Distribution and Pollution Index Analysis of Heavy Metals in Kolo Creek, Ogbia, Bayelsa State, Nigeria
Abstract
Sediment samples were collected from four designated points along the shores of Kolo Creek and analyzed for heavy metal concentrations using an atomic absorption spectrophotometer (AAS). The heavy metals investigated included lead (Pb), cadmium (Cd), nickel (Ni), chromium (Cr), copper (Cu), zinc (Zn), arsenic (As), cobalt (Co), and iron (Fe). The results revealed that lead (Pb) concentrations ranged from 4.899 ± 1.004 to 7.541 ± 1.123 mg/kg, Cd; 1.596±0.096 - 3.714±0.431 mg/Kg, Ni; 6.728±1.205 - 9.478±1.879 mg/Kg, Cr; 3.716±0.310 - 7.742±1.365 mg/Kg, Cu; 5.432±1.006 - 11.516±1.984 mg/Kg, Zn; 6.534±1.120 - 12.481±2.126 mg/Kg, As; 0.189±0.012 - 2.274±0.189 mg/Kg, Co; 0.943±0.048 - 3.653±0.334 mg/Kg and Fe; 181.581±8.972 - 238.416±10.055 mg/Kg. The concentrations of the studied heavy metals were further evaluated using selected pollution indices to determine their sources and environmental implications. The contamination factor results indicated that the sediments are generally unpolluted by the assessed heavy metals, although some metals were observed at the preliminary stage of contamination. The geo-accumulation index revealed low levels of contamination, suggesting that the presence of heavy metals in the sediments originates from both anthropogenic and non-anthropogenic sources. Ecological risk assessment showed that the sediments pose minimal to no ecological risk. However, the enrichment factor analysis indicated significant enrichment of certain heavy metals in the creek. These findings highlight the need for continuous monitoring of Kolo Creek to prevent potential accumulation and future environmental deterioration.