Mortality and cancer incidence of Australian participants in the British nuclear tests in Australia

Our plain-English summary of Mortality and cancer incidence of Australian participants in the British nuclear tests in Australia, by R.T. Gun, J. Parsons, P. Crouch, et al (Occupational and Environmental Medicine, 2008).

The study

• Authors: R.T. Gun, J. Parsons, P. Crouch, P. Ryan, J.E. Hiller
• Journal: Occupational and Environmental Medicine
• Published: 2008;65(12):843-8
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: To investigate the mortality and cancer incidence of Australian nuclear test participants, and to identify any association with exposure to ionising radiation.

Methods: A retrospective cohort study was carried out in which the mortality and cancer incidence rates of participants (n = 10,983) were compared with rates in the general male Australian population. Dose reconstructions were carried out by a panel of health physicists. Mortality and cancer rates were compared with the general population and between groups of subjects categorised by assessed radiation exposure.

Results: All-cause mortality was not raised. Mortality and incidence were significantly raised for cancers of the head and neck, lung, colon and rectum, and prostate, and for all cancers combined. For oesophageal cancer, melanoma, all leukaemias and non-chronic lymphatic leukaemia (non-CLL leukaemia), incidence was significantly raised, but mortality was non-significantly raised. No association was found between radiation exposure and overall cancer incidence or mortality, or with any cancer or cancer deaths occurring in excess.

Conclusions: There is no evidence that the excess cancers and cancer deaths were caused by radiation exposure at the test sites. Possible contributing factors are high smoking prevalence and demographic differences from the Australian population with whom rates were compared. Asbestos is a likely contributor to some cancers in naval personnel.

