Monitoring of the spatial and temporal variation of radon in an inhabited house, subjected to an underground source of radon from a well. Case study of Valsequillo in Gran Canaria..

Radon, a radioactive gas, is a recognized health hazard and a significant concern in residential environments. In this presentation, as part of a national radon project funded by the Nuclear Safety Council of Spain (CSN), a residential house in Valsequillo in Gran Canaria Island, Spain, was chosen for comprehensive radon monitoring. This study employed passive radon detectors as well as active radon detectors, to obtain long-term and real-time radon concentration data. Passive radon detectors were strategically placed in different rooms of the selected house and changed every three months to collect long-term radon concentration data. Active radon detectors were used to capture real-time measurements and provide a more detailed analysis of radon levels. Radon measurements were taken in the soil at a depth of one meter to evaluate radon emissions from the ground. Meteorological variables, including temperature, humidity, and atmospheric pressure, were recorded to characterize the local weather conditions. A comprehensive terrain characterization was performed, considering soil composition, permeability, and geological formations. The terrain characterization contributed to understanding the geological factors affecting radon levels in the area. The house was built on a characteristic terrain of superimposed lava flows, pyroclasts and mantles of volcanic breccias from the second eruptive cycle of the island of Gran Canaria (Roque Nublo Cycle), which form very thick packages (hundreds of meters). Regarding lithology, in the area there are basanitic-nephelitic, basaltic and olivinic-pyroxene lavas. The house is located on one of the slopes of the Barranco de San Miguel very close to the Protected Area of the Barranco de Los Cernícalos belonging to the Special Natural Reserve of Los Marteles. The area has a cold dry semi-arid climate, little influenced by the trade winds, with relatively little rainfall, more than 400 mm per year, and an average annual temperature of les