Measurements of natural radioactivity in phosphate fertilizers

The natural radioactivity, mainly due to radium (Ra-226), in phosphate fertilizers used in north-western Greece has been measured by gamma-spectroscopy. Also radioactivity measurements were performed in soil samples and were compared to samples from undisturbed soils. Ra-236 belongs to the U-238 chain and is the precursor of radon gas (Rn-222). The radon concentrations in warehouses, where large quantities of fertilizers are kept, were measured with CR-39 SSNTDs. The radium concentrations in the fertilizers ranged from 0 to 4584 Bq kg(-1) and the radon concentrations in warehouses were measured 540-3320 Bq m(-3). The results are discussed from the radiation protection point of view. (C) 1997 Elsevier Science B.V.