Uranium and 226Ra in drinking water supplied by Finnish waterworks

In a survey on uranium and 226Ra concentrations in water distributed by Finnish waterworks, 548 samples were analysed that covered drinking water networks servicing 84% of all consumers. Among all consumers, the mean and median uranium concentrations at the point of use were 0.58 and 0.15 g L–1. The mean uranium concentration in drinking water produced from groundwater was 0.88 g L–1, and when surface water was used in production the mean concentration was only 0.15 g L–1. 226Ra concentrations were generally below our detection limit of 0.01 Bq L–1. The annual effective doses to the public arising from these radionuclides were only a few microsieverts, and the 0.1mSv limit laid down in the EU Drinking Water Directive was not exceeded in any of the studied water distribution networks.