Iodine-129 in animal thyroids from Argentina

Area of Science:

• Environmental Science
• Radiochemistry
• Isotope Analysis

Background:

• Iodine-129 (129I) is a long-lived anthropogenic radionuclide.
• Understanding global 129I distribution is crucial for environmental monitoring.
• Animal thyroids serve as effective bioindicators for radioiodine uptake.

Purpose of the Study:

• To quantify Iodine-129 (129I) and stable Iodine-127 (127I) concentrations in Argentine animal thyroids.
• To compare 129I/127I ratios in Argentina with those reported for the Northern Hemisphere.
• To investigate the geographical and seasonal variations of 129I in the Southern Hemisphere.

Main Methods:

• Accelerator Mass Spectrometry (AMS) was employed for precise 129I measurements.
• Gas Chromatography (GC) was utilized for determining 127I concentrations.
• Analysis covered thyroid samples from diverse regions across Argentina.

Main Results:

• Measured 129I/127I ratios in Argentina ranged from 3 × 10(-12) to 4 × 10(-10).
• These ratios are substantially lower than typical Northern Hemisphere values (10(-10)-10(-7)).
• Significant latitudinal and seasonal dependencies were observed for 129I concentrations.

Conclusions:

• Argentine animal thyroids exhibit lower 129I contamination compared to the Northern Hemisphere.
• Observed variations in 129I concentrations are attributable to atmospheric circulation, potential sources, and precipitation patterns.
• The study provides valuable baseline data for Southern Hemisphere radioiodine monitoring.