Tomatis L
International Agency for Research on Cancer, Lyon, France.
Ann N Y Acad Sci. 1988;534:31-8. doi: 10.1111/j.1749-6632.1988.tb30086.x.
The differences between cancers that occur as a consequence of occupational exposure and other cancers are not only their preventability but, more importantly, their social unacceptability. Occupational cancer occurs, by definition, among individuals who have been exposed to carcinogens because of their occupation, and most, if not all, of these individuals are drawn from the less favoured social classes. This is probably one reason why mortality from cancer and from all causes is greater in people in classes IV and V than in those in I and II. We cannot precisely quantify the proportion of cases, among the total number of cancer cases observed, attributable to occupational exposures. It is very likely, however, in some of the most industrialized countries, although not in certain developing countries, that the number of those cancers that are indisputably due to occupational exposure is not increasing and is perhaps decreasing. This is due to the combined effect of two factors: the banning of certain chemicals, as, for instance, aromatic amines--even if this did not take place in all countries and, where it did, not at the same time; and improved working conditions, as, for instance, in the case of vinyl chloride. We do not know, however, to what extent low levels of exposure to which the general population is commonly exposed, as well as workers in occupations where levels of exposure to carcinogens have recently been significantly reduced, play a role in the causation of human cancer. While it is important to stress that a large proportion of the chemicals to which humans are exposed, either because of their occupation or in the general environment, and for which experimental evidence of carcinogenicity is available, have not been the object of epidemiological surveys, it is also important to realize that epidemiological methods are generally insufficient to provide reliable information on risks generated by low levels of exposure. It is certainly important to encourage epidemiological surveillance, but it should at the same time be made clear that the epidemiological approach will never entirely replace the considered use of experimental data in the implementation of primary prevention.
职业暴露导致的癌症与其他癌症之间的差异，不仅在于其可预防性，更重要的是其社会不可接受性。根据定义，职业性癌症发生在因职业接触致癌物的个体中，而且这些个体中的大多数（如果不是全部的话）来自社会地位较低的阶层。这可能是第四和第五阶层人群的癌症死亡率及全因死亡率高于第一和第二阶层人群的原因之一。我们无法精确量化在观察到的所有癌症病例中，可归因于职业暴露的病例比例。然而，在一些工业化程度最高的国家，尽管某些发展中国家并非如此，但无可争议地归因于职业暴露的癌症数量很可能并未增加，甚至可能在减少。这是两个因素共同作用的结果：一是某些化学物质被禁止使用，例如芳香胺——即便并非在所有国家都如此，而且即便实施了禁令，时间也不尽相同；二是工作条件得到改善，例如氯乙烯的情况。然而，我们并不清楚，普通人群普遍接触的低水平暴露，以及致癌物暴露水平近期已大幅降低的职业中的工人接触情况，在人类癌症病因中起到何种作用。虽然必须强调，人类因职业或在一般环境中接触的大量化学物质，已有致癌性的实验证据，但尚未成为流行病学调查的对象，同样重要的是要认识到，流行病学方法通常不足以提供有关低水平暴露所产生风险的可靠信息。鼓励进行流行病学监测固然重要，但同时也应明确，在实施一级预防时，流行病学方法永远无法完全取代对实验数据的审慎运用。
