Radioactive Concentrations in Chemical Fertilizers

Abstract

Background: The aim of the present study was to determine radioactive concentrations in fertilizers known to contain essential nutrients. Results of this study could be used as basic data to monitor the impact of chemical fertilizers on the environment and public health. Nitrogen fertilizers, calcium fertilizers, sulfur fertilizers, phosphate acid fertilizers, and potassium chloride fertilizers were used in this study.Materials and Methods: Five chemical fertilizers were pulverized, placed in polyethylene containers, and weighed. The time to measure each specimen was set to be 3,600 seconds for a scintillator-based gamma-ray spectroscopy system. Concentration of gamma radionuclide was analyzed based on obtained spectra. At the end of the measurement, the spectrum file was stored and used to calculate radioactive concentrations using a gamma-ray spectrometer software.Results and Discussion: In the nitrogen fertilizer, 3.49 ± 5.71 Bq/kg of <sup>137</sup>Cs, 34.43 ± 7.61 Bq/kg of <sup>134</sup>Cs, and 569.16 ± 91.15 of <sup>40</sup>K were detected whereas <sup>131</sup>I was not detected. In the calcium fertilizer, 5.74 ± 4.40 Bq/kg of <sup>137</sup>Cs (the highest concentration among all fertilizers), 22.37 ± 5.39 Bq/kg of <sup>134</sup>Cs, and 433.67 ± 64.24 Bq/kg of <sup>40</sup>K were detected whereas <sup>131</sup>I was not detected. In the sulfur fertilizer, 347.31 ± 55.73 Bq/kg of <sup>40</sup>K, 19.42 ± 4.53 Bq/kg of <sup>134</sup>Cs, 2.21 ± 3.49 of <sup>137</sup>Cs, and 0.04 ± 0.22 Bq/Kg of <sup>131</sup>I were detected. In the phosphoric acid fertilizer, 70,007.34 ± 844.18 Bq/kg of <sup>40</sup>K (the highest concentration among all fertilizers) and 46.07 ± 70.40 Bq/kg of <sup>134</sup>Cs were detected whereas neither <sup>137</sup>Cs nor <sup>131</sup>I was detected. In the potassium chloride fertilizer, 12,827.92 ± 1542.19 Bq/kg of <sup>40</sup>K was and 94.76 ± 128.79 Bq/kg of <sup>134</sup>Cs were detected whereas neither <sup>137</sup>Cs nor <sup>131</sup>I was detected. The present study examined inorganic fertilizers produced by a single manufacturer. There might be different results according to the country and area from which fertilizers are imported. Further studies about inorganic fertilizers in more detail are needed to create measures to reduce <sup>40</sup>K.Conclusion: Measures are needed to reduce radiation exposure to <sup>40</sup>K contained in fertilizers including phosphoric acid and potassium chloride fertilizers.