Radiation: what we do and do not know

Accidents at Chernobyl and Fukushima expose how little we know about radiation

As the baton of nuclear disaster is handed after 25 years from Chernobyl to Fukushima, scientists still find themselves with more questions than answers on the effects of radiation on human health.

Vitalik Dashkevich is 18, has blonde hair and sparkling hazel eyes, but beneath his chin is the scar where doctors cut a tumour from his neck before his sixteenth birthday. He is among hundreds of children and teenagers the Chernobyl Children’s Project brings on respite holidays from contaminated areas of Belarus to Britain every year.

Despite being out of school for two years and spending months in the Minsk cancer hospital, he is not against nuclear power. “The old reactors were unsafe. The new generation of reactors are safer, it couldn’t happen again,” he says.

But it has. Tragically, 25 years almost to the month after Chernobyl, history threatens to repeat itself at the stricken Fukushima Daiichi power plant in Japan, where partial meltdowns in four reactors have yet to be brought under control after eight weeks.

Described as “apocalyptic” by Germany’s chancellor Angela Merkel, Fukushima was this month updated to a level 7 event on the International Nuclear Events Scale – the highest level, which it shares only with Chernobyl. Germany, where anti-nuclear feeling has always run high, looks likely to invest in renewable energy rather than nuclear power.

It remains a highly divisive issue. Talk of radiation provokes fear and hostility despite the presence of background radiation across the planet in rocks, soils, food, the air and in our bodies, and despite the undeniable benefits of radiotherapy, X-rays, CT scans, or power. Radiation is invisible and poorly understood by the public, but even in scientific circles there is still much that is debated.

Our understanding of ionizing radiation comes mostly from the Life Span Studies of the Hiroshima and Nagasaki atomic bomb survivors. The effects of large doses of radiation, especially when received in short periods of time, are generally agreed: radiation sickness occurs at around 1 sievert (Sv, the unit of radiological dose, equivalent to 1,000 millisieverts or mSv), severe radiation sickness after 2,000 mSv, and death is likely beyond 4,000 mSv. Background radiation in Britain is 2.7 millisieverts per year, of which man-made radiation makes up around 20 per cent, mostly from medical imaging.

By comparison, the radiation levels around the Fukushima nuclear plant are in the range of 0.03 mSv to 0.5 mSv per hour indicating that, at worst, spending five hours at the plant would be about the same as a year’s background dose in Britain.

The Linear No Threshold theory (LNT) adopted by the International Commission on Radiological Protection (ICRP) holds that risk increases with radiation dose, with near-zero levels posing a near-zero risk, increasing in line with dose. So according to the models used to draw up safety codes, low levels of radiation below 1 mSv – considerably lower than the background radiation – pose a risk so small as to be statistically invisible. This is the model used by the industry and other government watchdogs such as Britain’s Health Protection Agency.

But a growing number of scientific studies claim to show the LNT theory is inaccurate and unscientific, although perhaps demonstrating the limits of our understanding of radiation, however, it is either more dangerous, or less dangerous than the LNT model represents depending on who you ask. Some even suggest a little radiation is good for you.

One problem is that we don’t understand the mechanism by which radiation affects the body. Former World Health Organisation radiation biologist Dr Keith Baverstock says: “We know that after a dose of radiation you can find chromosomal damage and cell mutations. Then there’s a big gap, and then cancer appears. But until we know how we’re on shaky ground making any claims.” With cancer already running as high as one in three people among some populations, this makes it difficult for studies to accurately identify additional cancers that may have been caused by radiation.

Some have taken the lack of coherent findings that are not contradicted by other studies as proof that radiation poses no danger below the high levels required to cause radiation sickness. The radiation hormesis theory suggests that, similar to a vaccine, small amounts of radiation stimulate the body’s natural defences, actually increasing health. Belle, Beneficial Effects of Low Level Exposures, was set up in 1990 to study such theories and gather evidence that demonstrates the hormesis effect. For example, one study of residents from an apartment block in Taiwan built with steel accidentally contaminated with radioactive cobalt-60, found that among the 10,000 residents who had lived there for nine or more years rates of cancer were much lower than the model predicted, despite the dose they had received.

However, other studies suggest that the LNT model is wrong because it fails to take into account the impact of radioactive particles absorbed by the body in food, water or air – so-called internal emitters – which potentially effect the body very differently to the strong, external radiation blast experienced by the atom bomb survivors on which the risk model is based. Independent radiological consultant Dr Ian Fairlie says even background radiation, while occurring naturally, is not benign. In fact radioactive radon gas, a by-product of natural uranium found in the earth, causes an estimated 21,000 lung cancers a year according to the US Environmental Protection Agency. Strictly, the doses of radiation received by inhaling radon gas are not sufficient to cause harm under the model used by the ICRP. Yet while radon is the accepted cause, the same model rejects the idea that low doses from caesium, strontium and plutonium fallout from Chernobyl – and now Fukushima – is high enough to cause harm.

Fairlie says: “It has everything to do with the politics of nuclear power, and nothing to do with the science. It is a case of fitting the science around the policy. We all do it to an extent, but it is important to take the most unbiased approach possible, and not cherry-pick the evidence.”

