ABSTRACT
Industrial, agricultural municipal and natural (e.g., volcanic activities, leaching from rocks electroplating and mining of metals, wear and tear of machine parts, leak from electronic components) has produce enormous amounts of heavy metals and/or compounds into our environment from year to year, which has contaminated water bodies in some parts of our environment including ground water bodies. Heavy metals are toxic to our health causing adverse effects to us when consumed. Carcinogenic effects, severe respiratory, cardiovascular, hematological, hepatic, gastrointestinal, neurological, renal, epidemiological disorders e.t.c has been linked to bioaccumulation of heavy metals in humans. Ground water could be a host for such toxic metals, this have been of, and should be of serious concern to us, if we are to stay healthy and have higher life expectancies. Food, Heath and Environmental agencies e.g NAFDAC, WHO, US EPA has over the decades states down permissible limits on various parameters (including heavy metals). Groundwater samples was obtained from 20 different boreholes situated at various locations, with 10 boreholes located in Ekosodin and another 10 boreholes located in Evbuomore community in Benin city, Edo state. Samples were collected following standard procedures of sampling; Clean clear High Density Polyethylene containers was used to collect samples from each borehole points. The analysis on levels of the selected heavy metals have been carried out. samples were analyzed for levels of Lead (Pb), Cadmium (Cd), Zinc (Zn) and Nickel (Ni) using an atomic absorption spectrometer (AAS). Results obtained reviews that the levels of heavy metals analyzed for, were below or at the range of permissible limit postulated by environmental agencies e.g., NAFDAC, WHO and US.EPA. Concentrations (levels) of Cadmium (Cd) and Nickel (Ni) weren't detected, these are possibly due to their absence or their levels being too low to be detected. Levels of Lead varies among samples, from level below detectable limits to levels as high as 0.02ppm which is above all permissible limits of Lead. Samples Ek6, Ev5 and Ev9 All exceeds WHO'S, NAFDAC'S and US EPA'S permissible limits of Lead concentration, All Zinc levels are within permissible limits (acceptable), ranging from 0.20ppm in Ek4 to 0.31 in Ek8 and from 0.20ppm in Ev4 to 0.32ppm in Ev5. Lead levels from some samples are high, this indirectly correspondingly means that the Lead levels in some areas in these communities are high. There is need for appropriate measures to lower the Lead levels to acceptable permissible limits).
