Determination of Heavy Metal Concentrations of Rain Water Harvested from Different Roofing Sheets in Outskirt of Makurdi, Benue State, Nigeria

Roofing sheets (coloured, colorless and rusted) in Sochia and Demekpe areas of Makurdi Benue state, Nigeria were analyzed to determine the level of heavy metals (Fe Zn, Cu, Pb and Cd) using Atomic Absorption Spectrophotometeric method (AAS). The result ranged from 1.58 mgL – 3.00 mg/L (Zn), 2.15 m/gL - 3.80 mg/L (Fe), 0.04 mg/L – 0.06 mg/L (Cu), 0.02 mg/L – 0.09 mg/L (Pb) and 0.02 mg/L – 0.08 mg/L (Cd). For Zn, Fe, Cu and Cd in coloured, colourless and rusted roofing sheets respectively. There was significant difference (P≤0.05) between water from coloured, colourless and rusted roofing sheets. The concentration of Zn, Fe, Cu and Cd in the rain from rusted roofing sheets were higher, followed by that from the coloured roofing sheets while that from the colourless roofing sheets have the least concentration. All the parameters examined in the rain water samples have values that are below or within the maximum permissible limits of WHO [8] standard for drinking water quality except in rusted roofing sheets where the rain water have values above the maximum permissible limits of WHO standard for drinking water. Therefore rain water harvested from rusted roofing sheets is not safe for human consumption.