Chernobyl: Consequences of the Catastrophe for People and the Environment (Annals of the New York Academy of Sciences), Alexey V. Yablokov, Vassily B. Nesterenko, Alexey V. Nesterenko (Editors). Janette D. Sherman-Nevinger (Consulting Editor)
Reviewed by Dr Ian Fairlie
Many readers will remember that in April 1986, a reactor at the Chernobyl nuclear power plant exploded, triggering a graphite fire which lasted for 10 days. This massive fire ejected large quantities of radionuclides into the atmosphere which were then distributed by prevailing weather patterns across most of Europe and the Northern Hemisphere. The IAEA stated (1996) Chernobyl was “the foremost nuclear catastrophe in human history”. The IAEA/WHO (2005a) stated “the magnitude and scope of the disaster, the size of the affected population, and the long-term consequences make it, by far, the worst industrial disaster on record”. According to IPHECA (1995), the radioactivity released at Chernobyl (in Bq terms) was 200 times that from the Hiroshima and Nagasaki atomic bombs combined.
The authors of this volume on Chernobyl’s adverse effects are Alexey Yablokov, Vassily Nesterenko and Alexey Nesterenko. Yablokov is a member of the Russian Academy of Sciences and former environmental advisor to Gorbachev and Yeltsin. Vassily Nesterenko was director of Ukraine’s nuclear power establishment in the 1980s and 1990s. In August 2009, he died mainly as a result of his radiation exposures from the Chernobyl reactor, but earlier he established the independent Belarussian Institute of Radiation Safety (BELRAD) to help Belarus children. Alexey Nesterenko is the Institute’s senior scientist. The book was translated by Janette Sherman-Nevinger, Adjunct Professor at the Environmental Institute at Western Michigan University.
The authors summarize hundreds of 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. Exposures to affected people are actually increasing. Collectively, the studies suggest significant risks to those exposed to relatively low levels of radioactivity in the environment.
The report consists of four main chapters containing 15 smaller sub-chapters. Chapter I on the distribution of Chernobyl’s fallout, states that, although Belarus, Ukraine and Russia were the most highly contaminated countries, in fact Western Europe received more than half of Chernobyl’s fallout, and accounted for two thirds of Chernobyl’s collective dose to the northern hemisphere. Chernobyl’s fallout was spread over 40% of the land area of western Europe. In 1986, nearly 400 million people lived in areas contaminated with radioactivity at levels higher than 4 kBq/m2 – the lowest level for official acknowledgement. Nearly 5 million people still live in areas with very high levels of radioactive contamination (>40 kBq/m2) in Belarus (18,000 km2), Ukraine (12,000 km2) and European Russia (16,000 km2).
Chapter II on health consequences states that reported adverse effects continue to increase in Belarus, Ukraine and Russia. Comparisons of morbidity/mortality in areas with low and high radioactive contamination reveal significant chromosomal abnormalities, marked increases in general morbidity, increased numbers of sick and weak newborns, and apparent accelerated ageing. As regards non-malignant effects, studies have found increased incidences of brain damage; premature eye cataracts; tooth and mouth abnormalities; blood, lymphatic, heart, lung, gastrointestinal, urologic, bone, and skin diseases; thyroid disease (with ~1,000 cases of thyroid dysfunction for every thyroid cancer); genetic damage and birth defects in the children of liquidators and those born in areas with high levels of radioactive contamination; and immunological abnormalities. However information on doses is limited. Official estimates by international agencies predict 9,000 – 28,000 fatal cancers between 1986 and 2056 in Belarus, Ukraine and Russia. The independent TORCH report for the Green Party in the European Parliament (www.chernobylreport.org) estimated between 30,000 and 60,000 excess deaths, based on UNSCEAR data. In contrast, the chapter estimates 212,000 to 245,000 deaths in Europe and 19,000 in the rest of the world.
A western study by Cardis et al (2005) has predicted 18,000 to 66,000 thyroid cancers in Belarus (the higher number assuming a constant relative risk over life). Continuing radiation from Cs-137 and Sr-90 will affect millions of people for hundreds of years.
