Passive sumps as a method of reducing radon levels in Irish dwellings

Radon gas is the second biggest cause of lung cancer after smoking and is directly linked to approximately 350 lung cancer cases in Ireland each year. It is a serious public health hazard, and the Government has published a National Radon Control Strategy to tackle the problem. The most cost-effective way of protecting the population from radon is to ensure that new dwellings are built to prevent the entry of this gas from below the building.   
The two methods most commonly used to protect new buildings from radon are the installation of a radon membrane and a mechanism to depressurize the building. Since 1998, Irish Building Regulations have required that all new dwellings are fitted with a capped standby sump which can be activated if high radon levels are measured.    Dwellings built in areas that are more at risk from radon (High Radon Areas) are also required to have a radon membrane installed.   EPA data has shown a decrease of 13% in the average indoor radon level in Irish dwellings since the introduction of these requirements.   
The protection of new buildings through depressurisation has been successfully achieved in other countries through the installation of a passive radon sump. The application of this simple, effective and inexpensive measure in Irish dwellings was researched by University of Galway in laboratory studies.  This research showed that passive radon sumps have significant potential to reduce indoor radon levels and that the fitting of a static cowl to the passive sump increased its effectiveness.  A limitation of the University of Galway study was that the system was not tested with natural wind conditions in dwellings.