Approximately half of the person’s exposure dose is caused by radioactive gas coming from the ground – radon.
Radon and its daughter radionuclides as well as additional natural exposures significantly increase the risk of developing malignant tumours, primarily lung cancer.
Radon is formed by natural decay of uranium. Uranium is found in a greater or lesser extent throughout the earth’s crust. Thus, radon can also be found everywhere.
The high levels of radon may be found almost everywhere in Estonia. Radon danger is mostly present in North Estonia, where porous and fractured limestone lies on the graptolitic argillite rich in uranium.
Radon that is generated from the decay of uranium will be free to rise to the surface in such cases. Radon danger is also present in certain areas in Lääne-Virumaa and Tartumaa, where high radon concentrations are caused by the ice age sediments carried here from Scandinavia.
Radon enters the house due to cracks caused by the poor quality of construction and in case of the ageing of the building. Inhalation of radon-rich air increases the risk of lung cancer. Therefore, it is extremely important to protect yourself from excessive radiation exposure caused by radon.
Groundwater and domestic building materials have generally low radon content.