All posts by fukushimainform

Cesium, Fukushima, Japan, Marine Life, Peer Reviewed

Impact of the Fukushima Nuclear Disaster on Marine Animals Along the Coast of Japan

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By Jay T. Cullen

Samurai Crab (Paradorippe sp.)
Samurai Crab (Paradorippe sp.)

The purpose of this diary is to share the results of a recently published, peer reviewed, study that examined the radiological impact of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) meltdowns on invertebrates living in coastal waters close to the disaster site in Japan.  The paper by Sohtome and colleagues measured the activity of artificial radionuclides 134-Cesium (134Cs half life ~ 2 years) and 137-Cesium (137Cs half life ~ 30 years) in 592 specimens representing 46 different taxonomic families collected in coastal waters in Fukushima Prefecture between July 2011 and August 2013.  The authors found 137Cs in 77% of the samples with highest activities in the organisms near to or south of the FDNPP where highest levels in seawater and marine sediments were found after the large initial releases in 2011.  Levels of 137Cs decreased exponentially with time with differences between the various taxonomic groups.  Continue reading Impact of the Fukushima Nuclear Disaster on Marine Animals Along the Coast of Japan →

Cesium, Humans, Japan, Peer Reviewed

Residents Living South of the Fukushima Dai-ichi Have Minimal Internal Radiation Exposure

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Areas to the south of the Fukushima Daiichi nuclear power plant. WBC measurement were performed at the Jyoban Hospital in central Iwaki, which is located about 50 km south of the Fukushima Daiichi nuclear power plant. Study subjects were mainly hospital visitors from Iwaki and its suburbs.

By Jay T. Cullen

The purpose of this post is to relate findings published (open access) in the peer-reviewed journal PLOSOne by Akiyama and colleagues who investigated internal radiocesium contamination in residents living south of the Fukushima Dai-ichi Nuclear Power Plant. This post is the most recent in a series dedicated to sharing the results of scientific research into the impact of the nuclear power plant disaster on ecosystem and public health. The Akiyama study builds on recent work by this group using a whole body counter (WBC) to look for internal contamination of residents living near (north and west) the reactors at the time of the meltdowns. Measurements were made on 9,206 affected individuals, including 6,446 school children (4-15 years) living south of the reactors or evacuated to Iwaki city following the bulk of radionuclide releases. Measurements began one year after the accident and continued for two years. The authors conclude that, despite lack of data for the first year following the disaster, internal doses experienced by residents to the south of the FNPP were minimal. This suggests that efforts to mitigate foodborne exposure have been largely successful and that nearly all the annual effective doses for this segment of the population more than one year after the disaster are likely due to external exposure. Continue reading Residents Living South of the Fukushima Dai-ichi Have Minimal Internal Radiation Exposure →

Cesium, Japan, Marine Life, Peer Reviewed, Potassium

Fukushima Derived Contamination of Whales and Dolphins in Northern Japan

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By Jay T. Cullen

Pacific white sided dolphins (Photo from the Nakamura et al. (2015) study published in MEPS)


The purpose of this post is to report on a recently published, peer-reviewed study documenting the contamination of whales and dolphins in northern Japan following the Fukushima Dai-ichi Nuclear Power Plant disaster in March 2011. This post is the most recent in an ongoing series that documents scientific research into the impacts of the FDNPP disaster on the health of the marine environment. The paper by Nakamura and colleagues investigated the levels of artificial radionuclides 134Cs (half life ~ 2 years) and 137Cs (half life ~30 years) and naturally occurring 40K (half life 1.25 x 109 years) in stranded whales and dolphins in 2011 and 2012 following the disaster. While there was little radiocesium present in the seawater around the northern island of Hokkaido after the disaster some of the animals had detectable levels of radiocesium from the FDNPP in the months following the disaster. By 2012 most stranded animals did not have detectable levels of FDNPP derived radiocesium. According to the authors, the sudden rise in radiocesium levels in the animals following the disaster suggests that the contamination in the animals reflected the seawater activities of the radionuclides through which they swam north rather than bioconcentration through the marine food web. Levels of artificial radionuclides were about 10-fold lower than naturally occurring isotopes in the organisms and are not likely to be causing negative health impacts but may be useful for helping to better understand the migration routes of these animals. Continue reading Fukushima Derived Contamination of Whales and Dolphins in Northern Japan →

Presentations, Presentations & Media

Radioactivity In Our Ocean: Fukushima & Its Impact On The Pacific

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The following presentation is for those interested in the most recent, scientifically rigorous, monitoring data related to the impact of the Fukushima Dai-ichi disaster on the health of North Pacific Ocean ecosystem and inhabitants of western North America. Last evening, Sept. 14, 2015 Dr. Ken Buesseler and I reported on monitoring efforts through the Fukushima InFORM and Our Radioactive Ocean projects at a public lecture hosted by the Vancouver Aquarium. The presentation was followed by a Question and Answer period and discussion.

Link to the YouTube video is here in case of browser compatibility problems.

Monitoring, Oceanic

Update: Sampling for Fukushima Derived Radionuclides in the Northeast Pacific and Arctic 2015

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By Jay T. Cullen

Locations where surface seawater samples were collected for the InFORM project in July 2015. Surface seawater temperatures at the time of collection are shown with values greater than 16C in the anomalous region referred to colloquially as “the blob”.


The purpose of this short post is to update readers on the activities of the Integrated Fukushima Ocean Radionuclide Monitoring (InFORM) project. This post is the most recent in a series documenting scientific research into the impact of the Fukushima Dai-ichi disaster on environmental and public health. Surface seawater samples were collected from the icebreaker CCGS Sir Wilfrid Laurier as it traveled between Victoria BC to Dutch Harbor Alaska during July 2015. These seawater samples will be analyzed to characterize the distribution of Fukushima derived radionuclides 137-Cesium (137Cs half life ~30 years), and 134-Cesium (134Cs half life ~2 years). As in previous years this information will help to determine how well model predictions of the activities and progression of ocean borne contamination across the Pacific Ocean match with observations. Understanding the spread of this contamination provides important information on the impact of the Fukushima Dai-ichi disaster on the health of the Pacific ecosystem and the North American public. The evolution of the contaminant plume in time and space also helps the scientific community to better understand ocean mixing which is a key parameter toward understanding the oceans role in mitigating atmospheric greenhouse gas increases and climate change.
Continue reading Update: Sampling for Fukushima Derived Radionuclides in the Northeast Pacific and Arctic 2015 →