Ecological Study on Digestive and Bladder Cancer in Relation to the Level of Trihalomethanes in Drinking Water

Complex mixtures of disinfection by-products are formed in drinking waters when chlorine is used as disinfectant, among which are found trihalomethanes. Trihalomethanes are very stable in the natural environment and are moderately lipophilic. Thus they accumulate in the human organism, which may be related to a greater risk of certain cancers.The objective of this study is to investigate the association between trihalomethanes exposure (e.g. total trihalomethane concentration, TTHM; occurring as chlorination of drinking water) and bladder and certain digestive cancers. Data were collected on different districts inside a Mediterranean city (Valencia, Spain). Samples were analyzed via head-space and electron capture detector to determine TTHM concentrations. The relative influence of different factors has been evaluated. Our results suggest a possible association between bladder cancer in women and trihalomethanes’ exposure at levels below the European Community legal limit; that, at least, advices that such studies deserves more attention.