Environmental exposure, chlorinated drinking water, and bladder cancer.

Environmental and/or occupational factors have been proposed to play a critical role in urological malignancies and, in particular, in bladder cancer. Epidemiological studies have demonstrated with sufficient evidence that factors such as smoking and exposure to aromatic amines, paints and solvents, leather dust, inks, some metals, polycyclic aromatic hydrocarbons, combustion products, or diesel exhaust fumes are associated with the development of bladder cancer. Candidates with an uncertain potential for inducing this type of cancer include dietary factors, specifically fats and cholesterol, and the exposure to contaminants in drinking water. This chapter will describe and discuss the respective literature on environmental and occupational factors linked to carcinogenesis in bladder cancer. For several reasons, the potential effects of tea and coffee consumption will also be considered. A solid epidemiological evaluation of environmental and occupational factors linked to carcinogenesis has to meet many challenges: the number of confounding factors is often large, exposure needs to be determined retrospectively, and elevation of the attributable risk is low in most cases. In view of the long-term exposure of the vast majority of the population to, for instance, drinking- water contaminants, however, the impact of even small elevations of risk warrants evaluation. This complex task needs comprehensive approaches on a large scale including modern analytical, molecular biological and epidemiological methods.