Radon Distribution in Domestic Water of Texas

Abstract

ABSTRACTConcern is mounting over possible adverse health effects associated with exposure to elevated domestic alpha radiation levels (Bean et al, 1982); Petersen et al., 1966; Lyman et al, 1985; Cothern, 1987). Radon released during domestic use of ground water is one of the potential routes of such exposure. However, relatively little is known worldwide about the distribution of alpha‐emitting radioisotopes in ground‐water supplies. In Texas, deposits of uranium occur, rich enough to be mined commercially, and the possibility existed that significant concentrations of uranium disintegration products may have been present in ground‐water supplies. Cech et al. (1987a) identified two regions with anomalously high concentrations of radium‐226: in the Gulf Coast, downdip from uranium deposits, and in west‐central Texas, on the periphery of an igneous uplift. Radium‐226 is a parent of radon‐222 which is a focus of the present paper. Concentrations of radon up to 3300 pCi/1 were observed in several domestic‐water supplies. This study suggests that it may be external sources (interaction of Tertiary aquifers with salt domes, leaky faults, and uranium‐bearing volcanic ashes) and not the bulk mineralogy of the aquifers, which cause anomalous concentrations of alpha‐emitting radioisotopes in well water. The distinction is important, as it offers the possibility of avoiding high risk areas when selecting well drilling locations.