Much of what happened at Chernobyl in the early hours of 26th April 1986 is clear.

The plant’s senior management had undertaken a required safety test – an experiment, really – on the reactor in Unit 4, and it went disastrously wrong.

There was a least one explosion of hydrogen gas and a huge blast and fire which wrecked the reactor’s highly-radioactive core and blew it and its protective concrete shield onto their sides. The roof of the building (never designed as a shield) was ripped off and, in the intense heat, a funnel of highly radioactive material – metals, gases and building fabric – was shot a mile high into the sky. A plume of radioactivity spread patchily, mostly north-west. An aberrant sub-plume dumped stuff in an area to the south west of the plant.

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The reactors at Chernobyl were RBMKs, which moderate their fission processes with graphite and are cooled by water. Hence their common Western name: LWGR, or light-water graphite reactor.

http://www.world-nuclear.org/info/chernobyl/rbmk.htm”>http://www.world-nuclear.org/info/chernobyl/rbmk.htm

It was a type unusual in the West but was common throughout the old Soviet Union, not least because it could be adapted to produce weapons-grade uranium as well as heat. Its design had an inherent weakness: the reactors needed to be managed with special care when at low power.

The two year old Unit 4 was a version of the station’s four Soviet-designed RBMK plant Though up-to-date, it was not built to the highest standards, and some of its safety devices (especially a particular emergency switch and its circuitry) were dangerous in that they did not do what their name implied.

But design flaws and faulty manufacture did not cause the explosion. The accident happened because a fatal dose of bad management was added.

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In some sense all errors are human. Reactor 4’s design made it fallible, but Soviet secrecy made it impossible for its designers to explain the weaknesses of their work. Soviet bureaucracy also made it likely that the reactor might not be well built and maintained. If top people were over-confident (at least in public), junior people were over-confiding, and had to be so in private as well as in public.

The design and planning elites were secretive about their failings. The plant’s managers were both rule-bound and aware that many rules were flawed and had to be over-ridden in some circumstances, including on the fatal night.

The Soviet elite and their servants
The RBMK was designed and managed by the elite of a sprawling network of institutes, ministries, and military organisations, some of which over-lapped, and all of which thrived by their ability to deliver the goals of the most senior echelons of the Communist Party, which itself had complicated and competing channels of power.  

Mostly designed within powerful institutes run by powerful Academicians of the soviet science establishment, the RBMK reactors went on to be built and run by ministry officials, many of the most powerful of whom worked with the Ministry of Medium Machine Building, which was a secretive military-industrial complex with covert operations, and which controlled cities and plant throughout the Soviet Union. But there was also a competing energy ministry (which actually ran the Chernobyl plant). All these bodies were committed to maintaining a supply of nuclear-generated electricity.

The designers not only produced a fallible reactor, but they wrote a manual for its operation which diverted attention away from its weaknesses and helped its operators miss the warnings signs about them.  

This was a culture in which senior people, including designers, were not frank with the people who had to work their machinery and those who ran the machinery could not rigorously interrogate the designers.

There was little regulatory tension. Though following the Three Mile Island scare in the US one Academician had been charged with producing an institute with a regulatory role, it was weak. There was no-one outside the nuclear bureaucracy charged with seriously challenging it, and certainly no challenger who was feared as much as those demanding that power keep flowing.

It would be quite wrong to paint these people as careless or stupid. Far from it, there was idealism, intelligence and passion in many of them. Unit 4 blew up because it was routine to try to improve safety procedures. The same Soviet apparatus which produced the April 26 accident, also managed a vast amount of nuclear generation with few major accidents (though it denied those it had). It was a similar apparatus, after all, which first put a man in space, and has always been able to service its space stations.

Alcohol was probably as important as subservience in defining how things used to be run. And then there was the problem of over-manning, which ensured that whilst there was a very large team to run everything, elementary good sense required that how the real power structures worked, and who the real workers were, be clear and understood.

