Category Archives: North America

Update on Fukushima Monitoring Activities in North America: 7 Years On

The Fukushima Daiichi Nuclear Power Plant (FDNPP) and surroundings before the tragic events of March 11, 2011

By Jay T. Cullen

The purpose of this post is to bring the community up to date on monitoring efforts aimed at understanding the impact of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on environmental and public health. This post is part of an ongoing series and will focus on North American monitoring, summarizing work carried out by the Integrated Fukushima Ocean Radionuclide Monitoring (InFORM) project. Seven years since the peak in releases to the environment our project continues to measure environmental levels of radioisotopes that could represent a radiological health risk to living things. InFORM makes measurements of levels in seawater and common marine organisms as consumption of seafood is one of the most likely ways that residents of North America could be exposed to Fukushima derived contamination. Maximum contamination levels in seawater from Fukushima measured in waters offshore and onshore British Columbia and in the Arctic Ocean are about 8 to 10-fold lower than levels present in the North Pacific during the height of atmospheric nuclear weapons testing in the 1950’s and 1960’s.  These levels are roughly 1000-fold below the maximum allowable drinking water standards for these isotopes.  Levels in marine organisms have not changed significantly since before the disaster.  As was reported in 2015 in this comprehensive study by Health Canada and backed up by measurements made by the international scientific community the release of radioisotopes from Fukushima will have no measurable impact on the health of the marine ecosystem in the northeast Pacific nor on public health in North America.


On March 11, 2011 all eyes were on Japan and I was watching too and feeling acutely the loss of life that the earthquake and tsunami brought on the Japanese people. A little later I watched as events at the FDNPP began to unfold and it became clear that a major nuclear accident was underway. I wondered what it meant for me and my family and friends in Victoria, BC Canada. I catalogued all the monitoring data coming in in 2011 I could find from the international scientific community and kept careful watch on the scientific literature. In 2013 I began communicating with the public about what the triple meltdowns at the FDNPP meant for the health of our marine ecosystem and public health because much of the information getting to the public was not scientifically sound, misinformed the public in general and overestimated the risk to people living in North America. The short of the story then was that nothing in the measurements of air, soil and water suggested any significant risk to public or environmental health.  But it was clear that many in the public were being mislead by information online. To address the lack of quality information getting to the public I and other scientists in Canada and the USA, non-Governmental Organizations and citizen scientist volunteers put together the InFORM network. This is what we have found so far.

Offshore Monitoring of Seawater Contamination

The levels of radionuclide contamination in seawater is important to understand as the levels that ultimately are found in marine organisms is set by seawater levels.  InFORM recently published a peer-reviewed paper in Environmental Science and Technology summarizing our results to date. Offshore levels of Fukushima derived isotopes have peaked and are now decreasing at our westernmost stations 1000-1500 kilometers from the North American coast.  The peak levels are well below levels measured in the same waters during the 1950’s and 1960’s when atmospheric nuclear weapons tests were common.  The study area is shown in the figure below along with the prevailing currents that brought the contaminated seawater to North America.

Study area showing the onshore-offshore sampling line occupied by the InFORM project with the support of Department of Fisheries and Oceans Canada. Station P26 is ~1500 kilometers from the coast of North America.


​Measurements of radiocesium isotopes help scientists determine how much impact Fukushima has had on seawater at any given location on the globe. Off North America levels peaked at about 10 Bq per cubic meter of seawater (a Bq = Becquerel is one decay of an atom per second).  This peak contamination is about 10-fold below levels measured here in the middle of the 20th century and 1000-fold below levels allowed in drinking water in Canada. The figure below shows how Fukushima derived contamination arrived in the upper ~400 meters of seawater from June 2013 until August of 2016.

Progression of Fukushima contamination in the upper 500 meters of seawater over time toward the coast of North America along the Line P times series stations. Data J. Smith (DFO). The coast is on the right hand side of the figure with distance offshore plotted on the x-axis and depth in the ocean on the y-axis. Red values would indicate seawater with cesium concentrations that exceed drinking water standards. The color scheme is on a logarithmic scale.


