Sunday, April 17, 2011

Reviewing the Reviewers

A long while is shorter than it seems.

I have been kindly provided (thank you CV) with copies of the reviews mentioned in The least Fortunate Island, one of which was cited by George Monbiot in his “I’m shocked, shocked, I tells ‘e” article published globally to the delight and disdain of many depending on prior convictions.

This post provides a summary of two reviews, one used by George Monbiot in his public tiff. George bends it a bit.

My take on this issue. I think about it this way:

Just as no individual cancer can be easily attributed to Chernobyl, no individual weather event can be easily attributed to climate change.

Does this mean we ignore the cumulative effects of an increase in temperature? No. So how about those of radiation?

One of the reasons for the adoption of the (conservative) Linear No Threshold model is that the consequences of making a Type II statistical error (i.e. failing to detect an effect when there is one) are so serious (i.e. cancer).

Pro Nuclear advocates of a self proclaimed green persuasion (Nuclear Greens) should remember that taking action against climate change started well before all the evidence was in for the same reason.

This is the precautionary principle.

Read the rest if you need some sleep material…

... and don't say I didn't warn you.

The book is CHERNOBYL: CONSEQUENCES OF THE CATASTROPHE FOR PEOPLE AND THE ENVIRONMENT which is an English translation of an original work in Russian citing literature originally published in non English (Slavic) languages.

At issue is the authors contention that some UN reports have underestimated the health effects of the Chernobyl accident, and have not considered evidence from the countries affected. Much of the discussions in the reviews centers on the use/misuse of the Linear No Dose model, the quality of the data presented, differences in epidemiological methods and statistical interpretations.

The first review (Radiation Protection Dosimetry (2010), Vol. 141, No. 1, pp. 97–101) is by Ian Farlie (Independent Consultant,London N5 2SU, UK). He summarizes the discrepancies between the official (at least in the West) view and those from the workers cited in this report. I have quoted some sections extensively. First to get a taste of the book being reviewed and secondly to highlight some of the technical points where questions arise. This first review can be considered the “gentle”, unquoted by George Monbiot, review. Note however, that Ian Farlie was used as a source by the Russian authors.

The Soft Review

The authors summarise studies demonstrating health effects in humans, animals and plants exposed to Chernobyl fallout over eastern and western Europe and the rest of the Northern Hemisphere. Their main conclusions are that the health and environmental consequences of the Chernobyl disaster are much larger than previously estimated.

The authors state that, collectively, the studies suggest that those exposed to low levels of radioactivity in the environment have higher risks than those estimated by western dose models.

The authors remark that IAEA and WHO reports have failed to consider Chernobyl’s health effects in western European countries.

Official estimates by international agencies predict 9000–28 000 fatal cancers between 1986 and 2056. On the basis of predicted 131I and 137Cs doses, the chapter estimates 212,000–245,000 deaths in Europe and 19,000 in the rest of the world. These are much higher than IAEA estimates: the main reason is that the authors’ estimates include collective doses from very low exposures.

The International Commission on Radiological Protection (ICRP) does not recommend including collective doses from low exposures; however, this practice is soundly based on the linear no threshold hypothesis for radiation’s dose–effect relationship. The ICRP and most radiation protection agencies around the world continue to support the Linear No Threshold Theory (LNT) and routinely use it in estimating radiation effects. Therefore, the ICRP is being inconsistent when it says collective doses from very low exposures should not be used to estimate the effects.

[The report states that] reports of a ‘healthy’ environment near Chernobyl for rare species of birds/mammals are the result of immigration and not local sustained populations. Mutation rates in animal populations are significantly higher in contaminated than in noncontaminated areas: transgenerational genomic instability is seen in animal populations.[extra detail omitted]

Chapter IV on the continuing consequences states that food contamination from Chernobyl remains a major problem. As of 2007 in the Gomel, Mogilev and Brest provinces of Belarus, 8 % of milk and 16 % of other food products from small farms exceeded the permissible 137Cs levels. As of 2000, up to 90 % of berries and mushrooms exceeded the permissible 137Cs levels in the Rovno and Zhytomir provinces of Ukraine. [extra detail omitted]

Ever since the Chernobyl accident occurred, its effects have been the subject of polarised views with claims and counterclaims on the scale of adverse effects especially on the estimated numbers of resulting deaths.

