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Exclusive: Nuclear test ban agency has valuable radiation monitoring data from Japan nuclear accident — but can’t share them

An international agency set up to monitor for nuclear tests is collecting extensive data on the levels of radionuclides in the air in and around Japan and the Asia-Pacific and transmitting this daily to its member states. The data would be of enormous public interest as it would provide a far fuller picture of the extent and spread of any current or future radioactive release from the major Japanese nuclear accident now under way. But none of these data are being released to the public, Nature has learned.

The worldwide network of radionuclide particulate monitoring stations is operated by the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), a Vienna-based body setup to build a verification regime for a global ban on the testing of nuclear weapons, so that this is operational when enough of the organization’s member states have ratified the treaty for it to enter force. The organization monitors radionuclide, seismic, hydroacoustic, and infrasound characteristics at stations across the globe to check for the tell-tale signals of a nuclear bomb test.

The CTBTO has 60 radionuclide particulate monitoring stations currently in operation, and two of these are in Japan, near Tokyo, while there are dozens of others, often on islands, throughout the Asia-Pacific region (see map). These stations monitor the air continuously, and so will have extensive data on any radionuclides detected during the ongoing nuclear disaster that followed the 9.0-magnitude earthquake, and destructive tsunami, that hit Japan on 11 March.


Radionuclide monitoring stations of the CTBTO International Monitoring System in the Asia-Pacific region (Map credit: CTBTO)

The CTBTO does make available its hydroacoustic and seismic data – among the most reliable and rapid around – for the purposes of tsunami warnings, and indeed these data helped contribute to the rapid alerts issued by tsunami warning systems following the 9.0-magnitude earthquake – the agency’s member states agreed to this following the 2004 Indian Ocean tsunami. But the CTBTO has no mandate for making radionuclide data publicly available for the purposes of monitoring nuclear accidents, because its member states have not yet agreed for it to have this role — it does, however, have a mandate to release radionuclide data within its mandate for detecting nuclear tests (see for example, “North Korea’s ignoble blast“).

Yet it’s radionuclide network is also well-adapted to monitoring levels of radiation in the fallout from nuclear accidents – it is still picking up background levels of radioactive Caesium-137 (which has a 30-year half-life) from the 1986 Chernobyl reactor explosion in the Ukraine, for example – and its website lists such work as one of the civilian benefits of its network of monitoring stations. Each particulate monitoring station sends one gamma ray spectrum per day, a two-dimensional plot showing which radionuclides, and how much of each, occur in its sampling – as radionuclides decay they emit specific energies of gamma radiation which act as signatures allowing radionuclides to be identified.

The CTBTO’s data processing is geared towards detecting the tiny quantities of radioactivity – micro to tens of Becquerels, relevant to its mandate for detecting nuclear tests. The levels from nuclear accidents relevant to public health radiation protection are many orders of magnitude higher, but its sensor network nonetheless does detect and quantify them, explains Lassina Zerbo director of the CTBTO Preparatory Commission’s International Data Centre Division in Vienna.

Although the Vienna centre doesn’t process the nuclear accident relevant data itself, it does transmit the raw data to member states. Nuclear accidents produce a spectrum of radioactive fission products – including various radioisotopes of iodine, caesium, zirconium – and the network can pick up all of them, says Zerbo.

“The data is being sent continuously [to member states], and we are monitoring the situation, our people were here specifically for this over the weekend,” says Annika Thunborg, chief spokesperson for the CTBTO’s Preparatory Commission. The CTBTO is monitoring carefully the nuclear disaster, she adds, and has offered the Japanese government its assistance in it’s areas of expertise, which also include modelling of radiation plumes under different weather patterns.

But the agency, which like all intergovernmental organizations, answers to its member states, is not allowed to make data about nuclear accidents public. “We have a mandate from our 182 member states to communicate seismic data to the outside world,” she says, “When it comes to this radionuclide data [for monitoring nuclear accidents], we don’t have such a mandate, so I can’t tell you, for example, what it is that we are finding.” Even for seismic and hydroacoustic data for the purposes of tsunami warning systems, which saves lives, there were some countries that in the past resisted the idea of making it public. There has been some discussion among member states about disseminating radionuclide data more widely.

Zerbo says that the CTBTO’s radionuclide monitoring service would be well-placed to take on any international role in monitoring nuclear accidents for radiation protection purposes. “Japan and other countries have their own national radiation protection services, but where we could be useful is the worldwide nature of our monitoring network, because countries lack monitoring capabilities outside their own countries.,” he says, “We are the only truly worldwide radionuclide monitoring network.”

For full coverage of the Fukushima disaster, go to Nature’s news special.


