Natural Radioactivity In Poultry Rations And DCP For Bovine Nutrition

The aim of this study is to determine the level of radioactivity present in samples of poultry rations and dicalcium phosphate (DCP) used for cattle feed. Knowledge of these levels is of fundamental importance, because part of this radioactivity will possibly be transferred to humans. The radiation found in such samples is due to the presence of radioactive series of ²³⁸U and ²³²Th and ⁴⁰K. Measurements were performed with a 66% HPGe detector at the Laboratory of Applied Nuclear Physics, State University of Londrina. The measured samples were commercialized in Londrina, Brazil, in the second half of 2007. The accommodation recipient of the samples was a 1 L Marinelli beaker. Poultry rations were divided into two types: for young chickens and adult chickens. Among these, the ration for adult chickens showed the highest values for the activities of ²²⁶Ra and ²²⁸Ra, 0.23±0.17 and 0.493±0.091 Bq/kg respectively. But the ration for young chickens showed the highest activity for the ⁴⁰K, 304±15 Bq/kg. The DCP sample showed a much higher value for the series of ²³⁸U and ²³²Th, 83±26 and 7.79±0.70 Bq/kg, respectively. However, the ⁴⁰K activity in this sample was about 5 or 6 times lower than samples for poultry feed, reaching 46.6±2.8 Bq/kg.