Results of the fourth combined scientific expedition for the radition monitoring in the Kurily-Kamchatka region of the Pacific ocean

This paper continues the series of publications on evaluation of the consequences of the Fukushima-1 nuclear power plant accident and the impact of the emergency radionuclide discharges on the contamination of the sea biota and coastal areas of the Far-East regions. In autumn 2019, the fourth scientific expedition of the Russian geographic society on the monitoring of the radiation situation in Kurily-Kamchatka region was performed on the training vessel «Professor Khlyustin». The expedition included 9 specialists from noncommercial organization «Polar research Fund «Polar Fund», «Russian state hydrometeorological institute», «Radium institute after V.G. Khlopin» of the State Corporation «Rosatom», «Kurchatov institute», «SaintPetersburg research institute of radiation hygiene after prof. P.V. Ramzaev» and «Marine state university after admiral G.I. Nevelsky». The aim of the fourth expedition was to evaluate the radiation situation in the Sea of Japan and Kurily-Kamchatka region after the Fukushima-1 NPP accident as a continuation of the similar marine expeditions in 2011, 2012 and 2014. The survey was performed in the water area of the sea of Japan and Okhotsk sea. The results indicate that the concentration of 137Cs and 90Sr in sea water, hydrobionts, soil, ground and sea vegetation is still on the baseline level due to the global fallouts.