Arctic Ocean: Radionuclides

Abstract

This article presents an overview of the major sources, transport pathways, and fate of anthropogenic radionuclides in the Arctic marine environment. The dominant anthropogenic radionuclides present in Arctic seawater, sediments, and marine biota are cesium‐137 ( 137 Cs), plutonium‐239 ( 239 Pu), plutonium‐240 ( 240 Pu), technetium‐99 ( 99 Tc), and strontium‐90 ( 90 Sr). Major sources contributing to the inventory of radionuclides in the Arctic Ocean and surrounding shelf seas include atmospheric fallout, European nuclear reprocessing facilities, the Chernobyl accident, and discharges from major Arctic rivers. Anthropogenic radionuclides from these sources are supplied to and redistributed within the Arctic Ocean via atmospheric, sea ice, currents, sediment, and river transport pathways. With the exception of a few locations, e.g., the underwater nuclear test site at Chernaya Bay, sediment, seawater, and biota activity concentrations in the Arctic are today very low, posing negligible biological and human‐health risks. However, the rate of warming of the Arctic is three times faster than other parts of the globe, raising the prospect of significant reorganization of system properties and processes with consequent changes to both the sources and fate of radionuclides in the Arctic in the decades to come.