But within their lights, almost everyone was conscientious. In a typically Soviet manner, they were required to be obedient, politically-correct, but capable of ducking-and-weaving as well.

Indeed, one might argue that every country produces a nuclear elite which mirrors the strengths and weaknesses of its national culture. It became fashionable to argue that what the Soviet Union most lacked was a “safety culture”, and there’s merit in the argument. This is to say that everything everyone does around the plant should be predicated on alertness and caution. There is a sense, too, that an industry cannot have a safety culture unless it is institutionally challenged by regulators. Actually, even a “safety culture” may produce its own problems: for instance, a box-ticking devotion to precaution, with imagination gradually stifled. Anyway, for intelligence, ingenuity and courage, it would be hard to beat the Soviet machinery which found itself with the Chernobyl accident on its hands. We see that, arguably, in the extraordinary response of the soviet system to the crisis.

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For several hours, they sent out messages to their staff and bosses saying that there had been an accident, but nothing catastrophic, in terms of physical damage or radiation releases. Meanwhile, the first-responders – fire crews – valiantly and conventionally fought the conventional fires which had broken out around the plant. They had no anti-radiation protection and several died hideous deaths within hours, days and weeks.

Partly because they misunderstood what had happened, and partly because they seem not to have understood the nature of their plant, the plant’s managers attempted to cool the burning reactor by flooding its lower regions with water. This turns out to have been somewhere between redundant and disastrous.

Because officials sought to reassure their citizenry, which was enjoying a May Day celebration at the time, the dormitory town’s 50,000 people were not warned that the fire they could see from their windows was highly dangerous. Outdoor life at Pripyat went on as usual, and ensured that many more people – especially vulnerable children – got an elevated dose of radiation. For most, this was not particularly hazardous, though many children did go on to develop thyroid cancer.

As dawn broke on 27 April (30-some hours after the accident), in a swift and well-organised evacuation, 1100 buses emptied Pripyat with the minimum of outdoor exposure for the inhabitants. Arguably, the timing of this process was ideal.

Meanwhile, the USSRs nuclear elite from top to bottom threw themselves into understanding and tackling the crisis. Senior people descended on Chernobyl and largely took over from the local managers.

Military helicopters and crews took on the hazardous work of “bombing” the reactor with sand and boron. This was the beginning of several months intensive work in which hundreds of thousands of men were deployed to handle radioactive material. Some, working with the most highly radioactive materials, could only operate for few tens of seconds before being exposed to the maximum permissible dose.   

Within the 30 kilometre zone immediately around the plant, one could argue that the necessary work was done. There are places which are hazardous, and a few of those are not properly marked. But it is reasonable to suggest that – granted the available resources and the desire not to over-expose workers – a pretty good and even a very remarkable job was done.

However, and it’s a big however, this relaxed view probably depends on accepting that the 30 kilometre zone ought to stay a No-Go or at least a heavily controlled area. This has advantages, however. It is probable that the decommissioning of the reactor waste at Chernobyl will not be done to a “green field” standard, and therefore the whole area will probably always require strong security measures.

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The design elite could only then hand their plans over to builders who worked in a system both corrupt and inefficient. The resulting plant could only be operated by a technological class which wanted to shine in front of its masters, and dare not question them.

There were highly educated people all along this chain, but they were working to production targets and in the dark.

By definition, everyone in this chain of processes was compromised. They would not have survived without being alert to the main chance.

The lower you look in the chain of command, the more trust and obedience of, say, the station’s control room operators was both impressive and dangerous. Some of them rather bravely questioned some of the steps towards disaster. They did their best as they pressed their buttons and flicked their switches. As you go up to the shift managers, and as the test went wrong, you find people who did their best to see past the increasingly redundant manuals and tried to work out what to do in the increasingly uncharted circumstances which were unfolding. When you arrive as high as you can go within the plant, you find the people who authorised the tests with a quite scary lack of awareness of their potential danger. But even they were diligent.