  1. Report this comment

    Chris Evelo said:

    The announcement tweet for this story read:

    EXCLUSIVE: Governments withholding data on possible fallout from Japan nuclear disaster: #HelpJapan #Japan

    Now if you read the blog it describes a standing policy to not release data on nucleotides in the atmosphere that has nothing to do with the current situation in Japan. Of course that is bad, the data should be known to the public. But… The tweet gives the impression that the government (and most people will read the Japanese government) is withholding data about the current disaster on purpose. And one will easily expect that that means that there is something to hide. Now the actual blog does not indicate that that is indeed the case, and I think the tweet could have been a little less suggestive.

  2. Report this comment

    Darkstar said:

    Hmm… if the CTBTO is not allowed to make the findings public, maybe the member states are? If one could convince one member state to release the relayed reports, wouldn’t that be an option?


  3. Report this comment

    Dennis Argall said:

    It is important to acknowledge the primary role of this organisation, see its web site:

    Achieving a comprehensive nuclear test ban is a difficult task. There are risks to sustained organisational purpose if new tasks outside the core obligation are added, simple though the proposed task may seem.

    An organisation like this leads a politically precarious existence. Decisions about data use among other things clearly must take place within a decision regime.

    Were there evidence of significant long-lasting radioactive waste in the air near the site then there might be a prospect of some findings in remote places in the Pacific.

    The downstream air flow is to Canada and the US west coasts. I think it unrealistic to imagine that those governments are unable to collect information of relevance or withholding any information of national health concern. As much as it is unfair to suggest Japan withholds such information

    This CTBTO story is a nice piece of journalistic effort on a day when the world is hungry for information, but to report every rabbit that pops its head up on a hill may sell magazines but could do with some peer review. Why is it that a major science journal that would review science carefully gallops off with a story like this? To get publicity for itself?

  4. Report this comment

    Brett said:

    Concur…the tweet is HIGHLY misleading. This is hardly a story at all. Is a doctor “withholding” his patients’ medical records by failing to publish them online? Umm, yes; it just happens that that’s what the LAW stipulates.

  5. Report this comment

    Brian Owens said:

    Thanks for all your comments…we have changed the headline to better reflect the situation.

  6. Report this comment

    prof john tamine said:

    i read the comments and was dumbfounded. it boggles my mind that ANYONE could write a comment in defense of the people who CHOOSE to withhold the information. pre-existing policies not withstanding, there are STILL individual persons in possession of the information, and EACH of them makes a conscious decision whether or not to abide the the policies intended for normal circumstances and DELIBERATELY WITHHOLD the data, OR take it upon themselves to DO THE RIGHT THING and release the information. the lives and well-being of 7 billion people take precedent over any pre-existing arbitrary and anal retentive policies. the most frustrating thing right at this moment is that this site prevents me from using the expletive deleted’s that i so passionately wish to apply to ALL the pretentious, pompous stuffed shirts who have the temerity to defend the unconscionable act of withholding the information. cudos to Science for reporting it, and shame on them for not sticking to their guns and keeping the original headline.

  7. Report this comment

    tunnelends said:

    I found this – urging provision of the specified data as visualisations:

    “From Japan — Urgent Request for Information”

  8. Report this comment

    Zeno Davatz said:

    CTBTO needs to free all data and put into the public domain. They need to do so fast! A bunch of good looking bureaucrats is worth nothing if they do not share data with the rest of the world.

  9. Report this comment

    Rob said:


    The patient can also allow the doctor to release that information. Please don’t try to defend governments that have a track record of dishonesty.

  10. Report this comment

    Phil long said:

    From what I read and all evidence it looks like we have a situation where we are destroying our world. Not so slowly but surely.

    If the governments were not so influenced by multinational corps we may stand a chance but unless something miraculous does give, we have no hope. Knowing that plutonium is one of the most toxic substances in the world the following is a sobering result

    “   Plutonium, a very heavy radioactive isotope with a half-life of about 24,000 years, is not found in nature and is a by-product of a nuclear fission reaction.

       The expert said the plutonium picked up showed clear signs of having come from ground nuclear tests conducted in the 1950s and 1960s as well as underwater detonation experiments carried out in the South Pacific. Countries such as the United States, the former Soviet Union, China and France all carried out tests using live nuclear weapons."

    Happy days if you love your oceans

  11. Report this comment

    las vegas said:

    I may be wrong but my take on this is that it appears to me like the CTBTO is one of those agencies that serves a good purpose but is catching all the flack about not publicizing their data due to bureaucratic intervention. But then, I feel all federally funded and operated agencies like this are obligated to disclose all findings.

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