With few if any exceptions, self-styled pro-nuclear environmentalists peddle misinformation 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 here).
Epidemiological public health studies are of course important but they’re not much 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 (see here for the most recent scientific review of the epidemiological 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 which holds that the risks are proportional to dose. LNT enjoys heavy-hitting scientific support ‒ for example the 2006 report of the U.S. National Academy of Sciences’ Committee on the Biological Effects of Ionising Radiation states that “the risk of cancer proceeds in a linear fashion at lower doses without a threshold and … the smallest dose has the potential to cause a small increase in risk to humans.” Likewise, a report in the Proceedings of the National Academy of Sciences states: “Given that it is supported by experimentally grounded, quantifiable, biophysical arguments, a linear extrapolation of cancer risks from intermediate to very low doses currently appears to be the most appropriate methodology.”
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 National Academy of Sciences’ report 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.”
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.
The third of the two defensible positions ‒ 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.
Those illiterate supporters include every last one of the self-styled pro-nuclear environmentalists (PNEs). We should note in passing that some PNE’s have genuine environmental credentials while others ‒ such as Patrick Moore and Australian Ben Heard ‒ are in the pay of the nuclear industry.
James Hansen and George Monbiot cite UNSCEAR to justify a Chernobyl death toll of 43, without noting that the UNSCEAR report did not attempt to calculate long-term deaths. James Lovelock asserts that “in fact, only 42 people died” from the Chernobyl disaster.
Patrick Moore, citing the UN Chernobyl Forum (which included UN agencies such as the IAEA, UNSCEAR, and WHO), states that Chernobyl resulted in 56 deaths. In fact, the Chernobyl Forum’s 2005 report (p.16) estimated up to 4,000 long-term cancer deaths among the higher-exposed Chernobyl populations, and a follow-up study by the World Health Organization in 2006 estimated an additional 5,000 deaths among people exposed to lower doses in Belarus, the Russian Federation and Ukraine.
Australian ‘ecomodernist‘ academic Barry Brook says the Chernobyl death toll is less than 60. Ben Heard, another Australian ‘ecomodernist’ (in fact a uranium and nuclear industry consultant), claims that the death toll was 43.
In 2010, Mark Lynas said the Chernobyl death toll “has likely been only around 65.” Two years earlier, Lynas said that the WHO estimates “a few thousand deaths” (actually 9,000 deaths) but downplays the death toll by saying it was “indiscernible” in the context of overall deaths. Yes, the Chernobyl death toll is indiscernible … and the 9/11 terrorist attacks accounted for an indiscernible 0.1 percent of all deaths in the U.S. in 2001.
There doesn’t appear to be a single example of a PNE ‒ or a comparable organisation ‒ providing a credible account of the Chernobyl death toll. They’re perfectly entitled to follow UNSCEAR’s lead and argue that the long-term death toll is uncertain, but conflating or confusing that uncertainty with a long-term death toll of zero clearly isn’t a defensible approach.
The Breakthrough Institute comes closest to a credible account of the Chernobyl death toll (which isn’t saying much), stating that “UN officials say that the death toll could be as high as 4,000”. However the Breakthrough Institute ignores: the follow-up World Health Organization study that estimated an additional 5,000 deaths in ex-Soviet states; scientific estimates of the death toll beyond ex-Soviet states (more than half of the Chernobyl fallout was deposited beyond the three most contaminated Soviet states); scientific literature regarding diseases other than cancer linked to radiation exposure; and indirect deaths associated with the permanent relocation of over 350,000 people after the Chernobyl disaster.
PNEs also trivialize Chernobyl by peddling the ruse that the psychological trauma was greater than the biological effects from radiation exposure. There’s no dispute that, as the WHO states, the relocation of more than 350,000 people in the aftermath of the Chernobyl disaster “proved a deeply traumatic experience because of disruption to social networks and having no possibility to return to their homes.”
How to compare that psychological trauma to estimates of the death toll, such as the UN/WHO estimate of 9,000 cancer deaths in ex-Soviet states? Your guess is as good as mine.
Perhaps the biological damage and psychological trauma can be compared and ranked if we consider the second of the two defensible positions regarding the long-term death toll ‒ UNSCEAR’s position that the death toll is uncertain. Does the psychological trauma outweigh the 50 or so known deaths, around 6,000 non-fatal thyroid cancers (with another 16,000 to come), and an uncertain long-term death toll?
The argument only begins to make sense if you accept the third of the two defensible positions regarding the death toll ‒ the view that there were no deaths other than emergency workers and a small number of deaths from thyroid cancers. Thus Mark Lynas asserts that “as Chernobyl showed, fear of radiation is a far greater risk than radiation itself in the low doses experienced by the affected populations” and he goes on to blame anti-nuclear campaigners for contributing to the fear.
But the trauma isn’t simply a result of a fear of radiation ‒ it arises from a myriad of factors, particularly for the 350,000 displaced people. Nor is the fear of radiation necessarily misplaced given that the mainstream scientific view is that there is no threshold below which radiation exposure is risk-free.
Most importantly, why on earth would anyone want to rank the biological damage and the psychological trauma from the Chernobyl disaster? Chernobyl resulted in both biological damage and psychological trauma, in spades. Psychological insult has been added to biological injury. One doesn’t negate the other.