For example, IAEA and WHO reports (especially the Chernobyl Forum reports (2, 4) in (2005) based their findings mainly on research published in the west and referred to relatively few of the thousands of research papers published in eastern Europe.

The IAEA often seeks to justify their dismissal of eastern European reports on Chernobyl by disparaging eastern scientific protocols. This is an important issue which is repeatedly referred to by the authors and as these matters are rarely discussed in refereed journals, this reviewer examines them below.

For example, the IAEA/WHO(2, 4) have cited questionable scientific practices in eastern epidemiological studies, such as poor case identification, nonuniform registration, variable or uncertain diagnostic criteria and uncertainties in the uniformity of data collation. But to be fair, epidemiology is not an exact science and many of these methodological shortcomings exist, at least to some extent, in western epidemiological studies uncriticised by the IAEA. For example, studies(5, 6) by independent scientists have shown surprising lapses of standards in officially sponsored epidemiology studies in the West. As for cancer registries, not many western European countries had excellent detailed cancer registries in 1986. The IAEA/WHO(2, 4) have also stated that excess mortality or morbidity may be uncertain due to confounding factors, competing causes and different risk projection models. This may be correct, but it is often the case in western studies as well. Of course, two wrongs do not make a right, but it is unfair to single out eastern reports in this regard.

However, one major difficulty in interpreting Chernobyl mortality studies is the large recent decrease in average male life spans in Belarus, Russia and Ukraine in all areas not just contaminated ones: this deserves more attention in eastern studies.

It is a common practice in the West to test the findings of epidemiological studies of radiation exposures for statistical significance. [There] are two types of epidemiological studies—observational studies of (usually) expected effects where data may be known beforehand and analytical studies of (usually) unexpected or unknown effects where the data are unknown beforehand.

The eastern studies are mostly the former observational type.

From the knowledge on radiation’s effects, these findings are not unexpected. Radiation from exposures to 137Cs can lead to increased incidences of cancers: it is not necessary to prove it again via statistical tests as if these were chance or unexpected findings. Therefore, many eastern scientists consider that there is little need to apply p-values and/or confidence intervals to their observed data. Interestingly, some western scientists(7–11) have in fact criticised the widespread practice and inappropriate use of significance testing.

The crux of the matter is that the inappropriate application and incorrect use of statistical tests allows IAEA scientists to challenge the findings of eastern European studies and to question whether the observed effects are due to chance. The problem with statistical tests is that if eastern scientists do not perform them, they are criticised on the grounds that western scientific norms are being ignored. On the other hand, if they do apply them and the data sets are too small for statistical significance (which can often be the case), western scientists often conclude—incorrectly—that there is no real effect.

In the views of IAEA and WHO, the large observed increases in morbidity and mortality are explained possibly by confounding factors, possibly by other causes of death, possibly by increased medical surveillance, possibly by social breakdown and possibly by psychological depression. However, few studies are carried out to provide evidence of these assertions.

Clearly, there is a continuing and profound difference of views over Chernobyl’s health effects. Some readers will disagree with the discussion presented in this volume and will consider its authors to be too polemical in their views. On the other hand, others will concur with the book’s findings. The author’s view is that there is much valuable information here, notwithstanding western criticisms of eastern science’s protocols. This does not necessarily mean every detailed point in these summaries is accepted without question.[omitted technical recommendation]

Nevertheless, the publication of summaries of hundreds of research reports on the health and environmental consequences of Chernobyl originally published in Russian and Ukrainian is a welcome addition to the literature in English.

In the opinion of the reviewer, this volume makes it clear that international nuclear agencies and some national authorities remain in denial about the scale of the health disasters in their countries due to Chernobyl’s fallout. This is shown by their reluctance to acknowledge contamination and health outcomes data, their ascribing observed morbidity/mortality increases to non-radiation causes, and their refusal to devote resources to rehabilitation anddisaster management.

