by Joan Smith
Less than 150 men got between 20 and 70 millisieverts. Five hundred got doses between 3.5 and 20. About 1,500 got less than 3.5 millisieverts. The remaining records of exposure, which show 4,000 occasions on which men were exposed, do not give detailed readings: they establish that exposure took place, but the amount was too small for the equipment used to measure radiation to register it accurately.
The government says exposure at these levels is too small to produce a significant increase in cancer levels. But what is the evidence about the effects of low-level radiation? In fact, the history of radiation protection from the 1950s to the present day has been one in which critics of the nuclear industry have repeatedly argued that the risks of low-level radiation are much greater than the industry admits. Although the controversy has not been resolved, some studies in favour of this hypothesis which were angrily rejected in the 1950s have now won wide acceptance in the scientific community.
Dr Alice Stewart, the epidemiologist who carried out an initial survey of the Christmas Island veterans in 1983, has played a key role in identifying the hazards of low-level radiation. In 1955, as head of the Department of Preventive Medicine at Oxford University, she embarked on a study to find the cause of a sharp rise since the war in the number of children contracting leukaemia.
She discovered that X-rays given to pregnant women were the culprit. She published the results of her work in 1958: it suggested that children whose mothers had had X-rays during pregnancy were twice as likely to develop cancer before the age of ten as children whose mothers had not been X-rayed. If the X-ray was given in the first three months of pregnancy, the Oxford study also showed, the child was ten times more likely to develop cancer than if it happened towards the end.
At the time, Stewart’s work was challenged. Today, it is so widely accepted that major changes have been made in the use of X-rays during pregnancy. In 1970, Stewart published a follow-up to the Oxford study. It demonstrated a direct relationship between the dose of radiation received by the foetus and the chance of getting cancer. Doubling the number of X-rays also doubled the risk. Significantly, the dose of radiation from an X-ray in the 1960s was only 2 millisieverts.
Alice Stewart’s work on the effect of X-rays on the foetus has been complemented by a large-scale study into their effect on adults in the US. In the 1960s, the American scientist, Dr Rosalie Bertell, began work on data from the Tri-State Study, a massive investigation into the health of sixteen million adults in New York State, Maryland and Minnesota. The data included details of each person’s life history, including their occupations, where they lived and the illnesses they had suffered.
Before working on the study, Bertell had given little thought to radiation. She had originally trained as a mathematician, but joined a closed order of Carmelite nuns, where she was expected to perform backbreaking physical labour. After an early heart attack, she was advised to join a teaching order, where less physical strength would be required of her. She joined the Grey Nuns of the Sacred Heart and returned to academic work, particularly in the field of the application of maths to medicine and biology. This was exactly the kind of work she was expected to do on the Tri-State Study.
The conclusions she drew from analysis of the data over ten years turned her into a passionate anti-nuclear campaigner. She noticed that the people who suffered from leukaemia were those from wealthy backgrounds with access to private medical care -and X-rays. She also noticed that these people were suffering from a particular sort of leukaemia usually associated with old age very much earlier in life than expected.
Bertell’s work, like Stewart’s, has brought about changes in the use of X-rays for diagnostic purposes - hospitals in the US use them much more cautiously as a result. But evidence from the effects of X-rays is far from being the only source which suggests low-level radiation is dangerous. In the 1970s, Alice Stewart was asked to go to the US to help analyse the results of a massive study of the health of workers at one of the longest-running nuclear plants in the world - the Hanford works, near Richland, in Washington state.
The Hanford plant was one of the installations set up during the Second World War to carry out work for the Manhattan Project. During the war, its job was to produce plutonium for the bomb; it is now a huge site which houses various types of nuclear reactor, as well as storage tanks for nuclear waste. In 1965, the American nuclear regulatory body, the Atomic Energy Commission, asked Dr Thomas Mancuso, of Pittsburgh University, to look at the health of workers at the Hanford plant.
In 1974, while Mancuso was still working on his study, evidence of a high cancer rate among the Hanford workers was published by Dr Sam Milham, Epidemiology Director of the Washington State Health Department. Milham found there was a higher death rate from certain cancers - cancer of the pancreas, and multiple myeloma, a rare type of bone cancer – among Hanford workers than there was among other industrial employees in the area.
Mancuso’s work started to show a similar pattern among the Hanford workers. Suddenly, the US government withdrew his funding and transferred the study elsewhere. Fortunately, Mancuso had kept copies of the data and was able to get funding from the independent Environmental Policy Center in Washington DC. In 1976, he asked Alice Stewart and one of her colleagues at Birmingham University, Dr George Kneale, to help analyse the data. Their initial findings were published in 1977, followed in 1978 by an updated version of the study.
The 1978 report was based on an examination of death certificates for more than 5,000 people who had worked at Hanford over a period of thirty-three years - 1944 to 1977. It found elevated cancer rates among those workers who, according to plant records, had been exposed to radiation. The doses they received were very low - nearly three-quarters had been exposed to less than 20 millisieverts.
