Seasonal variations in the levels of heavy metals in river waters of Ebonyi state, Nigeria

Abstract

Concentrations of Cadmium (Cd), Chromium (Cr), Mercury (Hg), Copper (Cu), Zinc (Zn), Lead (Pb) and Iron (Fe) were sampled four rivers in Ebonyi State, Nigeria across two seasons to determine their degree of pollution and portability considering the incidental industrial, agricultural and other activities in the area. Mean concentrations of iron were significantly (p<0.05) higher than those of other metals in all the rivers sampled during the two seasons. The range of dry and rainy seasons values in mg/l, 0.00-0.018 and 0.00 – 0.014 for Cd, 0.0 and 0.111 - 0.500 for Cr, 0.0 and 0.0 – 0.009 for Hg and 0.064 - 0.176 and 0.005 –0.021 for Zn were within the permissible levels of contamination allowed by FEPA and WHO for river waters. The values recorded during dry and rainy seasons for CU (0.0 – 0.070mg/l and 0.0- 0.056mg/l), Fe (1.50- 3.48 mg/l and 2.70 – 5.50 mg/l) and Pb (0.120 –0.300 mg/l and 0.162 – 0.744 mg/l) however, exceeded the permissible levels. These results of CU, Fe and Pb pollution of the rivers studied suggest their unwholesome discharges into the rivers through industrial and agricultural and other human activities in the area.

International Journal of Natural and Applied Sciences Vol. 1(2) 2005: 113-117