Natural ventilation considerations for radon prone areas of Ramsar

Background: In Iran, architectures are often unaware of the risk of radon inhalation and how to reduce radon levels. Furthermore, radon considerations are not implemented in construction methods, construction materials and building utilization by regulatory authorities. Materials and Methods: In this study after reviewing the meteorological changes of Ramsar over the past 50 years (1955-2005), a novel design for constructing dwellings in radon prone areas is introduced. Out of building interventions such as planting wind-tunnel-making trees will be discussed in another paper. Ramsar soil samples with 4 levels of specific activities (extremely hot, severely hot, very hot, and hot) were placed in a model house. Radon level monitoring was performed by using a PRASSI portable radon gas survey meter. Results: For extremely hot soil samples, the radon levels inside the model house when windows were closed for 24 hours were 1615 ±516 Bq/m3. When windows which were in the wind direction or opposite the wind direction were opened for 24 h, the radon level decreased to 89 ±286 and 139 ±314 Bq/m3, respectively. Interestingly, when crossed windows were opened for the same duration, Radon level was 144 ±92 Bq/m3. In cold seasons, when windows are usually closed, Chimney effect reduced the radon level to 323±641. For severely hot, very hot and hot soil samples, natural ventilation-based interventions effectively reduced the radon level. Conclusion: Results obtained in this study clearly show that natural ventilation-based simple cost-effective interventions can significantly reduce the radon concentration in radon prone areas of Ramsar.