Seasonal Variations of Heavy Metals Concentrations in Sediment Samples Around Major Tributaries in Ibeno Coastal Area Niger Delta Nigeria

Abstract Seasonal Variations of Heavy Metals Concentrations in Sediment Samples around major Tributaries in Ibeno Coastal Area Niger Delta Nigeria was investigated using Atomic Absorption Spectrophotometer Unicam 939 model. Fifteen composite sediment samples were collected in February 2013 and June 2014 representing dry and wet seasons respectively. The concentrations mg kg-1 of heavy metals in sediment for dry and wet seasons were in decreasing order of dry Fe 22.1814.82 Mn 9.672.75 V 3.393.30 Ni 2.180.78 Cd 0.480.75 Co 0.100.01 Zn 0.490.08 Pb 0.050.07 and wet Fe 23.280.24 Mn 9.452.63 V 3.313.34 Ni 1.941.48 Cd 0.480.74 Pb 0.030.04. The mean concentrations of Mn Ni Pb Zn in dry season were higher when compared to the mean concentrations of the heavy metals in wet season except Fe V and Co. The mean concentrations of Cd for dry and wet seasons were the same in dry and wet seasons. All the heavy metals were detected in all the sediment samples. The mean concentrations of all the heavy metals were higher than the control sediment in both dry and wet seasons but below the World Health Organization standards. Iron was found to be the most abundant metal in sediment for both seasons. The average pH 6.170 of the sediment was slightly acidic and below WHO and DPR standards. Frequent monitoring of aquatic environments is necessary in order to detect and prevent cumulative consequences of heavy metallic pollutants which may lead to sub-lethal effects in the aquatic fauna and clinical poisoning to man and farm animals that depend on them for food.