Assessment of Radon Concentrations Inside a High School Building in Guarda (Portugal): Legislation Implications and Mitigation Measures Proposed

The maximum accepted radon concentration in buildings represents the national reference level for radon and is an important parameter in the indoor air quality (IAQ). In Portugal, national regulations defines the maximum concentrations of 400 Bq/m3 of radon, being there search mandatory only in dwellings in granitic areas as Guarda district. With the aim of assessing the average values of indoor radon, it was made a study of radon concentrations inside of Instituto Politécnico da Guarda (IPG). It was used a continuous Radon Monitoring equipment for real-time measurements in two different periods – winter and summer. The results obtained show an IAQ for radon gas above 400 Bq/m3, with some seasonal variations, as well as variations related to the occupation of these divisions.According to that some mitigation solutions are proposed.