Fukushima-linked cancer surge unlikely: U.N.

U.N. experts expect no jump in cases despite higher risk



The Fukushima nuclear disaster is unlikely to lead to a rise in people developing cancer as happened after Chernobyl in 1986, even though the most exposed children may face an increased risk, U.N. scientists said Wednesday.

In a major study, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) said it did not expect “significant changes” in future cancer rates that could be attributed to radiation exposure from the reactor meltdowns.

The amounts of radioactive substances such as iodine-131 released after the 2011 accident were much lower than after Chernobyl, and Japanese authorities also took action to protect people living near the stricken plant, including evacuations.

However, some children — estimated at fewer than 1,000 — might have received doses that could affect their risk of developing thyroid cancer later in life, UNSCEAR said, while emphasizing the probability of that happening was still low.

UNSCEAR chairman Carl-Magnus Larsson said there was a theoretical increased risk among the most exposed children for this type of cancer, which is rare among the young.

But “we are not sure that this is going to be something that will be captured in the thyroid cancer statistics in future,” he told a news conference.

Wolfgang Weiss, who chaired the Fukushima assessment, said the thyroid cancer risk was much lower compared with Chernobyl and any increase would be limited.

On March 11, 2011, the magnitude-9 earthquake and tsunami devastated the Fukushima No. 1 nuclear plant in Fukushima Prefecture, spewing radiation and forcing about 160,000 people to flee their homes.

It was the world’s worst nuclear disaster since the Chernobyl reactor explosion sent radioactive dust across much of Europe. People close to the then-Soviet plant were exposed to radioactive iodine that contaminated milk and radiation that turned surrounding areas into ghost towns for decades.

In contrast, UNSCEAR’s Fukushima report said it expected a low impact on cancer rates for the population and that this was largely due to “prompt protective actions” after the meltdowns.

A 30-km radius around the plant was eventually declared a no-go zone, while areas where radiation was not so critically high took steps such as replacing or turning over earth in parks and playgrounds, decontaminating public spaces and limiting children’s outdoor play time.

“No discernible changes in future cancer rates and hereditary diseases are expected due to exposure to radiation as a result of the Fukushima nuclear accident,” UNSCEAR said in a statement accompanying its nearly 300-page study.

The thyroid — a gland in the neck that produces hormones that regulate vital bodily functions — is the most exposed organ because radioactive iodine concentrates there. Children are deemed especially vulnerable.

UNSCEAR said the normal thyroid cancer risk for children was very low.

“The occurrence of a large number of radiation-induced thyroid cancers as were observed after Chernobyl can be discounted because doses were substantially lower,” it said.

In Belarus, Russia and Ukraine, the countries most affected by Chernobyl, more than 6,000 cases of thyroid cancer had been reported by 2005 in children and adolescents who were exposed during the disaster, UNSCEAR says on its website.

  • yellowroz

    This report is scoped only to the Japanese, and does not include analysis of the groundwater to the sea.

  • Aholl Urang

    If you believe this, I suggest you go live there and I’ll be watching for results.

  • Enkidu

    Hi Oregonstu,

    This is a fine example of the ridiculous “reporting” of enenews: “They ignore the data from Chernobyl that show [thyroid] cancer began appearing within 1 year.” This is meaningless. Of course thyroid cancer was appearing within 1 year of the accident. It was appearing one year before the accident, too! What is critical was not if it was appearing, but what the rates were, and here, enenews, as it so often does, leaves you in the dark. The earliest rate comparison this little excerpt provides is to 1998, more than ten years after the accident, in effect supporting the 4-5 year statement(!).

    You then say, “The UNSCEAR report pretends that all these early indications of thyroid cancer in Japan are unrelated to Fukushima, because they say it takes 4 to 5 years after exposure to show up.”