​The figure below shows the change in contamination with time and the levels in comparison to historical levels in the eastern North Pacific Ocean.

Peak levels of contamination from Fukushima in the northeast Pacific at stations P26 (offshore), P16 (intermediate) and P4 (coastal) since 2011 compared with model predictions of Rossi.  Insert shows Fukushima contamination relative to weapons testing fallout. Levels at P26 have peaked and are declining reflecting the large releases in the weeks following the meltdown with sustained by much lower releases persisting from that time on.


​Levels measured now and predicted to arrive along the coast in the future will not approach levels known to represent a significant risk to the health of marine organisms or human beings.

Coastal Monitoring Efforts by InFORM Citizen Scientists

Every month since about December 2014 volunteer citizen scientists in 15 coastal communities up and down the shores of British Columbia have collected seawater samples at the beach and returned them to our laboratories for analysis.  The sampling network is shown below.

Coastal seawater monitoring stations in British Columbia.


Since monitoring began coastal seawater concentrations have increased as the Fukushima contamination plume arrives.  The first detection of Fukushima contamination at the coast occurred in Feb. 2015 in the coastal community of Ucluelet on the west coast of Vancouver Island. Since that time levels have increased moderately and likely reflect that fact that the mixing of freshwaters coming from the land with the contaminated oceanic waters tend to insulate the coast from higher levels of contamination measured offshore.  At the coastal locations contamination levels of human-made isotopes (which are a very small fraction of the radioactive elements in seawater) have increased 2-4 times relative to the pre-Fukushima levels.

Levels of radiocesium detected at the coast of British Columbia since monitoring began in 2014.  Regional patterns are shown in the second panel with more ocean exposed (west coast of Vancouver Island and north coast of BC) sites showing more Fukushima derived contamination than sites in the Salish Sea or in sheltered areas of the central coast.


Our coastal ecosystem and food supply are not at risk from these low levels of radioisotope contamination.

Monitoring of Pacific Salmon and Other Marine Organisms

Since 2014 we have collected and analyzed ~100 Pacific salmon and steel head trout per year returning to rivers up and down the BC coast from the Pacific Ocean.  There has been no statistically significant increase in the levels of human-made isotopes in the fish since before the Fukushima disaster. The dose of ionizing radiation experienced by consumers of Pacific fish and shellfish is still dominated by the presence of naturally occurring radioisotopes in the Uranium and Thorium decay series (principally 210-Polonium) and remains well below levels that might represent a health risk. Our results are summarized in the following two figures.

Monitoring results for Pacific fish as of September 2017. Approximately 450 fish have been collected over the period 2014-2017. No significant increase in artificial, human made isotopes has been detected.


​The ionizing dose from consuming these fish is insignificant relative to other sources of ionizing radiation dose experienced by members of the public in North America. No measurable health impacts are expected.

Dose of ionizing radiation from Fukushima derived isotopes relative to other sources.



Our intensive monitoring of environmental levels of contamination from Fukushima here in North America indicate that there is insignificant risk to ecosystem or public health resulting from the levels of radioisotopes detected in seawater and marine organisms.  A summary of our program results thus far and monitoring of conditions off of Fukushima in Japan are given in the following figure.


Consistent with model predictions and the measurements made by scientists around the globe, the FDNPP accident will not have measurable negative impacts on North America’s marine ecosystems or public health. Levels of contamination are simply too far below those known to represent a threat to wildlife or human health. The InFORM project will continue its monitoring efforts into March 2019 and will continue to report its results and make them available to the public as soon as possible. I am available and happy to answer and questions related to the project, its goals and results. As always on this somber anniversary I think about the incredible loss of life from the tsunami and wish the best for the recovery of Japan’s coastal communities.


The fate of atmospheric Fukushima radiation

Did you enjoy your trip? If you were alive during the Fukushima meltdown in 2011, you received an extra dose of radiation equal to that received on a roundtrip flight from Vancouver to Tokyo. This is the result according to research presented by Nikolaos Evangeliou of the Norwegian Institute for Air Research at the annual meeting of the European Geophysical Union earlier this year.

