ACTIVITY CONCENTRATIONS OF RADIOCAESIUM, 90SR AND 129I IN AGRICULTURAL CROPS COLLECTED FROM FUKUSHIMA AND REFERENCE...

Area of Science:

• Environmental Science
• Radiological Protection
• Food Safety

Background:

• The 2011 Fukushima Daiichi Nuclear Power Plant (FDNPS) accident released significant radionuclides.
• Radiocaesium (137Cs) is a key radionuclide for radiation dose assessment, alongside 90Sr and 129I.

Purpose of the Study:

• To assess the activity concentrations of 137Cs, 90Sr, and 129I in crops from Fukushima and surrounding areas.
• To evaluate the internal radiation doses from consuming these contaminated crops.

Main Methods:

• Collected spinach, potato, and brown rice from Fukushima, neighboring prefectures, and reference areas in 2018 and 2019.
• Measured activity concentrations of 137Cs, 90Sr, and 129I using gamma-ray spectrometry and other methods.
• Calculated internal radiation doses from ingested crops.

Main Results:

• Higher 137Cs activity concentrations were found in crops from Hamadori (coastal Fukushima).
• 90Sr levels were similar across Fukushima areas and comparable to national levels.
• 129I concentrations were higher in Hamadori crops, but the 129I/137Cs ratio was very low.
• Estimated internal radiation doses from radiocaesium and 129I were minimal (0.0046 mSv and 0.00000045 mSv, respectively, in 2019).

Conclusions:

• While coastal Fukushima showed higher radionuclide levels in crops, the overall internal radiation dose remains low.
• The low 129I/137Cs ratio suggests limited long-term risk from iodine-129.
• Continued monitoring ensures food safety and public health protection following the FDNPS accident.