One might argue that culpability should rest at this level, within the plant’s senior managers. They authorised a test whose riskiness it was their business to understand, even if the power structure around them resisted questioning. But they could argue that the tests were part of unfinished business from the reactor’s commissioning and that they were fulfilling a duty.

Besides, it is arguable that at this level – within the plant – there was no-one with the authority to doubt the bland confidence and reassurance which came from the plant’s designers and the authorities which ordained that RBMKs were safe and robust.

In the end, the Soviet regime only branded as criminal half dozen people, all at plant level, and did not distinguish between their seniority. But many other much more senior people did feel the cold winds of official disapproval, even if amore propre often required that they stay in their posts.

What’s more many senior people within the old Soviet system felt intensely guilty about their role in the accident. One of them – and very far from the most blameworthy amongst them – killed himself.

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Chernobyl became part of the means of beating the dying old regime (and later its memory) but it also became a rallying point for the nationalism of the newly-independent states of Belorussia and Ukraine and a means to secure funding for them.

So, in the late 80s, the new owners of the Chernobyl plant – the Ukrainians – found it convenient to note that the plant had been designed, built and run (and regulated) by a Soviet system whose real power lay in Moscow. It was often convenient, in those years, to push for approaches which seemed “Ukrainian”, and designed to help Ukrainians, rather than  “Soviet” and designed to suit the system.

Thus, for instance, it suited Kiev to claim that Moscow had been dilatory about evacuation of contaminated people and places – and to press for action. But actually, it was very far from clear that evacuation made much sense.

Chernobyl and the end of the Soviet Union

In the last years of Soviet rule, it suited the USSR to claim that there was no safe dose of radiation. It was able to cover up its own nuclear accidents and their fall-out, but to emphasise both the dangers of accidents such as Three Mile Island, in the US, and of nuclear warheads (which it said it was keen to dismantle in the face of US intransigence)…

In the last years of Soviet rule, it suited the USSR to claim that there was no safe dose of radiation. It was able to cover up its own nuclear accidents and their fall-out, but to emphasise both the dangers of accidents such as Three Mile Island, in the US, and of nuclear warheads (which it said it was keen to dismantle in the face of US intransigence).

Come the Chernobyl accident, and there were varied responses within the Moscow elites. The immediate problem was to mobilise the forces of the state to stop the fire, seal the station, help the afflicted, and manage the news. All but the last were quite well done (though mistakes were of course made).

The state had to decide where to lay the blame for the accident. But almost as big was the problem of deciding what the consequences were, and – very differently – what to say about them.

The decision was taken to lay the public blame for the accident as far down the chain of command as possible – that is to say, on the ChNPP management and staff. In private, the state punished more senior designers and planners. But in public, the overwhelming blame attached to people working at the plant.

Once that was done, it became safer to admit that the consequences were serious. Indeed it fitted the pattern of discussing radiation as a diabolical force (which, in very different circumstances, the West might well unleash).

What is more, so far as the consequences went, it suited both the West and the Soviets to stick as closely as possible to some agreed “facts” about the consequences.

Chernobyl and Western politics

Many Western politicians were in no mood to beat-up Moscow too severely about the Chernobyl accident. They were mostly quite keen to support Mikhail Gorbachev as a man one “could do business with” (in Margaret Thatcher?s words), and who was trying to take the USSR in broadly the right direction…

Many Western politicians were in no mood to beat-up Moscow too severely about the Chernobyl accident. They were mostly quite keen to support Mikhail Gorbachev as a man one “could do business with” (in Margaret Thatcher’s words), and who was trying to take the USSR in broadly the right direction. They thought he was being quite open about Chernobyl and that his being so was a sign of improvement on a wider front. Piling on the agony might backfire by slowing his wider political progress.

The Western public, however, were alarmed, and highly precautionary measures were taken when the radiation from Chernobyl reached northern Europe. At least in the UK measures which were arguably excessive (very strict controls were put on meat produced on “contaminated” grass, with very little evidence that anyone faced anything like a problem from it).

