Radon measurements in homes are easy to perform but need to follow defined national protocols.
Long-term radon measurements (over several weeks) are preferred for assessing the annual average radon concentration within a house.

Radon prevention and mitigation
Professionals in the building sector are key players for radon prevention and mitigation. Strategies are needed to train them and to ensure their competence in this area.
Strategies both for radon prevention (new dwellings) and mitigation (existing dwellings) are needed to achieve an overall risk reduction.
Research-based guidelines and/or standards for radon prevention and mitigation should be established at national level.

Cost effectiveness of radon control
The cost-effectiveness of preventive measures improves as the average radon concentration in an area increases. In many cases, it is most cost-effective to install radon prevention measures such as a radon barrier in all new buildings.

The cost-effectiveness of remediating existing buildings is strongly influenced by the costs of identifying affected homes and by the remediation costs themselves.
Even if cost-effectiveness analyses indicate that remediation programmes are not cost-efficient on a nationwide basis, in areas of high radon concentration remediation should still be undertaken.

Radon risk communication
The communication of radon risk and prevention messages poses serious challenges because radon is not widely known and may not be perceived as a health risk by the public or policy makers.

National radon programmes
Properly installing radon prevention measures in new homes is the most cost-effective and efficient way to obtain low radon concentrations in individual households and consequently to reduce the average national radon concentration. Over time, this approach will lead to a greater reduction in the total number of lung cancers attributed to radon exposure than the alternative way of only reducing radon in existing buildings that exceed the reference level.

Countries should set their national reference level, which is the radon concentration above which remedial action is recommended, between 100 Bq/m3 and 300 Bq/m3 depending on country specific factors such as the distribution of radon, the number of existing homes with high radon concentrations, the arithmetic mean indoor radon level and the prevalence of smoking should be taken into consideration.

No one agency is equipped to effectively tackle the radon problem therefore an effective national radon programme requires input from several agencies within a country.
What does this mean for radon policy in Ireland?
Are there differences between the approach to radon policy by the WHO and Ireland?
The WHO and current Irish policy advocate a two pronged approach to reducing radon exposure.

Reducing the population dose from radon by implementing radon preventative measures in new homes so that, over time, the average radon concentration in the country will be reduced.
The majority of people live in homes with relatively low radon levels. Therefore, the majority of lung cancers are observed in people exposed to radon concentrations below the reference level. By progressively reducing the average radon concentration in the national housing stock, considerable benefit can be achieved. The best way of doing this is to build new homes with properly installed radon prevention measures so as to ensure they have low radon concentrations.

Reducing the individual’s risk from radon to all householders by identifying and remediating homes with high radon concentrations
Is there a need to revise the risk estimates for radon exposure in Ireland?
No. The WHO base their risk estimates on the same international scientific studies that were used to estimate the risks in Ireland. Radon exposure in Ireland can be linked to some 200 lung cancer deaths each year.

Are the radon measurement devices and protocols currently used in Ireland in keeping with WHO advice?
Yes. The RPII recommends that radon measurements be carried out over a minimum period of 3 months and be carried in accordance with RPII protocols.

Is there a need to modify radon prevention and practices in Ireland?
The effectiveness of radon preventive measures in new buildings can only be judged if a radon measurement is carried out. In this context, the RPII’s view is that radon measurement needs to be included in the conveyancing process.

The level of inspection of new buildings should be increased. Research carried out by the RPII found that new homes where radon barriers were required still had high radon levels. The RPII recommended better enforcement of the building regulations as a means of improving radon protection in new buildings.

Could current radon control measures in Ireland be made more cost effective?
The RPII has recommended that a cost benefit analysis of different radon remediation strategies to identify the optimum approach. The model for carrying out a cost benefit analysis set out in the Handbook is helpful in identifying the relevant parameters.

Should the Irish Reference Level of 200 Bq/m3 be reduced?
The Reference Level is not a rigid boundary between safety and danger but a guideline indicating the radon concentration above which one should consider taking action. In 2005, the RPII reviewed the applicability of the Reference Level in Ireland. At that time, the review recommended continuing with the present Reference Level of 200 Bq/m3 as it represented a level of risk to the population as a whole comparable to other everyday risks.

The present Reference Level of 200 Bq/m3 is within the range recommended by the WHO. Ireland, at 89 Bq/m3, has one of the highest average indoor radon levels in the world. Reducing the Reference Level to below 200 Bq/m3 for example to 100 Bq/m3 may not be achievable as it would require considerable resources.