Spatial and seasonal characteristics of heavy metals in Ikpa River, Niger Delta - Nigeria

Spatial and seasonal trend of Lead (Pb), Iron (Fe), Nickel (Ni), Cadmium (Cd), Chromium (Cr), and Copper (Cu) in surface waters of Ikpa River were determined using standard methods. The twelve months survey revealed spatial and seasonal variations. In wet season, average concentrations of heavy metals followed the pattern: Fe > Cd > Ni > Pb > Cu > Cr with concentration values 0.59 mg/L, 0.0105 mg/L, 0.005075 mg/L, 0.002575 mg/L, 0.00225 mg/L, 0.000325 mg/L respectively. In dry season, average concentrations followed the pattern Fe > Cu > Cd > Ni > Cr > Pb with concentration values of 3.01 mg/L, 0.6075 mg/L, 0.0065 mg/L, 0.000575 mg/L, 0.000325 mg/L, 0.000165 mg/L respectively. Heavy metal levels in Ikpa River were within the recommended limits set by World Health Organization (WHO). In dry season however, Cu levels across the stations exceeded the guidelines of Federal Environmental Protection Agency (FEPA). Statistically, there was no significant difference in the seasonal variations of respective heavy metals concentrations, except for Fe which showed significant difference in stations one (t = 3.635, p