Environmental risk assessment of natural background radiation and estimation of lifetime cancer risk in Ogwashi-Uku, Delta State, Nigeria

Abstract

This study aims to evaluate and measure the level of background radiation providing a radiometric map of the area that includes the effective dose and lifetime cancer risk to the local populace. A portable handheld GQ GMC-320 radiation detector was used to measure background radiation at selected locations within Ogwashi-Uku. To measure background radiation, a total of ten locations were chosen. For each measurement point, readings were taken and the average was noted with a 2- minutes interval. The result shows that the highest and lowest dose rates absorbed were 90.0 and 34.2 (nGy/ hr) respectively and the annual effective dose (AED) of 0.16 and 0.44 mSv/yr. In Ogwashi-Uku, the excess average lifetime cancer risk was 1.76 × 10⁻³ and 0.64 × 10⁻³ , respectively. The AED from background radiation in the selected locations were below the permissible limit of 0.48 mSv/yr. It is however safe to conclude that there is no health challenge to the local populace from high levels of effective dose.