Background gamma radiation and soil activity measurements in the northern Marshall Islands

Researchers found that external gamma radiation levels and soil radionuclide activity vary significantly across nine islands in four atolls of the northern Marshall Islands, which were affected by U.S. nuclear testing from 1946 to 1958. Elevated radiation was detected on Enjebi Island (Enewetak Atoll), Bikini Atoll, and Naen Island (Rongelap Atoll), while low levels were observed in other islands of Enewetak and Utirik atolls. Soil samples from Runit, Enjebi, Bikini, and Naen islands showed the highest concentrations of americium-241, cesium-137, plutonium-238, and plutonium-239,240, with no detectable radionuclides in Majuro Island soils. Ordinary kriging was used to create interpolated radiation maps. The study contextualizes findings against global nuclear accident regions and provides insights for local decision-making on island resettlement.

Abella, M. K. I. L., Molina, M. R., Nikolić-Hughes, I., Hughes, E. W., & Ruderman, M. A. (2019). Background gamma radiation and soil activity measurements in the northern Marshall Islands. Proceedings of the National Academy of Sciences, 116(31), 15425–15434. https://doi.org/10.1073/pnas.1903421116