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