Independent LAB TEST RESULTS: RadioIsotope Analysis of Hokkaido Kelp and other Samples

January 19, 2014 – Michaël Van Broekhoven

Introductory Summary & Results Overview

The investigation:  9 food samples, bought in stores in Japan (in Iwaki, Kyoto, Nara, Nagano, and Tokyo) between mid-November and early December 2013, were sent to a professional fully-certified independent quality scientific lab in the United States in mid-December 2013 for radioisotope analysis.   Samples measured from 20% to over 400% above local background radiation.

The objective was to find out which radioisotopes precisely caused the elevated radioactivity.  The aim was to check whether or not the Japanese government’s claim that “all their food is perfectly safe to eat” is true (or not) for these samples, as well as to get independent scientific data regarding the spread of radiation from the ongoing Fukushima-Daiichi Nuclear Disaster through ocean currents over relatively long distances.  (See more further below, where I describe each sample, and my research objectives in detail.)

The samples:

  • 6 kelp seaweeds (from various parts of ‘Hokkaido’, in Northern Japan)
  • 1 nori seaweed (Processed in Fukuoka,  Southern Japan)
  • 1 dried Urume-Iwashi (round herring) fish snack (caught in Bungo Channel area, Japan)
  • Tea sample (Green Tea, growing region unknown, but from Japan)

The tests conducted were:

  • All 9 samples received Gammaspectroscopy Analysis.  
  • Of those 9 samples, unrelated to the gammaspectroscopy results, purely for additional scientific data:  3 kelp seaweed samples were also submitted for Plutonium analysis, Strontium-90 analysis, and Gross Alpha and Gross Beta analysis.  

— This very long blogpost is summarized in the next one, ‘the short version‘.  In this one, an enormous amount of additional details are included, from how I selected the samples, detailed samples description, more test result details, maps with locations, links to the run-up to this investigation, etc.   (Much of this blogpost was written before I had lab results, describing the samples and research objectives at length.  Additional data on natural isotopes, which I’m still waiting on, will be added (hopefully! if they become available…) in a future blogpost.)

WHY I conducted this investigation & Research Context:

My suspicion and serious concern about the main cause of Fukushima’s radioactive fallout in food grew out of my discovery that some Japanese food (mainly Hokkaido kelps) showed significantly elevated radiation levels.  It is not why I was visiting Japan in autumn 2013 (See also Nov 18, 2013, “A Visit to Fukushima, Cut Short. With PHOTOS and Reflections“), but it is what started this scientific side-project.

I’ve been concerned that the Fukushima-Daiichi nuclear disaster is affecting not only sea life in and near Japan, but also thousands of miles from Japan, and that food in North America may end up containing increasing amounts of man-made radioactive materials.  The cause for this concern, apart from the ongoing disaster in Fukushima on the shore of the Western Pacific, is the impression that government agencies on the Eastern side of the Northern Pacific Ocean (US, Canada, Mexico) are strangely unresponsive to this widespread concern.

Last spring (2013) when I lived near Arcata, in Northern coastal California, I sent 4 samples to a lab (1 mushrooms, 2 soils, 1 seaweeds – See Northern Humboldt Samples: Lab Results (June 5, 2013)).   The lab results did not particularly raise my concerns (in fact they were somewhat of a relief, too); they just confirmed the need for more testing, especially as to identify where the (very likely) relative hotspots are in North America.  My seaweed sample then, unlike mushrooms and soils, contained only naturally occurring isotopes, not even a trace of Cesium-137 or Iodine-131.  I had not previously observed my Geiger Counter respond to food the way it did to those seaweeds in Japan.

Since then, elevated levels of radiation have been observed in California (in rain (See EnviroReporter Nov 27, 2013), and on beach near San Francisco (See ENEnews Jan 4., 2014), yet (this is true regardless of what the cause(s) of these events end up being revealed to be) officials keep making statements about there being ‘no health hazard’, all being ‘below levels of concern’, etc, usually – and this is the problem: – BEFORE having up-to-date location-specific sample radioisotope-analysis data.  Geiger Counters only show elevated levels, they don’t tell you the precise causes; that takes laboratory tests of samples.   Expecting to blow the lid of a potential cover-up, I  decided to go forward with having samples analyzed.

