This issue of RaT is mainly devoted to DU, but we must include a review of an earlier military exposure problem, that of the UK servicemen who were exposed at the nuclear bomb test sites in the Pacific (Christmas Island, now Kiribati) and at Maralinga in Australia. US Test veterans with cancer are automatically given pensions on the basis that their cancer may have been caused by the radiation but their counterparts in the UK have great difficulty getting justice at the hands of the MoD and pensions agencies. In just the same way as the MoD are biasing their responses to the Gulf War veterans and Gulf War syndrome they used bogus studies of cause and effect to deny the problems experienced by the Test veterans, with whom LLRC has often talked.
In November 2002 we gave expert evidence at a services pension appeals tribunal on behalf of Eva Adshead, whose late husband, Gerald, was an RAF driver who witnessed the Antler series of atomic tests at Maralinga in 1957.
Our evidence included an analysis of epidemiological studies by Sarah Darby and Richard Doll, on which the MoD's case relied. The tribunal accepted that these studies were significantly flawed, so there's some hope for further successful appeals.
Mr Adshead died in 1999 from a malignant brain tumour. His wife Eva was refused a war widow's pension because it was deemed unlikely that the exposure at Maralinga, which did not register on the film badge dosimeter, could have been sufficient to result in the cancer.
LLRC has always argued that, for the test veterans, film badge doses are irrelevant because the badges only register external radiation, whereas the hazard was in the internal dose from fallout material. The exposure in this case was from material Mr Adshead inhaled while he was in the test area. All this is familiar stuff for RaT readers. The arguments in the case involved two epidemiological studies of the UK Test Veterans undertaken by Darby and Doll in 1988 [1] and in 1993 [2]. Sarah Darby, lead author on these papers, collaborated with Richard Doll and researchers from NRPB. They examined rates of mortality and cancer incidence in UK test veterans compared with a suitable control group.
The first study showed a significantly higher level of leukaemia and multiple myeloma in the test veterans. This caused the MoD to accept that these diseases were radiation related and to admit that the test veterans had a case. The success was short lived, however, for in 1993 Darby, Doll and a new line-up of NRPB researchers published a new study. It used an expanded and altered study group in which the excess leukaemia and multiple myeloma had disappeared. The MoD changed their decisions about awarding pensions and went back to denying any culpability. The tests caused cancer in 1988. In 1993 they did not. What had happened?
This study [1] was published in the British Medical Journal. It examined death from 38 causes in 22347 men who, according to MoD archives, participated in the UK atmospheric tests between 1952 and 1967. Their mortality and cancer incidence was compared with 22,326 matched controls. The numbers are given in the table below.
Study/period | Number of test participants | Leukaemia deaths in whole period | Leukaemia deaths admitted to study | Excess of leukaemia? |
[1] 1952 - 84 | 22,347 | 22 | 22 | Yes |
[1] 1952 - 91 | 21,358 | 28 | 20 | No |
Mortality from all causes was slightly elevated in the veterans (Relative Risk = 1.01) and for cancers was slightly reduced (Relative Risk = 0.96) but for leukaemia and multiple myeloma there were significant excess risks (leukaemia RR = 3.45, based on 22 deaths observed, 6 in controls; multiple myeloma RR = infinite; 6 deaths observed, 0 in controls). For incidence, the risk from leukaemia was also high (RR = 2.43 with 28 cases of disease compared with 11 in the controls) and for multiple myeloma the incidence was 10 in test participants and none in the controls. (Interestingly the incidence of leukaemia decreased with increasing dose!) On the basis of these findings, the military were forced to concede that at least leukaemia and multiple myeloma were caused by the exposures and gave pensions to war widows. Clearly this cost the military relatively little, but it had serious implications for radiation risk models generally, since the participants should not have been developing leukaemia at the film badge doses involved which were generally, like Gerald Adshead's, below 1 mSv. So something had to be done and it was.
