Statistical relationship between activity concentrations of radionuclides ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs and geological formations in surface soil of Jordan

ABSTRACT

An extensive study was conducted to determine the activity concentrations of natural and artificial radionuclides ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs in soil samples of each governate of Jordan. A total of 370 samples have been measured using a high-purity germanium detector. The activity concentration for ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs has mean values of 42 ± 3, 23 ± 3, 309 ± 21, and 3.7 ± 0.9 Bq kg^–1, respectively. The highest mean activity concentration for ²²⁶Ra was found to be 138 ± 4 Bq kg^–1 in the Alkarak governate. In the Ajloun and Jarash governates, the highest mean activity concentration was 35 ± 3 Bq kg^–1 for ²³²Th, and 14.2 ± 1.9 Bq kg^–1 for ¹³⁷Cs, respectively. Geological influence on the activity concentrations was investigated using the one-way analysis of variance (ANOVA) and independent samples. The ANOVA results indicate that there are strong significant differences between the activity concentrations of ²³²Th, ⁴⁰K, and ¹³⁷Cs based on geological formations the radionuclides occur. The main contribution to gamma dose rate was due to ²²⁶Ra activity concentration. Radium equivalent and external hazard index are associated with a mean value of 98 Bq kg^–1, and 0.266, respectively.

KEYWORDS:

• Activity concentrations
• geological formation
• Jordan
• natural radioactivity
• radiological hazard
• radionuclides
• soil
• statistical analysis

Acknowledgements

Technical support received by Jordan atomic energy commission, water authority of Jordan, and energy and minerals regulatory commission was acknowledged.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors would like to thank the Ministry of Higher Education Malaysia (MOHE) and Universiti Teknologi Malaysia (UTM) for support and funding under UTM Research University Grant [grant number Q. J130000.2546.19H71].