Evaluation of radiation doses and associated risk from the Fukushima nuclear accident to marine biota and human consumers of seafood

Abstract

Radioactive isotopes originating from the damaged Fukushima nuclear reactor in Japan following the earthquake and tsunami in March 2011 were found in resident marine animals and in migratory Pacific bluefin tuna (PBFT). Publication of this information resulted in a worldwide response that caused public anxiety and concern, although PBFT captured off California in August 2011 contained activity concentrations below those from naturally occurring radionuclides. To link the radioactivity to possible health impairments, we calculated doses, attributable to the Fukushima-derived and the naturally occurring radionuclides, to both the marine biota and human fish consumers. We showed that doses in all cases were dominated by the naturally occurring alpha-emitter (210)Po and that Fukushima-derived doses were three to four orders of magnitude below (210)Po-derived doses. Doses to marine biota were about two orders of magnitude below the lowest benchmark protection level proposed for ecosystems (10 µGy⋅h(-1)). The additional dose from Fukushima radionuclides to humans consuming tainted PBFT in the United States was calculated to be 0.9 and 4.7 µSv for average consumers and subsistence fishermen, respectively. Such doses are comparable to, or less than, the dose all humans routinely obtain from naturally occurring radionuclides in many food items, medical treatments, air travel, or other background sources. Although uncertainties remain regarding the assessment of cancer risk at low doses of ionizing radiation to humans, the dose received from PBFT consumption by subsistence fishermen can be estimated to result in two additional fatal cancer cases per 10,000,000 similarly exposed people.

Radiation dose rates now and in the future for residents neighboring restricted areas of the Fukushima Daiichi Nuclear Power Plant

“…Except for the early stage of the accident, such food sources have been screened, and those containing more than 100 Bq/kg of radiocesium (current regulation value) have been eliminated from circulation (14). Recent research, including our own previous study, has shown that doses from the ingestion of radiocesium 5-10 mo after the nuclear accident are considered to be less than those from natural radionuclides such as 40 K and 210 Po (15,16). The inhalation of airborne dust comprising resuspended radioactive deposits represents an additional route of internal exposure (17,18).…”

Ecosystem model-based approach for modeling the dynamics of <sup>137</sup>Cs transfer to marine plankton populations: application to the western North Pacific Ocean after the Fukushima nuclear power plant accident

“…The calculated internal dose rates for zooplankton in June 2011 were about 10 −4 µGy h −1 , and were, therefore, about 5 times greater than those reported by Fisher et al (2013) for copepods and euphausiids collected 30-600 km off Japan. This difference is mainly due to the fact that in this study the dose rates were calculated for the populations located at 0-30 km from FNPP, where the activity level of 137 Cs was higher.…”

Agricultural Impacts of the Great East Japan Earthquake Six Years Later

“…Nevertheless, there have been debates and great concerns about the risks for people exposed to lower doses since risks are lower and hardly to detect [Akiyama et al, 2012;Fisher et al, 2013;Hasegawa, 2013;Rosen, 2013]. Fukushima prefecture has been conducting thyroid checkups regularly on more than 380,000 residents who were younger than 18 at the time of the disaster.…”