This was sold as an update to the first study with seven extra years of data to 1990 during which 6 more men had died of leukaemia and 3 more of multiple myeloma. It was published by NRPB (R-266-1993) and also in the BMJ [2] Its findings were different - the abstract of R-266 concludes:
The suggestion from a previous study that participants may have experienced small
hazards of leukaemia and multiple myeloma is not supported by the additional data and the
excesses observed now appear likely to be a chance finding although the possibility that test
participation may have caused a small risk of leukaemia in the early years after the tests cannot
be ruled out.
This allowed the MoD to argue that they should not have to pay pensions.
Crucial shortcomings
There were, however, crucial shortcomings, revealing that every available trick had been used to minimise the appearance of risk in the veterans.
High risk data excluded
The 1993 study excluded 1520 men who had been part of the 1988 study. They were taken out on the basis that they had no more potential for radiation exposure than the general public, but they had even higher leukaemia incidence and mortality than the other veterans. Their exclusion therefore diluted the effect.
The 1993 study also highlighted a subset of the data - the period between 2 and 25 years after the tests when in the authors' opinion leukaemia risk would be concentrated - ignoring the fact that veteran's leukaemia risks were elevated throughout.
"Healthy squaddie" effect ignored
The so-called "healthy worker" effect bedevils studies of industrial employees where comparisons can only be made with the general population which contains unemployed, unwell and otherwise disadvantaged people; the benefits of being employed tend to mask any detriment from exposure to workplace contaminants. By contrast the 1988 study went to great lengths to match the veterans closely with a control group of servicemen who, like the vets., had not only seen service in the tropics but had also been screened for fitness. This isolated the key factor - participation in the atomic tests. The fitness screening makes it unsurprising that the controls had a very low leukaemia incidence and the figures reveal that taking part in the tests more than wiped out the "healthy worker" effect. The 1993 study, however, compared leukaemia in the veterans with national rates, reducing the apparent effect.
Wrong significance test
Even though every trick in the book was used to minimise the impact of test participation the figures still show that veterans' health was damaged. An unspecified statistical method was used to reduce the significance, but still the findings are statistically significant. LLRC has reanalysed using the more appropriate Poisson statistics, revealing that the rates are highly significant.
Finally, since the results could not be reduced below the conventional significance threshold, the authors claimed that because disease in the veterans showed no correlation with recorded radiation doses the low incidence in the controls was a chance occurrence and that consequently the excess risk was an illusion.
Chris Busby pointed all this out to the Tribunal hearing Gerald Adshead's case and also presented the new 2003 report of the European Committee on Radiation Risk to back up his arguments. The MoD advisor called for a three month recess but the Tribunal refused it and found for the widow, a success for LLRC.
A third study, 2003
This latest report [3] adds a few years' data but shares the flaws of the second study, leading to the same conclusion - that there was no significant excess of leukaemia. As in the second study the excess of multiple myeloma was ignored on the grounds that the original huge excess had been cancelled out by subsequent rising rates among the controls.
Maralinga postscript
50 years on the Australian government is keen to give the Maralinga test site back to its original occupants, the Tjarutja people. They're not sure they want it. The UK did a clean-up in 1967 but more contamination was found and a new project costing £41 million began in 1995. More than 1000 tons of Plutonium contaminated material have been buried in an unlined trench only 8 metres deep in unsuitable geology. The Tjarutja are said to be concerned that still more contamination may be found and that as radiological standards change the present remediation may come to be considered inadequate.
[1] Darby SC, Doll R, Fell TP et al. (1988) A summary of mortality and incidence of cancer in men from the UK who participated in the UK atmospheric nuclear weapon tests and experimental programmes. BMJ 296 332-9
[2] DarbySC, Doll R, Fell TP et al. (1993) Further follow up and incidence of cancer in men from the UK who participated in the UK's atmospheric nuclear weapons tests and experimental programmes'. BMJ 307 1530-5
[3] Muirhead CR, Bingham D et al. (2003) Mortality and cancer incidence 1952-98 in UK partcipants in the UK atmospheric nuclear weapons tests and experimental programmes. NRPB-W27 Chilton: NRPB.Send email to: lowradcampaign@gmail.com with questions or comments about this web site.