Why Alaskan Fish Oil is safe and not contaminated by radiation

by Sam and Dan Wiley


Some of our customers have asked us: how do I know your fish oil is free from radiation from Japan’s Fukushima nuclear plant?

The quick and simple answer is: our Wild Alaskan Fish Oil supplements (and actually ALL of the seafood from Alaskan waters) is safe and free from harmful radioactive contaminants. But, we’re guessing if you’re reading this, you’re looking for a more detailed explanation.

The two most important questions are:

  1. Are the levels of radiation in Alaskan Seafood elevated because of the Fukushima accident? The short answer is no.  The radioactive isotopes formed from Uranium-238 decay have not been shown to bioaccumulate in Alaskan fish & seafood.
  2. Are radiative isotopes present in Alaskan Seafood at unsafe levels? No.  These specific radioactive isotopes are not present in Alaskan Seafood (which is caught thousands of miles from Japan).

Before we delve into the specific details for these two questions, let’s get some basic physics out of the way:

What is Radiation? Radiation, or more accurately, radioactive decay, is when an atom emits a particle (such as an alpha or beta, or gamma particle). Alpha particles trigger nuclear fission. Certain atomic isotopes, such as Uranium 238, will split into two other atoms when stimulated by an alpha particle (this is called fission). This controlled fission reaction is used to power nuclear power plants around the world (such as Japan’s Fukushima Daichi plant) When nuclear fission occurs, uranium decays into many different radioactive isotopes, most commonly Iodine-131 and Cesium-137. These radioactive isotopes don’t stay radioactive forever, but go through a process called decay where they continue to emit alpha, beta, and gamma particles until they are no longer considered radioactive.

The measurement of radioactive decay from a radioactive substance is called “half-life”. As a point of reference, Iodine-131 has a radioactive half-life of only about 8 days, whereas Cesium-137 has a half life of about 30 years. Any Iodine-131 is long gone by the time your food will have reached you, so Cesium-137 is the isotope that we want to be sure is not present in our food.

How is Radiation Exposure Measured? Radiation exposure is measured in units called a “Sievert”. An annual dose of 1 Sievert is estimated to cause a 5% increase in the risk of death from cancer over the lifetime of the individual (1). 1 in 5 lifetime causes of death (we all die from something) are from cancer. So exposure to 1 Sievert in the course of a year (a truly massive dose) would increase your risk of death by cancer about 5%.

To keep things in perspective, we need to describe the extremely small units of radiation we are talking about.  As mentioned previously, 1 Sievert is a truly massive dose, about 13% of a fatal radiation dose (8 Sieverts). There’s two units that we’ll cover:

Micro-Sievert: 1 μSv = 0.000001 Sievert = 1 millionth of a Sievert

Milli-Sievert: 1 mSv = 0.001 Sievert = 1 thousandth of a Sievert

However, I can start to see your eyes glazing over, so let’s use a new unit to measure radiation exposure: The Banana.  Yes, that ubiquitous yellow fruit has an embarrassing secret that makes for good party conversation.  Bananas are radioactive!


Eating a banana exposes you to about 0.01 microSievert (µSv), or 1/100th of a μSv which is about 0.000003% of one’s average yearly radiation intake.

So, let’s talk about some everyday sources of radiation exposure in terms of bananas.

Getting a dental X-ray – 5µSv…or 500 bananas!

Flying for 6hours from New York to LA… 4000 bananas!

Getting a Mammogram… 40,000 bananas!

Average yearly radiation dose (rocks, soil, sun, food) …300,000 bananas!

And you thought science was boring and dry!  It brings a whole new meaning to the phrase “I’m going bananas”.

The food we eat inevitably exposes us to radiation. The question is not “How do I eat radiation-free food?” but rather, “How much radiation exposure (dose) from my food is too much?”

