Fukushima Fallout: Addressing Current Concerns
The 2011 Fukushima disaster released radionuclides directly into the Pacific ocean causing serious concern over radiation contamination of the food supply. This concern led to extensive testing by both government and academic networks.
Since 2011 The Big Carrot has been monitoring this issue, as it pertains to our products, in order to provide information and assurance to our customers.
Recently, there has been a new wave of concern as ocean currents have dispersed contaminated water as far as the North American Pacific coast. Measurements made by a Canadian monitoring program indicate that the plume arrived in Canadian coastal waters in June 2013 and concentrations are expected to increase in 2015-2016.1 While the plume effect is a valid concern, it has unfortunately generated a great deal of misinformation and sensationalizing across the internet.
In light of some customer concern we thought we would share the information we have gathered. We are confident in the sources we have referenced and feel they provide a necessary counterbalance to the current internet conversation. There are several research networks (governmental and academic) continuously monitoring the Pacific coast of the US and Canada.
These networks are testing water, kelp and fish. Thus far any isotope traces have been well below allowable limits.
Cesium 134 (134Cs) and Cesium 137 (137Cs) are the largest components of the initial radioactive releases that could still be in the environment. It is important to measure both Cesium isotopes, not just the longer-lived 137Cs. The reason is that decades of above-ground nuclear weapons testing (mostly in the 1950s and 1960s) released significant amounts of 137Cs into the Pacific Ocean. Since 137Cs has a 30 year half-life, any 137Cs measured in the environment could be from these “legacy” sources and not from Fukushima Dai-ichi.2
Is the North American Pacific coast contaminated?
In 2014 some traces of 134Cs were detected in seawater approximately 500 miles off the coast of British Columbia by the Woods Hole Oceanographic Institute. This includes the highest detected level to date from a sample collected about 1,600 miles west of San Francisco. The level of radioactive cesium isotopes in the sample is 50 percent higher than other samples collected along the West Coast so far, but is still more than 500 times lower than US government safety limits for drinking water, and well below limits of concern for direct exposure while swimming, boating, or other recreational activities.3
Results from 20 samples, mostly collected in November 2015 – January 2016 by the INFORM network, did not find any of the Fukushima fingerprint isotope, 134Cs in coastal waters. Low levels of 137Cs were present in all of the samples. These new data continue to lie along the increasing trend, which indicates that the leading edge of the Fukushima plume is in BC’s coastal waters. While a rise in 137Cs levels is expected they would still be far below allowable concentrations in drinking water.
Is it safe to eat fish from the North American Pacific coast?
Since 2011 Health Canada has continued to assure the public that the radiation dose received from both radioactive cesium and naturally occurring radionuclides as a result of eating fish is of no heath concern. In 2013 more than 60 fish samples of adult salmon and ground fish harvested from the Canadian west coast were tested. None of the samples contained any detectable levels of 134Cs or 137Cs.4
The Alaskan Department of Environmental Conservation tests show no appreciable iodine-131, 137Cs or 134Cs in samples of cod, halibut, herring, pollock, sablefish and king, chum, sockeye and pink salmon. The fish were collected from the Aleutian Islands and the Bering Sea, the Gulf of Alaska, Bristol Bay and Southeast Alaska following negative test results on Alaska seafood last year.5
As of summer 2015 INFORM network testing found no radioactivity in BC fish and any 137Cs detected was far below levels known to be a health risk to salmon or human consumers.6
Kelp: Testing fish food
Marine brown seaweeds are known to concentrate Cesium, Strontium and Iodine into their tissues among many other elements. This is especially true for kelps. There are 50 known organisms that directly graze on kelp tissue or its detached tissue. It is logical to assume that radioisotopes taken up by kelp and concentrated in its tissues will be taken up by the organisms that feed upon it, and distributed throughout the kelp bed community as a whole.7
Kelp Watch is a scientific campaign, based out of California State University and UC Berkeley designed to determine the extent of possible radionuclide contamination (primarily 134Cs and 137Cs) of our kelp forest ecosystem from seawater arriving from Fukushima. The project relies on sampling canopy blades of the Giant Kelp and Bull Kelp along the California coastline as well as locations in Baja-Mexico, Oregon, Washington, British Columbia and Alaska.
Results from the third sampling period (January through March 2015) of Kelp Watch were released on April 6, 2015 and can be found here. As with previously reported results here, here and here no radioactive isotopes from Fukushima were detected in kelp growing at sampling sites spread along our Pacific coast. Monitoring continues.8
Our last review of seaweed procurement was in 2014. At that time all of our suppliers had undertaken independent testing. All seaweeds complied and were well below government issued standards. We offer a variety of seaweeds from diverse locations including China, Japan, Iceland, and the US Maine coast.
If you remain concerned about contamination risk you have several options. You can reduce your consumption of seafood and/or choose small fish which will naturally have a less toxic load. We encourage you to reach out to your favourite companies to find out how they are monitoring contamination risk. Navigating food safety is becoming ever more complex. Our best defence is to be active and educated consumers. At The Big Carrot we strongly advocate consumer awareness and engagement and strive to be a trusted resource for our customers.
Kate McMurray Certified Holistic Nutritionist