Measurement of ambient gamma dose rate in Metro Manila, Philippines, using a portable NaI(TI) scintillation survey meter

• Published in: Environmental monitoring and assessment Vol. 192; no. 6; p. 400
• Main Authors: Encabo, Rosario R., Cruz, Paolo Tristan F., Bonga, Antonio C., Dela Sada, Christian L., Omandam, Vanessa J., Olivares, Juanario U., Iwaoka, Kazuki, Feliciano, Chitho P.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2020; Springer Nature B.V
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Background radiation; Earth and Environmental Science; Ecology; Ecotoxicology; Emergencies; Emergency response; Environment; Environmental Management; Environmental monitoring; Environmental radioactivity; Environmental science; Equivalence; Global positioning systems; GPS; Monitoring/Environmental Analysis; Monthly variations; Nuclear accidents & safety; Nuclear physics; Nuclear power plants; Nuclear research; Polls & surveys; Radiation; Radiation dosage; Radiation measurement; Radiation monitoring; Radioactivity; Scintillation; Surveying; Trends; Philippines; Ambient gamma dose rate; Environmental radioactivity; Ambient dose equivalent rate; NaI(TI) scintillation survey meter; Dose rate distribution map; Environmental radiation monitoring; Metro Manila
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-020-08361-8

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.