Waters in Croatia between practice and needs: public health challenge.

AIM To describe waters monitoring in Croatia and legislation status for their evaluation, and to present health-relevant data and long-term analysis of the Drava river water, which is used in drinking water production. METHODS Survey of databanks of various Croatian institutions related to waters, and physical and chemical analysis of 13 surface water pollutants, applying HRN ISO laboratory methods. RESULTS Since 1992 until 2000, water systems had 10% of contaminated samples, whereas local community and private water sources had 30% of such samples. Since 1981, 84 waterborne epidemics have been registered, affecting 7,581 people with predominantly gastrointestinal problems. The Drava river monitoring revealed that lead, cadmium, and mercury concentrations have constantly exceeded, whereas nickel and copper remained within allowed values for the Drava river to be classified into the second category of surface waters. Both nitrates and nitrites have been increasing with time, nitrates exceeding and nitrites remaining within guideline values. Total phosphorus and nitrogen concentrations also increased with time, still being below allowed maximum values. Chemical oxygen demand has been decreasing. Alkalinity has been satisfactory. Salt burden has been increasing. Both drinking water quality assessment and surface water monitoring in Croatia use less parameters then recommended by World Health Organization or signed conventions. CONCLUSION The quality of Drava water has been improving, but still does not fully conform to the second category of surface water. More parameters should be used in its monitoring, as recommended by EU conventions and laws.