So, I present a small data puzzle piece here, which may shed a little bit of extra light on the radioactive contamination situation of the Pacific Ocean.   My data is not simulated, anecdotal or speculative, but comes from precise scientific lab tests.  It’s surprisingly good news, especially for seaweed lovers like myself.  The data on man-made radioactivity in my sampled food items is in:

The samples were analyzed for any traces of manmade fission materials, such as Iodine-131, Cesium-134, Cesium-137, Cobalt-60, and many others.  Further below, many more details are provided in copies of original reporting, but for the purpose of giving a quick impression of the results in SI units, see this first table with data, below.

For a quick impression, the basics of the lab results are summerized in this overview table.  There isn’t much to see, as the samples’ elevated radioactivity was apparently not from Fukushima, but nearly all from high Potassium content (and thus Potassium-40 – Updated: K40 data now included!):

Figure: Overview of selected sample lab analysis results.  Potassium's Potassium-40 is very clearly was caused the high Geiger Counter measurements. © Michaël Van Broekhoven, 2014

Figure: Overview of selected sample lab analysis results. Potassium’s Potassium-40 is very clearly what caused the high Geiger Counter measurements.
© Michaël Van Broekhoven, 2014

  • Many more isotopes were tested for than shown in this overview table, see under ‘Full Disclosure Lab Results’, below.
  • Lab note:  Insufficient sample volumes [less than 150 g] were submitted for Samples 2, 3, 4, 8, and 9.  The results for these samples should be considered qualitative and not quantitative, in other words, Cobalt-60 and Cesium-137 were ‘detected’, but their precise amounts have a larger than standard margin of error, so they cannot be used for scientific calculations that would require quantitative precision.

Summary of findings (more further below):

The significantly elevated radioactivity of these samples, as I measured them with my Medcom Inspector Alert Geiger Counter, are clearly NOT due to radioactive contamination from Fukushima, but rather from naturally occurring radioisotopes, mostly due to impressive Potassium-40 content.  Amazingly, these Japanese seaweeds are simply exceptionally nutritious, NOT contaminated.  

I was very concerned that I would be writing something very different, along the lines of, “My inquiry has revealed that the nuclear industry, near-certainly as a direct result of TEPCO’s [Stock market ticker: 9501:JP] still-leaking Fukushima-Daiichi nuclear disaster, has ruined at least part of the previously famously pristine coastal kelp forests of Hokkaido in far-Northern Japan,” (in fact, that is one of the lines of what I had ready in draft before I received the data…), but wow-was-I-wrong my lab results in fact revealed that the elevated radioactivity found in those kelps is in most cases entirely the result of naturally occurring radioisotopes, particularly Potassium-40.  

Although I began considering this possibility recently (see my Jan. 9, 2014 blogpost, “Could (natural, normal) radioactive Potassium-40 (K-40) be the main cause of elevated radiation levels in food?“), this is NOT what I expected to find:

  • 2/3rds of my suspected-to-be-significantly-contaminated samples contained no nuclear pollution at all.  None.   (Scientifically: the detected levels, if there were any, were below quantifiable levels).
  • The levels of artificial radionuclides in the other 1/3rd are extremely low, amounting to no more than unquantifiable ‘trace levels detected’.
  • !-> Eating these samples would actually have been harmless;
  • !!!–>  Geiger Counters, like the Medcom Inspector Alert I used, are so incredibly sensitive to naturally occurring radioisotopes, that any conclusion based on them, both that they might show something ‘alarming‘ or that what they show is ‘of no concern‘, without being backed up with sample-specific lab data, is premature unscientific guess work.
  • One seaweed sample does show evidence of  clearly measurable nuclear contamination (detection of Co-60 in kelp harvested over 500 km from Fukushima-Daiichi Nuclear Power Disaster site).
  • !!!–> Naturally occurring radiation can be surprisingly high. Incredibly high Gross Beta is likely entirely, or almost entirely, due to Potassium-40.  Added:  Several days after this blogpoast first appeared, the lab ran the samples again to determine the K40 levels.  They are now included in the tables.  It was indeed K40, which for sample #1 reached a whopping 5,094.9 Bq/kg (!!!).  
  • What precisely caused the elevated Gross Alpha Count in Sample #1 remains a mystery.   More research might shed light on this.  (See more in Conclusions & Reflections section).

Although this is a very small quantity of samples, nevertheless, based on these lab results, which powerfully undermined the grounds for my own concerns for current long-distance nuclear contamination (voiced HEREhereherehereherehere and in the previous blogpost), my own newly-adjusted personal conclusion  is that at least HOKKAIDO SEAWEEDS are essentially SAFE TO EAT (mid-January 2014, subject to change based on other new information).

This independent investigation was conducted by © Michaël Van Broekhoven, and made public through his personal blog,

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