Although this study confirmed Milham’s earlier work, it provoked a fierce controversy. It is easy to see why. The Hanford study suggested that the ICRP’s recommended limit for radiation workers - 50 millisieverts per year - underestimates the risk by at least ten times and possibly as much as thirty times.
This is certainly not the sort of thing the nuclear industry wants to hear, as Dr Rosalie Bertell has pointed out. ‘The large number of criticisms of the Hanford worker analysis seems to be related more to its perceived political importance to the foundation of the whole nuclear industry than to its scientific merit.’
Another American study published at the same time as the Hanford findings showed high cancer rates among nuclear workers. Dr Thomas Najarian, of the Boston Veterans Administration Hospital, looked at death certificates for nearly 2,000 workers at the Portsmouth Naval Shipyard, in New Hampshire. He found that their death rate from cancer was twice the national average.
In 1980, yet another significant report was published. It examined the health of more than 3,000 men who participated in an American atom bomb test, code-named Smoky, which took place at the Nevada test site in August 1957. Dr Glyn Caldwell, of the Center for Disease Control in Atlanta, Georgia, reported that the incidence of leukaemia among the men was nearly three times higher than it should have been. Records of exposure were available for eight of the nine men; they all received less than 30 millisieverts. The mean dose for the eight men was only just over 10 millisieverts.
The Smoky test study seemed to provide valuable corroborative evidence of the dangers of low-level radiation, and of the claims of both the American and British veterans. But three years later, Caldwell inexplicably withdrew support from his own study. Dr Rosalie Bertell found herself in the unusual position of defending a study against its author: she considers the Smoky study valid, and says there have been no new findings which necessitate rejection of it.
These studies, and others, suggest the ICRP has consistently underestimated the risk from low-level radiation. A committee set up by the prestigious US National Academy of Science reported on the risk in 1980 and came up with figures that put the risk up to five times higher than the ICRP’s estimate. Even then, the commit
tee warned that its own figures ‘should in no way be interpreted as precise numerical expectations. They are based on incomplete data and involved a large degree of uncertainty, especially in the low-dose region.’
The committee’s own chairman, Professor Edward Radford, of Pittsburgh University, disagreed with its findings. He published a minority report, arguing that the committee was still underestimating the risk. In April 1983, Radford told me he expected a ‘cancer epidemic’ among nuclear workers unless limits are lowered drastically. They have not been.
Radford came to London in February 1985 to give evidence to the Royal Commission into the British atom bomb tests. He described his research into the health of people in Canonsburg, Pennsylvania, a town still polluted by radioactive waste from its part in the Manhattan Project. During the war, Canonsburg was the site of a factory which processed uranium for the atom bomb; large quantities of radioactive waste are buried beneath the town. The US government has already offered out-of-court settlements to more than thirty residents who claim their health has been affected by radiation.
But Radford’s research in Canonsburg threw up one particularly alarming piece of evidence about low-level radiation. ‘To my surprise, we found that in Canonsburg there was a significant number of radiation-induced thyroid abnormalities,’ he told the Royal Commission. ‘I was surprised because the figures said these people had been exposed to radiation in the order of only two or three times natural background.’ The thyroid is known to be particularly sensitive to radiation. But the Canonsburg cases appear to have been caused by startlingly low levels of radiation.
In the 1980s, evidence of health problems near nuclear installations in Britain began to mount. Clusters of leukaemia have been reported among people living close to nuclear power stations. One of these is next to the Sizewell A power station, in east Suffolk. A high incidence of leukaemia and cancer of the lymph glands has been noticed among children living near the Oldbury and Berkeley power stations, in the West Country. People living near these plants are exposed to very low levels of radiation.
But the most serious and sustained allegations centre on the reprocessing plant at Windscale, in Cumbria. In November 1983, Yorkshire Television reported high levels of cancer among children in villages near the plant. The government set up an inquiry, under Sir Douglas Black; as it began work, I reported in the Sunday Times that doctors were investigating high levels of leukaemia on the west coast of Scotland, right in the path of tides from Windscale. I also reported that doctors in Fleetwood, in Lancashire, to the south of Windscale, had found an unexpectedly high rate of bone-marrow cancer in the area.
When the Black report was published, in July 1984, it proved to be a rather curious document. It confirmed the high incidence of leukaemia in villages near Windscale but shied away from linking it with the plant. Black himself even offered the public a ‘qualified reassurance’ that the problem had not been caused by Windscale.
The Black report is seriously flawed. First, as James Cutler of Yorkshire Television has shown, it underestimated the cancer rate close to Windscale. Nearly half the cases of childhood cancer in Seascale and nearby villages were left out of the report’s analysis. This fact undermines the report’s conclusion that the childhood cancer rate in the area is ‘unusual but not unparalleled’.
Cutler has also demonstrated that the inquiry miscalculated the dose of radiation received by local children. A meeting held at the DHSS since the publication of the report was told that the inquiry had made an incorrect assumption about the dose to the bone marrow, an error which might mean children living near the plant had got much higher doses of radiation than the Black inquiry assumed.
