Lambert B E
Department of Radiation Biology, Medical College of St. Bartholomew's Hospital, University of London, England.
Occup Med. 1991 Oct-Dec;6(4):725-39.
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.
从上述内容可以清楚地看出，自核工业起步以来的过去30至40年间，职业标准一直在变化。我们对癌症死亡率和遗传效应风险率的认知发生了变化，以至于这些风险率不断向上修正。从逻辑上讲，剂量限值本应相应降低，但这假定了对风险“可容忍性”或“可接受性”的恒定态度，而这一点并未得到证实。核工业管理层并不认为剂量限值是辐射防护体系的唯一支柱；“优化”原则也受到重视。在这种情况下，需要对辐射控制体系在限制健康影响方面的有效性进行良好的检验。可以看出，目前尚无此类研究，而且鉴于所接受的剂量和涉及的工人数量，除了对矿工的研究外，任何流行病学研究都不太可能有足够的统计效力来做到完全明确。然而，一些研究已经表明癌症死亡率与辐射暴露之间存在显著关联。减轻这些研究中固有缺陷的最佳方法可能是汇总数据集，目前正在这样做。其他改进措施将包括对设有癌症登记处的国家（如英国、加拿大和瑞典）的癌症发病率进行估计，并且可能超越流行病学数据，将敏感的生物标志物作为暴露指标来考虑。总体而言，必须得出的结论是，辐射行业不能自满，而且在所涉及的过程中的某些任务（如铀矿开采），有确凿证据表明存在不可接受的健康影响历史。
