Uranium Concentration in Groundwater and Assessment of Radiation Doses Within Naraguta Sheet 168, North Central Nigeria

Abstract

Water samples collected from 60 wells located within Naraguta Sheet 168 in North Central Nigeria were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) for uranium concentrations and other selected trace elements. This is aimed at assessing the radiation dose arising from intake of uranium through drinking water pathway for different age groups in the area. Results obtained show that uranium concentration in groundwater within the study area is generally within the acceptable reference level of 0.1mSv/y except in some places around Bukuru, Rayfield and Bishichi areas underlain mainly by the Jos-Bukuru Younger Granite Complex. The uranium values in groundwater within Naraguta Sheet 168  vary from 0.02-168.7 ppb, representing an activity concentration of 0.516-4.353 mBq/l. Radiation dose due to intake of uranium through drinking water pathway from the area is calculated to be 0.045-378.098 (µSv/y) among infants of 0-6 months, 0.051-432.112 (µSv/y) among infants of 7-12 months,  0.029-247.829 (µSv/y) among children between 1-3 years of age, and 0.026-216.056 (µSv/y) for children between 4-8 years. For 9-13 years old male children, it is 0.031-259.267 (µSv/y), while for the female children of the same age range, it is 0.031-259.267 (µSv/y). Male teenagers of between 14-18 years receives 0.042-351.250 (µSv/y) and female in the same age category receives 0.042-244.811 (µSv/y). Among the adult males older than 18 years, the radiation dose is 0.031-264.710 (µSv/y) and among females of 18 years and above, it is 0.023-193.021 (µSv/y). With effective dose due to uranium in water exceeding the reference level of 0.1mSv/y in some localities, it is therefore necessary to always carryout radiological investigations alongside analysis of major anions and cations present in the groundwater for safety reasons.

Keywords: Uranium. Activity Concentration. Dose Rates. Ingestion Dose Co-efficient. Naraguta Sheet 168. Jos-Bukuru Younger Granite Complex.