But there was another reason why Western leaders were anxious not to overplay Chernobyl. While they did not believe that it was likely to be replicated in their own countries, no-one could say that such a thing would not happen. And in any case, anxiety about radiation was something which could get out of hand, whatever its source. Western leaders, on the whole, had a good deal to gain from a rational approach to this hazard.

But whilst some countries (Sweden, Austria and Germany, in particular) became more or less officially anti-nuclear, many – including some which said they wanted to renounce it – were stuck with running nuclear power. In many countries, it was not a technology which could be safely rubbished. Nor could they risk exaggerating the effects of its radiation, whether planned or not.

They neither wanted panic about Chernobyl’s fall-out nor increased anxiety about the risks of Western nuclear power stations.

There was a good deal of concern about the risks – real and imagined – of Soviet (shortly to be ex-Soviet) nuclear power stations, not least the remaining three plants at Chernobyl.

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It happens that the United Nations has always been the location of a pro-nuclear body, the International Atomic Energy Authority, which seeks to oversee civil nuclear power and to limit the degree to which it is used as a source of fissile material for military use.

Almost immediately after the accident, Moscow agreed to discuss the Chernobyl accident – its causes and consequences – within this forum. This approach had the merit for all parties that it was not overtly political and was overtly scientific.

Focussing attention on this forum seems to have involved a sort of deal: Western governments would not criticise the Soviets for causing the accident, and the Soviets would be as open as possible about their handling of its consequences.

This was a sensible approach because not only was the accident history (and there was no point crying over split milk); but

• Moscow did respond fairly well to the accident;
• Moscow did agree with West about the effects of the fall-out;
• Moscow did agree to modify the RBMK (not least with Western help);
• Moscow did embrace the idea of a “safety culture”.

The UN’s response

From the start, the UN’s International Atomic Energy Authority sent task forces to Chernobyl, Belorussia, Ukraine and other affected parts of the Soviet Union. It held meetings of Western and Soviet experts in Kiev and Vienna, and issued reports. This process continued after the fall of the USSR.

The results were often disputed. The greens hated the relative optimism of the reports. So too did Ukrainian nationalists, who for various reasons were inclined to think that the reports understated the damage down to their innocent fellow countrymen by an oppressive Soviet regime.

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1986, August: UN-IAEA-USSR assessment meeting, 25 August (and an IAEA  document INSAG-1)
This was the crucial meeting at which Soviet specialists gave a surprisingly frank but still slanted account of the causes and effects of the accident. It seems to have provided the acceptable common ground which allowed the West to work with the Soviets as honest partners in the cleanup.

The western experts accepted that the USSR had been right to evacuate the 50,000 inhabitants of Pripyat, and people from the 30-kilometre Zone around the plant. They accepted more reluctantly that it may have been right to evacuate 135,000 people from land under the “plume” or radiation. They accepted that children had received iodine (which should have guarded them against thyroid cancers), though they were worried about the doses and timing of the medication.

Editor’s note: I can’t find this online now, 2011

1988, May: Kiev meeting of Soviet and international health experts
The scale of the disaster was presented for perhaps the first time. Soviet scientists admitted that “17.5 million people, including 2.5 million children under seven, had lived in the most seriously affected areas of Russia, Belorussia and the Ukraine. 135,000 had been evacuated from Pripyat and the 30-kilometre zone. Pregnant women and as many as 350,000 children had been sent to sanatoriums, rest homes and Pioneer holiday camps”. [a316] 25,000 square kilometres of land and 2,225 towns and villages were affected – 1,846 in Belorussia alone. [a320]

The Soviet scientists insisted, though, that the initial assessment of casualties remained accurate: 31 dead, with 209 under observation for varying degrees of radiation sickness. But, said one: “One must say definitely that we can today be certain that there are no effects of the Chernobyl accident on human heath”. A318

