Question to the Department of Health and Social Care:

To ask His Majesty's Government what steps they are taking, if any, to analyse the risk of radon gas build-up in homes arising from the installation of insulation and other retrofit products approved by Government.

Indoor radon concentration is a complex combination of factors, including underlying geology, building structure and settlement, usage, occupancy, indoor versus outdoor air temperature, ventilation, air pressure, wind speed and outdoor radon concentration. Radon concentration cannot be predicted; only the probability that a property in a particular location will have a radon level above the ‘Action Level’ threshold.

In 2019, the former Public Health England co-authored a paper through the Complex Urban Systems for Sustainability and Health project, which analyses the effect of energy efficiency measures on radon levels in homes. This analysis suggested that energy efficiency measures in homes should be reviewed to account for the potential for increased radon exposure as a result of air tightening and especially in high radon areas. A copy of the analysis is attached.

The UK Health Security Agency (UKHSA) is continuing research on radon levels, including indoor air quality. On 3 November 2022, the UKHSA held an annual forum for stakeholders during Radon Awareness week, including discussions on the effect of energy efficiency and sustainability on indoor radon concentrations.