Cancer mortality in relation to monitoring for radionuclide exposure in three UK nuclear industry workforces

Abstract

Summary Cancer mortality in 40 761 employees of three UK nuclear industry facilities who had been monitored for extemal radiation exposure was examined according to whether they had also been monitored for possible intemal exposure to tritium, plutonium or other radionuclides (uranium, polonium, actinium or other unspecified). Death rates from cancer were compared both with national rates and with rates in radiation workers not monitored for exposure to any radionuclides. Among workers monitored for tritium exposure, overall cancer mortality was significantly below national rates [standardized mortality ratio (SMR) = 83, 165 deaths; 2P = 0.02] and none of the cancerspecific death rates was significantly above either the national average or rates in non-monitored workers. Although the overall death rate from cancer in workers monitored for plutonium exposure was also significantly low relative to national rates (SMR = 89, 581 deaths; 2P = 0.005), mortality from pleural cancer was signfficantly raised (SMR = 357, nine deaths; 2P = 0.002); none of the rates differed significantly from those of non-monitored workers. Workers monitored for radionuclides other than tritium or plutonium also had a death rate from all cancers combined that was below the national average (SMR = 86, 418 deaths; 2P= 0.002) but prostatic cancer mortality was raised both in relation to death rates in the general population (SMR = 153, 37 deaths; 2P = 0.02) and to death rates in radiation workers who had not been monitored for exposure to any radionuclide [rate ratio (RR) = 1.65; 2P = 0.03]. Mortality from cancer of the lung was also significantly increased in workers monitored for other radionuclides compared with those of radiation workers not monitored for exposure to radionuclides (RR = 1.31. 164 deaths; 2P = 0.01). For cancers of the lung, prostate and all cancers combined, death rates in monitored workers were examined according to the timing and duration of monitoring for radionuclide exposure, with rates of radiation workers not monitored for any radionuclide forming the comparison group. In tritium-monitored workers, RRs for prostatic cancer varied significantly according to the number of years in which they were monitored (2P = 0.03). In workers monitored for plutonium exposure, RRs for all cancers combined increased with the number of years in which they were monitored (2P = 0.04) and with the number of years since first monitoring (2P = 0.0003). There was little suggestion of systematic variation in RRs for workers monitored for other radionuclides in relation to the timing or duration of monitoring. nor did it appear that their raised rates of cancer of the lung and prostate were explained by extemal radiation dose. These analyses of cancer mortality in relation to monitoring for radionuclide exposure reported in a large cohort of nuclear industry workers suggest that certain pattems of monitoring for some radionuclides may be associated with higher death rates from cancers of the lung, pleura. prostate and all cancers combined. ...

Cancer mortality and morbidity among plutonium workers at the Sellafield plant of British Nuclear Fuels

“…Compared with the former group, there were excesses of deaths from cancers of the pleura, breast, and ill-defined and secondary sites, but for none of these sites was there evidence that risk was associated with cumulative dose. Because of the indications from a parallel study of an association between the time since first monitoring for plutonium and the risk of deaths from all malignant neoplasms considered (Carpenter et al, 1998), we repeated those analyses using our data for the Sellafield workforce. Comparing plutonium workers with other radiation workers, the ratio of the death rates in the two groups in the periods <10 years, 10Ð19 years and ³20 years since monitoring started were 0.82, 1.03 and 1.12.…”

The non-Hodgkin lymphomas: A review of the epidemiologic literature

“…No significant associations were reported in Sellafield, Atomic Weapons Establishment, Hanford, Japanese, or combined US, UK and Canadian cohorts. [305][306][307][308][309][310][311][312] Furthermore, there were no trends in NHL risk based on cumulative radiation dose in these cohorts. Other studies have reported no significant associations among US military personnel who participated in atmospheric nuclear weapons tests, 313 participants in the UK atmospheric nuclear weapons tests, 314 residents living near nuclear installations, 315,316 uranium miners, 317 dental workers 318 or cohort members of the National Dose Registry of Canada.…”

The cancer epidemiology of radiation

“…Carpenter et al (1998) examined a large cohort of British nuclear industry workers who had been monitored for internal exposures and found that certain patterns of monitoring may be associated with particular cancers; however, the measures of exposure were relatively crude. Omar et al (1999) studied the group of workers exposed to plutonium at the Sellafield nuclear installation in Britain for whom assessed organ-specific doses due to plutonium were available, and concluded that the plutonium workers were not at an increased risk of cancer when compared with other radiation workers.…”