Assessment of Natural Radioactivity in Phosphate Ore, Phosphogypsum and Soil Samples Around a Phosphate Fertilizer Plant in Nigeria

The radionuclides present in phosphate ore, phosphogypsum and soil samples in the vicinity of a phosphate fertilizer plants in Nigeria were identified and their activity concentration determined to assess the potential radiation impact on the environment due to fertilizer production. The mean activity concentration of U-238, Th-232, and K-40 radionuclides in phosphate ore samples were 616 +/- A 38.6, BDL (Below Detection Level) and 323.7 +/- A 57.5 Bq kg(-1) respectively. For the phosphogypsum, 334.8 +/- A 8.8, 4.0 +/- A 1.4, and 199.9 +/- A 9.3 Bq kg(-1) respectively and for soil samples range from 20.5 +/- A 7.3 to 175.7 +/- A 10.5 Bq kg(-1) for Ra-226, 15.5 +/- A 1.5 to 50.4 +/- A 0.6 Bq kg(-1) for Th-232 and 89.5 +/- A 8.1 to 316.1 +/- A 41.3 Bq kg(-1) for K-40 respectively. The mean absorbed dose rate was 71.4 nGy h(-1). The mean annual effective dose was 86 mu Sv.