So, back to our first question: Are the levels of radiation in Alaskan Seafood elevated because of the Fukushima accident? The answer is “no” and here’s the reason why:

Radiation is naturally present in fish from natural, non-nuclear sources. Researchers at Stanford University’s Hopkins Marine Station published a fascinating study that looks at levels of cesium-137 isotopes in migrating bluefin tuna caught off of the coast of San Diego, CA in August 2011 and August 2012, 5 months and 18 months after the Fukushima accident respectively.  They were able to detect increases in radiation present specifically from Fukushima, but the elevated levels accounted for only 0.2% of the total radiation naturally present in the fish.  Here’s a quote form their study:

Consumption of 200 g (a typical restaurant-sized serving) of PBFT contaminated with 4.0 Bq·kg-1 dry weight of 134Cs and 6.3 Bq·kg-1 dry weight of 137Cs (mean values for PBFT caught off San Diego in August 2011) resulted in committed effective doses of 3.7 and 4.0 nSv, respectively (Table 1). To put this into perspective, the combined dose of 7.7 nSv from these two Cs isotopes is only about 5% of the dose acquired from eating one uncontaminated banana (assuming 200 g weight) and absorbing its naturally occurring 40K (28), and only about 7% of the dose attributable to the 40K in the PBFT. (2)

The study goes on to hypothesize a worst-case scenario: what if a subsistence fisherman who eats 273 lbs of seafood in a year (5 times more than average US consumption) were to eat only this affected bluefin Tuna for an entire year? It concluded the fisherman would receive about 2.8mSv additional per year (from natural sources), but only 4.7 μSv specifically from Fukushima radiation, or 5 millionths of the dose necessary to increase their risk of death from cancer by 5%, or about 12% of the radiation exposure he would get from a single flight from Los Angeles to New York.

Our second question: Are radioactive isotopes present in Alaskan Seafood at unsafe levels?

Radiation limits in Food. Long before the Fukushima incident, the FDA established DIL (Derived Intervention Levels) for food – the action limit is 1200 Becquerels/kg of Cesium-137. A Becquerel is a weird unit that measures the amount of radiation (remember – alpha, beta, or gamma particles) emitted by a substance. The FDA’s official laboratory test method can be found here.

US Government Testing– As a result of the Fukushima accident, the FDA now regularly monitors radiation levels of two basic categories of food:

1. Seafood caught in US waters

2. Food imported from Japan, both land-based food (vegetables, meat, etc) and seafood.

Both food imported from Japan and US caught Seafood have been tested by FDA for radioactive nucleotides – over 1313 samples of Japanese food have been tested. 199 were seafood – all of the samples except one were free of cesium-137, and of the one where cesium-137 was found, it was far below the FDA’s established DIL.

FDA had tested 1313 samples, 199 which were seafood or seafood products. 1312 samples had no Iodine-131, Cesium-134, Cesium-137, or other gamma-ray emitting radionuclides of concern (FDA)

Migratory Fish populations. Some fish populations, such as albacore tuna, migrate thousands of miles across the Pacific from areas around Japan to the US Pacific coast, and back to the South Pacific islands. Other fish, such as Alaska Pollock (our fish oil products come from Alaska Pollock) do not migrate, sticking within a few hundred miles (or typically less) of their breeding and spawning grounds in the Bering Sea and Gulf of Alaska.

Image courtesy Alaska Seafood Marketing Institute
Image courtesy Alaska Seafood Marketing Institute

It’s important to understand that the radioactive pollution involved from the Fukushima plant is literally analogous to peeing in the ocean.  The enormous volume of the Pacific Ocean (estimated at 188,000,000,000,000,000,000 gallons) vastly dilutes the much smaller volume of radioactive pollution emitted from the Fukushima plant. Even water only 18 miles off of the coast of Japan has been tested to meet US FDA drinking water standards for radiation levels. By contrast, Dutch Harbor, Alaska, where most Alaskan seafood comes from, is 2687 miles away from Fukushima, which is 150times farther than the safe water tested 18 miles from the coast of Japan.

At Wiley’s Finest, we want you to be informed about the safety of our fish oil supplements.  We stand behind the safety and quality of our products and want you to know that we have been monitoring the unfortunate situation in Japan and how radiation might possibly affect our products.  We can get a little geeky about the science, but that’s just part of the passion that gets us so excited about Omega-3 EPA and DHA in the first place.

Some further reading:

FDA Response to the Fukushima Dai-ichi Nuclear Power Facility Incident

Woods Hole Scientist: Fukushima Leak Not Affecting U.S. Seafood

Fukushima Radiation – Little Impact on Alaska Seafood



  1. Nuclear Radiation and Health Effects, World Nuclear Association, 19 Oct 2013.
  2. “Evaluation of radiation doses and associated risk from the Fukushima nuclear accident to marine biota and human consumers of seafood”, Fisher, et. al. PNAS 2013

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