The second review (Radiation Protection Dosimetry (2010), Vol. 141, No. 1, pp. 101–104) is by Monty Charles, School of Physics and Astronomy, University of Birmingham.

The Bad Review

In the few weeks before I was asked to review this book there was media coverage of two diametrically opposed views regarding the magnitude of health effects associated with the Chernobyl reactor accident. One is expressed in the book under review and
the other came from Zbigniew Jaworowski (former chair of the United Nations Scientific Committee on the Effects of Atomic Radiation, UNSCEAR).

In the opinion of this reviewer, the wide range of estimates that can be found in the scientific literature is mainly due to different estimates of population dose, the use of different radiation risk figures and different interpretations of epidemiological data ( particularly the use of different control groups). … This often makes meaningful comparisons difficult or impossible although it often remains clear that there is a large disparity between different authors.

With such a range of views, an already vast and increasing literature, and claims that there has been coercion on an international scale, how can professional scientists—such as most readers of this review—arrive at an informed opinion on the radiation-related adverse health effects from the Chernobyl accident? The answer is with great difficulty! I personally find it necessary to critically read at least selected contributions from the whole spectrum of views. For that purpose this book covers the high cancer mortality tail of the distribution of predictions of health effects from Chernobyl.

The foreword by Prof. Grodzinsky (Chairman of the Ukrainian National Commission on Radiation Protection) proposes an explanation for this omission in terms of the influence of a pro-nuclear lobby, which has inhibited the funding of medical studies, diverted human resources away from Chernobyl studies and has ‘liquidated government bodies that were in charge of the affairs of Chernobyl’.

The next section is relevant to the article by George Monbiot

[The] book has its origins in the two conflicting evaluations of Chernobyl health effects published in 2006 around the time of the 20th anniversary of the Chernobyl accident (26 April 1986). Some appreciation of this history is useful to understand the context of this book. One of the conflicting evaluations was by the Chernobyl Forum, an expert scientific panel that was created in 2001 by the Director of the IAEA to conduct an exhaustive assessment of the health, environmental and social impacts of the accident. The other evaluation was by Greenpeace, an international non-governmental organisation with a strong anti-nuclear stance.

[see documents at]

Chernobyl Forum summary report: or

Technical papers presented at an IAEA conference:

The report by Greenpeace:

Greenpeace give numerous numbers for excess incidence and mortality of a wide range of diseases but in many cases it is not stated over what period the excess cancer risk is integrated. It is therefore not possible to easily compare on an equal basis the claims of the Greenpeace report with the predictions of the Chernobyl Forum but it is clear that Greenpeace’s predictions are significantly higher—probably by a factor of 3–10.

Greenpeace describes their report as involving 52 respected scientists and includes information never before published in English.

The Greenpeace approach is primarily to link temporal changes in health statistics after 1986 in Belarus, the Ukraine and other countries with the Chernobyl accident. That is, all increases in disease, regardless of type, are assumed to be the result of the Chernobyl accident.

During the production of the reports from the Chernobyl Forum and Greenpeace, a vast body of previously unknown data began to emerge in the form of publications, reports, theses, etc. from Belarus, Ukraine and Russia, much of it in Slavic languages. Little of these data appears to have been incorporated into the international literature. The quality of these publications and whether they would sustain critical peer-review in the western scientific literature is unknown.

The book by Yablokov et al. is part of an attempt to summarize these new findings and include them to extend the findings of the Greenpeace report. About 1000 of these translated titles are referred to among the more than 1400 references included in the volume.

By my reading of this section, quoted in full, George Monbiots criticism of the book CHERNOBYL: CONSEQUENCES OF THE CATASTROPHE FOR PEOPLE AND THE ENVIRONMENT, published in English by the New York Academy of Science is IN FACT a criticism of the methodology used by GREENPEACE  who cited some of the papers eventually included in this book.

There is clearly a massive overload of information—which we are all becoming used to on the internet in everyday life. It is not at all clear how these many sources have been used by Yablokov et al. and how they have influenced the conclusions made. This is not an issue related to Chernobyl alone. When I first visited Russia in 1982 as part of a UK-USSR Health Ministry exchange I was made aware of a very valuable  and extensive literature in the fields of hot particle and neutron radiobiology research. These were mainly in Russian and published in obscure journals. I offered to facilitate publication in the west of the most important papers but the political situation at the time prevented this. The literature remains largely unknown in the west.