Chapter III on the environmental effects states that Chernobyl radionuclides have concentrated in sediments, water, plants, and animals, at up to 100,000 times higher than background levels. Despite downward nuclide migration into soil, plant root systems transport nuclides back to the surface. This transfer is a major cause of the increasing radiation doses to people in contaminated territories from ingested contaminated foods observed in recent years. Genetic disorders, structural anomalies and tumour – like changes have occurred in many plant species including unique pathologic complexes in the Chernobyl zone: genes silent over long evolutionary timeframes appear to have awakened. Chernobyl radiation has resulted in morphologic, physiologic, and genetic disorders in every animal species studied. Reports of a “healthy” environment near Chernobyl for rare species of birds and mammals are the result of immigration not local sustained populations.
Chapter IV on the continuing consequences states that food contamination remains a major problem. From 1995 to 2007, up to 90% of children in heavily contaminated territories of Belarus had Cs-137 levels higher than 15-20 Bq/kg – the action level recommended by BELRAD. Worryingly, average Cs-137 and Sr-90 body levels in heavily contaminated territories of Belarus, Ukraine, and European Russia have been increasing since 1991 mainly due to eating contaminated food. The result is that individual radiation doses in the contaminated territories of Belarus, Ukraine, and Russia have also been increasing steadily since 1994. In 2008, the average dose in heavily contaminated territories of Belarus, Ukraine, and European Russia exceeded 1 mSv/year – primarily from eating locally contaminated food. However the administration of apple-pectin food additives is considered helpful for body decontamination of Cs-137. Between 1996 and 2007, 160,000 Belarussian children received pectin food additives for 18 to 25 days: Cs-137 levels decreased by 30% to 40%.
Ever since the Chernobyl accident occurred, its effects have been the subject of polarised views with claims and counterclaims on the size of the adverse effects especially on the estimated numbers of resulting deaths. The volume lists many major reports which have been published (in English) in western European countries and in eastern European countries (in Russian or Ukrainian): about a dozen major reports were published at the 20th anniversary of the accident in April 2006. Official reports by the IAEA and WHO (and especially the “context” applied by these two organisations) differ markedly in their approach, contents and conclusions to independent and some national Government reports. For example, IAEA and WHO reports (especially the Chernobyl Forum reports 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.
From this volume, many eastern European scientists evidently consider that nuclear agencies in the West fail to acknowledge the scale of Chernobyl’s effects and refuse to accept that radiation exposures from Chernobyl’s fallout are the prime cause. Nuclear agencies in the West often seek to justify their dismissal of eastern European reports on Chernobyl by disparaging eastern scientific protocols.
This is an important issue repeatedly referred to by the authors and as these matters are rarely discussed in scientific journals, it is perhaps worth examining the matter. There are three matters which need to be discussed.
First, nuclear agencies (IAEA/WHO 2005a) cite questionable scientific practices in eastern epidemiological studies, such as poor case identification, non-uniform 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 nuclear agencies. For example, studies by independent scientists have shown surprising lapses of standards in officially-sponsored epidemiology studies in the West (Fairlie and Körblein 2009, Körblein and Fairlie 2009).
Nuclear agencies (IAEA/WHO 2005b) also have stated that excess mortality or morbidity found in eastern studies 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. One major difficulty in interpreting Chernobyl mortality studies is the large recent decrease in average male lifespan in Belarus, Russia and Ukraine in all areas not just contaminated ones: this deserves more attention in eastern studies.
Second is the common practice in the West to test the findings of epidemiological studies of radiation exposures for statistical significance. Broadly speaking, there are two types of epidemiological studies – observational studies of expected effects where data may be known beforehand and analytical studies of unexpected or unknown effects where the data is unknown beforehand. The latter usually have defined hypotheses that can be tested with formal statistical tests, thus allowing quantitative conclusions unlikely to be due to chance and offering some proof of effect. Statistical tests are used in the latter, but may not be necessary in the former.
