Assessment of residual radionuclide levels at the Bokak and Bikar Atolls in the northern Marshall Islands

Residual levels of artificial radionuclides, including plutonium isotopes (239Pu, 240Pu), americium-241 (241Am), cesium-137 (137Cs), and strontium-90 (90Sr), were measured in marine and terrestrial samples from Bikar and Bokak Atolls in the northern Marshall Islands. The study found significantly higher radioactivity levels in Bikar compared to Majuro, with contamination primarily attributed to fallout from the 1954 Castle Bravo nuclear test. Isotope ratio analysis and dating estimates confirmed this source. While Bikar's levels were lower than those in more severely affected atolls like Rongerik or Enewetak, they remained comparable to other nearby regions impacted by global nuclear testing.

Corcho-Alvarado, J. A., Guavis, C., McGinnity, P., Röllin, S., Ketedromo, T., Sahli, H., Levy, I. N., de Brum, K., Stauffer, M., Osvath, I., & Burger, M. (2021). Assessment of residual radionuclide levels at the Bokak and Bikar Atolls in the northern Marshall Islands. Science of the Total Environment, 801, 149541. https://doi.org/10.1016/j.scitotenv.2021.149541