Editor’s note: I’m afraid I can’t now find the reference for the quotes above. But there is a useful NYT account of the upshot of the conference’s work:
http://www.nytimes.com/1988/05/23/world/fear-of-chernobyl-radiation-lingers-for-the-people-of-kiev.html?pagewanted=all&src=pm

1992: IAEA:  IAEA  document INSAG-7 (updating the earlier INSAG-1)
http://www-pub.iaea.org/MTCD/publications/PDF/Pub913e_web.pdf

1996: Chernobyl, IAEA Bulletin, Volume 38, Number 3 – a report of the International Chernobyl Conference, Vienna,  April 1996
http://www-ns.iaea.org/projects/chernobyl.asp

2005, September: UN assessment, Chernobyl’s Legacy: health, environmental and socio-economic impact
http://www.iaea.org/Publications/Booklets/Chernobyl/chernobyl.pdf

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Media note

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). 

Cancer deaths

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.

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Copy begins:

The BBC’s Horizon has done excellent work debunking the scare stories surrounding low level radiation risk – the sort most people are frightened of on account of the Chernobyl accident in 1986.

Horizon, the BBC’s science flagship has – rather belatedly – reported research which suggests that low-level radiation is not a risk to humans. This should reassure people worried about the “victims” of Chernobyl and the danger posed by the rest of the nuclear power industry.

A recent BBC Horizon (http://news.bbc.co.uk/2/hi/science/nature/5173310.stm) questioned whether the Linear No Threshold (LNT) model that has formed the basis for assessing radiation risks in the nuclear industry since 1958 reflects the evidence we have observed since then. The programme suggested not, and if it’s right, it’s time at last to radically alter how we assess radiation risks.

This ought to matter to every man-jack of us: the dangers of civil nuclear power largely consist of low-level radiation risk. Over-estimate them, and fear stalks the land.

LNT has been a two-edged sword for those who argue that most “manmade” sources of radiation for most people add very little to what was already a low “natural” risk from radiation. On the one hand, it helped people understand that risk was dose-related (and very small where there was a small dose). On the other, however, it assumed (with little or no evidence) that there was no dose so low that it posed no risk whatever. It was, in short, a precautionary hypothesis rather than a scientifically proven one.

“When people hear of radiation they think of the atomic bomb and they think of thousands of deaths, and they think the Chernobyl reactor accident was equivalent to the atomic bombing in Japan which is absolutely untrue,” says Dr Mike Repacholi, a radiation scientist working at the World Health Organization (WHO). http://news.bbc.co.uk/2/hi/science/nature/5173310.stm

Nevertheless, the experience of the survivors of the atomic explosions in Nagasaki and Hiroshima in Japan had a major impact on radiological protection policy making. And therein lies the paradox. The atomic survivors mostly received a one-off high dose of radiation. However, doses received by victims of the Chernobyl accident – like those received by almost every “exposed” person in the world – were relatively low, on average not much higher than normal background radiation, and the exposure was more long lasting. As The Chernobyl Forum’s – http://www-ns.iaea.org/meetings/rw-summaries/chernobyl_forum.htm – chairman, Dr Burton Bennett puts it:

“The risk factor (effects or deaths per unit dose) was derived from other studies of exposed populations, e.g. the atomic-bomb survivors in Japan. The exposure circumstances and the background level of cancers in the Japanese population are different from the Chernobyl-affected population. This makes the validity of the estimation [ed’s note: from the Chernobyl Forum] quite uncertain. The projections do, however, provide rough, order-of-magnitude estimates that refute the speculation that there could be tens or even hundreds of thousands of deaths caused by radiation exposures. The doses were simply not high enough to elicit such consequences. This is quite definite.” http://www.chernobyllegacy.com/index.php?cat=3&sub=8&storyid=75

