Fukushima radionuclides in the NW Pacific and assessment of doses for Japanese and world population from ingestion of seafood

Abstract

Variations of Fukushima-derived radionuclides (90Sr, 134Cs and 137Cs) in seawater and biota offshore Fukushima and in the NW Pacific Ocean were investigated and radiation doses to the Japanese and world population from ingestion of seafood contaminated by Fukushima radionuclides were estimated and compared with those from other sources of anthropogenic and natural radionuclides. The total effective dose commitment from ingestion of radionuclides in fish, shellfish and seaweed caught in coastal waters off Fukushima was estimated to be 0.6 ± 0.4 mSv/y. The individual effective dose commitment from consumption of radioactive-contaminated fish caught in the open Pacific Ocean was estimated to be 0.07 ± 0.05 mSv/y. These doses are comparable or much lower than doses delivered from the consumption of natural 210Po in fish and in shellfish (0.7 mSv/y). The estimated individual doses have been below the levels when any health damage of the Japanese and world population could be expected.

Impact of the Fukushima accident on tritium, radiocarbon and radiocesium levels in seawater of the western North Pacific Ocean: A comparison with pre-Fukushima situation

“…Presence of 134 Cs in seawater clearly indicates its Fukushima origin as because of the short half-life 134 Cs from global fallout and the 1986 Chernobyl accident has already decayed. The nuclear accident at the Fukushima Dai-ichi NPP increased 137 Cs concentrations in coastal seawater in March 2011 up to 68 kBq L -1 , eight orders of magnitude above the global fallout background (Povinec et al, 2013a;Povinec and Hirose, 2015). This increase was due to direct liquid releases of 137 Cs contaminated fresh and later also seawater to coastal waters, which was estimated to be around 4 PBq (Kawamura et al, 2011;Tsumune et al, 2012Tsumune et al, , 2013Aoyama et al, 2016a, b).…”

Fukushima Daiichi–Derived Radionuclides in the Ocean: Transport, Fate, and Impacts

“…Many other species exhibited activities above 100 Bq kg −1 in the first year after the FDNPP releases (e.g., Buesseler 2012) ( Figure 5). Povinec & Hirose (2015) estimated the effective dose for someone ingesting seafood from off the coast of the FDNPPs between 2011 and 2013 to be 0.6 ± 0.4 mSv y −1 , as compared with a dose of 0.7 mSv y −1 from naturally occurring 210 Po in fish and shellfish. This is in agreement with Johansen et al (2014), who calculated a dose of 0.13 mSv y −1 from radioactive Cs for a hypothetical consumer of 50 kg of fish collected in 2013 within 3 km of the FDNPPs.…”

Recent results from the AMS/IBA laboratory at the Comenius University in Bratislava: preparation of targets and optimization of ion sources

“…Except the most frequently studied 134 Cs and 137 Cs (gamma-ray emitters easily measured with HPGe detectors [31,32]), which have been important for delivery of postaccident radiation doses to the public and biota [33], there have been many other radionuclides released during the accident [30,[34][35][36], requiring our attention. This has been motivated first of all because of delivery of radiation doses to the public and biota by long-lived radionuclides (e.g.…”