Airborne radionuclides in mosses collected at different latitudes

Area of Science:

• Environmental Science
• Radiochemistry
• Atmospheric Science

Background:

• Terrestrial mosses are ideal bioindicators for airborne radionuclide deposition.
• Their widespread distribution and ease of sampling facilitate environmental monitoring.
• High-resolution gamma spectrometry can be performed without extensive sample preparation.

Purpose of the Study:

• To compare activity concentrations of beryllium-7 (7Be), lead-210 (210Pb), and cesium-137 (137Cs) in moss samples.
• To investigate airborne radionuclide deposition in two distinct climate zones: southern Thailand (7°N) and Serbia (~45°N).

Main Methods:

• Collection of terrestrial moss samples from Thailand and Serbia.
• Analysis of radionuclide activity concentrations (Bq/kg) using high-resolution gamma spectrometry.
• Statistical comparison of (7)Be, (210)Pb, and (137)Cs levels between the two locations.

Main Results:

• A significant difference in (210)Pb content was observed, with concentrations nearly double between the two sites.
• Mean (7)Be activity in Serbian moss samples was approximately 40% higher than in Thai samples.
• (137)Cs levels in Thailand mosses were below the detection limit.

Conclusions:

• Mosses effectively reflect regional differences in airborne radionuclide deposition.
• Atmospheric transport, particularly in areas with water droplets and turbulence, can influence the deposition of uranium (U) and thorium (Th) daughter nuclei.
• The study highlights the utility of mosses for comparative environmental monitoring across diverse geographical regions.