Natural Radionuclides And Potential Radiological Hazard Associated with Consumption of Water, Oreochromis niloticus and Chrysichthys nigrodigitatus from Ero Dam, Ekiti, Nigeria

Abstract

Introduction: This study aims to evaluate the potential radiological hazard associated with the consumption of water and fish products from Ero Dam.Material and Methods: The activity concentrations of 238U, 232Th and 40K in the samples were determined using gamma ray spectrometry.Results: Mean activity concentrations of 238U, 232Th and 40K in water were 8.49 1.38, 4.12 0.40 and 150.99 10.80 Bq/l respectively. In Oreochromis niloticus and Chrysichthys nigrodigitatus mean specific activity were 23.17 7.25, 14.25 , 740.86 Bq/kg and 77.92 , 16.26 1.63, 842.90 Bq/kg respectively. Average annual effective dose for water (Hw) was 1.58 mSv/yr and for fish edible tissue (Hf) 0.16 mSv/yr. Mean concentrations of 232Th and 40K in water are 312% and 1400% higher than guidance levels and mean specific activity for 238U and 232Th in fish were about three orders of magnitude higher than reference values. Mean Hw is about 1500% higher than the reference level and the average Hf for fish is 540% higher than the recommended Hf for natural radionuclides in fish products. Mean ELCR from consumption of water, Oreochromis and Chrysichthys are 1900%, 62% and 131% higher than the world’s average value from carcinogens respectively.Conclusion: Continuous consumption of water and fish products from Ero Dam is associated with potential radiation risks.

Keywords

• excess life cancer risk
• annual effective ingestion dose
• water
• fish
• gamma spectrometry