Lead in drinking water of Vienna in comparison to other European countries and accordance with recent guidelines

Due to the decrease of lead intake via inhalation route, the oral route, particularly from drinking water in cities with lead installations, gains relative importance. In two surveys a total of 288 objects were investigated and 1768 samples were analysed. The first series with 51 objects using a field experimental approach systematically investigated the effects of daytime, floor and flushing. Because only objects built before 1945 and suspected of lead plumbing were chosen, the first series approaches worst case conditions. The second series investigating 237 randomly chosen objects stratified according to time of consumption should allow inferences about the present situation in Viennese households. Each sampling procedure comprised one sample without flushing and three further samples with flushing of 1 l, 3 l and 10 l, respectively. Statistically significant decreases occurred between these flushing conditions. The sampling data of the upper floors showed significantly higher lead contents compared to the lower floors, which indicates that house installations are the main causes of lead contamination in Viennese drinking water. In comparison to other European countries the percentage of samples exceeding the guideline levels (50 micrograms/l as current value and 10 micrograms/l as target value) was lower.