Seasonal variations of iron (Fe), copper (Cu), zinc (Zn), and lead (Pb) concentrations in selected surface waters of Enugu State of Nigeria

Fe, Cu, Pb, and Zn concentrations were determined using flame atomic absorption spectrometric method (FAAS) in Coal Camp, Asata, and Aria rivers found in Enugu urban in eastern Nigeria. The sampling areas were mapped and sites were chosen in the rivers at intervals of 300m. Analyses were done for four years (2005-2008). Physicalassessment of the rivers prior to analyses show heavy dumping of metal scraps from a metal works/market (Tinker) village within the area. Results show average concentrations for Fe, Cu, Pb, and Zn for the four year period to be 0.21-2.66mg/L, 0.18-3.35mg/L, 0.10-1.50mg/L, and 0.18-2.11mg/L, respectively. Flame Atomic Absorption Spectrometric method (FAAS) was used for the analyses. Tolerance limit test at 95% coverage with 95% confidence revealed that only site-5 was free from pollution with these metals. Site-5 also shows negative correlations with the other sites. Normality assumption was not rejected for all the metals determinations, using Kolmogorov Smirnov (KS) test. Undoubtedly, there are strong evidences to believe that the rivers are polluted with Fe, Cu, Pb, and Zn metals.