Japanese in the aftermath of the Fukushima Disaster

Latest issue of Journal of Environmental Radioactivity contains a paper of Russian researchers, which covers distribution of radioactive isotopes from Fukushima nuclear power plant in space and time.

Everyone will remember March 2011 for an awful tragedy at Japanese Fukushima nuclear power plant, which was assigned the highest rank according to International Nuclear and Radiological Event Scale. The same rank – seven – was assigned to Chernobyl nuclear tragedy, which had happened in 1986 in USSR’s Ukraine. No wonder these two terrible events are being compared in many aspects.

The whole world breathlessly followed spreading of isotopes from Fukushima power plant. Radioactive cloud crossed the sky over the United States of America and Atlantic ocean, and finally arrived to Europe. By the end of ill-fated March 2011 radionuclides 134Cs, 137Cs and 131I were detected in air over Greece (they are for sure not to blame for Greek financial problems), and radioactive iodide was also found in rainwater and sheep milk.

The cloud continued its way to Asia, however, nothing appeared in mass media on distribution of radioactive isotopes in Asian countries. Researchers from Krasnoyarsk collected samples of rainwater, snow, pine needles and air in the city and around it between April, 3 and May, 3, 2011. Isotopes of cesium and iodide appeared in Krasnoyarsk snow as soon as on April 4-6, moreover, highest activity of radioactive iodide reached 0.62 becquerel/litre, which was comparable to that of Greek rainwater with 0.7 becquerel/litre.

Rainwater, collected in Krasnoyarsk between April 27 and May 3, showed lower activity of radioactive cesium and iodide. Pine needles demonstrated fantastic ability to accumulate radioactive isotopes. Activity of 131I, 137Cs and 134Cs in pine needles reached 3.28, 1.03 and 0.74 becquerel per kilogram, respectively. Siberian scientists regularly measure concentration of 137Cs in pine needles with latest data coming from 2009. After consideration of background activity of this isotope, the impact of Fukushima appeared to be 0.83 becquerel per kilogram. Ratios of radioactive isotopes 137Cs/134Cs and 131I/137Cs were the same as in nuclear tragedy traces in Greece, and that is why authors of the research conclude that they have been dealing with Fukushima isotopes.

Observations of Russian researchers show that a radioactive cloud from Fukushima nuclear power plant reached Siberia early in April this year on its way to Far East and Japan. The cloud was moving very fast and quickly traveled around the world. Russian researchers believe that Fukushima and Chernobyl tragedies have many things in common, like radioactive contamination areas and the speed of the radioactive cloud. However, some scientists tend to think that nuclear contamination from Fukushima equals to only 10% of Chernobyl tragedy and is dangerous only for those, dwelling near the nuclear power plant. Well, time will show who is right. We should remember that Fukushima threats to release long-leaving isotopes to the environment.

Paper Reference: Bolsunovsky, A., Dementyev, D., Evidence of the radioactive fallout in the center of Asia (Russia) following the Fukushima Nuclear Accident, Journal of Environmental Radioactivity (2011), doi:10.1016/j.jenvrad.2011.06.007. Read an extract or purchase a full article at Science Direct.

Source: Science and Technology. Image courtesy of Vladivostok: The City of Sea Cucumber Cliff.

Anna Kizilova