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Updated: Jul 2, 2026
09:28
Evaluation of the Spatial Distribution of γH2AX following Ionizing Radiation
Published on: August 8, 2010
Sydney's first terrestrial gamma-radiation map
Tengiz Ibrayev1, Matilda Lawton1, Giancarlo Ciotoli2
1The School of Physics, The University of Sydney, Physics Road, Caperdown, Sydney, 2050, NSW, Australia.
Journal of Environmental Radioactivity
|January 28, 2026
Summary
This study created Sydney's first terrestrial gamma-radiation map using low-cost spectrometers. The map reveals natural radioactivity levels are consistent with global averages, influenced by geological composition.
Area of Science:
- Environmental Science
- Radiological Science
- Geoscience
Background:
- Natural background radiation stems from radioactive isotopes in rocks and soils.
- Terrestrial radiation maps are crucial for environmental assessments and urban planning.
- Sydney previously lacked a comprehensive map of its natural radioactivity.
Purpose of the Study:
- To generate the first terrestrial gamma-radiation map for a 10x10km² area of Sydney.
- To quantify radionuclide activities and establish baseline radiation levels.
- To explore a reproducible, low-cost method for urban radiation mapping.
Main Methods:
- Utilized portable, low-cost gamma spectrometers (Radiacodes) for in-situ measurements.
- Employed high-purity germanium gamma spectroscopy for soil sample analysis.
- Conducted open-water measurements to isolate cosmic radiation.
- Applied regression-kriging integrating lithology and radionuclide concentrations.
Main Results:
- Produced Sydney's first terrestrial gamma-radiation map.
- Measured mean terrestrial and cosmic contributions at (0.24 ± 0.27) mSv/yr and (0.173 ± 0.035) mSv/yr, respectively.
- Found radiation levels align with global background averages.
- Explained 98% of spatial variation in radioactivity using geological composition.
Conclusions:
- Geological composition is the primary driver of natural radioactivity patterns in Sydney.
- The developed low-cost methodology is effective for urban radiation mapping.
- This work provides a foundation for citizen-science initiatives in environmental radioactivity monitoring.
Keywords:
(238)U (232)Th and (40)KAustraliaHPGe gamma spectrometryMappingRadiacodeTerrestrial gamma radiationMore Related Videos
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