Hydrochemical background of 222Rn in surface waters of Lower Silesia (SW Poland)

Abstract

The purpose of the conducted research was to create the first Polish database on 222Rn activity concentration in surface (river) waters in one of Poland’s 16 voivodeships (the highest-level administrative division unit in Poland), and thereby complement the worldwide database on 222Rn activity concentration in such waters. To this end, the research area was limited to Lower Silesian voivodeship (6.4% of the area of Poland; 7.8% of its population), which, in geological terms, can be divided into three parts differing in geological structure, characterised by a decreasing proportion of crystalline rocks on the surface. The ranges of 222Rn activity concentrations measured in these areas were: 0.21–24.44 Bq/dm3 for the Sudetes, 0.08–4.27 Bq/dm3 for the Fore-Sudetic Block, and 0.09–3.37 Bq/dm3 for the Fore-Sudetic Monocline. Based on the obtained 222Rn activity concentrations in river waters, the authors determined the hydrochemical background. It was: 0.26–1.33 Bq/dm3 for the Sudetes, 0.18–0.92 Bq/dm3 the Fore-Sudetic Block, and 0.12–0.48 Bq/dm3 for the Fore-Sudetic Monocline. The range of 222Rn activity concentrations measured in river waters in the whole Lower-Silesian voivodeship was 0.08–24.44 Bq/dm3. It means that river waters in this voivodeship satisfy the radiologic requirements for water intended for human consumption in terms of 222Rn activity concentration.