McMichael A J
Department of Community Medicine, University of Adelaide, S.A., Australia.
IARC Sci Publ. 1990(104):298-306.
The relatively low concentrations of the various natural and man-made contaminants of drinking water, together with the methodological problems of obtaining valid and complete exposure histories for individuals and of controlling for confounding factors, have made it difficult for epidemiological studies to detect and estimate risks of cancer. Nearly all studies to date, with some exceptions for the halogenated hydrocarbons, have been at the ecological level. For these and other reasons, quantitative risk assessment of the cancer risks due to this complex environmental exposure remains rudimentary. If, eventually, risks are assessed to be non-trivial, primary prevention could be sought by alternative choices of either methods of water treatment or of water sources. However, since we cannot eliminate all trace carcinogens from our environment, we need simultaneously to minimize both the exposures and the biological impact of such exposures. The latter will require studies of cancer chemoprevention, using biochemical and molecular epidemiological approaches.
饮用水中各种天然和人为污染物的浓度相对较低，再加上获取个体有效且完整的暴露史以及控制混杂因素存在方法学问题，使得流行病学研究难以检测和估计癌症风险。几乎所有迄今为止的研究，除了卤代烃有一些例外，都是在生态层面进行的。由于这些及其他原因，对这种复杂环境暴露导致的癌症风险进行定量风险评估仍处于初级阶段。如果最终评估出风险不可忽视，那么可以通过选择替代的水处理方法或水源来寻求一级预防。然而，由于我们无法从环境中消除所有痕量致癌物，我们需要同时尽量减少此类暴露及其生物学影响。后者将需要利用生化和分子流行病学方法开展癌症化学预防研究。
