MITIGATION OF INDOOR RADON POLLUTION IN BUILDINGS IN HONG-KONG - COVERING MATERIALS ON INTERNAL BUILDING SURFACES

The effects of typical covering materials used in Hong Kong on the radon exhalation rate from concrete surfaces have been studied. These covering materials are wallpaper, plaster, ceramic mosaics and glazed ceramic. Concrete blocks have been constructed in the laboratory. The radon exhalation rates from their surfaces, first without the covering materials and then with the covering material we want to investigate, are then measured using EPA-standardized activated charcoal canisters and gamma-spectroscopy. By comparing these radon exhalation rates, the effects of the covering materials can be determined. It is found that the radon exhalation rates from concrete surfaces covered by wallpaper and glazed ceramics are lower than the minimum detectable limit. It is therefore believed that these covering materials can satisfactorily inhibit the radon exhalation and reduce the corresponding indoor radon concentration.