The eastern studies are mostly the former observational kind and typically show cancer increases in areas of high Cs-137 concentrations compared with areas of low Cs-137 concentrations. These findings are hardly unexpected. Radiation exposures to Cs-137 can lead to increased incidences of cancers: it is unnecessary to prove this again via statistical tests as if these were chance or unexpected findings. Therefore many eastern scientists consider there is little need to apply p values and/or confidence intervals to their observed data.
Interestingly, many (non-radiation) western scientists have criticised the widespread practice and often inappropriate use of significance testing. See for example Axelson 2004, Whitley and Ball 2002, Sterne et al 2001, Everett et al 1998, and Altman and Bland 1995.
The crux of the matter is that the inappropriate application and incorrect use of statistical tests allow scientists from western nuclear agencies to challenge the findings of eastern European studies and to allege the observed effects are due to chance. The problem with these 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 datasets are too small for statistical significance (which can often be the case), nuclear agencies conclude – incorrectly1 – that there is no real effect. This catch 22 situation makes it easy to see why, as is apparent in this volume, eastern European scientists feel perplexed: they feel they are damned if they do these tests and damned if they don’t.
The third matter is the demand for dose estimates in order to establish a dose response relationship. However, as the authors point out, such demands by western nuclear agencies can be unreasonable. The authors state that because of official secrecy and obfuscation, radiation exposures to liquidators are difficult to reconstruct. This is only partly true, as western and eastern scientists (Cardis et al 1996) actually have reconstructed liquidator doses. It is more probably the case that, as dose reconstructions take much time and are costly, resource restrictions are the real reason. A more valid objection cited in the book is that major uncertainties exist in any estimates of exposures from ingestion/inhalation as shown by the UK Government’s CERRIE Committee (2004). Of course, it is always preferable to have dose estimates even if qualified by uncertainties. It may be possible, for instance, to look at different groups with low, medium and higher levels of exposure.
In the views of western nuclear agencies, the observed increases in morbidity and mortality following Chernobyl are explained by confounding factors such as other causes of death, or possibly by increased medical surveillance. Instead of Chernobyl fallout, the increases are stated to be caused by social breakdown or possibly psychological depression. However few official studies are carried out to provide evidence of these unfounded assertions.
Clearly there is a continuing and profound difference of views over Chernobyl’s health effects. Some readers will disagree with this evidence and consider it too polemical; others will concur with the book’s findings. My 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. For example, as shown above, more attention needs to be paid to the large recent decrease in average male lifespan in all areas not just contaminated ones. Also greater efforts should be made in reconstructing doses (and resources be made available for this), and in estimating collective doses and discussing their implications for both east and west Europe.
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. The New York Academy of Sciences, which states that it “…has a responsibility to provide an open forum for discussion of scientific questions”, is therefore to be congratulated for publishing this volume. The English translations will certainly permit more informed dialogue to take place.
The 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 bizarre non-radiation causes, and their refusal to devote resources to rehabilitation and disaster management.
This is all very unfortunate; however there is one silver lining. The volume relates that many tens of thousands of concerned citizens throughout the world have mobilised to help stricken people in the three countries most seriously affected. Hundreds of local, national and international voluntary groups have been established especially to help the children in these areas. This help includes holidays abroad for many tens of thousands of children to provide respites from their radioactively contaminated homelands. Hundreds of doctors from many countries work pro bono in contaminated territories, helping to minimize Chernobyl’s health consequences.
In this reviewer’s opinion, these humanitarian actions constitute a silent rebuke of the disregard shown by international nuclear agencies and some national authorities towards the continuing plight of affected children in Belarus, Ukraine, and Russia.
Dr Ian Fairlie
London N5 2SU
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1. In more detail, lack of statistical significance may be due to BOTH lack of effect AND small numbers of the dataset ie lack of statistical power. This means scientists have to exercise care in interpreting what lack of statistical significance may mean. In many studies, the failure to reach statistical significance may simply be due to insufficient numbers. In statistics, rejection of a (real) effect is known as a type II error. Unfortunately this error type is rife in radiation epidemiology studies in the west. In the worst examples, western studies reject positive findings of effect and conclude, incorrectly, that the lack of statistical significance means there is “no evidence” or “no suggestion” of effect. See Bithell et al 2008, Laurier et al 2008.