Radiological Assessment of Primordial Radionuclides in Crab Species from Igbokoda River in Southwest of Nigeria

Abstract

Olusegun  Sowole* and  Adesoji A. R. Adebambo

Primordial radionuclides are natural radionuclides of specific half-lives that are capable of disintegrating with the release of ionizing radiations along with huge amount of energy which can be so harmful to living organisms. Activity concentrations and radiological indices of ⁴⁰K, ²²⁶Ra and ²²⁸Ra in crab species from Igbokoda River in the coastal area of South Western Nigeria, have been determined using gamma spectrometry method. Twenty (20) samples of three different species (Callinectes latimanus, Callinectes amnicola and Cadiosoma armatum) of crabs were collected from the River. The results obtained indicated that the highest dose rates of ⁴⁰K, ²²⁶Ra and ²²⁸Ra were associated with Callinectes latimanus while the highest annual committed effective dose of ⁴⁰K to man was 0.0026mSvyr^-1 and was associated with Callinectes latimanus for ²²⁶Ra (0.0068mSvyr^-1) and ²²⁸Ra (0.0208mSvyr^-1). The highest excess lifetime cancer risk associated with ⁴⁰K, ²²⁶Ra and ²²⁸Ra 0.0237 x 10^-3 0.0728 x 10^-3. All the values obtained were within the limits recommended globally; indicating that there was no significant radiological health implication to the aquatic animals and man the consumer.