Occurrence of radioactive materials in pyroclastic flows of Tungurahua volcano using gamma spectrometry

Abstract

The Tungurahua volcano began its last eruptive process in 1999 and has not ceased its activity since then, as a result of this, tons of volcanic material has been deposited on its flanks in each episode of greatest activity. An exploratory study of radioactivity of natural origin has been carried out in the pyroclastic flows near the Palma Urcu ravine (Juive) of the Tungurahua volcano using gamma spectrometry. This pyroclastic material corresponds to the accumulation that occurred after the eruption of August 2006 in an area adjacent to this ravine after its overflow. This material is used in construction. At present, much emphasis is placed on the health risks associated with the radioactivity present in construction materials. In this context, concentrations of activity in several samples of material have been analyzed to determine their risk, finding average values of 27.58 ± 1.99 Bq / kg for Ra-226; 30.28 ± 2.48 Bq / kg for Th-232, and 411 ± 28.77 Bq / kg for K-40. Finding an activity index of 0.38 ± 0.03 It was also calculated the equivalent radio activity, external and internal risk indexes and effective annual equivalent doses found that is bordering the maximum permissible limit recommended by control organisms.