[en] There is only scarce information on the presence of radionuclides in water for public consumption in Brazil. A recently issued federal regulation requires that waters from public supplies be screened to determine their content of alpha and beta emitters. In order to comply with this requirement the present work was carried out with the purpose of determining the concentration of natural uranium, ²²² Rn and ²¹⁰ Po in water supplies in the metropolitan region of Recife, Brazil. The analyses were performed in 17 points of supply of superficial water and 94 points of groundwater supply. The concentrations of uranium were determined by the fluorimetric method, whereas the liquid scintillation method was used to determine the concentration of ²²² Rn. Polonium-210, on the other hand, was determined by alpha spectrometry, following its spontaneous deposition on copper disks. The water analyzer presented uranium concentrations varying from 35.3 to 1146.5 mBq/L for superficial resources and from 20.2 to 919.15 mBq/L for underground sources. The concentration of uranium in superficial water showed significant correlation with some parameters such as conductivity, alkalinity and total hardness, as well as, with the concentrations of Ca, Mg, Cl, K, SO₄ and Mn. No correlation, however, was shown with the concentrations of Fe, NO₂ and NO₃. The concentrations of ²²² Rn varied from 5.3 to 83.7 Bq/L in the groundwater analyzer. Radon concentration was not measured in superficial water due to the high emanation rate of radon in open air conditions. As far as ²¹⁰ Po is concerned, the analyses showed concentrations ranging from <22 mBq/L (the lowest limit of detection) to 57.4 mBq/L for superficial water and from <22 to 813 mBq/L for ground water samples. The concentrations of ²¹⁰ Po did not show and correlation with physico-chemical parameters. The average concentrations of uranium and ²¹⁰ Po in superficial water were of 44.7 mBq/L, respectively. These values correspond to effective doses of 5.8 x 10^-4 mSv/yr and 4.5 x 10^-2 mSv/yr, for uranium and ²¹⁰ Po, respectively. The average values for the concentrations of uranium, ²²² Rn and ²¹⁰ Po in ground samples, on the other hand, were 106.6 mBq/L, 24,3 Bq/L and 30 mBq/L, respectively, corresponding to effective doses of 8.0 x 10^-4 mSv/yr, 1.3 mSv/yr and 0.47 mSv/yr, respectively. (author)