摘要:The formation of Disinfection By-Products (DBPs) in drinking water results from the reaction of chlorine or other disinfectants added to the water with naturally occurring organic materials, and has raised concerns during the last decades because these compounds are harmful for human health. During the present work, the formation of different categories of DBPs was investigated in four water treatment plants (WTP) using chlorine as disinfectant, and in selected points of the distribution network of Athens, Greece, which is supplied from these four WTP, during a period of ten years. The concentrations of DBPs were generally low and the annual mean concentrations always well below the regulatory limit of the European Union (EU) for the total trihalomethanes (TTHMs). The haloacetic acids (HAAs) have not been regulated in the EU, but during this investigation they often occurred in significant levels, sometimes exceeding the levels of TTHMs, which highlights the importance of their monitoring in drinking water. Apart from THMs and HAAs, several other DBPs species were detected at much lower concentrations in the chlorinated waters: chloral hydrate, haloketones and, in a limited number of cases, haloacetonitriles.