Estudio de la exhalación de radón del río Chambo y sus afluentes

Abstract

The aim of this curricular integration work was to determine the radon-222 exhalation rate of sand samples collected from the Chambo river and its tributaries used as construction material in the province of Chimborazo. As well as the contribution of sand to the indoor radon concentration and the annual effective dose. Radon-222 exhalation measurements were performed using a closed chamber and a radon-222 detection system consisting of a Pylon AB7 monitor and a Lucas 600P cell. The highest exhalation rate was detected in the Guamote river sand sample (RGM1) with a value of (2.69 +/- 0.63) Bq/m2 h, while the Chambo river sample (RCH2) presents the lowest detected value (1.83 +/- 0.49) Bq/m2 h. The RGM1 sample, considering a room as a cavity and an average permanence period of 7000 hours in a year, presents a contribution to the indoor radon concentration of (10.76 +/- 2.52) Bq/m3, which is equivalent to an annual effective dose of (0.27+/- 0.06) mSv/year. This dose value represents 25% of the value recommended for natural radioactivity by UNSCEAR in 2006 (1.1 mSv/year). It is recommended to avoid direct sampling in rivers, and to collect samples directly from mines or quarries.