Evaluation of Health Effect of Gamma Radiation from Uburu and Okposi-Okwu Salt-Lakes in Ebonyi State, During Rainy and Dry Seasons

Abstract

A comparative study of the gamma radiation in Uburu and Okposi-Okwu Salt-Lakes located in Ohaozara Local Government Area of Ebonyi State, during rainy and dry seasons was carried out using a hand-held RadEye G20–ER10 gamma survey meter and a geographical position system. Three samples were taken randomly from five different points of the two Salt-Lakes and their host communities during both seasons and their averages were recorded. An in-situ exposure rate measurements were used to evaluate the absorbed dose rate, the annual effective dose and the Excess Lifetime Cancer Risk. The results obtained were compared with the world average so as to determine the health risk to the studied environment. The mean exposure rate, absorbed dose rate (ADR), annual effective dose (AED), and excess lifetime cancer risk (ELCR) from Uburu and Okposi-Okwu Salt-Lakes during rainy season were 0.139 µSv/h, 138.8 nGy/h, 0.170mSv/y and 0.596×10-3; 0.123 µSv/h, 121.8 nGy/h, 0.149mSv/y and 0.523×10-3 respectively. Also, the mean exposure rates, ADR, AED, and ELCR from Uburu and Okposi-Okwu Salt-Lake during dry season were 0.177 µSv/h, 176.6 nGy/h, 0.216mSv/y and 0.758×10-3; 0.174 µSv/h, 173.3 nGy/h, 0.213mSv/y and 0.746×10-3 respectively. All the assessed results are higher than the world standard value for the general public. These results showed that the studied areas are radiation contaminated. The results within the Salt Lake environment are higher than the results from their host communities. This may be attributed to the activities within the Salt Lake environment such as local salt processing. Also, the results from the two studied areas during dry season were higher than that of the rainy season.