Analysis of Fluoride Concentration in Drinking Water Sources in Selected Communities of Yobe State

Fluoride is an essential trace element at low concentrations but becomes toxic when ingested above safe limits, causing dental and skeletal fluorosis, both of which have been documented in communities across North East Nigeria. This study analysed fluoride concentration in drinking water sourced from boreholes, hand-dug wells, and surface water in five communities of Yobe State. A total of sixty water samples were collected and analysed for fluoride using the SPADNS colorimetric method with a spectrophotometer. Water samples were also characterised for pH, electrical conductivity, temperature, and total dissolved solids. Fluoride concentrations ranged from 0.3 to 4.8 mg/L across the sampled sources, with the WHO recommended maximum of 1.5 mg/L exceeded in 38 percent of samples. Borehole samples showed the highest fluoride levels, with an average of 2.6 mg/L, consistent with fluoride-bearing geological strata common in northern Nigeria. Surface water sources had the lowest concentrations, averaging 0.5 mg/L. A positive correlation between electrical conductivity and fluoride concentration was observed. Clinical observation data obtained from health records at the local government health facility confirmed a high prevalence of dental fluorosis in children from communities where fluoride levels were highest. The study highlights the urgent need for defluoridation treatment of borehole water in affected communities, promotion of low-fluoride water sources, and health education campaigns on fluorosis prevention in Yobe State.

Keywords: fluoride, drinking water, fluorosis, SPADNS method, Yobe State