Mortality and occupational exposure to radiation: first analysis of the National Registry for Radiation Workers.

Abstract

States indicated lower risk estimates than the com-Objective-To study cause specific mortality mission recommends, and when the American data of radiation workers with particular reference to are combined with our analysis the overall risks are associations between fatal neoplasms and level of close to those estimated by the commission. This exposure to radiation. first analysis of the National Registry for Radiation Design-Cohort study. Workers does not provide sufficient evidence to Setting-United Kingdom. justify a revision in risk estimates for radiological Subjects-95 217 radiation workers at major sites protection purposes. of the nuclear industry. Main outcome measure-Cause of death. Results-Most standardised mortality ratios were Introduction below 100: 83 unlagged, 85 with a 10 year lag for ali Estimates of the risks of ionising radiation rest causes; 84 unlagged, 86 lagged for all cancers; and 80 mainly on evidence from Japanese atomic bomb for all known other causes, indicating a "healthy survivors and from people exposed for medical reasons. worker effect." The deficit of lung cancer (75 These groups provide information on risks from unlagged, 76 lagged) was significant at the 0-1% exposure to high doses at high dose rates. There is little level. Standardised mortality ratios were signifi-direct evidence of the effects of lower doses and dose cantly raised (214 unlagged, 303 lagged) for thyroid rates typical of occupational exposures. To provide cancer, but there was no evidence for any trend with such direct evidence the National Radiological Protecexternal recorded radiation dose. Dose of external tion Board, after extensive consultation with the radiation and mortality from ali cancers were weakly nuclear industry and other interested groups, set up correlated (p= 010), and multiple myeloma was the National Registry for Radiation Workers in 1976 as more strongly correlated (p=0.06); for leukaemia, the national study of radiation workers, following National Radiological excluding chronic lymphatic, the trend was signifi-individuals through different employments.' Protection Board, Chilton, cant (p=0-03; all tests one tailed). The central The first analysis of the registry covers over 95000 Didcot OXII ORQ estimates of lifetime risk derived from these data radiation workers whose collective dose from external were 10-0% per Sv (90% confidence interval <0 to radiation is about 3200 man Sv. The essentials of the GM Kendall,PHD, principal 24%) for all cancers and 0-76% per Sv (0-07 to 24%) for study are described in this paper; more details can be scientific officer leukaemia (excluding chronic lymphatic leukaemia). found in a separate report.2 C R Muirhead, PHD, These are, respectively, 2-5 times and 1-9 times the BMJlf 1992;304:220-5 combined cohorts of radiation workers in the United (a) and (d) from

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

“…No association was found in studies of the United Kingdom Atomic Energy Authority workers (Fraser et al, 1993) or the Atomic Weapons Establishment (Beral et al, 1988). The correlation found in the analysis of the National Registry of Radiation Workers (Kendall et al, 1992a) can be attributed to the inclusion of the Sellafield workers in that study (Kendall et al, 1992b).…”

“…A significant excess for thyroid cancer has not been reported in other studies of workers in specific nuclear plants (Beral et al, 1988;Fraser et al, 1993;Gilbert et al, 1993), though in the study of employees of the United Kingdom Atomic Energy Authority there were five deaths among nonradiation workers, against 2.1 expected. An excess of thyroid cancer was found in the first analysis of data from the National Register for Radiation Workers (Kendall et al, 1992a), but four of the nine deaths from thyroid cancer in that study were among Sellafield workers (Kendall et al, 1992b) and are included in our study. If these are removed the remaining excess is not significant (five against about three expected).…”

“…The workers included in the study have been included in combined analyses of UK nuclear workers (Kendall et al, 1992a;Carpenter et al, 1994), but these gave only limited results for Sellafield workers specifically and neither included data on cancer incidence. The radiation doses that have been accumulated by workers at the Sellafield plant, since it opened in 1947, are higher, on average, than those experienced by workers at other nuclear facilities in the UK (Beral et al, 1988;Fraser et al, 1993) and in the USA Wing et al, 1991 (Table VII).…”

Nuclear industry family study: methods and description of a United Kingdom study linking occupational information held by employers to reproduction and child health

“…These databases are of a generally high quality, not only because radiation dose records have to be maintained for United Kingdom regulatory purposes, but also because the data have been used previously for several large epidemiological studies of the workers themselves. [15][16][17][18][19][20][21][22] Data were supplied for all those responding who had ever had, or who had ever attempted to have, children, and were linked by computer to the cleaned, coded, and validated questionnaire based data with the subjects' unique personal identifiers. Thus the researchers were blind to the occupational exposure status of the workers when collecting data on reproduction and child health outcomes.…”

“…1-4 6 8 10 14 Generally, when an occupational hazard is suspected the health of the workers in the industries concerned is studied directly: for example, within the nuclear industry, several cohort studies have investigated the relation between cancer and mortality in relation to exposure to ionising radiation at work. [15][16][17][18][19][20][21][22] The nuclear industry family study takes this one step further, linking the occupational exposure of workers to their pregnancies and the health of their children.…”