The effectiveness of passive sumps and static cowls in reducing radon levels in new build Irish dwellings.

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 the ground below the building. One of the most common methods used to protect buildings from radon is the installation of a system to depressurize the subsoil below the building, reducing the ingress of the gas indoors. Laboratory based research has shown that the use of a wind-driven passive radon sump and static cowl has significant potential to protect new buildings in Ireland through depressurization. A field trial of this system was carried out in a sample of new Irish dwellings built to the requirements of Irish Building Regulations. The study focused on six unoccupied, adjacent, south-east facing dwellings of identical construction. The variables of occupancy, geology, building type, building material and weather were all controlled for, consequently, the study was carried out under highly controlled conditions. The radon levels in each of the dwellings were measured over a 6-week period under three test conditions: the passive sump closed, the passive sump open and the passive sump open with a static cowl installed. The results show an average reduction of 65% in radon levels due to the installation of a wind-driven passive sump. The cumulative effect of the installation of a passive sump plus a static cowl was an average reduction in radon levels of 75%. The number of observations that exceed the Government's Reference Level for dwellings of 200 Bq/m3 was reduced from 38% with the passive sump closed to 9% when the passive radon sump was in operation and 0% when both the passive radon sump and static cowl were installed. These results are statistically significant, and the cost is estimated at €100 per dwelling. The study concludes that the installation of a passive sump fitted with a static cowl in new dwellings is a low cost, effective method of reducing radon exposure in new Irish dwellings.

Estimating population lung cancer risk from radon using a resource efficient stratified population weighted sample survey protocol - Lessons and results from Ireland.

A 2018 estimate indicates that there were 226,057 radon-attributable lung cancer deaths in 66 countries that had representative radon surveys. This is a shocking figure, and as it comes from only 66 countries it underestimates the worldwide death toll. Any research that enables countries to conduct representative radon surveys and to understand better the risk to citizens from radon is surely welcome. We hope this paper provides a useful methodology for estimating population risk. The estimation of population weighted average indoor radon levels requires statistically valid sampling methodologies that use a representative sample of occupied homes throughout the country. A literature review indicates that in many population weighted surveys, the sampling methodology may not have been designed to do this. This paper describes a simple, resource efficient methodology which produces statistically valid and reliable estimates based on a small scale sample that is representative of the population distribution. The resource efficient design of this study enables it to be repeated at frequent intervals providing for a longitudinal analysis of the population risk from indoor radon. This survey was conducted in Ireland using 653 measurements and a representative sampling strategy to provide a baseline population weighted radon exposure for future comparisons. This study estimates the average population weighted indoor radon concentration in Ireland to be 97.83 Bq m-3 (95% Confidence Interval 90.69 Bq m-3 to 105.53 Bq m-3), and that there are an estimated 350 lung cancer cases and 255 deaths per year due to radon exposure. The mortality rate of 5.3 per 100,000 due to indoor radon, demonstrates that radon remains one of the highest preventable causes of death in Ireland.

Update of Ireland's national average indoor radon concentration - Application of a new survey protocol.

In 2002, a National Radon Survey (NRS) in Ireland established that the geographically weighted national average indoor radon concentration was 89 Bq m-3. Since then a number of developments have taken place which are likely to have impacted on the national average radon level. Key among these was the introduction of amending Building Regulations in 1998 requiring radon preventive measures in new buildings in High Radon Areas (HRAs). In 2014, the Irish Government adopted the National Radon Control Strategy (NRCS) for Ireland. A knowledge gap identified in the NRCS was to update the national average for Ireland given the developments since 2002. The updated national average would also be used as a baseline metric to assess the effectiveness of the NRCS over time. A new national survey protocol was required that would measure radon in a sample of homes representative of radon risk and geographical location. The design of the survey protocol took into account that it is not feasible to repeat the 11,319 measurements carried out for the 2002 NRS due to time and resource constraints. However, the existence of that comprehensive survey allowed for a new protocol to be developed, involving measurements carried out in unbiased randomly selected volunteer homes. This paper sets out the development and application of that survey protocol. The results of the 2015 survey showed that the current national average indoor radon concentration for homes in Ireland is 77 Bq m-3, a decrease from the 89 Bq m-3 reported in the 2002 NRS. Analysis of the results by build date demonstrate that the introduction of the amending Building Regulations in 1998 have led to a reduction in the average indoor radon level in Ireland.

The rate of radon remediation in Ireland 2011-2015: Establishing a base line rate for Ireland's National Radon Control Strategy.

Radon is the greatest source of radiation exposure to the public. In Ireland, it is estimated that approximately 7% of the national housing stock have radon concentrations above the Reference Level of 200 Bq m-3. A radon test can be carried out to identify homes with radon levels above the Reference Level. However there is no health benefit associated with radon testing unless it leads to remediation. Surveys to establish the rate of remediation in Ireland, that is the proportion of householders who having found levels of radon above the Reference Level proceed to carry out remediation work have been carried out in 2011 and 2013. Reasons for not carrying out remediation work were also investigated. In 2015 the survey was repeated to establish the current rate of remediation and reasons for not remediating. This report presents the results of that survey. It also compiles the data from all three surveys to identify any trends over time. The rate of remediation is an important parameter in estimating the effectiveness of programmes aimed at reducing radon levels. Currently the rate of remediation is 22% and the main reasons householders gave for not remediating were not certain there is a serious risk and concern about the cost of the work. In Ireland, this figure of 22% will be now used as a baseline metric against which the effectiveness of its National Radon Control Strategy will be measured over time.