There can be no doubt that the LNT has helped discredit the more extreme claims made about radiation in general and the health consequences of the Chernobyl accident in particular. However the LNT is premised on the notion that all radiation carries a health risk. This notion has trapped people in fear, especially in areas of Belorussia and Ukraine which were much more affected by Chernobyl’s radiation than the rest of Europe. Hence it is important that we get a good scientific handle on the issue. http://www.timesonline.co.uk/article/0,,8122-2263204.html

At one extreme, Horizon pokes fun at how the LNT methodology is used to justify keeping 200,000 British sheep – located on hilly land – labelled too radioactive for human consumption as a consequence of the Chernobyl accident 20 years ago. What consumers are not generally told is that if they were to eat chops from these sheep every day for a year their additional annual radiation exposure would be equivalent to half of one dental x-ray.

More seriously, it is estimated elsewhere that in the USA, US$85 billion will be spent cleaning up the Hanford nuclear site to avoid low-level radioactive waste that may well pose no public health risk. And the public may also have been needlessly worried about the consequences of diagnostic x-rays and nuclear medicine to the detriment of their treatment and health. http://www.world-nuclear.org/sym/1998/cohen.htm

The LNT methodology produces seemingly bizarre predictions about the consequences of serious nuclear accidents. On the basis of the LNT it is posited that 90% of all deaths will result from low-level radiation sources. Put it another way: LNT generates an assumption that large numbers of people have been adversely affected, and does so on the basis that since they received a small increased dose of radiation, they must have been. Yet there is no evidence that most of these theoretical deaths relate to real people who can be expected to die or to develop any tangible illnesses. http://www.world-nuclear.org/sym/1998/cohen.htm

Today, the world’s radiological protection regulations are largely based on the recommendations of the International Commission on Radiological Protection (ICRP) which accepts the LNT hypothesis. Yet the epidemiological data from Chernobyl seems to contradict what the model predicts. The model says – and thus so do the official assessments from, for instance, the Chernobyl Forum – that there will be up to 4000 deaths among the most exposed group and a further 5000 deaths among the less affected but more numerous population living in contaminated regions.

This number is very low when compared with predictions by Greenpeace and many other campaigners and scientists (the last especially in Ukraine and Belorussia). But it may well be far too high.

There is a very serious argument which suggests that there are unlikely to be many future deaths from cancers caused by Chernobyl because we have probably already seen the vast majority of whatever cancers the accident caused.

For example, Dr Repacholi tells Horizon that leukaemia cases normally occur up to 10 years after radiation exposure. Moreover solid cancers should make themselves most apparent 20-to-25 years on from an exposure, and – twenty years out from the Chernobyl accident – there are no signs of them at all (the implication being that if they haven’t occurred in the rest of that timeframe they won’t occur at all). He concludes:

 ”We’re not going to get an epidemic of leukaemia… and, based on the exposure levels we’ve seen within these affected populations, we don’t expect an epidemic of solid cancers either.”

Horizon puts it more vividly: “Deaths directly attributable to radiation from Chernobyl currently stand at 56 – less than the weekly death toll on Britain’s roads… Scientists involved in the Forum expect the death toll to rise but not far….and these figures are hundreds of times lower than that based on the LNT” http://news.bbc.co.uk/2/hi/science/nature/5173310.stm

Horizon asks, what if the evidence actually suggests that radiation is not harmful below 100 millisieverts (mSv)? What if low doses could be proved to beneficial rather than harmful? http://www.awe.co.uk/main_site/scientific_and_technical/Factsheets/URR/index.html

There is strong evidence to suggest that low-level radiation is much less harmful than the LNT presupposes. There is other evidence to suggest that low-level radiation may have a positive impact on human and animal health. The programme-makers explore some strong examples.

Horizon highlights studies in the United States that show how background radiation varies by a factor of ten. Moreover they showed that the regions with the highest background radiation – such as Utah, Idaho and Colorado where it tops twice the national average – had the lowest frequency of cancer mortality rates. Commenting on this, Professor Antone L Brooks of Washington State University says, “if radiation is playing a role at all, it is not a big player.”

