Evaluation of Health Risks from Exposure to Low Levels of Ionizing Radiation in Some Oil Spilled Communities of Rivers State, Nigeria

Abstract

Background: Oil spillage is often an unintended release of crude oil into the environment as a result of human activity. Crude oil spills in the oil and gas installations, radionuclide material used for geological mapping, well logging and other related activities can also increase the background ionizing radiation. Long term exposure to this low level radiation can lead to many health related risks. Aim: The aim of this study is to evaluate the health risk from exposure to low levels of background ionizing radiation in some oil spilled communities of Rivers State. Method: An in-situ measurement of radiation exposure rate of Bon-ngia, Bolte-kpan, Te-oo-goo and Nupene communities were done using well calibrated radalert-50 and 100 meters, a Global Positioning System (Garmin 765) and radiation models. Results: The mean background radiation exposure rate of Bon-ngia, Bolte-kpan, Te-oo-goo and Nupene are 0.0110±0.005, 0.0132±0.002, 0.0103±0.003 and 0.0113±0.003 mRh-1 respectively. The mean of absorbed dose rates, annual effective dose equivalent (AEDE), are within their permissible safe values while the mean excess lifetime cancer risk calculated were slightly higher than the safe value. The estimated dose to organs showed that the testes have the highest organ dose of 0.11 mSvy-1 while the liver has the lowest organ dose of 0.06 mSvy-1. The radiation contour maps of the study area presented the distribution of radiation within the spilled communities. The estimated excess lifetime cancer risk values indicates that the chance of contracting cancer for residents of the study is low and the effective dose from present exposure rate to the adult organs investigated is insignificant.