Radiological Assessment of Soils on the Waysides of the Road Underconstruction in Ijebu-Ode, Ogun State, Southwestern Nigeria

Abstract

The ongoing road construction and rehabilitation of major highways in Ijebu-Ode involved the grading, refilling of the roads with different types of soils and the use of various materials that may be radioactive. Therefore the construction and the rehabilitation of the roads may lead to enhancement of the natural radioactivity levels in the area. Soil samples were collected from the sideways of the roads and analysed using a single crystal 0.51cm x 0.51cm NaI (Tl) detector, manufactured by Scintitech Instrument, USA, is coupled through a Hamamatsa (R1306NSV3068) photomultiplier tube to a Multichannel Analyser, MCA (2100R:01) manufactured by Price gamma Technology, USA. The activity concentrations in the entire area of study were 396.1±70.9 Bqkg^-1, 17.7±4.6 Bqkg^-1, and 33.9±6.7 Bqkg^-1 for ⁴⁰K, ²²⁶Ra and ²³²Th respectively. The absorbed dose rate and the outdoor effective dose rate were 27.6±5.5 nGyh^-1and 33.9±6.7µSvy^-1 respectively. The collective health detriment was 1.1 x 10^-4. The radiological health effect on the populace in the area were insignificant as the results showed very low radioactivity levels and collective health detriment indicated that 11 out of 100,000 people were vulnerable to any type of cancer.

Keywords: Impact assessment, natural radioactivity, road constructions, health detriment, Nigeria