A Study on the Correlation Between Indoor Radon Concentrations and the Construction Year of the Dwellings

The aim of this study is to assess the variation of indoor radon concentrations as a function of the construction year of the dwellings based on the data gathered by the nationwide radon survey performed in the framework of the Greek Radon Action Plan (GRAP). A radon measurements management system was developed and is under implementation to host all measurements. Within this framework, the data collected include the location and the radon concentration, as well as the construction year of the dwelling, the ventilation method and its frequency, the building materials, energy-saving class, etc. This work presents our study on the correlation between the construction year and the indoor radon concentration in the country and in the individual administrations where data were sufficient as Attica, Thessaly, etc. The main observation points out that the radon concentration decreases substantially as the focus moves from the oldest dwellings to those constructed in the 70 s, while the dwellings built from 1970 to 2000 show no trend. Although, high indoor radon concentrations in old dwellings could be attributed to structural problems, the newly built dwellings tend to show an increase in radon concentration, mainly due to the new regulation of Energy Efficiency of Buildings, established in the country in the last decade.