Estimation of Radiation levels due to Organic Agricultural Fertilizers

The usage of organic fertilizers in Iraq is increased because of the land reclamation and agriculture activities. The ore of some organic fertilizers contains various a mounts of natural radioactive elements such as 238U, 232Th and 40K. For this reason, organic fertilizers are considered one of many sources of radionuclide and radioactivity in the environment. So, it becomes necessary to study the naturally occurring radioactive materials (NORMs). In order to assess the level index for organic fertilizers, the specific activities of 238U, 232Th and 40K were measured by using a gamma ray spectrometer based on a NaI(Tl) detector. The results show that the specific activities of 238U, 232Th and 40K are (11.53-68.71 Bq/kg), (10.78 -52.33 Bq/kg) and (165.21- 3592.78 Bq/kg) respectively. The radium equivalent activity were also calculated and found to vary from (155.40-2842.86 Bq/kg), the radium equivalent activities were lower the world average in eight samples. In general, the results indicated that the highest level of radium equivalent activity was in animal organic fertilizers. The level index of organic fertilizers was calculated and the maximum value of level index is 2.91 which is found in local animal organic fertilizer, while the minimum value is 0.3 which is found in imported plant organic fertilizer.