Measurements of natural radioactivity in phosphate fertilizers

The natural radioactivity, mainly due to radium (226Ra), in phosphate fertilizers used in north-western Greece has been measured by γ-spectroscopy. Also radioactivity measurements were performed in soil samples and were compared to samples from undisturbed soils. 226Ra belongs to the 238U chain and is the precursor of radon gas (222Rn). 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 warchouses were measured 540–3320 Bq m−3. The results are discussed from the radiation protection point of view.