Authors: James A. McGrath and Miriam A. Byrne
Summary: In Ireland, radon gas is considered the greatest source of radiation exposure to the general population, accounting for just over 55% of the average radiation dose and is recognised as the second leading cause of lung cancer after tobacco smoke. Each year in Ireland, exposure to radon is linked to approximately 250 cases of lung cancer.
The EU Energy Performance of Buildings Directive (2010/31/EU) contains a range of provisions to improve the energy performance of new and existing buildings. In Ireland, regulations transposing this Directive (S.I. 243 of 2012) are aimed at improving the thermal and energy efficiency of the building envelope, window upgrades and specifying standards of building airtightness. Limited studies have examined radon concentrations in low-energy-efficient homes and fewer still have examined radon concentrations in pre/post retrofits. Ireland has some of the highest indoor radon concentrations in the world and, consequently, there is concern surrounding further increases in concentrations as a result of increased building airtightness. A survey of 142 Irish social homes showed radon concentration ratios for pre versus post retrofit ranging from 0.1 to 7.3, illustrating the need to fully understand the impact of retrofitting on indoor radon concentrations. This knowledge gap is emphasised in the National Radon Control Strategy (NRCS).
Since 1997, Technical Guidance Document C (Site Preparation and Resistance to Moisture) has stated that all new dwellings must incorporate radon protection measures in high radon areas. Research has shown the positive benefit of this legislation change; The Environmental Protection Agency report that the average indoor radon concentration was 86 Bq m-3 in dwellings built before 1998 and 64 Bq m-3 in dwellings built after 1998. Building Regulations 2011 (S.I. No. 259 of 2011), Technical Guidance Document L on Conservation of Fuel and Energy – Dwellings, specifies standards of building airtightness by reducing uncontrolled ventilation losses from the home. S.R. 54 of 2014, published by the National Standards Authority of Ireland, gives guidance on the provision of ventilation with retrofit works, with an air permeability of > 5 m–3 hr–1 m–2. The National Radon Control Strategy (NRCS) was developed to address the long-term radon exposure risk and highlights the need to strengthen technical guidance and legalisation to protect against and prevent radon exposure in buildings (Actions 4, 5, 20, 24 and 27 of the NRCS).
The European 7th Environment Action Programme (1386/2013/EU) aims to ensure a “healthy environment for healthy people”. To meet the above challenges, pressures and policies, Ireland needs to take account of the environmental health implications of developing building regulations that lean towards reducing ventilation rates. In the absence of a full-scale study of indoor radon concentrations in energy-efficient buildings, the current project has examined international research on radon concentrations in retrofitted houses and provides simulation data on the ventilation status of the national building stock and the implications of pre/post retrofits for indoor radon concentrations. This meets a strategic knowledge gap identified by the NRCS, under Action 9 (develop recommendations regarding future funding of research priorities). In addition, the project helps inform the development of further research needs under phase 2 of the NRCS, expected to be implemented from 2019.
https://www.epa.ie/media/epa-2020/publications/research/Research_273_Thumbnail[1].jpg