226Ra removal processes in Croatian water facilities.

Today, bottled and tap drinking water mainly originates from underground waters which might contain considerable amounts of naturally occurring radionuclides. One of the most toxic radionuclide in drinking water is 226Ra. Following the metabolism of calcium, it could be deposited into the bone where, in sufficient amount, it could cause bone sarcoma. Although current drinking water preparation techniques are not specifically designed for 226Ra removal they can reduce certain amounts of 226Ra. This paper presents the efficacy of standard water preparation processes (granular activated carbon, green sand and fixed-leaf filtrations) currently used by Zagreb water supply and two Croatian water bottlers in removing 226Ra. Compared with other studies, the results of our study show low to moderate efficacy in lowering the 226Ra concentration in drinking water. Even so, 226Ra concentrations still comply with the recommendation of the Word Health Organisation (WHO) and with Croatian legislation.