P-562 Introduction: Health risks from exposure to drinking-water pollution (DWP) may be considerable, particularly in children. Measures to reduce the impact of water on children's health were proposed at the Fourth Ministerial Conference on Environment and Health in Budapest, Hungary. Furthermore, one of the Regional Priority Goals of the Children's Environment and Health Action Plan for Europe is to ensure water quality and adequate sanitation. In this context, the project “Implementing Environment and Health Information System in Europe” (ENHIS) analysed the feasibility of using the Health Impact Assessment (HIA) methodology for DWP in a set of European countries, focussing mainly on children. Methods: A literature review based on international water expert advice was carried out to identify relevant DW pollutants, to select appropriate health outcomes and to obtain the most robust and pertinent Exposure-Response functions (ERFs) from the available epidemiological studies. Biological pollution, turbidity and chemical pollution (arsenic, lead, disinfection by-products, nitrates, pesticides and copper) were studied. The findings were compiled and discussed with international water experts to decide on the feasibility of implementing HIA for each pollutant. Results: The relationship between the selected pollutants in DW and health effects is not documented well enough to conduct a HIA. For biological pollution, there is a lack of available ERFs for each potential pathogen, due to the impossibility of finding the DWP origin of the infections observed on numerous occasions. In addition, the pathogens are not routinely monitored in DW and there is no quantitative relationship between positive results of faecal indicators and occurrence of pathogens in DW. In case of turbidity, any general quantification between this parameter values and health risks is unfeasible. As regards chemical pollution, epidemiological studies reported quantitative associations for arsenic, disinfection by-products, lead and pesticides, but not for nitrates and copper. However, findings were controversial in many aspects especially when considering chronic exposure. Discussion and Conclusions: The lack of specific ERFs hinders the development of HIA of DWP on European population and more epidemiological research is needed to provide them. Other approaches, such as Health Risk Assessment and/or Environmental Burden of Disease, can be used to quantify the adverse human health effects due to DWP for public health purposes. All ENHIS project partners. The ENHIS programme is supported by the European Commission DG SANCO (Grant: SPC 2003112). Elena Boldo was supported by a grant from the Regional Ministry of Education, Madrid, Regional Governement, Spain (Orden 7580/2003).