Assessment of Heavy Metal Pollution in Surface Water of the Qua Iboe River, Aka Ibom State, Nigeria

Abstract

Authors: A. Odoemelam, A. I. Okoro and A. M. Udongwo

Concentrations of Cd, Pb, Cr, Co, Cu, Se and Ni ions in Qua Iboe River system were assessed by analysing water samples collected from the river

at Iwuochang, Mkpanak, Ukpenekang, Atabong, Eketai, and Marina stations. The results obtained indicate that the overall mean concentrations for Cd, Pb, Cr, Co, Cu, Se and Ni ions in the samples were 44.22±44.71, 24.75±21.15, 39.78±34.24, 48.64±42.19, 64±62.33, 1.15±0.40 and 55.39±68.07

µg/L, respectively. These concentrations were higher than NESREA’s limits for surface waters. On comparing these values with the WHO standard for potable water, it was observed that the mean concentrations were higher than the acceptable limits. The coefficient of variations of the metals were also high with high degree of fluctuations in metal concentrations from station to station. Findings from this study show that Qua Iboe River, at the time of the present study, was polluted especially with respect to cadmium, lead and nickel. Copper was the most abundant metal ion while selenium had the lowest score. Highest concentrations of all the heavy metal ions were observed at Atabong and the general trend was Cu>Ni>Co>Cd>Cr>Pb>Se. The conclusion deduced from the present study that the pollution load of the Qua Iboe River system is on the increase corroborates previous reports on the river. This state of affairs portends serious threat to the health of this aquatic ecosystem and humans within the catchment of the river who depend on the river for seafood.