Study of activity concentrations of ⁴⁰K, ²³⁸U and ²³²Th for assessment of radiation dose in agricultural soils of southwestern Nigeria

ABSTRACT

Gamma spectrometric measurement of natural radionuclides activity concentrations by HPGe detectors was conducted in 150 agricultural soil samples collected from six states of southwestern Nigeria. The overall activity concentrations of radionuclides ranged from 15.27 to 972.00 Bqkg⁻¹ for ⁴⁰K, 0.66 to 336.19 Bqkg⁻¹ for ²³²Th and 1.32 to 123.01 Bqkg⁻¹ for ²³⁸U, with mean values of 143.95, 17.02 and 22.92 Bqkg⁻¹, respectively. The overall averages results from this study were generally lower than worldwide average value of 420, 33 and 45 Bqkg⁻¹ for ⁴⁰K, ²³⁸U and ²³²Th, respectively, thus minimal transfer to plant may be expected. The estimated radiation dose levels of the soil indicated acceptable limits for general public exposure. The radioactivity levels of ⁴⁰K, ²³²Th and ²³⁸U in the investigated agricultural soil of southwestern Nigeria are within acceptable limits. Therefore, stochastic radiological health effects of radiation exposure by farmers may not be feasible at the current moment.

KEYWORDS:

• Agricultural soil
• natural radioactivity
• activity concentration
• radiological hazard
• southwestern Nigeria

Acknowledgment

The authors are grateful to the University of Coimbra Environmental Research Laboratory, Portugal, for their kind gesture in allowing us to carry out the radioactivity measurement in their laboratory.

Disclosure statement

The authors of this study have agreed and declared that no any conflicting interest exist between them as regard to the study.

Availability of data and materials

The datasets and other relevant materials generated in the course of the study can be made available by the corresponding author upon reasonable request.

Additional information

Funding

The study did not receive any financial grant or assistance from any institution, agencies or cooperate body.