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Encabo RR, Cruz PTF, Bonga AC, Dela Sada CL, Omandam VJ, Olivares JU, Iwaoka K, Feliciano CP. Measurement of ambient gamma dose rate in Metro Manila, Philippines, using a portable NaI(TI) scintillation survey meter. Environ Monit Assess 2020; 192:400. [PMID: 32468213 DOI: 10.1007/s10661-020-08361-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
Radiological data such as ambient dose equivalent rate obtained from radiation monitoring in Metro Manila are useful for the detection of any anomalous increase of radiation dose rate levels due to nuclear or radiological emergencies. In this study, ambient dose equivalent rates were measured in different locations in Metro Manila using a portable NaI(Tl) scintillation survey meter to determine the background radiation levels within the capital. Ambient dose equivalent rates measured range from 32.7 ± 2.2 to 59.3 ± 8.7 nanosieverts per hour (nSv/h) with computed mean and median values of 41.7 and 39.6 nSv/h, respectively. These values were lower than the Philippines' average dose rate which is 52 nanograys per hour (nGy/h). No significant trend was also observed in the monthly variation of ambient dose equivalent rate for most locations, with the dose rates being relatively consistent throughout a year. No significant trend was further observed in the monthly variation of ambient dose equivalent rate for the whole Metro Manila. Data obtained in this study were used to develop a dose rate distribution map of Metro Manila which could be used as a baseline reference of emergency responders for environmental radioactivity monitoring during nuclear or radiological emergencies that may affect Metro Manila.
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Affiliation(s)
- Rosario R Encabo
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines.
| | - Paolo Tristan F Cruz
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines
| | - Antonio C Bonga
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines
| | - Christian L Dela Sada
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines
| | - Vanessa J Omandam
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines
| | - Juanario U Olivares
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines
| | - Kazuki Iwaoka
- National Institutes for Quantum and Radiological Sciences and Technology, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Chitho P Feliciano
- Health Physics Research Section, Atomic Research Division, Department of Science and Technology (DOST-PNRI), Philippine Nuclear Research Institute, Commonwealth Avenue, 1101 Diliman, Quezon City, Philippines
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Cruz PTF, Bonga AC, Dela Sada CL, Olivares JU, Dela Cruz FM, Palad LJH, Jesuitas AJ, Cabatbat EC, Omandam VJ, Garcia TY, Feliciano CP. Assessment of temporal variations of natural radionuclides Beryllium-7 and Lead-212 in surface air in Tanay, Philippines. J Environ Radioact 2019; 208-209:105989. [PMID: 31207564 DOI: 10.1016/j.jenvrad.2019.105989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/27/2019] [Accepted: 06/01/2019] [Indexed: 06/09/2023]
Abstract
Detection of radionuclides in surface air allows researchers to gain further insight on the behavior of radionuclides that may affect human radiation exposure especially in the event of a nuclear emergency. In this study, activity concentrations of naturally-occurring radionuclides Beryllium-7 (7Be) and Lead-212 (212Pb) in surface air and meteorological data collected in Tanay, Philippines from January 2012 to December 2017 were evaluated to determine the impact of atmospheric conditions and processes to airborne radioactivity. Surface air concentrations of 7Be and 212Pb were found to range from 0.00779 ± 0.00188 to 11.2 ± 0.116 mBq/m3 and from 1.371 ± 0.036 to 106.6 ± 1.075 mBq/m3, respectively. 7Be and 212Pb show distinct annual trends, suggesting that atmospheric conditions affect both radionuclides differently and independently. 7Be shows two peak concentrations annually, with the first peak occurring between January to April and the second lower peak occurring between October and November. 212Pb, on the other hand, shows annual peak concentrations occurring between April and June. Ambient temperature showed strong positive correlation with 212Pb concentration in surface air and a weak negative correlation with 7Be; relative humidity and precipitation showed varying degrees of negative correlation with radionuclide concentrations in surface air. Source locations for the unusually high 212Pb activity concentrations detected on 11-13 May 2013 and 19-31 May 2015 determined using WEB-GRAPE and HYSPLIT atmospheric transport models are presented as a case study. The data and findings of this study shall serve as basis for further studies on local and regional atmospheric transport and radiological impact assessment for the implementation of an effective nuclear and radiological emergency preparedness and response system in the country.
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Affiliation(s)
- Paolo Tristan F Cruz
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines.
| | - Antonio C Bonga
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Christian L Dela Sada
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Juanario U Olivares
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Fe M Dela Cruz
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Lorna Jean H Palad
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Alejandro J Jesuitas
- Synoptic and Upper Air Station, Philippine Atmospheric, Geophysical, and Astronomical Services Administration, Department of Science and Technology (DOST-PAGASA), Sitio Mayagay, Sampaloc, Tanay, Rizal, Philippines
| | - Edwin C Cabatbat
- Synoptic and Upper Air Station, Philippine Atmospheric, Geophysical, and Astronomical Services Administration, Department of Science and Technology (DOST-PAGASA), Sitio Mayagay, Sampaloc, Tanay, Rizal, Philippines
| | - Vanessa J Omandam
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Teofilo Y Garcia
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
| | - Chitho P Feliciano
- Health Physics Research Section, Philippine Nuclear Research Institute, Department of Science and Technology (DOST-PNRI), Commonwealth Avenue, Diliman, Quezon City, Philippines
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