Scientists understand how radionuclides accumulate in fish after the Fukushima accident

Research in Japan was carried out after the accident at the Fukushima-1 nuclear power plant in 2011. Then radioactive materials

in large volumes leaked into the soil and water bodies,whereupon they became heavily polluted. In view of this, a ban was placed on fishing in lakes and rivers. The ban has not yet been specified. Scientists are trying to find out when the use of natural resources in the affected areas after technological disasters becomes safe. Scientists from the National Institute of Environmental Research in Japan, led by Dr. Yumiko Ishii, identified biotic and abiotic factors affecting the accumulation of radionuclides in fish. The information received helped predict and manage environmental pollution in Fukushima.

It remains to be seen how theseunderlying factors in different ecosystems. A group of scientists from analyzed monitoring data for 30 species of fish and aquatic organisms from five rivers and three lakes in the Fukushima area. They conducted their research two to four years after the accident at the nuclear power plant. In their work, they statistically correlated measurements of radiocaesium with a number of biotic and abiotic factors. Radio cesium, especially cesium-137, has a long half-life of about 30 years and is the main pollutant in the area. As Dr. Ishii explains: “After the Fukushima-1 accident, cesium became the main pollutant in the region, and the risk of exposure to its radiation became a matter of serious concern.”

Scientists considered the following factors: fish characteristics - feeding habit, body size and habitat; water chemistry - salinity, total organic carbon and concentration of suspended solids. Their analysis showed that factors affecting the levels of radiocaesium in river organisms do not necessarily affect its levels in organisms from the lake. In particular, the concentration of suspended solids, total organic carbon and salinity were significant factors in rivers, but not in lakes. Food habits have affected fish-eating fish in lakes more, but not in rivers; this became clear from the fact that a significant biomagnification of radiocaesium (that is, an increase in its concentration as it moves along the food chain) was observed only in lakes. Finally, the size of the individual influenced those fish that live both in lakes and in rivers.

In general, these results show thatThe biotic and abiotic factors affecting the accumulation of radionuclides in fish clearly depend on the ecosystem - and they differ between lakes and rivers. The results of this study could potentially lead to the implementation of more effective strategies for responding to environmental disasters in the future.