Assessment of health risk levels associated with terrestrial gamma radiation dose rates in Nigeria

Abstract

A decree on radiation safety and protection have been signed by the Federal Government of Nigeria that established a regulatory body to control the importation, application, transportation and disposal of radioactive materials in the environment. The fundamental function of the body is embodied on radiation protection of the country's population and the environment. However, the protection and assessment of any radiation pollution in the environment to a large extent is based on the knowledge of the baseline of radiation dose rate levels due to natural radionuclides. This study assesses the risks associated with terrestrial gamma radiation dose rate levels in some cities across the major geological formations of the country. Results showed that in the Northern region the number of individuals at risk of incurring cancer ranged between 0.25 and 3.25 yr −1 with an average value of 1.46±0.45, while in the southwestern region it ranged between 0.76 and 5.50 yr −1 with a mean value of 1.66±0.63 and in the southeastern region it was between 0.17 and 0.89 yr −1 with a mean value of 0.35±0.14. Assuming uniform exposure for the entire population of 98.5 million, it has been estimated that about 160 individuals annually are at risk of incurring cancer due to exposure to terrestrial gamma radiation.