These findings follow a comprehensive monitoring programme involving 135 non-domestic workplaces and public buildings, in line with UK Health and Safety legislation.

The affected properties are:

• Caithness House
• Lochaber Leisure Centre
• Highland Council Headquarters
• Highland Archive Centre
• Dalneigh Primary School
• Kilchuimen Academy
• Crossroads Primary School
• Inverness High School
• North Kessock Primary School

Council officials have moved to reassure the building users that the levels detected do not pose an immediate health risk. All buildings remain open and operational, and precautionary measures have already been taken to reduce potential exposure. These include increased ventilation, sealing of entry points, and restricting access to specific areas.

Finlay MacDonald, chief officer property and assets, said: “We are working closely with specialist consultants to ensure that all necessary mitigation measures are put in place. Our priority is the safety of building users, and we are confident that the steps being taken will effectively manage radon levels.”

Dr Jenny Wares, consultant in public health medicine with NHS Highland, said: “Radon is present in all air, and we all breathe in radon every day, usually at very low levels. However, exposure to higher levels over many years can increase the risk of lung cancer especially in those who currently smoke or who smoked in the past. Whilst the increased risk to pupils or staff caused by exposure to radon while at school or the workplace is very low, measures have been put in place to reduce the risk of exposure.”

Tailored mitigation strategies are being developed for each site, including the installation of active sump and fan systems, positive pressure ventilation, and further structural sealing. Post-installation testing will be carried out to confirm the effectiveness of these measures, and ongoing monitoring will ensure continued safety.