Continue reading The fate of atmospheric Fukushima radiation

Update: 2016 Sampling of North American Pacific Kelp Finds No Signature of Fukushima Contamination

By Jay T. Cullen

Wikipedia image by Ed Bierman from Redwood City, USA of diver exploring a coastal kelp forest


The purpose of this post is to report the most recent and last results from Kelp Watch 2015, a program dedicated to monitoring for Fukushima derived contamination along the Pacific Coast of North America.  This post is the latest in a series dedicated to public outreach and dissemination of scientifically derived information about the impacts of the Fukushima Dai-ichi disaster on the health of the North Pacific Ocean ecosystem and health of North American residents. Results from the fifth sampling period (March 2 through June 3 2016)  were released on July 15, 2016 and can be found here. As with previously reported results here, here, here, here, and here no radioactive isotopes from Fukushima were detected in kelp growing at sampling sites along our Pacific coast or elsewhere in the Pacific (see sampling sites).  The absence of 134Cs in kelp suggests that ocean transport of Fukushima contamination had yet to reach persistently high enough levels in North American coastal water to bioaccumulate in kelp. The levels of Fukushima derived contamination in kelp in 2016 will not pose a significant risk to the health of the kelp or other species, including humans, which rely on them as a foodstuff.

Continue reading Update: 2016 Sampling of North American Pacific Kelp Finds No Signature of Fukushima Contamination

Fukushima nuclear accident is ‘wake-up call’ for US to improve monitoring of spent fuel pools

by National Academies of Sciences, Engineering, and Medicine
Published by EurekAlert! on 20 May 2016

The Phase 2 report from the National Academies focuses on three issues: (1) lessons learned from the accident for nuclear plant security, (2) lessons learned for spent fuel storage, and (3) reevaluation of conclusions from previous Academies studies on spent fuel storage.

The 2011 Fukushima Daiichi nuclear accident should serve as a wake-up call to nuclear plant operators and regulators on the critical importance of measuring, maintaining, and restoring cooling in spent fuel pools during severe accidents and terrorist attacks, says a new report from the National Academies of Sciences, Engineering, and Medicine. This report is the second and final phase of a congressionally mandated study on what lessons can be learned from the Fukushima Daiichi nuclear accident. The report from Phase 1 of this study was released in July 2014. The Phase 2 report provides findings and recommendations for improving U.S. nuclear plant security and spent fuel storage as well as re-evaluates conclusions from previous Academies studies on spent fuel storage safety and security.

[Links to the Phase 1 and Phase 2 reports are available under the Resources menu.]

Continue reading Fukushima nuclear accident is ‘wake-up call’ for US to improve monitoring of spent fuel pools

The Impact of the Fukushima on Canada: Health Canada Reports

By Jay T. Cullen

The purpose of this post is to bring to the attention of interested readers a recently released report that provides comprehensive account of the environmental radiation surveillance activities conducted by Health Canada in the months immediately following the Fukushima accident.  This report includes an assessment of the overall levels of contamination and resulting impacts to the health of Canadians.  Contrary to irresponsible and inaccurate rumors that Health Canada suspended monitoring in the wake of the triple meltdowns, monitoring activities were, in fact, enhanced and expanded to increase the flow of information and improve understanding of the implications of the contamination for environmental and public health.  While there was no discernible change in total background radiation a distributed system of monitoring stations and the rapid collection and measurement of environmental samples tracked the trace levels of atmospheric contamination across the country. The report concludes:

  1. conservative estimates of the maximum individual dose from Fukushima was less than 0.0003 (1/ 3,000) of the typical annual dose for a Canadian owing to natural background sources
  2. the additional dose resulting from Fukushima derived contamination is far less than the normal variation in dose from place to place in Canada
  3. there are likely to be no health impacts related to this small, incremental dose

Continue reading The Impact of the Fukushima on Canada: Health Canada Reports