Accumulation of Cadmium (Cd) and Lead (Pb) in the Niger River and Environs

The study investigates the levels, variability of cadmium (Cd) and lead (Pb) in surface waters of Niger River and adjoining areas. Investigation of lead and cadmium concentration in surface water within Onitsha metropolis range from 0.204 mg/L- 2.316mg/L (River Niger upstream surface and Nwanaene lake) to 0.004 – 1.431 mg/L (River Niger upstream surface/ Creek surface and Nwanaene lake). All samples collected and tested by AAS were above the WHO standard of 0.01mg/ L for Lead and 0.003mg/L for Cadmium. Mean concentration of lead (Pb) and cadmium (Cd) shows that a significant difference exists in some of the sampled water sources. The concentrations of Cadmium in sampled sources varied from slight to very high (Cv = 18.52-148.57%) while in Lead, the concentration was slight to moderate (Cv =15.54-64.85%). Pollution of surface water in sampled locations was anthropogenic/ site specific (mainly from waste deposition as noticed in Nwangene Lake), urban treatment of effluent from industries and prohibition of dumping of any kinds of refuse and sewage into the rivers and lakes within Onitsha and environs need to be fully enforced.