CCT La Plata, CC 67, 115 & 49, 1900, La Plata, Argentina; Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina; Facultad de Ingeniería UNLP, La Plata, Argentina
| |
Collapse
|
2
|
Shrestha AK, Shrestha GK, Shah BR, Koirala RP. Assessment of radioactivity in sand samples from eastern Nepal in perspective of radiological hazards. RADIATION PROTECTION DOSIMETRY 2024; 200:429-436. [PMID: 38221673 DOI: 10.1093/rpd/ncad324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 12/10/2023] [Accepted: 12/12/2023] [Indexed: 01/16/2024]
Abstract
This study was conducted to investigate the activity concentrations of 226Ra, 232Th and 40K in the sand samples and the health hazards associated with them utilizing a NaI (Tl) gamma spectrometer. The average activity concentrations of 226Ra, 232Th and 40K were found to be 24.8 ± 10.1, 39.8 ± 16.4 and 531.3 ± 52.8 Bq kg-1, respectively. The calculated radiological hazard parameters, including radium equivalent activity, absorbed gamma dose and effective dose rate, were found to be 122.7 ± 34.0 Bq kg-1, 57.7 ± 14.9 nGy h-1 and 0.3 ± 0.1 mSv y-1, respectively. Notably, these results were observed to be below the recommended thresholds. Other measured hazard indices were also lower than the prescribed values. From a radiological perspective, the present study concludes that the sand samples do not pose any threat to human health when utilized as a building material.
Collapse
Affiliation(s)
- Arun Kumar Shrestha
- Damak Multiple Campus, Tribhuvan University, Damak, Nepal
- Central Department of Physics, Tribhuvan University, Kirtipur, Nepal
| | | | | | - Ram Prasad Koirala
- Mahendra Morang Adarsh Multiple Campus, Tribhuvan University, Biratnagar, Nepal
| |
Collapse
|
3
|
Shrestha AK, Shrestha GK, Shah BR, Koirala RP. Assessment of radioactivity and radiological hazards associated with bricks in eastern Nepal. Heliyon 2024; 10:e24844. [PMID: 38312633 PMCID: PMC10835328 DOI: 10.1016/j.heliyon.2024.e24844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 12/22/2023] [Accepted: 01/15/2024] [Indexed: 02/06/2024] Open
Abstract
This comprehensive study examines the concentration of natural radionuclides in bricks from the Terai region of the Koshi province, aiming to assess the radioactivity levels and associated radiological hazards, ultimately quantifying the dose limit. The average concentrations of 226Ra, 232Th, and 40K were 27.1 ± 5.7, 42.6 ± 9.8, and 601.5 ± 93.8 Bq/kg, with their respective contributions to total activity being 20.18 %, 45.35 %, 34.48 %,. Despite this, their concentration distribution followed the pattern 40K > 232Th > 226Ra. The elevated presence of 40K in the bricks is attributed to the use of phosphate fertilizers in the soil to enhance crop productivity. Notably, the calculated values of radiological hazard parameters, including radium equivalent activity, absorbed gamma dose, and effective dose, are well below the recommended safety thresholds. Consequently, this study suggests that bricks, when used in substantial quantities, pose no significant radiological risks and are considered safe for use as a building material. The extension of such investigations nationwide is recommended to assess the overall radioactivity levels and establish dose limits.
Collapse
Affiliation(s)
- Arun Kumar Shrestha
- Damak Multiple Campus, Tribhuvan University, Nepal
- Central Department of Physics, Tribhuvan University, Nepal
| | | | | | | |
Collapse
|
4
|
Kotb NA, Abd El Ghany MS, El-Sayed AA. Radiological assessment of different monazite grades after mechanical separation from black sand. Sci Rep 2023; 13:15389. [PMID: 37717074 PMCID: PMC10505136 DOI: 10.1038/s41598-023-42287-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 09/07/2023] [Indexed: 09/18/2023] Open
Abstract
In Egyptian black sands, monazite is a precious mineral characterized by its composition, which includes crucial constituents such as thorium, trace amounts of uranium, and rare earth elements. It is essential to evaluate and quantify the extent of gamma-ray exposure resulting from the presence of primordial radionuclides. This necessity arises from human activities that extract and retrieve raw materials in uranium and thorium mining operations. The current study focuses on the radiological assessment of Monazite raw material in various grades and calculates the associated hazard indices. A hyper pure Germanium detector (HPGe) determined the particular activity. For grade, 90% Monazite samples, the average activities for 232Th, 238U, and 40K were 348,008 ± 1406, 69,299 ± 2086, and 27,510 ± 245 Bq/kg, respectively. For grade 75% Monazite samples, the average activities were 219,000 ± 901, 55,000 ± 500, and 18,300 ± 86 Bq/kg, while for grade 50% Monazite samples, it was 43,294 ± 1549, 9593 ± 629, and 4000 ± 211 Bq/kg for the same element, respectively. Also, 138La's inherent radioactivity was taken into account. The computed effective and absorbed dosages exceed the worker's exempt limit of 20 mSv/y. The calculated hazard parameters are higher than the maximum recommended limits. Therefore, it is imperative to employ radiation safety measures to mitigate the potential hazards of ionizing radiation.
Collapse
Affiliation(s)
- N A Kotb
- Radiation Protection Department, Hot Labs Center, Egyptian Atomic Energy Authority, Cairo, Egypt.
| | | | - Ashraf A El-Sayed
- Analytical Chemistry Department, Hot Labs Center, Egyptian Atomic Energy Authority, Cairo, Egypt
| |
Collapse
|
5
|
Shuaibu HK, Khandaker MU, Alrefae T, Bradley DA. Assessment of natural radioactivity and gamma-ray dose in monazite rich black Sand Beach of Penang Island, Malaysia. MARINE POLLUTION BULLETIN 2017; 119:423-428. [PMID: 28342594 DOI: 10.1016/j.marpolbul.2017.03.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 03/08/2017] [Accepted: 03/15/2017] [Indexed: 06/06/2023]
Abstract
Activity concentrations of primordial radionuclides in sand samples collected from the coastal beaches surrounding Penang Island have been measured using conventional γ-ray spectrometry, while in-situ γ-ray doses have been measured through use of a portable radiation survey meter. The mean activity concentrations for 226Ra, 232Th and 40K at different locations were found to be less than the world average values, while the Miami Bay values for 226Ra and 232Th were found to be greater, at 1023±47 and 2086±96Bqkg̶ 1 respectively. The main contributor to radionuclide enrichment in Miami Bay is the presence of monazite-rich black sands. The measured data were compared against literature values and also recommended limits set by the relevant international bodies. With the exception of Miami Bay, considered an elevated background radiation area that would benefit from regular monitoring, Penang island beach sands typically pose no significant radiological risk to the local populace and tourists visiting the leisure beaches.
Collapse
Affiliation(s)
- Hauwau Kulu Shuaibu
- Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Mayeen Uddin Khandaker
- Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Tareq Alrefae
- Department of Physics, Faculty of Science, Kuwait University, Khaldia, Kuwait
| | - D A Bradley
- Department of Physics, University of Surrey, Guildford, Surrey GU4 8JU, UK; Sunway University, Institute for Health Care Development, Jalan Universiti, 46150 PJ, Malaysia
| |
Collapse
|