Determination of concentrations and Annual Effective Dose of Pb, Cr, Rn in Groundwater Sources in Shika and Zaria City, Kaduna State, Nigeria

The levels of some physicochemical parameters, heavy metals and 222Rn in some underground water of Shika and Zaria, Nigeria are reported. The Cr in the hand-dug wells and borehole water was in the range of 0.008 ± 0.006 mg/L to 0.338±0.39 mg/L for the rainy, and 0.09± 0.13 mg/L to 0.66 ± 0.06 mg/L for the dry season; while Pb ranged from 0.001 ± 0.00 mg/L to 0.862 ± 0.569 mg/L for rainy season in Shika and Zaria. The 222Rn concentration ranged from 0.1 ± 0.0141 Bq/L to 66.56Bq/L for rainy and 1.5 ± 0.0141Bq/L to 71.53 ± 0.007 Bq/L for dry season. The borehole samples have higher 222Rn than the permissible limit and most physicochemical parameters of Shika water were within the safe limit. The highest annual effective dose was 14.30 µSv/year and 12.0 µSv/year in the rainy and dry seasons respectively. There was significant difference between the parameters across the season. Therefore, caution should be taken to avoid the elevation of these elements in water bodies as a result of anthropogenic activities.