A Study of Indoor Air Quality in Buildings of the University of Malaga: Radon Concentrations

Abstract

The results of the CAI_UMA Project are herein presented, the purpose of which was to quantify the average annual radon concentration in the university education sector by comparing it with current regulations and to estimate the consequent radiological risk. Radon ²²²Rn measurements were taken in five classrooms from March 2019 to April 2020. ²²²Rn is a naturally occurring radioactive noble gas belonging to the decay chain of uranium ²³⁸U. Measurements were taken using 5 Saphymo® AlphaE active monitors and 70 CR-39® passive detectors and developed at the Radioactivity Laboratory of the University of Cantabria (LARUC). The average annual concentration was 59 Bq/m3. These results match those predicted in national studies such as the Radon Potential Map, the Natural Gamma Radiation Map (MARNA) and the lithostratigraphic and permeability map and in existing radon measurement studies. The effective dose at the University of Malaga (UMA) due to indoor radon exposure for members of the public was determined for the first time: 0.80 mSv/yr. These concentrations do not exceed the legal reference level, although monthly average values above 300 Bq/m3 were measured in certain months. This can be ascribed to poor ventilation and to the accumulation of gas inside the classrooms via various pathways. Quantifying average annual ²²²Rn concentrations allows the radiological risk to be assessed and compared to reference levels, the risk being low. The goal of informing the public and raising its awareness of the risks of radon exposure was thus achieved.