Category Archives: NE Pacific

Insignificant Environmental and Public Health Risk from Fukushima in North America 8 Years On

By Jay T. Cullen

Summary infographic for the Fukushima InFORM project including our measurements in North America, Japanese measurements, historical data and safety guidelines.

I am writing this post is to bring the public up to date on monitoring efforts of my research program into the impact of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on environmental and public health here in North America. This post is part of an ongoing series summarizing work carried out by the Integrated Fukushima Ocean Radionuclide Monitoring (InFORM) project. Eight years since the peak in releases to the environment our project continues to measure radioisotopes released from the FDNPP that have the potential to present radiological health risks 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. We have found that:

  • Maximum contamination levels in seawater from Fukushima measured in waters offshore (~1500 km) and onshore British Columbia are now known to be 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 Pacific salmon returning to North America have not changed in a statistically significant way since before the disaster and are lower than peak levels measured in the 1960’s.
  •  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.

Eight years after this disaster it is important to remember those lost in the tsunami and those still displaced from their homes and communities struggling to recover.


Offshore and Onshore Citizen Science 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.  Our study area is shown in the figure below along with the prevailing currents that brought the contaminated seawater to North America.

es-2017-02712h_0001.jpeg
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.

​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.

mar-2016-cs-update-01.png
Coastal seawater monitoring stations in British Columbia.

Since monitoring began coastal seawater concentrations have increased as the Fukushima ​contamination plume arrives.  For the first time we can report that contamination levels have ceased increasing near the coast and are beginning to diminish. The activity of 137Cs leveled off at ~4 Bq per cubic meter of seawater which is about 2-4 times the background from weapons testing that existed here before Fukushima. Both the open ocean and coastal monitoring data are summarized in the figures below.

InFORM_trendcomp_Mar19-01.png
Monthly averaged 137Cs detected in seawater in Bq per cubic meter collected along the coast of BC from 2014-2018.

InFORMenews_Mar19-01.png
Levels of 137Cs in seawater (Bq per cubic meter) measured in samples collected by our citizen scientists along the BC coast compared to maximum levels measured offshore, weapons testing fallout maximum activities in the eastern Pacific in early 1960’s and Canada’s action level for the isotope in drinking water.

Offshore levels of 137Cs peaked at a little less than 10 Bq per cubic meter and have been diminishing as less contaminated water moves across the Pacific from the west. Coastal activities have peaked at lower levels likely because freshwater runoff from the continent is less contaminated than the seawater and dilutes the Fukushima contamination.

Monitoring of Pacific Salmon

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. Below we plot the maximum levels we have detected in fish returning to BC from 2011-2017 compared to levels measured in Pacific salmon during the 1960’s when weapons fallout levels were highest surface waters.

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Maximum levels of 137Cs detected in BC salmon post Fukushima compared to levels in Pacific salmon in the mid-1960’s owing to weapons testing fallout.

 

On average our Pacific salmon have ~0.2 Bq per kilogram wet weight and it is important to note that there is no statistically significant different in the average contamination level in the fish in years 2011-2017. We are only showing the maximum value detected in each year and have not shown how much variability exists in the yearly data for clarity. Levels of contamination in the 1960’s were >10-fold higher than our average levels in years post-Fukushima. 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.

We will continue our monitoring efforts likely through the end of this calendar year and continue to report our results as they are generated. As always I am happy to answer any questions related to the project and our findings.

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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.

es-2017-02712h_0001.jpeg
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.

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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.

es-2017-02712h_0006.jpeg
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.

mar-2016-cs-update-01.png
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.

InFORMenews_Jan18_2-01.png
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.

InFORM_Salmon_2016_river_-_Sep17-01.png
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.

Salmon_2016_concentration_dose_simplified-01.png
Dose of ionizing radiation from Fukushima derived isotopes relative to other sources.

 

Summary

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.

InFORM_at_a_Glance-01.png

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.

Updated – No Fukushima radiation found in 2016 Alaskan fish

Alaska Department of Environmental ConservationNo Fukushima contamination was found in any of the 14 fish Alaskan fish samples that were collected between February and September 2016, according to the Alaska Department of Environmental Conservation. The results, released on the Alaksa DEC website, show that the sampled herring, cod, and pollock, halibut, and salmon did not have any detectable levels of 131I, 134Cs (the Fukushima fingerprint radionuclide with a half-life of ~2 years) or 137Cs in the tissues.  These samples were from across Alaskan waters from Southeast to Bristol Bay and the Aleutian archipelago and the Bering Sea. Results from 2016 are similar to their results from 2015 and are part of the network of institutions monitoring for Fukushima radiation in marine waters and seafoods.

The average minimum detectable concentrations for these Alaskan samples on this gamma spectrometer were 63.7 Bq kg-1, 2.1 Bq kg-1, and 1.9 Bq kg-1 respectively for 131I 137Cs,  and 134Cs. While InFORM does not analyze for 131I, those detection thresholds for cesium are 2-3 times higher than are typical for our biotic monitoring program. This may be due to either a smaller sample size or a shorter time in the gamma spectrometer for the Alaskan samples, but the result remains that levels are well below those where intervention is needed (intervention levels for 131I = 170 Bq kg-1 and 134Cs + 137Cs = 1200 Bq kg-1 according to the US Food and Drug Administration). InFORM monitoring in 2016 found 9 salmon (out of 123) from BC and Yukon rivers with detectable levels (where the minimum detectable concentrations were less than 1 Bq kg-1) of  137Cs after a six hour detector run. These nine samples are currently being freeze-dried for an extended, 2 week long, detection run. Results from this additional analysis are expected probably mid-late spring 2017.

An interesting aspect of these 2016 Alaskan samples is that this was the first time a field-deployable gamma spectrometer has been sent by the US Food and Drug Administration to a site for local analyses of samples. Data from the spectrometer were then electronically sent to FDA scientists for analysis. The thought is that this model could be used in the event of nuclear emergency to allow for more rapid analyses of environmental samples.

Alaska DEC will continue monitoring fish samples for Fukushima radiation for at least 2017 and possibly beyond.

No Fukushima radiation found in 2016 Alaskan fish

Alaska Department of Environmental ConservationNo Fukushima contamination was found in any of the 7 fish Alaskan fish samples that were collected during February and March of 2016. The results, released on the Department of Environmental Conservation website, show that the herring, cod, and pollock sampled did not have any detectable levels of 131I, 134Cs (the Fukushima fingerprint radionuclide with a half-life of ~2 years) or 137Cs in the tissues.  These samples follow on their similar results from 2015 and are part of the network of institutions monitoring for Fukushima radiation in marine waters and seafoods. Continue reading No Fukushima radiation found in 2016 Alaskan fish

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