The one thing that both the Chernobyl Forum and the Greenpeace reports agree on is the fact that trying to estimate the health consequences from Chernobyl is extremely uncertain and may not, in fact, be possible.

Small differences in the assumptions concerning radiation risks can lead to large differences in the predicted health consequences, which are therefore highly uncertain’. Greenpeace notes, ‘It is widely acknowledged that neither the available data nor current epidemiological methodology allows holistic and robust estimations of the death toll caused by the Chernobyl accident’.

Having described the origins of this book and given some references to alternative opinions the interested reader will hopefully be able to draw a balanced view as far as is possible on this complex subject. So what information does the book provide?

To be clear, up to this point in the review Monty Charles has just given the background and origins of the book.

The preface provides a useful summary of the Chernobyl literature. The introduction addresses the issue of why assessments of health effects from Chernobyl are so disparate. The authors disparage the approach favoured by the majority of the epidemiology community, which seeks a correlation of health effects with levels of contamination or dose. They believe this approach is ‘impossible’ due to lack of measurements in the first few days, lack of information on ‘hot spots’ and lack of information on all of the isotopes involved. They consider that the USSR authorities distorted links between health effects and radiation exposure and they prefer therefore to rely on what they consider are independent investigations of comparative health measures in various territories that they consider are identical in terms of ethnic, social and economic characteristics and differ only in the exposure to radiation. The authors believe it is unreasonable to attribute the increased occurrence of disease in the contaminated territories to screening or socioeconomic factors (as considered by UNSCEAR) because they consider the only variable properly significant for this purpose should be radioactive contamination.

The problem of ‘hot particles’ is raised— a topic which I have spent 30 years researching. The discussion is cursory and does not include a wide range of peer-reviewed research publications in this field relating to dosimetry and biological effects of hot particles—including important contributions from Eastern Europe and Russia.

The authors rely heavily on a review published in 2006 by Fairlie and Sumner(3) where the highest collective dose estimates are from the US Department of Energy and UNSCEAR (930 000 and 600 000 Person-Sv, respectively for the world up to 2056) rather than figures, which have included any input from the new Eastern European literature that is supposedly influential in driving the authors’ views.

Chapter II has six sections … I found this a very difficult read. Numerous facts and figures are given with a range of references but with little explanation and little critical evaluation. Apparently related tables, figures and statements, which refer to particular publications often disagree with one another.

…the predicted radiation- related cancer deaths in Europe would be 212 000–245 000 and 19 000 in the remainder of the world. I could not however find any specific discussion within the section to support these numbers.

One is left unsure about the meaning of many of these numbers and which is preferred. Considerable effort would be required to consult a large number of the source documents to check the veracity of the numerical estimates and the conclusions drawn.

And that’s the critique. The book is sloppy. The methods can be questioned. Some references appear hard to source (check) the authors (and possibly translators) needed better proofing. Monty Charles notes that an interesting finding is;

Chapter IV deals with radiation protection after the accident and is made up of four sections dealing with contamination of food and people, reduction of levels of internal emitters (decorporation), protective measures and consequences for public health and the environment. The most useful discussions appear to be those describing decorporation experience such as the use of meat additives (ferrocyanides, zeolites and mineral salts) and claimed dramatic reductions of incorporated 137Cs in children with the use of pectin based food and drinks (using apples, currants, grapes, seaweed, etc.).


George Monbiot has attacked a weak source heavily relied upon by Caldicott and Greenpeace. The source has weak sections according to the reviewers, but should not be dismissed entirely as it contributes some important information and raises some valid questions, but it makes controversial allegations that may not be easy (if at all) to substantiate. But, the main allegation made by George Monbiot is from the background section and refers to a prior report by Greenpeace.

Both reviews conclude that variability in the data is high and that an exact number of deaths may never be known. That does not mean they do not occur.


An interesting read is Seven deadly sins of environmental epidemiology and the virtues of precaution

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