Radioactivity is ubiquitous in the natural environment as a result of i) cosmic radiation from space and secondary radiation from the interaction of cosmic rays with atoms in the atmosphere, ii) terrestrial sources from mineral grains in soils and rocks, particularly Potassium (K-40), Uranium (U-238) and Thorium (Th-232), and their decay products, and iii) Radon gas (Rn-222). The use of nuclear techniques enables the measurement of natural radioactivity in air, soils and water even at trace levels, making it a particularly appealing tool for characterizing time-varying environmental phenomena. This session welcomes contributions addressing the application of naturally occurring radionuclides as environmental tracers in all fields of geosciences. The stage will be open for the presentation of novel approaches of measurement and data interpretation in the fields of, but not limited to,

- groundwater / surface water interaction and related processes
- volcanic monitoring and surveillance
- identification of faults and tectonic structures
- earthquakes
- groundwater contamination
- coastal and marine monitoring
- atmospheric tracing, including of CO2 and pollutants
- atmospheric electricity
- cosmic rays

The discussion of novel methods and instrumentation for environmental radioactivity monitoring is particularly encouraged.