Résumé
Radioactivity measurements were carried out in and around Warri Refining and Petrochemical Company in the Niger Delta region of Nigeria for the naturally occurring radionuclides of 40K, 238U and 232Th. The values were used to determine the excess lifetime cancer risk (ELCR) and the radiation health hazard indices. Results show that the ELCR value within the company premises is 0.12×10-3 while the highest value was 0.17×10-3 from Ugborikoko Community. The internal health hazard index ranged from 0.02 – to 0.64 and the external health hazard index ranged from 0.02 – 0.33. All these values were less than the world permissible standards. It could be concluded that the potential carcinogenic risk from gamma radiation doses to the population in and around the refining and petrochemical company is low.