Tuesday, March 1, 2011

Chernobyl 25th Anniversary Fear-Fest.

The 26th of April this year shall mark the twenty-fifth anniversary of the worst accident in the history of nuclear power generation, the reactor core explosion which took place in Reactor 4 in the Chernobyl Nuclear Power Plant near the town of Pripyat in what was then the Ukrainian Soviet Socialist Republic. Anti-nuclear activists and organisations around the world are gearing up to honour the event's anniversary with a predictable outpouring of propaganda aimed at frightening people out of their wits at the prospect of using nuclear power. The following article from Voice of America is doubtless one of an avalanche of similar reports which shall flood the media over the next couple of months.


It's informative to see how this report is structured. First we have the headline, which tells us "UN Reports Thousands of Thyroid Cancers 25 Years After Chernobyl Nuclear Disaster". This turns out to be rather misleading. One could be forgiven for thinking that the UN had found thousands of thyroid cancers stemming from the accident happening now, but no. The headline actually means that a UN report has found that thousands of cases of thyroid cancer were caused by the accident (which is not in dispute), and at the moment it just happens to be twenty five years since that occurred.

We also have a photograph of a clearly distressed nine year old child, Yulia Kostina, in the intensive care unit of the Endocrinology Institute in Kiev, Ukraine, recovering from surgery to treat cancer (presumably thyroid cancer). There is no date for the photo, so the reader might be tempted to think that it is recent or current. It is actually from the year 2000, so Yulia would have been born in 1990 or 1991. The source appears to be the following article:


The clear implication of the photo is that Yulia's condition arose as a result of exposure to radioactive fallout from the Chernobyl accident. Most casual readers of the original article in 2000 probably thought this a reasonable conclusion, given that she was born a few years after the accident. Readers of the current Voice of America article would most likely think the same thing, even if they thought that the photo was current. After all, we all know that radioactive fallout lasts for centuries, so surely there's still plenty around to go on causing the sort of cancer the article speaks of.

The trouble is that the danger of thyroid cancer for children in the wake of the Chernobyl accident came from the ingestion of the radioactive isotope iodine-131, a highly radioactive fission product which was released in large quantities by the explosion of the reactor core. Iodine is rapidly absorbed by the thyroid in humans, and the biological processes responsible make no distinction between ordinary non-radioactive iodine and the chemically identical radioactive isotope. Iodine-131 was deposited on grasslands, consumed by dairy cows and concentrated in milk products. The Soviet-era authorities recognised the danger and distributed iodine tablets to be given to children (if the thyroid is already saturated with iodine it wont take up any extra from contaminated milk), but it seems that many parents did not trust those authorities, and many thousands of children were unnecessarily exposed to the radionuclide. This effect caused a massive jump in thyroid cancer rates for children, and sadly, nine of those children did in fact die as a result. In the region in question, only a handful of cases would usually show each year.

Of course, because iodine-131 is so very radioactive, it has a short half life of just over eight days. As a general rule of thumb, there is virtually nothing left of an initial mass of radioactive material after about ten half lives have elapsed. Practically all of the iodine-131 released by the accident had decayed away within three months, around four years before Yulia Kostina was born. It is simply impossible for Yulia's thyroid cancer to have been caused by the radioactive release from Chernobyl. It seems that Yulia was one of those few unfortunate children who contracted the disease as part of the normal course of events.

The article uses extensive quotes from Dr. Fred Mettler, a respected figure in the field of radiology and a major contributor to the UN report. Dr. Mettler's comments are quite reasonable, but they are interspersed with quotes from a source many consider compromised, Professor Anders Moller, a Danish evolutionary biologist who specialises in avian evolution. Professor Moller's reputation has been under a cloud since being found guilty of misconduct by the Danish Committees on Scientific Dishonesty in 2003:


Moller has recently published a study in which he claims that birds living in the Chernobyl fallout zone have smaller brains than their counterparts elsewhere. This paper has been making the rounds of the media, and came to the attention of Rod Adams, publisher of Atomic Insights in early February. Rod's treatment of the subject is thorough, so I will direct the reader's attention there rather than try to recapitulate his analysis. I also strongly recommend reading through the comments thread:


It is clear that Voice of America has cobbled together a bunch of factoids and misrepresented quotes from sources of widely varying credibility in order to produce a typical hyped-up anti-nuke scare story. Unfortunately we can expect plenty more of the same as the anniversary approaches.