Monitoring of radioactive contamination in Polish surface waters in 2012-2013.

The 90Sr and 137Cs contamination in Polish surface waters has been monitoring since 1994. Surface water samples from six lakes and the Vistula and Oder Rivers were collected in spring and autumn 2012 and 2013. The mean 90Sr and 137Cs concentrations were 3.92 ± 0.40 and 4.49 ± 2.00 mBq L-1, respectively. Correlations were identified between the radionuclide concentrations and meteorological conditions and the original fallout distribution from the Chernobyl disaster. The annual average radionuclide concentrations were not significantly different from the concentrations found between 1994 and 2011. The 137Cs and 90Sr concentrations have been decreasing only slowly.