Airline crew, for example, receive on average 11 mSv per year, or equivalent to 1100 chest x-rays every year of their working lives.  While an aeroplane passenger flying at 35,000 feet, a typical height of an international flight, receives an equivalent annual dose of nearly 36 mSv per year or 20 times normal background levels. But there is no record of any increased cancer risk or birth defects among airline staff despite numerous studies designed to check if any link exists.

Horizon reports how a team of scientists visited Ramsar in Iran where natural background radiation is well in excess of 200 mSv per year. The team took blood samples from residents there and from their neighbours living in towns nearby with normal background radiation levels (world average 2.5 mSv). They subjected all the samples to 1.5 sieverts of radiation exposure: a very large dose. They then studied the chromosomal abnormalities that resulted. What they found, reports scientist Dr Andrew Karam of Rochester Institute of Technology, “was that people living in Ramsar had significantly fewer chromosomal abnormalities than their neighbours living a few kilometres away in areas where background radiation was normal”. (For comparison, the population evacuated after the Chernobyl accident received an average dose of between 17 mSv and 31 mSv in 1986 in Ukraine and Belarus respectively.)

Professor Ron Chesser of Texas Tech University, US, tells Horizon how he compared voles living around the stricken Reactor Four to another set of voles living elsewhere. He examined 100,000 cells from each animal in the two sets to see how much genetic damage – proportion of broken chromosomes – a lifetime’s exposure equivalent to 8, 000 chest x-rays per day had done to the voles living near Chernobyl. Surprisingly, he found no difference between them (the radioactive and non radioactive voles). In fact, after double checking his results, the Chernobyl voles were shown to have boosted those genes that protected them against cancer; this was evidence he was able to quantify.

“One of the thoughts that comes out of this is that prior exposure to low levels of radiation actually may have a beneficial effect,” Professor Chesser tells Horizon.

Fear certainly has few benefits. Tatiana and her daughter Allyona (phonetic) go back to Pripyat with the Horizon crew. The mother shows us where she lived in the town. For her the accident and subsequent evacuation was very traumatic because she was pregnant at the time. She recalls how women were put under heavy pressure to have abortions because hospital doctors argued Chernobyl’s radiation threatened their unborn children. She says, “there wasn’t enough room in the ward, so many had them (abortions) in the corridors.” Some two hundred thousand pressurised abortions were carried out immediately after the accident, according to Horizon. Tatiana was one of the few to resist. As she says this, she looks at her healthy 19-year-old daughter who is standing beside her, pauses, and starts crying.

“It is the fear of radiation that has caused a huge number of health complaints (rather than radiation) which has overloaded the healthcare system”, says Dr Repacholi. And in a memorable phrase the Horizon narrator refers to Chernobyl sending “a radiation plume of fear across Europe”. But it was the concluding words of Dr Karam which summed up my worries best: “If we continue to set risk estimates based on LNT what we are doing basically as society is accepting a myth and letting the myth set our energy policy.”

Whatever the truth of that view, the evidence certainly seems to suggest that the risk of low levels of radiation has been overstated. “The model was based on high doses and we just didn’t know what was going on at lower doses of between one and 200 millisieverts,” says Dr Repacholi. http://news.bbc.co.uk/2/hi/science/nature/5173310.stm

But, as Horizon demonstrated, we are beginning to have the epidemiology and the cause-and-effect science of low level radiation exposure. Indeed, it may be time to base our assumption on the reassuring factual evidence from Chernobyl rather than continue with old gloomy assumptions for Chernobyl which were based on flawed extrapolation from Hiroshima and Nagasaki.

People suffered in all kinds of ways as a result of Chernobyl. We need a fitting testimony to the radiation sickness of a very few, the thyroid cancer endured by thousands, and the anxiety of millions. How about honouring them by taking the facts of Chernobyl and using them to dump LNT?

Ends.

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