Evaluation of radioactivity levels in fertilizers commonly used in the Southern USA.

A study was performed to evaluate radioactive concentrations in three categories of fertilizers, phosphate (0-46-0); potash (0-0-60); and NPK (13-13-13) using gamma spectroscopic techniques. The experimental analyses indicated mean concentrations of 697 ± 15, 8.9 ± 1.0 and 47 ± 12 Bq kg of Ra, Th, and K, respectively, in phosphate fertilizers. Potash fertilizers had the average levels of 1.1 ± 0.10, 0.40 ± 0.05, and 15,162 ± 1017 Bq kg of Ra, Th, and K, respectively. The NPK fertilizers contained 7.45 ± 2.76, 2.63 ± 0.29, 3581 ± 601 Bq kg of Ra, Th, and K, respectively. Based on the measured activities, the radiological health hazard parameters are assessed and compared with the U.S. acceptable dose limits. [ABSTRACT FROM AUTHOR]