    However, here’s what the report actual says on the issue (page 11):

    Increased rates of detection of nodules, cysts and cancers have been observed during the first round of screening; however, these are to be expected in view of the high detection efficiency. Data from similar screening protocols in areas not affected by the accident imply that the apparent increased rates of detection among children in Fukushima Prefecture are unrelated to radiation exposure.

    I encourage you to read the full report, including the annexes, available on the UNSCEAR website.

    I would also recommend that you avoid enenews as it regularly preys on those with little science background or Japanese language ability. That being said, if you do choose to read it, please feel free to post anything that worries you here and I can address it.

  • Enkidu

    Hi Oregonstu,

    Yes, generally speaking, I think it wise to read something before criticizing it.

  • Enkidu

    Hi Oregonstu,

    Thanks for the comments, I’ll try to address all three in one go:

    1. With respect to Akira Sugenoya, I’d encourage him to read the materials that have been published to date. Here, for example, is the fourteenth and most recent public report on the prefectural thyroid survey:
    http://www.pref.fukushima.lg.jp/uploaded/attachment/51093.pdf. This includes various breakdowns of the results, including by age. After fourteen of these regularly published reports, it’s hard to see how they are “acting almost in secret”.

    2. With respect to the critique from the International Physicians for the Prevention of Nuclear War, again, I’d invite them to read the report. They say that UNSCEAR should utilize neutral sets of data, so I’d recommend that they read pages 99 to 105 of the report which list the various datasets used in the assessment, including those from Safecast and Greenpeace. As for the comment that UNSCEAR should “consider the increased vulnerability of certain population groups”, it’s hard to square this with the main conclusion of the report highlighted in the article above that _children_ (i.e., a vulnerable population group) face increased risk. As for the comment that UNSCEAR should “analyze the effects of radiation on the non-human biota”, they should read Section VII, entitled “Assessment of Doses and Effects for Non-Human Biota” (!) and the similarly titled 15-page Appendix F.

    3. With respect to Yuri Oiwa and Teruhiko Nose, I think they are confusing the cancer registry statistics, which show the rates of thyroid cancers that typically presented either symptomatically (i.e., difficulty swallowing) or as a by-product of another test, with the rates from a thyroid-specific screening of a broad population using modern ultrasonography. Unfortunately, it became clear early on that a comparable data set for this kind of broad survey did not exist, and as a result, as referenced in my comment above, a new survey was commissioned using similar protocols and equipment on 4,000 children located outside of Fukushima prefecture. This survey showed that the number of thyroid abnormalities being detected in Fukushima at this time are consistent with those in less-affected areas. Now, over time, we would expect a divergence between these two datasets as the negative effects of the radiation take hold. (I would note, however, that this parallel study could be improved to research more thoroughly those cysts and nodules which result in positive cancer diagnoses, and I hope it will be updated accordingly in the future.)

    4. With respect to the “very good investigative journalism” of ENEnews, perhaps you could name one or two of their investigative journalists? As far as I can tell, their technique is to chop-up articles and re-assemble them in a series of non-sequiturs so as to breed the most fear. As for them citing their sources, I encourage you to actually read their sources. One of my favorite examples was when Arnie Gundersen was going on about a first-degree Euler strut “defect” at Unit 4. Now, any first-year engineering student or someone with a basic mechanics class under their belt knows that Arnie didn’t know what he was talking about (as is often the case) because if it’s Euler, the word is “buckle”. Arnie finally figured this out after a week or so, so ENEnews revised his quote in their original article to include “buckle” even though the accompanying source shows that Arnie didn’t say that. That’s the level of “investigative journalism” we’re talking about here. (Here’s the report: http://enenews.com/buckling-unit-4-caused-quake-indications-building-didnt-ride-quake-anywhere-thought-audio-video)

    5. As for your offer to address the UNSCEAR “propaganda” I’ve posted here, please, by all means, do. I have no doubt that this report, as with all reports, would benefit from substantive criticism.

  • oregonstu

    Because I am a member of the group and this observation is based on the content of the group discussion which I am on the e mail list for.