Radiological impact on uncultivated soil and Dittrichia viscosa plants around a Lebanese coastal fertilizer industry

Abstract

Chemical fertilizers, phosphate ore treatments, and phosphogypsum wastes contribute to enhanced levels of natural radionuclides in the environment. A total of 27 soil samples were collected from nine uncultivated sites around a Lebanese fertilizer plant in order to analyze the gamma emitter radionuclides (238U,232Th,226Ra,210Pb,137Cs, and40K) and to assess the radiological impact on the surrounding environment, through the calculation of different radiological index parameters. In addition, a total of 27 Dittrichia viscosa plant samples were gathered including roots, leaves, and stems, and the radionuclide transfer factors were determined. Measurements were conducted using a gamma spectrometer with high-purity germanium detectors. The highest values measured in soil samples were 77 ± 9 Bq/kg, 102 ± 10 Bq/kg, and 143 ± 5 Bq/kg for238U,226Ra, and210Pb, respectively.40K levels were comparable to other Lebanese provinces and about 50% less than the worldwide average value. The results showed the absence of radionuclide transfer between soil and plants, except for40K. The average values of the total absorbed dose rate and the annual effective dose were comparable to the worldwide average values. Therefore, the external exposure index and Radium equivalent were found to be below the international recommended values.

Keywords

• radiological index parameters
• fertilizer plant
• gamma emitters
• gamma spectrometer
• phosphogypsum
• radionuclides