Geoenvironmental Evaluation and Risk Assessment of Heavy Metals in Sediment, Minichinda Stream, Port Harcourt, Nigeria

Benjamin Bameyi Otene; Peace C. Nnadi

Abstract

The pollution status and risk assessment of the heavy metals in the sediment from Minichinda stream, Port Harcourt were studied. Sediment samples collected for twelve Months from four stations were analyzed for heavy metals using spectrophotometer as in the standard method. The mean values for the respective heavy metals (mg/kg) include Cd (0.496±0.20), Cr (0.460±0.17), Pb (0.469±0.20), Cu (0.738±0.26) and Fe (15.05). The spatial mean concentration of the metals varied significantly at p<0.05 with Fe having the highest value (24.10±0.30mg/kg) in station 3. The order of concentration of the metals studied was Fe>Cu>Pb>Cr with Fe concentration consistently high across the stations. Contamination factor (Cf) showed that Cr, Pb and Cu exhibited low contamination status across all the stations while Cd and Fe exhibited moderate and considerable contamination status in the sediment. PER index of Cd were consistently high across the stations while values for other metals such as Cr, Pb and Cu were consistently low. The contamination levels for all the stations were considered high due to Cd values. Toxicity value of the metals decreased in the order, Cu > Cd with Cr and Pb maintaining similar level. It was concluded that sediment of Minichinda stream is contaminated with Fe and Cd. It was also recommended that adequate measures should be taken to avoid further contamination of the area.

Abstract

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