This error is important; it was the estimate of doses to local children that led the inquiry to rule out radiation as the cause of their cancer. The researchers worked out how many cancers they would expect in the villages if dissident scientists like Alice Stewart were correct about the risk. Because they found more cases than this number, they decided radiation could not be the cause. Two other explanations are equally possible: that the inquiry team had underestimated the dose in just the way it now appears they did; or that low-level radiation is more damaging even than critical scientists like Alice Stewart have suggested.
The publication of the Black report has not in any way exonerated Windscale or given a clean bill of health to low doses of radiation. The fact remains that, since the 1950s, a substantial body of evidence has emerged to suggest low-level radiation is very damaging indeed. More and more scientists have added their voices to the growing chorus of concern.
Curiously, one person who seems unaware of these developments is the government’s spokesman on the bomb tests, junior Defence Minister Adam Butler. The risks of radiation have been known for years, he said in December 1984, categorically rejecting the suggestion that the British didn’t know what they were doing in the 1950s.
‘I believe that what I have said … confirms that the international scientific view of the acceptability of the risks of exposure to ionising radiation has not altered, despite the vastly greater body of data on its effects which has been collected and examined during the period since then,’ he announced inexplicably to the House of Commons.
Chapter Eight
The cloud drifts on
The British government’s vehemence in rejecting the allegations of the veterans has been strangely unaffected by the mass of evidence which has emerged since their campaign in the UK started at the end of 1982. Official statements betray not a scintilla of doubt; if anything, the line has become tougher since the questions first began.
Several plausible explanations can be advanced for this state of affairs. One is the traditional reluctance of any current administration to admit faults in its predecessors, even if the events concerned happened thirty years ago and no contemporary ministers are implicated. This convention has a logical, if self-interested origin: each government hopes that its restraint in relation to previous administrations will be emulated by its own successors. It is certainly the case that a degree of loyalty is involved; although the bomb was given the go-ahead by Labour politicians, it was tested in the atmosphere exclusively by Conservatives.
The spectre of numerous compensation claims is another important factor. Although the government is protected by statute from claims for compensation by ex-servicemen for injuries sustained during their period of service, any admission that the tests had led to ill-health would inevitably spark off demands that an exception be made for the men who served at the bomb tests. Since 20,000 men took part, most of them servicemen, such claims could be substantial.
The most powerful motivation to resist the veterans’ claims emerges clearly, however, when you look at the direction in which the evidence points. The description of the immediate effects of the bombs given by veterans from various tests – reddening of the skin resembling sunburn - can be explained by heat and blast from the weapons, particularly at the hydrogen tests, where the energy released was immense. In themselves, these effects tell us little about levels of radiation.
Certain bits and pieces of evidence undoubtedly suggest that men were exposed, on some occasions, to much higher levels of radiation than the government has admitted. Alice Stewart’s study of the Christmas Island veterans, published in 1982, contained reports of men suffering from cataracts in middle age. Professor Rotblat pointed out at the time that the occurrence of this disease, usually found only in the elderly, suggested exposure to fairly high levels of radiation.
This situation has an exact parallel in the US. The Defense Nuclear Agency insists American test veterans got only a tenth of the level now permitted annually for radiation workers; Dr Rosalie Bertell says some of the men have symptoms consistent with doses sixty times greater than this amount.
Evidence given to the Australian Royal Commission supports the hypothesis that certain individuals at the British tests - aircrew who flew through atomic clouds, for instance - received fairly high dose
s of radiation. But if these instances are left to one side, the question remains as to whether large numbers of men could have been exposed to high levels of radiation.
It is clear that some people who appear in official records as receiving no dose of radiation at all nevertheless were exposed – the tasks they were given were mistakenly thought to be safe and they were simply not given monitoring equipment, or it was not collected in. It is also clear that the monitoring equipment used was not as reliable as the British government likes to claim. The evidence is that one of the methods used - film badges – may have underestimated individual doses by 40 per cent.
But there is little evidence to suggest that the doses recorded in official papers are out by a significant degree. What seems more likely is that, with spectacular exceptions, the veterans got doses a little larger than the records suggest but still smaller than those received routinely every year by workers in the nuclear industry.
Once you arrive at this point, it becomes clear that the British government has the strongest possible motive to resist claims by the veterans that radiation has damaged their health. If men exposed to such tiny doses of radiation have suffered elevated rates of disease, what future is there for the nuclear industry, which exposes its workers annually to more radiation than most of the veterans received once in their lifetimes?
The British government must now fear that Conservative ministers did more in the 1950s than explode a series of nuclear weapons in Australia and the Pacific. They may have unintentionally planted a time-bomb under every nuclear power station in Britain.
If the government was committed to a searching and unimpeachably independent study into the veterans’ claims about the bomb tests, it chose a curious way of going about it. Instead of selecting a university department to carry out the study, it gave the job to a body with close links to the nuclear industry. It was a peculiar choice for a study whose results could, in the end, do untold damage to that industry.