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Sunday, August 15, 2010

Local journalism

The local newspaper reports on the visit of some children from the Ukraine as part of a programme that goes back to the famous Chernobyl incident. The newspaper reports that "thousands" of children in the area develop bone cancer, leukemia and thyroid cancer every year. So I thought to myself "that sounds terrible, why isn't more being done to help these people", after all, if thousands of children are developing these terrible cancers a quarter of a century after the event, that should be on the front page, not BP and a bit of an oil leak. Nevertheless, I also had a terrible suspicion that the figure simply can't be true. Thousands? So I thought I'd try and find some figures. I went off to the UN and began to rummage around.

By 2002 [16 years after the disaster], more than 4,000 thyroid cancer cases had been diagnosed in this group, and it is most likely that a large fraction of these thyroid cancers is attributable to radioiodine intake.

[From UNSCEAR assessments of the Chernobyl accident]

That's far from "thousands" every year, but still terrible.

In a letter published yesterday in Nature, a British science journal, Dr. Vasily S. Kazakov of the Belarus Ministry of Health in Minsk and his colleagues say that the thyroid cancer rates in the regions most heavily irradiated began to soar in 1990. In Gomel, the most contaminated region studied, there used to be just one or two cases of thyroid children a year. But Kazakov and his colleagues found that there were 38 cases in 1991. In six regions of Belarus and the city of Minsk, the investigators found 131 cases of thyroid cancer in young children, some of whom were still in the womb when the Chernobyl accident occurred.

[From 9/92 "Nature" magazine: Thyroid Cancer 7.5 yrs after Chernobyl soaring]

So in the most heavily contaminated area, there were an additional hundred cases of thyroid cancer (for comparison, about 2,000 people per annum get thyroid cancer in the UK) in the years immediately after the event. What about the other cancers mentioned. The British Journal of Cancer (1996) 73, 1006-1012, reports on leukemia.

There was a slight increase in the incidence of childhood leukaemia in Europe during this period,but the overall geographical pattern of change bears no relation to estimated exposure to radiation resulting from the accident. We conclude that at this stage of follow-up any changes in incidence consequent upon the Chernobyl accident remain undetectable against the usual background rates. Our results are consistent with current estimates of the leukaemogenic risk of radiation exposure, which, outside the immediate vicinity of the accident, was small.

What do the UN say? Do they agree? Well, yes they do.

there is no clearly demonstrated increase in the incidence of solid cancers or leukaemia due to radiation in the most affected populations. Neither is there any proof of other non-malignant disorders that are related to ionizing radiation.

[From UNSCEAR assessments of the Chernobyl accident]

So with the exception of thyroid cancer in people who were babies and lived closed to the event, no-one appears to be getting cancer because of Chernobyl. Not what I was expecting to find. By far the most interesting result of my trawl around, though, was this:

There were widespread psychological reactions to the accident, which were due to fear of the radiation, not to the actual radiation doses.

There is a tendency to attribute increases in the rates of all cancers over time to the Chernobyl accident, but it should be noted that increases were also observed before the accident in the affected areas. Moreover, a general increase in mortality has been reported in recent years in most areas of the former Soviet Union, and this must be taken into account when interpreting the results of Chernobyl-related studies.

[From UNSCEAR assessments of the Chernobyl accident]

Those kids still deserve our help, but it's important to have the proper perspective. Generally speaking, I think the UN's assessment holds true for nuclear power in the UK as much as in Russia. The problem is the fear of nuclear power, not nuclear power itself (especially since as far as I am aware, all research seems to show that our bodies are far more tolerant of low-level ionising radiation than we thought back it the early days).

In the future, everyone will be famous to fifteen people.
[posted with ecto]

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