Concentrations of selected heavy metals in sediments of ifie creek and a section of Warri River, delta state, Nigeria.

Sediments of rivers or streams close to industrial areas and receive effluents or drains from these industries often contain pollutants received from these industries e.g. heavy metals. Ifie Creek and the section of Warri River studied are located near the industrial areas of Ekpan and Warri (Ubeji) and they also receive effluents and drains from industries in these areas. Sediment samples were collected from Ifie Creek and section of Warri River in two wet seasons and two dry seasons (for two years, i.e. from June, 2009 to March, 2011). Concentrations of four heavy metals (Cd, Pb, Ni and Fe) were determined by Atomic absorption spectrometry after appropriate wet digestion with 2M HNO3. Important results obtained for study area and given in mean±standard deviation are, Cd (1.62±0.50 mgkg-1), Pb (4.55±0.71 mgkg-1), Ni (4.6±1.1 mgkg-1), and Fe (345±62 mgkg-1). Concentrations of all metals decreased from upstream to downstream. The average value of Cd in the study area very much exceeded corresponding value in the control area. It also exceeded guideline values with which it was compared. The contamination factor for Fe in all the sampling stations exceeded 6 showing very high contamination with Fe. The sediments of the study area were thus polluted with Cd and Fe.