ABSTRACT
The contamination of groundwater by heavy metals presents significant environmental and public health concerns. The spatial distribution of heavy metals in groundwater was analyzed using kriging and interpolation techniques to estimate the concentration variability across the study area. Interpolation maps were used to illustrate the distribution patterns of iron (Fe), manganese (Mn), nickel (Ni), sodium (Na), potassium (K), copper (Cu), magnesium (Mg), calcium (Ca), and zinc (Zn) in groundwater within Ago-Isiame and environs. A total of 15 groundwater samples were randomly collected, filtered, acidified, and analyzed using Atomic Absorption Spectrophotometry (AAS). Geospatial analysis, conducted using kriging interpolation techniques, revealed distinct spatial patterns of heavy metal distribution in groundwater. Manganese (Mn) concentration ranged from 0.035 to >0.0601 mg/L and peaked in the Northwestern region, indicating it as the pollution hotspot. Zinc (Zn) ranged from 0.5 to >0.701 mg/L, also concentrated in the Northwest, indicating it as the pollution hotspot. Nickel (Ni) varied from 0.03 to >0.401 mg/L and exhibited its highest levels in the Northwest, marking the Northwest as the contamination hotspot for Nickel. Sodium (Na) ranged from 0.24 to >0.301 mg/L, with the contamination hotspot observed in the Southeastern region. Potassium (K) varied from 2.5 to >3.301 mg/L and had its hotspot in the Southern region. Copper (Cu) ranged from 0.24 to >0.34 mg/L and was predominantly concentrated in the Northwest. Iron (Fe) ranged from 0.9 to 1.80 mg/L and showed peak concentrations in the Northwest as its contamination hotspot. Magnesium (Mg) and Calcium varied from 5.5 to >7.01 mg/L and 1.2 to >1.601 mg/L respectively. Both metals were highest in the Southeastern region as their contamination hotspot. The spatial distribution analysis indicates that the Northwestern region is the primary hotspot for Fe, Mn, Zn, Ni, and Cu contamination, likely due to both geogenic sources and anthropogenic activities such as mining and industrial discharge. In contrast, the Southeastern region exhibited elevated concentrations of Na, Mg, and Ca, which may be attributed to natural hydrogeological processes and human influences
