Radiation hazards assessment of phosphate fertilizers used in Latifiyah region, Iraq

• Main Authors: Neymea Al-Mousawi, Raghad Mouhamad, Naseer Alsaadie
• Format: Article
• Language: English
• Published: E-NAMTILA 2020-07-01
• Series: Dysona. Applied Science
• Subjects: phosphate fertilizers; natural radionuclides; gamma spectrometry; radiation hazard indices
• Online Access: http://applied.dysona.org/article_109573_5b584670e27ad7fb63d2516211c4ec45.pdf

The excessive use of fertilizers has become a necessity to support agricultural production in vast areas in Iraq. Phosphate fertilizers are known to contain relatively high concentrations of uranium‐238 (238U), radium‐226 (226Ra), thorium‐232 (232Th), and potassium‐40 (40K) radionuclides which accumulate in soil with time. In the current study, gamma-ray spectrometry was used to measure the radioactivity concentration of naturally occurring radionuclide in fertilized and non-fertilized soil samples within Latifiyah region in Iraq. The results showed that the average concentrations of 226Ra, 232Th, and 40K in fertilized soil were 12.7, 10.6, and 334 Bqkg-1 respectively which was 30.6%, 29.4%, and 12.9% higher than its concentration in non-fertilized soils with 8.81 7.48 and 291 Bqkg-1. Additionally, the average values of radium equivalent activity (Raeq), absorbed dose rates 𝐷 (nGyh−1), annual effective dose (indoors and outdoors), external hazard index (Hex), and Excess Lifetime Cancer Risk (ELCR) for fertilized and non-fertilized soils samples were evaluated. The results showed that the studied indices were 53.6 Bqkg−1, 26.4 nGyh−1, (0.129 and 0.032 mSvy−1), 0.145 Bqkg-1, 0.106 respectively in fertilized soils compared to 41.9 Bqkg−1, 20.7 nGyh−1, (0.102 and 0.025 mSvy−1), 0.113 Bqkg-1, 0.084 in non-fertilized samples. The Mann-Whitney U test showed a significant difference (p <0.05) between the studied fertilized and non-fertilized soils in terms of radioactivity concentrations in addition to all the investigated radiation hazard indices. However, the mean values of radioactivity concentrations and radiological hazard indices for study soils were well below the internationally recognized and therefore, fertilizer rates did not pose any radiological risk.