Effectiveness of passive ventilation on radon indoor level in Puglia Region according to European Directive 2013/59/EURATOM

The effectiveness of the increase in passive ventilation was studied as remedial action for high concentrations of indoor radon gas activity. The rationale has been to apply the provisions of Directive 2013/59/EURATOM, partially implemented by a regional law of Puglia Region (Southern Italy). Residential buildings were selected based on characteristics common to those of commercial premises, which are the recipients of legislative obligations. The final goal of this study was to evaluate the feasibility of carrying out the same remediation activity for both types of buildings. From a previous survey in Puglia in 2013–2014, 18 houses were selected and passive ventilation strategy was applied in order to evaluate its effect on the radon activity concentration. A specially designed protocol defined frequency and time of windows operation. The average value of the annual measurement revealed a significant reduction of the internal radon activity concentration: mitigation ranged from 21 ± 5% to 58 ± 2% with an average value of 33 ± 3%. The results of the study showed that passive ventilation is an effective method of mitigation of the internal radon concentration if correctly designed according to the local characteristics of the buildings and habits of the occupants.