Preface

Writing of the book on occupational canceris motivated fi rst of all by the fact that a greatproportion of occupational cancers are not recognized even in post-industrial countries. In fact, onlysome rare tumor types with a very strong association with certain exogenous factors, such as pleural malignant mesothelioma with asbestos exposure, liverangiosarcoma with vinyl chloride exposure, and intestinal type sinonasal adenocarcinoma with hardwood exposure, are considered as occupational diseases on a regular basis. These tumors are accepted asworkrelated because they rarely exist in the non-exposed, while occupational etiology of common cancers ismore diffi cult to recognize. The best example is asbestos-related lung cancer: On the basis of epidemiology the numbers can be estimated, but muchfewer cases than expected are identifi ed and reported, although there are some differences between countries. For most common cancer types the fraction attributable to occupational factors is small and risk ratios low, but together with life-style and genetic factors, they may signifi cantly increase an individual’s personal cancer risk. Awareness of occupational and other risk factors offers an opportunity for preventive actions, such as encouragement for thecessation of smoking in order to reduce lung cancerrisk and caution with hormone replacement therapy to lessen a person’s breast cancer risk. The most important consequence of the identifi cation of occupational causes of cancer, however, remains with theopportunity to eliminate the relevant exposures – or at least reduce them to a level entailing no risk.