The Committee Examining Radiological Risks of Internal Emitters, set up by the government and on which Fairlie sat, concluded in 2004 that the uncertainties surrounding internal doses were so large – differences of between two and ten times predictions – as to make the model’s estimates almost useless.

In 2008, the German KiKK study (Kinderkrebs in der Umgebung von KernKraftwerken, Childhood Cancer in the Vicinity of Nuclear Power Plants) examined data stretching back 10 years and found a regular pattern of childhood leukaemias that increased with proximity to nuclear plants. Similar studies had been carried out at Sellafield in the 1980s, which discovered no less than seven cases of childhood leukaemia in one village, Seascale, four miles from the plant.

“You have to be upfront and transparent about nuclear power. The government should have stated that in the worst instance we could expect a few deaths in the local population,” Fairlie says.

But is it reasonable to single out the dangers from nuclear power when the alternatives also come with risk attached? Fly ash released by coal-burning power stations contains radioactive uranium, thorium and radium – something known since at least a 1978 study of Tennessee and Alabama coal plants found doses of up to 1.8 mSv to those living within a mile – but without sparking the same media hysteria. That’s to say nothing of the tens hundreds of thousands of deaths from air pollution the world over, and the thousands of deaths in mines – 30 a year in the US; more than 2,000 a year in China alone. Even wind turbines have led to 69 deaths since the 1970s according to Caithness Windfarms Information Forum – comparable to those killed in nuclear accidents, but having produced a fraction of the power.

Modern society needs power, and it is prepared to accept a degree of risk in generating it but, says Baverstock, our approach to risk is not rational: “People will happily do things that are high risk like smoking. People are prepared to accept risk if they feel they’re getting a benefit from it, but perhaps don’t see nuclear power sustaining the electricity grid as benefit enough.

“We must be consistent,” he warns. “How are the public to make a decision if we tell them to avoid unnecessary CT scans because of the risk they pose, while at the same time telling us that radiation of a similar level radiation from power plants is harmless?”

Part one of this debate on nuclear power is here.


[This article was originally published in The Big Issue, May 2011]


Chernobyl has taught us more about the industry and politics than radiation and health

Pripyat is still abandoned, and 25 years later the same mistakes are made and the same questions hang over the IAEA and nuclear industry.

A quarter century after the world’s worst nuclear accident in Chernobyl, Michael Parker finds a power generating industry happy to keep the public in the dark.

Old habits die hard. When reactor no. 4 of the Chernobyl nuclear power plant in northern Ukraine blew itself apart just before 1.30am on April 26 1986, it was natural for the Soviet government to deny it, even as the radioactive cloud swept far to the north and set Geiger counters shrieking in Finland and Sweden.

Denial, misinformation and cover-up were stock in trade for Soviet authorities, and a previous major accident – an exploding nuclear fuel dump at the Mayak processing site in 1957 – was not revealed until 1979. In the days after the Chernobyl disaster, Grigori Medvedev, the former deputy chief engineer at Chernobyl then working at the energy ministry, was put in charge of an investigation.

His 1991 book, The Truth about Chernobyl, lays bare the incompetence and negligence of staff who disabled safety systems, the lax safety culture, and the design flaws of the RBMK type reactors that were known but ignored. He records how the authorities issued no warnings to the population of Pripyat, the town which housed the plant’s workers barely two miles from the stricken reactor from which streamed radioactivity equivalent to 100 times that released from the Hiroshima and Nagasaki bombs. School children played outside and weddings took place.

When Pripyat’s 50,000 inhabitants were finally evacuated 36 hours later, the official line was that it was only for a few days – the town remains abandoned 25 years later. The official line still held on May 1, when Communist Party bigwigs came out to watch the parades knowing full well they, and all those marching, did so under the radioactive plume. There was even a show trial of senior managers, who were only freed from prison when the USSR collapsed.

The conniving did not stop there. Journalist and former politician Alla Yaroshinskaya dug out previously classified government documents which revealed how in the face of rising numbers of people diagnosed with acute radiation sickness, the ministry of health simply raised the safe acceptable radiation doses tenfold, redefining the sick as healthy. Without irony, the statement from May 8 1986 claims: “By these means the health safety of the public of all ages is guaranteed, even should the current radiation situation last for 25 years.” Doctors were banned from writing radiation-related causes on death certificates, and statistics were falsified.

However, since 1990 the International Atomic Energy Agency (IAEA), World Health Organisation (WHO), UN Scientific Committee on the Effects Atomic Radiation (UNSCEAR) and other UN agencies have produced numerous reports on the accident. But despite the involvement of the democratic western nations, a sense that the whole picture is not being revealed remains.

The Chernobyl Forum, set up by the IAEA and including the WHO and other agencies, reported in 2005 the controversial claim that around 50 had died, and 9,000 could be expected to die from radiation-related causes following the accident.

