The aim of the thesis was to resolve how the radon concentration of soil is observed in the statement of foundation engineering of a new building. Long-term exposure to radon in the building’s indoor air causes the risk of lung cancer and therefore radon should be observed as early as possible in the construction process. In addition, different norms and rules require that radon is observed in design and construction of a building. The second purpose of the thesis was to develop a possible business within the sector of soil radon measurement.

In this study, the health effects caused by radon were investigated, as well as radon-related laws, norms and rules. In addition, existing measurement results of indoor radon concentrations in the Pori and Satakunta area were reviewed. Research data from STUK (Radiation and Nuclear Safety Authority) were used to evaluate on indoor radon concentrations in small houses and soil maps from GTK (Geological Survey of Finland) were used to estimate potential areas of high radon concentration. In the thesis, different existing methods for measuring the radon concentrations of soil were investigated and the most suitable measurement method and equipment for business purposes were chosen. From this method field study guidelines for soil radon measurement according to ISO 11665-11 standard were prepared. At the end of the thesis existing solutions for radon control of a new building were reviewed.

There is still limited number of measurement results of indoor radon concentrations available by STUK in Pori and Satakunta area. These results don’t completely determine the radon concentration of an individual building site. Radon is always present everywhere in the soil to some extent. The only way to determine a building site’s radon concentration is to measure it from the soil before construction. Unless the radon concentration cannot be measured directly from the soil, a good solution to combat indoor radon levels in residential buildings (either residence or workplace) could be: regardless of the location of the building site, the foundations of all new buildings will be carefully sealed and freely ventilated radon pipelines will be installed into the foundation, especially to those buildings with ground slab. The foundation type of the building to be constructed is not always known at the time of preparing the statement of the foundation engineering for the new building. It’s therefore difficult to determine the need for a certain type of radon protection. For example, in a building with a ventilated base or an edge-reinforced slab, even careful sealing of the structures with mechanical supply and exhaust ventilation, might already be sufficient protection against radon risks.