Radiological characterization of phosphate fertilizers: Comparison between alpha and gamma spectrometry

The natural radioactivity in phosphate fertilizers used in central Italy has been measured by alpha and gamma spectrometry. The results show that the specific activities of 238U, 234U and 235U ranged within interval from < 0.5 to 2628.8, from < 0.5 to 2826.3 and from < 0.9 to 138.0 Bq kg− 1 respectively and those of 210Pb and 210Po ranged within interval from < 15.0 to 401.5 and < 0.5 to 351.6 Bq kg− 1 respectively. The 228Th, 230Th and 232Th concentrations found by alpha spectrometry ranged from < 0.5 to 50.2, from 0.9 to 2727.2 and from < 0.5 to 60.8 Bq kg− 1 respectively. 226Ra and 228Ra activity concentrations ranged from < 14.3 to 290.9 and from < 2.9 to 24.9 respectively. 40K specific activities ranged from 39.2 to 8263.7 Bq kg− 1. A very good correlation exists between the activity concentrations found by alpha spectrometry and those found by gamma spectrometry.