MEASUREMENTS OF SEASONAL VARIATIONS OF RADIOACTIVITY DISTRIBUTIONS IN RIVERINE SOIL SEDIMENT OF ADO-ODO OTA,...

Area of Science:

• Environmental Science
• Radiological Science
• Geoscience

Background:

• Riverine environments can accumulate naturally occurring radioactive materials.
• Understanding seasonal variations in radioactivity is crucial for environmental and health risk assessment.
• Previous radiological assessments in the Ado-Odo Ota region are limited.

Purpose of the Study:

• To evaluate the seasonal variation of radioactivity levels in the riverine area of Ado-Odo Ota.
• To measure gamma dose rates and specific radionuclide concentrations (U-238, Th-232, K-40).
• To assess radiological risks by comparing measured values with international safety standards.

Main Methods:

• Utilized a hand-held gamma-ray survey meter for radioactivity measurement.
• Employed NaI (Tl) based gamma spectroscopy for detailed analysis.
• Applied Monte Carlo simulation to determine probability percentiles for risk assessment.

Main Results:

• Measured gamma dose rate was 79 nGy/h, approximately 34% higher than the world average (59 nGy/h).
• Mean activity levels for U-238, Th-232, and K-40 were 26.1, 55.6, and 499.3 Bq/kg, respectively.
• Radium equivalent activities and absorbed dose rates were found to be within recommended safety limits.

Conclusions:

• The study establishes baseline radioactivity data for the Ado-Odo Ota region.
• While gamma dose rates exceed the global average, radiological risks are currently within acceptable limits.
• The findings are vital for monitoring dose rates and radiological risks across West Africa.