Radiological Assessment of using Phosphogypsum as Building Material

In order to assess the feasibility of using phosphogypsum as a building material, an experimental house was built with phosphogypsum panels of different origins. The aim of this study is to assess the external and internal exposure of residents. Phosphogypsum samples were analysed by high resolution gamma spectrometry for their 226Ra, 232Th, 210Pb and 40K content. The activity concentrations were 0.016-0.393 Bq/g for 226Ra, 0.026-0.253 Bq/g for 232Th and 0.027-0.852 Bq/g for 210Pb. The results for 40K were lower than 0.081 Bq/g. The effective dose was evaluated for each type of phosphogypsum panel. The effective doses due to external exposure were always below 1 mSv/a, the dose limit for the general public. Radon measurements in the house were carried out using the passive method with solid state nuclear track detectors (CR-39) over a period of 15 months. The detectors were changed every three months, in order to determine the long term average levels of the indoor radon concentrations with varying seasons. The radon concentration varied from 45 to 119 Bq/m3. These results are below 200 Bq/m3, the recommended investigation level for radon in dwellings. (author)