During the last few years, many private homeowners have become aware of radon in their homes. In Denmark, the municipalities are responsible for the indoor climate in public buildings. In relation hereto, NIRAS executed a large radon inspection for one of the Danish municipalities last year.
The winter months are upon us and according to Mette Neerup, Head of Water and Environment in NIRAS, now is the optimal time to conduct radon inspections in buildings. Radon is a radioactive gas, which increases the risk of lung cancer. It not possible to taste, feel, smell, or see radon.
The gas is found in the ground from where it sneaks into buildings and homes through cracks and leakages in the foundation. This could be through an old plumbing trap, a grate, or other crevices close to the ground. Although radon primarily makes its way into basements, it can also spread to the ground floor in lower concentrations.
During the winter months, radon levels increase as a result of warmer temperatures inside than out, and a lack of ventilation. Warm air rises and creates pressure in the house that is lower than in the soil. The difference in pressure causes the house or building to act like a vacuum, drawing radon inside. This is why this time of year is optimal to test for radon.
According to Danish law, the municipalities are responsible for ensuring a healthy indoor climate. NIRAS was therefore approached by Horsens Municipality to conduct an inspection of radon levels in their public buildings.
The buildings were scrutinised for any cracks or leakages. Subsequently, radon levels were measured over a period of three months. Finally, a laboratory made a compiled analysis of the results.
“The strategy in Horsens Municipality worked very well. Buildings with the highest exposure to radon were inspected first, and if they showed significant radon levels, they were then indemnified against radon intrusion. This is a very effective and cost-beneficial way to achieve a good indoor climate,” Mette Neerup explains about the radon inspections.
After the inspections were finished, NIRAS offered the municipality recommendations regarding each particular point of inspection. Some locations required indemnifying initiatives, some locations required further measurements, and luckily, the majority of the locations were in great condition.
The inspections were followed up with a course for the employees in the municipality, who work with construction and buildings. They were presented with the results and introduced to specific examples from the buildings in their municipality. Energy technologist Charlotte Høitbjerg Davidsen from Horsens Municipality says:
“In relation to the radon screening, it was a priority for us in Horsens Municipality to expand our own knowledge on radon and how it behaves, to better protect our buildings against it in the future.”