Chernobyl illness and death toll denial by the nuclear lobby

Radiation harm deniers? Pro-nuclear environmentalists and the Chernobyl death toll Jim Green, The Ecologist, 7 April 2016,  With few if any exceptions, self-styled pro-nuclear environmentalists peddle flapdoodle and tommyrot regarding the Chernobyl death toll.

 Before considering their misinformation, a brief summary of credible positions and scientific studies regarding the Chernobyl cancer death toll (for detail see this earlier article in The Ecologist).

 Epidemiological studies are of course important but they’re of limited use in estimating the overall Chernobyl death toll. The effects of Chernobyl, however large or small, are largely lost in the statistical noise of widespread cancer incidence and mortality.

The most up-to-date scientific review is the TORCH-2016 report written by radiation biologist Dr Ian Fairlie. Dr Fairlie sifts through a vast number of scientific papers and points to studies indicative of Chernobyl impacts: an increased incidence of radiogenic thyroid cancers in Austria; an increased incidence of leukemia among sub-populations in ex-Soviet states (and possibly other countries ‒ more research needs to be done); increases in solid cancers, leukemia and thyroid cancer among clean-up workers; increased rates of cardiovascular disease and stroke that might be connected to Chernobyl (more research needs to be done); a large study revealing statistically significant increases in nervous system birth defects in highly contaminated areas in Russia, similar to the elevated rates observed in contaminated areas in Ukraine; and more.

Without for a moment dismissing the importance of the epidemiological record, let alone the importance of further research, suffice it here to note that there is no way that one could even begin to estimate the total Chernobyl death toll from the existing body of studies.

 Estimates of collective radiation exposure are available ‒ for example the International Atomic Energy Agency (IAEA) estimates a total collective dose of 600,000 person-Sieverts over 50 years from Chernobyl fallout. And the collective radiation dose can be used to estimate the death toll using the Linear No Threshold (LNT) model.

 If we use the IAEA’s collective radiation dose estimate, and a risk estimate derived from LNT (0.1 cancer deaths per person-Sievert), we get an estimate of 60,000 cancer deaths. Sometimes a risk estimate of 0.05 is used to account for the possibility of decreased risks at low doses and/or low dose rates ‒ in other words, 0.05 is the risk estimate when applying a ‘dose and dose rate effectiveness factor’ or DDREF of two. That gives an estimate of 30,000 deaths.

 Any number of studies (including studies published in peer-reviewed scientific literature) use LNT ‒ or LNT with a DDREF ‒ to estimate the Chernobyl death toll. These studies produce estimates ranging from 9,000 cancer deaths (in the most contaminated parts of the former Soviet Union) to 93,000 cancer deaths (across Europe).

 Those are the credible estimates of the cancer death toll from Chernobyl. None of them are conclusive ‒ far from it ‒ but that’s the nature of the problem we’re dealing with. Moreover, LNT may underestimate risks. The 2006 report of the US National Academy of Sciences’ Committee on the Biological Effects of Ionising Radiation (BEIR) states: “The committee recognizes that its risk estimates become more uncertain when applied to very low doses. Departures from a linear model at low doses, however, could either increase or decrease the risk per unit dose.”

 So the true Chernobyl cancer death toll could be lower or higher than the LNT-derived estimate of 60,000 deaths ‒ a point that needs emphasis and constant repetition since the nuclear industry and its supporters frequently conflate an uncertain long-term death toll with a long-term death toll of zero.

 Another defensible position is that the long-term Chernobyl cancer death toll is unknown and unknowable because of the uncertainties associated with the science. The UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) states (p.64):

“The Committee has decided not to use models to project absolute numbers of effects in populations exposed to low radiation doses from the Chernobyl accident, because of unacceptable uncertainties in the predictions. It should be stressed that the approach outlined in no way contradicts the application of the LNT model for the purposes of radiation protection, where a cautious approach is conventionally and consciously applied.”

 Pro-nuclear environmentalists

 So there are two defensible positions regarding the Chernobyl cancer death toll ‒ estimates based on collective dose estimates (with or without a DDREF or a margin of error in either direction), and UNSCEAR’s position that the death toll is uncertain.

 A third position ‒ unqualified claims that the Chernobyl death toll was just 50 or so, comprising some emergency responders and a small percentage of those who later suffered from thyroid cancer ‒ should be rejected as dishonest or uninformed spin from the nuclear industry and some of its scientifically-illiterate supporters……..www.theecologist.org/News/news_analysis/2987515/radiation_harm_deniers_pronuclear_environmentalists_and_the_chernobyl_death_toll.html

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