Epidemiological studies of radiation workers: preliminary communication.

British Nuclear Fuels Limited has embarked on a study of the mortality data among those of its workforce who were employed prior to 1 January 1976. The study covers a total population of about 41 000 current and ex-employees, but is initially concerned with a radiation worker cohort of 7500 at the Sellafield establishment where the highest radiation doses are received. Tracing of the health status of ex-employees has been undertaken using the services provided by the Office of Population Censuses and Surveys (OPCS) and the Department of Health and Social Security (DHSS) and it is expected that ultimately the level of trace will be better than 97%. Mortality data not specifically related to radiation workers are included and relate to male deaths among serving staff and pensioners during the years 1962-1978. Those observed deaths (O) are compared on an age standardized basis with those expected (E) from the general population, the ratio O/E being about 1 for all cancers and less than 1 for non-cancer deaths. This pattern is consistent with the well known 'healthy worker' effect seen in industry.