Assessment of the Heavy Metal Contamination in the Coastal Sediments of Meme River in Lokoja, Nigeria Using Geoaccumulation Index

Abstract

The Meme River in Lokoja is a tributary of the River Niger and a place where household discharge their 
domestic and industrial refuse. This however makes the river to be highly polluted due to these discharges. 
This necessitates the present study to assess the level of heavy metals contamination in the coastal sediment 
of Meme River in Lokoja using Flame Atomic Absorption Spectrometric technique. The various levels of 
contamination was analysed using the geo-accumulation index. Results of this study for water analysis 
indicates a concentration range of 0.04 – 0.06 ppm (Fe), 2.33 – 10.40 ppm (Cr), 0.30 – 0.72 ppm (Zn), 0 – 
1.81 ppm (Ni), 0.01 – 0.70 ppm (Cu) and 0.03 – 0.10 ppm (Cd). The observed metal concentrations for 
sediments ranged from 3.50 – 5.60 mg/kg (Fe), 5.93 – 9.89 mg/kg (Cr), 0.65 – 1.04 mg/kg (Zn), 0.13 – 2.45 
mg/kg (Ni), 0.10 – 0.20 mg/kg (Cu) and 0.070 – 0.61 mg/kg (Cd). Results of some measured metals like 
K, Mg and Na in the water ranged from 30.0 – 44.0 ppm, 9.30 – 9.80 ppm, and 5.40 – 5.70 ppm respectively, 
while the concentration observed in the sediment samples ranged from 49.0 – 78.0 mg/kg (K), 9.50 – 9.80 
mg/kg (Mg) and 5.55 – 5.68 mg/kg (Na). The geo-accumulation index analysis showed that the sediment 
and water samples are not polluted with Cr, Zn, Cu and Cd. However, the water samples are highly polluted 
with Fe. The measured metals such as Mg and K indicated a moderately high concentration in the water 
and sediment samples. The results of this work generally indicate that the sediment and water samples are 
moderately polluted by Fe which possibly may be due to anthropogenic activities along the River bank