In plain English

This retrospective cohort study included 10,983 male Australian military and civilian participants in British nuclear tests in Australia (major tests 1952 to 1957; minor trials 1953 to 1963). Deaths were tracked to 31 December 2001; 862 men were never traced. Rates were compared with national rates for Australian men; health physicists estimated doses, but 6% could not be assigned a category. All-cause mortality was not raised (SMR 1.02, 95% CI 0.99 to 1.05). Cancer deaths (SMR 1.18, 95% CI 1.12 to 1.24) and cancer incidence (SIR 1.23, 95% CI 1.18 to 1.28) were raised. Mesothelioma incidence was not significantly raised overall (SIR 1.46, 95% CI 0.95 to 2.14), but 16 of 26 cases were naval personnel, whose incidence was significantly raised (SIR 2.79, 95% CI 1.59 to 4.52). Lung cancer incidence was also highest in naval personnel (SIR 1.50, 95% CI 1.26 to 1.77). Estimated dose showed no trend with overall cancer incidence. The authors concluded radiation did not explain the excess, suggesting smoking (prevalence unknown) and population differences, and considered asbestos in naval vessels the likely source of most naval mesothelioma.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective cohort study comparing death and cancer rates with national rates, plus internal comparisons between groups with different estimated radiation doses
• Who was studied: 10,983 male Australian participants in British nuclear tests in Australia. The 12 major tests took place from 1952 to 1957, and minor trials were run from 1953 to 1963. Of the participants, 7,116 were military (3,097 Navy, 1,245 Army, 2,774 Air Force) and 3,867 were civilians. Participants were defined as those present at a test site during a test or in the 2-year period after a test. Mortality was followed to a cut-off of 31 December 2001. 200 men were censored earlier, and 862 could not be traced at any time after the tests. Cancer incidence was studied for 1982 to 2001 in 8,728 subjects. Females (n = 209) and Aboriginal people were not included.
• Exposure: The main exposure was ionising radiation from the tests. A dosimetry panel estimated doses and placed people in categories: A, less than 1 mSv; B, 1 to less than 5 mSv; C, 5 to less than 20 mSv; D, 20 to 50 mSv; E, more than 50 mSv; and F, insufficient information (695 people, 6%). Asbestos exposure was not measured and no fiber type is named. The authors attributed most naval mesothelioma cases to asbestos in naval vessels. They noted this exposure need not have occurred at the time of the tests, and that some personnel were issued respirators fitted with asbestos filters.
• Main results:
  • Whole cohort, all-cause mortality was not raised: 4233 deaths observed vs 4150.4 expected, SMR 1.02 (95% CI 0.99 to 1.05)
  • Whole cohort, all-cancer mortality was raised: SMR 1.18 (95% CI 1.12 to 1.24), 1465 observed vs 1238.7 expected
  • Whole cohort, all-cancer incidence was raised: 2456 observed vs 2000.3 expected, SIR 1.23 (95% CI 1.18 to 1.28)
  • Whole cohort, mesothelioma incidence was not significantly raised: 26 cases vs 17.8 expected, SIR 1.46 (95% CI 0.95 to 2.14). Mesothelioma deaths were 10 vs 8.2 expected, SMR 1.22 (95% CI 0.58 to 2.23).
  • Naval personnel: 16 of the 26 mesothelioma cases occurred in this group, which had significantly raised incidence, SIR 2.79 (95% CI 1.59 to 4.52). The Discussion prints this figure as 2.70.
  • Naval personnel had the highest lung cancer incidence, SIR 1.50 (95% CI 1.26 to 1.77). Lung cancer incidence was not significantly elevated in Army and Air Force personnel. For the whole cohort, the lung cancer SIR was 1.28 (95% CI 1.16 to 1.41).
  • 79% of the cohort were assigned to the lowest dose category (less than 1 mSv). 6% could not be allocated an exposure category. The estimated mean dose was 2.8 mSv.
  • There was no trend of increasing all-cancer incidence with increasing estimated radiation dose (p = 0.90). Compared with category A, categories B to E combined had an RIR of 0.94 (95% CI 0.84 to 1.06).
  • The only significant dose trend was for chronic lymphatic leukaemia (p = 0.02). The article states that CLL is not considered a radiogenic cancer. The overall SIR for CLL was non-significantly elevated (1.28, 95% CI 0.83 to 1.87).
• The authors' conclusion: The authors concluded there is no evidence that the excess cancers and cancer deaths were caused by radiation exposure at the test sites. They named a high smoking prevalence and demographic differences from the comparison population as possible contributing factors. They considered asbestos in naval vessels the likely source of exposure in most of the naval mesothelioma cases. They also considered it likely that asbestos caused some of the lung cancer excess. They stated that a causal link between test participation and non-CLL leukaemia cannot be excluded, although radiation as a cause can be eliminated.
• Limitations the authors state:
  • The actual smoking prevalence in the cohort was not known; the authors could only estimate it hypothetically
  • Non-cancer deaths were probably undercounted by about 4%: the cancer registry search found 42 cancer deaths that the mortality search had missed
  • Comparison with other service personnel, as in the British study, was impracticable because 35% of participants were civilians. National rates were used instead, and these comparisons may be subject to a healthy worker effect.
  • Virtually no monitoring data were available for internal radiation exposure, so computer modelling was used

Topics

Medical terms in this study, explained in our Lexicon: Cohort Study, Incidence, Esophageal Cancer.

Related studies

• Mortality among U.S. military participants at eight aboveground nuclear weapons test series — J.D. Boice, S.S. Cohen, et al. (2022)
• Yield of Low-Dose Computerized Tomography Screening for Lung Cancer in High-Risk Workers: The Case of 7189 US Nuclear Weapons Workers — S.B. Markowitz, A. Manowitz, et al. (2018)
• Asbestos-related cancer in naval personnel: findings from participants in the British nuclear tests 1952-1967 — R.T. Gun, G.M. Kendall (2023)
• Solid cancer mortality associated with chronic external radiation exposure at the French atomic energy commission and nuclear fuel company — C. Metz-Flamant, E. Samson, et al. (2011)
• Update of mortality and cancer incidence in the Australian petroleum industry cohort — R.T. Gun, N. Pratt, et al. (2006)
• Comparison of x-ray films and low-dose computed tomographic scans: demonstration of asbestos-related changes in 2760 nuclear weapons workers screened for lung cancer — A. Miller, S.A. Widman, et al. (2013)

Browse more research in Occupational and Environmental Medicine, or return to medical research.