Given the scale of the disaster – a complete reactor meltdown, a radioactive fire burning in the open air for 10 days, a radioactive cloud across the continent contaminating hundreds of thousands of square kilometres – many felt this played down the consequences. The press release that accompanied the report’s publication even used the figure of 4,000 deaths, when the body of the report concludes the total is 9,000. There were other complaints: the tone seemed overly final, when any figures are only vague estimates, the report only examined the effects on Ukraine, Belarus and Russia, and emphasised only cancer deaths, rather than the wide range of non-cancer effects such as heart disease, cataracts, nervous disorders and genetic genome instability reported from the former Soviet republics. It is very hard to accurately connect deaths among exposed populations to radiation – studies are inconclusive, data incomplete, possible other factors too numerous – but science demands an objective assessment.

Some scientists felt it was a familiar routine. Radiation biologist Dr Keith Baverstock headed the WHO’s European radiation protection programme, where in 1992 he investigated claims of high rates of thyroid cancer appearing in Belarus. “We were shown around 11 children, all having had recent thyroid operations,” he recalls. “Thyroid cancer is so rare there was no way it was possible to have that many cases in one hospital. “I had been put under pressure not to go, and when we published a letter of our findings, a senior WHO manager strongly suggested I withdraw the letter, which I refused.”

Thyroid cancers in Chernobyl-affected children stand around 7,000 and rising. Treatment is readily available and generally successful, but while only a handful have died, the standard treatment of removing the thyroid leaves the patient dependent on medicine for the rest of their lives. Scars from the operation are so common they have a name – the ‘Chernobyl necklace‘.

Ultimately funded by their member states, the IAEA, WHO and other UN organisations are inclined to ensure that governments hear what they want to hear, Baverstock says. The discovery that radioactive fallout from power stations could be dangerous would “not be welcome”. “The upper levels of UN organisations are not technically qualified people, and make decisions based on politics.”

Based on their findings, Baverstock and his colleagues drew up new safety guidelines that would ensure potassium-iodide capsules, which prevent the thyroid from absorbing cancer-inducing radioactive iodine-131, would be distributed at a radiation dose ten times lower than previously. On publication, the IAEA announced the guidelines were “draft”, and should be ignored.

“We were furious,” Baverstock says. “When we finally had a meeting it turned out there were no scientific objections to this, only financial ones – from France, who with reactors near so many large cities objected to the expense of all those capsules.”

Other organisations such as Greenpeace, Green Party-associated groups and environmentalists and scientists from the former Soviet Union issued their own reports, with death estimates ranging from 30,000 to one million. But if anti-nuclear groups could be said to have a vested interest in maximizing the Chernobyl bodycount, it must be said that the IAEA also has vested interests of a different nature. After all, this is a body set up to promote civil nuclear power, yet a 1959 agreement between it and the WHO gives it precedence in any nuclear-related matter – such as carrying out research to ascertain health risks of radiation and nuclear power. The conflict of interest is obvious, but Baverstock says in reality the agreement is irrelevant: the WHO and UN Development Programme sit on the UN Economic and Social Council, while IAEA with its role monitoring nuclear weapons sits on the more senior Security Council, and thus pulls rank.

Following the crisis at the Fukushima Daiichi nuclear plant in Japan, where partial meltdown in three reactors has yet to be brought under control after six weeks, IAEA chief Yukiya Amano stated the organisation is not the “nuclear watchdog” it is frequently described as. “Responsibility for nuclear safety lies with our member states. The IAEA acts as a hub for international cooperation, to establish safety standards and provide expert advice.” Applying and enforcing safety standards is up to national governments, he said.

Poor standards were to blame at Chernobyl, and perhaps also at Fukushima, where criticisms of the 40-year-old reactor design’s poor secondary containment – destroyed by the explosions last month – had been made since the 1970s, with recommended upgrades never rolled out. Tepco, the plant’s owner, was investigated for falsifying repair records in 2002.

Perhaps nuclear technology is incompatible with the profit motive? Not necessarily, Baverstock says. “What Fukushima has shown is that governments and the industry have not learned. There needs to be a watchdog with enforcement powers, perhaps even owning the plants,” he says.

“We still don’t fully understand radiation risks, and there is certainly irrational fear of radiation among the public. We are not always rational, but if there is incompetence and deception from the nuclear industry then that will, not unreasonably, colour the public’s view.”

At the birth of the atomic age nuclear power stations were the means to manufacture weapons-grade material for nuclear bombs. The industry grew up in an era of Cold War secrecy and the demands of the military over public interest. The state of the world has changed, but the institutional secrecy of the nuclear industry and the organisations created to excuse it remains.

The eventual acknowledgement of the link between iodine-131 and thyroid cancer meant Japanese authorities knew to act quickly and distribute potassium iodide capsules around Fukushima. This will have saved many lives and much suffering – yet were it not for the persistence of scientists like Baverstock and his colleagues, the link might never have been made. By trying so hard to fit the evidence to how they would prefer the world to appear, the industry’s cheerleaders run the risk of learning nothing from Chernobyl – and the accidents that will, and have, come after it.

Part two of the nuclear debate is here.

[This article was originally published in The Big Issue, April 2011]