Heavy Metals Pollution of Ground Water in Urban and Sub-Urban Areas of Makurdi Metropolis – Nigeria

ABSTRACT:

This study examines heavy metals pollution of ground water in the residential sector of Makurdi urban area and Yaikyô settlement – a peri-urban area of Makurdi metropolis. Water samples from fifteen (15) wells in Makurdi urban area and fifteen (15) wells in Yaikyô settlement were analysed for chromium (Cr), Cadmium (cd), Iron (Fe), and Copper (Cu). Atomic Absorption Spectrometer (AAS) method was used for water sample analysis. This was done in the peak of rainy season, in the month of September, 2012. The results of the analysis show that 100% of wells in Makurdi urban area had chromium levels above WHO guide limit for drinking water, while Yaikyô, a sub-urban area of Makurdi, had only 35.5% of wells with chromium levels above WHO standards. Ten out of fifteen wells representing 67% displayed cadmium levels above WHO limits in Makurdi urban area, while eleven out of fifteen wells (85%) displayed cadmium levels above WHO limits in Yaikyô. Twelve out of fifteen wells representing 80% displayed iron levels above WHO guide limits in Makurdi, while thirteen out of fifteen wells representing 90%, showed iron levels above WHO guide limit in Yaikyô. All wells representing 100% displayed copper levels below WHO guide limit in both areas. High concentrations of heavy metals in drinking water are undesirable, toxic, hazardous, and affects portability of water. Source of metals in these wells is attributed to soil mineralogy, use of agro- chemicals on farms and other land use activities. All land use activities capable of polluting water should be properly controlled. Water from these wells may be used for other domestic purposes other than drinking. Boiling of water from these wells should be encouraged to reduce the risk of contracting illness.