#9 The Chernobyl health and cancer death toll
Posted by RDN under Mind and body on 1 January 2011
Some people promote and millions believe the idea of a very high number for Chernobyl’s cancer death toll. (See the 100,000 figure promoted by some Greens, and that’s almost moderate.) Some others also adduce huge and horrible birth defects and other health effects. Assessing the cancer toll, and the wider health effects, is complicated…….
There is a sort of perfect storm in this issue, and it involves John Vidal (see a Guardian piece, 1 April 2011) and George Monbiot (see a Guardian blog, 5 April 2011). Vidal promotes the old myths and Monbiot, who has had a damascene conversion, debunks them. Goodness knows how either could have lived so long in so unsubtle – so uninquiring – a world, and the former still does. (Even Monbiot may be going too far, if the work of Bavertsock and Williams is right – see below).
Most of the definite, inarguable cancer deaths from the Chernobyl accident were amongst 134 firefighters and others who were exposed to very large doses of radiation and suffered Acute Radiation Syndrome working near the disaster: 28 of these died.
So far, there have been around 7000 cases of thyroid cancer in children (all but 15 or so non-fatal).
For both these facts, see “Sources and effects of ionizing radiation, United Nations Scientific Committee on the Effects of Atomic Radiation”, UNSCEAR 2008, Report to the General Assembly, with Scientific Annexes, Volume II, Annex D, page 18, called UNSCEAR below.]
If I read UNSCEAR right, it is very sceptical that it is worth postulating the numbers of long-term cancer or other health effects from Chernobyl’s radiation. The data is too awful and most of the radiation exposures too slight. UNSCEAR implies that it is respectable to argue that in the case of Chernobyl even for the 600,000 worst exposed, or the next worse 5m exposed, and still less the vast majority of Europeans who were barely exposed at all, we do not have evidence that there was or is a cause for anxiety.
Even if we did think there was elevated risk, it would be lost in the sea of radiation risk nature and industry (and the coal industy in particular) expose us to.
But people are determined to answer the imponderable question: how to address the chance of a slightly (or greatly) elevated cancer and health risk?
In 2005 New Scientist noted that ”in a report this week for the Green group in the European Parliament, Ian Fairlie and David Sumner, two independent radiation scientists from the UK, say that the death toll from cancers caused by Chernobyl will in fact lie somewhere between 30,000 and 60,000″.
Elisabeth Cardis, an experienced analyst of the consequences of Chernobyl at the WHO’s International Agency for Research on Cancer, is reported as saying that the number is of “the right order of magnitude”. In 2006, she told RDN that the number is reasonable, given the researchers’ “approach and the data they used”.
IARC’s full view was published shortly afterwards and used a figure of about 16,000 deaths by 2065. (Remember, and see below, this was fatalities which are in a sense statistical, across the whole of Europe.)
Also for the 20th anniversary of the accident, a press release advertising a full report by the Chernobyl Forum (spear-headed by UN bodies but with buy-in from the Russian Federation, Ukraine and Belarus governments) said that its scientific study predicted:
“… up to about 4000 eventual deaths among the higher-exposed Chernobyl populations, i.e., emergency workers from 1986-1987, evacuees and residents of the most contaminated areas.”
This seems to be a press office mistake and figures within the main document imply maybe 9,000 fatalities amongst these populations (all within the former USSR). (Again, see below for a note of caution.)
The IARC was assessing a far more nebulous figure for the toll of deaths across wider Europe, where huge populations got a very much smaller dose. (But see the reference to the work of Keith Baverstock and others below.)
The difficulty is in how one discusses these numbers. A third of westerners die from cancer – so the disease claims millions of people every year. That number may be higher in polluted or relatively primitive countries (such as the old USSR). Chernobyl has presumably been the cause of only a very small percentage of the deaths from cancer anywhere, whether in places hit hard by the plume or not.
The vast majority of “Chernobyl’s cancer fatalities” won’t have a fingerprint or a smoking gun. Chernobyl won’t be on the death cerificate. Indeed, many of the deaths “caused” by Chernobyl may more accurately be thought of as deaths to which Chernobyl was a contributory factor. They may also be thought of as deaths which took place a year of so earlier than might otherwise have been the case.
There is real difficulty in discussing the death toll which results from a small increase in the radiation dose which a population receives. It may well not be nothing (but see the posting #10 in this series), and yet probably very few will die exclusively from the small extra dose they received. For most, we are discussing a range of carcinogenic influences: a few less cigarettes, one less holiday in rather radioactive Cornwall, one less longhaul flight, and a person could “undo” (could make up for) the damage Chernobyl caused them.
More general health effects (including cancers)
I am inclined to think this is where some of the greatest mischief is done by the anxiety industry. The John Vidal piece is a classic example. ( Guardian piece by John Vidal, 1 April 2011.)
The assumption that there have been and are still gross birth defects caused by Chernobyl seems not to be accepted by conventional Western radiological medicine. One piece of evidence cited by the Chernobyl Forum is that the rate of birth defects (see page 20) seems about the same in Belarus in or out of areas contaminated by Chernobyl’s plume.
There is increasing discussion of the increase in cataracts in people who suffer ARS and increases in leukaemia and circulatory problems in people exposed to high doses of radiation.
I half-heartedly recommend the work of Keith Baverstock and Dillwyn Williams as a challenge and update to complacency: it’s anything but relaxed or gung-ho. ( The Chernobyl Accident 20 Years On: An Assessment of the Health Consequences and the International Response, In Environmental Health Perspectives, September 2006.)
My reading of this document is no more informed than the next layman’s, but I am fairly confident that it is very unclear.
I think it says that modern radiological research suggests that the long-term effects of doses of radioactivity may be greater than had been assumed until the 1990s. The new uncertainty is about the cancers which may form, other health effects, and some genetic effects. But these are matters of great uncertainty and - by the way – the authors do not discuss the gross birth defects which some claim as having been caused by Chernobyl.
It is worth noting that Baverstock and Williams have come to the conclusion that the UN process – and especially the Chernobyl Forum - was too biased toward reassurance (it had nuclear-sponsors amongst its institutions) and that Chernobyl radiation needs much more future study. (To be fair to them, the Chernobyl Forum and UNCEAR do mention some Baverstock/Williams sorts of concerns.)
The problem with the Baverstock/Williams work is that is interested in the problem of informing public debate (and even in allaying unnecessary fears) but seems to this layman to lob in new anxieties whose seriousness it does little explain in layman’s terms.