Radon permeability of insulating building materials

The common presence of the radioactive nuclides in the environment cause that the whole population are exposed to radiation. The dose that is annually received by Polish population from natural sources of radiation is about 2.4 mSv per year [1]. According to the UNSCEAR 2000 Report [2], radon is the greatest contributor of exposure to natural radiation for humans. Soil and the rocks on which the buildings are embedded constitute the main source of radon in the closed spaces, such as buildings. The building materials used to construct and fi nish the houses are the second major source. Radon penetrates from the soil into the homes through all of kinds of leaks in the foundations, primarily because of the difference in air pressure between the building and the ground. About 80% of radon in the buildings comes from the soil. About 12% of radon in building materials comes from radium contained therein [3]. The remaining portion of radon found in the homes comes from the outside ambient air, water and fuel gas. 222Rn concentration in the home atmospheres is affected by various factors, including the 226Ra contained in the ground, the tectonic setting and features of the subsurface layers of soil that determine the intensity of radon exhalation (porosity, moisture, permeability, temperature gradient). Also the meteorological conditions affect the concentration of radon in the lower troposphere in a specifi ed location and have Radon permeability of insulating building materials Katarzyna Walczak, Jerzy Olszewski, Marek Zmyślony