Baysson H, Laurier D, Tirmarche M, Valenty M, Giraud J M
Institute for Protection and Nuclear Safety, Human Health Protection, Fontenay aux Roses, France.
Occup Environ Med. 2000 Mar;57(3):188-94. doi: 10.1136/oem.57.3.188.
An excess of cancer was suspected by workers of the metallurgy department at the French Atomic Energy Commissariat (CEA) after several deaths from cancer were reported in 1983 and 1984. After a descriptive study performed by the CEA in 1985 the results of which were not conclusive enough to put an end to the controversy, the present cohort study was undertaken in 1989.
As no specific exposure, or a precise cancer site was suspected, it was decided to include all subjects who had worked at the metallurgy department for at least 1 year between 1950 and 1968. The cohort was followed up to 31 December 1990. Individual occupational exposures were determined retrospectively for each year from 1950 to 1990, both qualitatively (annual job, and hazard records, and assistance from former workers) and quantitatively (for external radiation). On the basis of these exposures, three types of occupational tasks were identified: handling of chemicals, radionuclides, and external radiation. Standardised mortality ratios (SMRs) were calculated to estimate the risk of death, and the existence of an association between risk of cancer and each of the three tasks was tested.
The cohort included 356 workers, followed up for an average of 30 years (total of 10,820 person-years). The number of deaths from all causes and from all cancer sites were respectively 44 and 21. No excess of cancer deaths was found for the study period (SMR 0.77), nor was there a peak in 1983-4. The risk of death from all cancer sites increased with the duration of exposure to chemicals.
The results do not justify the workers' impression of an excess of cancer. They suggest, however, that the duration of work at some tasks that involved handling chemicals may be an indicator of risk of cancer. Communication to the workers during the study played an important part in reducing their concern, contributing to their better understanding of the results.
1983年和1984年报告了几例癌症死亡病例后，法国原子能委员会（CEA）冶金部门的工作人员怀疑存在癌症过量情况。1985年CEA进行了一项描述性研究，但其结果不足以消除争议，于是在1989年开展了本次队列研究。
由于未怀疑有特定暴露或精确的癌症部位，决定纳入1950年至1968年间在冶金部门工作至少1年的所有受试者。该队列随访至1990年12月31日。从1950年至1990年每年回顾性确定个体职业暴露情况，包括定性（年度工作、危险记录以及 former workers的协助）和定量（针对外照射）。基于这些暴露情况，确定了三种职业任务类型：化学品处理、放射性核素处理和外照射。计算标准化死亡比（SMRs）以估计死亡风险，并检验癌症风险与这三种任务中每一种之间是否存在关联。
该队列包括356名工人，平均随访30年（总计10820人年）。所有原因和所有癌症部位的死亡人数分别为44人和21人。在研究期间未发现癌症死亡过量情况（SMR 0.77），1983 - 1984年也没有峰值。所有癌症部位的死亡风险随着接触化学品时间的延长而增加。
结果并不支持工人关于癌症过量的印象。然而，研究表明，从事某些涉及化学品处理任务的工作时间可能是癌症风险的一个指标。研究期间与工人的沟通在减轻他们的担忧方面发挥了重要作用，有助于他们更好地理解研究结果。
