The adequacy of current occupational standards for protecting the health of nuclear workers

It will be clear from the aforegoing that occupational standards have varied over the past 30-40 years since the beginnings of the nuclear industry. Our perception of risk rates for cancer mortality and genetic effects has changed, such that the rates have been constantly revised upwards. Logically, dose limits should have been reduced in proportion, but this assumes a constant approach to the "tolerability" or "acceptability" of risk and this has not been demonstrated. Dose limits are not seen by management in the nuclear industry as the only plank in the structure of radiation protection; emphasis is also being given to the "optimization" ethic. In these circumstances a good test of the efficacy of the system of radiation control in limiting health effects is needed. As can be seen, no such study is available and, given the doses received and the numbers of workers involved, it is unlikely that any epidemiologic study, apart from studies on miners, will have sufficient statistical power to be totally unequivocal. However, some studies have shown cancer mortality associations with radiation exposure that are significant. Probably the best way to mitigate the inherent drawbacks in these studies is to pool data-sets, and this is being done. Other improvements will include estimates of cancer incidence in countries with cancer registries (e.g., U.K., Canada, and Sweden) and to perhaps go beyond epidemiologic data to consider sensitive biologic markers as indices of exposure. Overall the conclusion must be that the radiation industry cannot be complacent and for some tasks in the processes involved (e.g., uranium mining) there is strong evidence of a history of unacceptable health effects occurring.