Assessment of outdoor gamma exposure levels at some borehole and well sites in Dutse, Nigeria

Abstract

The lives on the earth are continuously exposed to ionizing radiation originating mainly from natural sources. Fortunately, the associated health hazard is not an acute problem globally. However, health complications are inevitable in areas assumed to have high background ionizing radiation levels. The present study aims to unveil the scenarios of outdoor gamma radiation levels at Dutse, the northwestern part of Nigeria. In this study, gamma exposure levels (GEL) across sixty-six (66) selected boreholes and local wells located in the said region have been measured using a well-calibrated hand dosimeter (Radiation Alert Inspector). Using the GEL values some significant radiation parameters were calculated to determine the possibility of radiological health risks to the local people. The measured gamma exposure level around the boreholes is seen to vary from 1.1 - 1.9 μrem/hr with a mean of 1.5 μrem/hr and around the wells it ranges between 1.1 – 1.8 μrem/hr with a mean of 1.5 μrem/hr. For boreholes, the estimated annual effective dose (AED) varies between 13.50 – 23.31 μSv/yr with a mean of 17.29 μSv/yr and for wells the same resulted 13.50 – 22.08 μSv/yr with a mean of 17.92 μSv/yr. All the obtained dose values are lower than the UNSCEAR proposed world average level of 70 μSv/yr. The estimated average ELCR values was found to be 0.061 × 10-3 and 0.064 × 10-3 for boreholes and wells respectively. All findings were below the UNSCEAR recommended world average level of (0.29 × 10-3). In summary, this work indicates a low risk of exposure to outdoor ionizing radiation among the inhabitants around the study locations.