In this paper, the concentrations of Ra-226 and Ra-224 in water (sprin
g water, thermal water and bottled mineral water) have been determined
. Ra-226 concentrations in drinking water show values ranging from 2 t
o 892 mBq/l and Ra-224 concentrations vary from 2 to 200 mBq/l. An exp
lanation for the different concentrations of Ra 226 in thermal, bottle
d mineral water and spring water relating to temperature, dissolved in
organic salts, geological composition and other factors is suggested.