~ 2228 ~ International Journal of Chemical Studies 2018; 6(5): 2228-2231 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2018; 6(5): 2228-2231 © 2018 IJCS Received: 22-07-2018 Accepted: 23-08-2018 BW Tukura Department of Chemistry, Nasarawa State University, Keffi Nigeria PC Madu Department of Science Laboratory and Technology, Federal Polytechnic, P.M.B 001, Nasarawa, Nigeria Y Usman Department of Science Laboratory and Technology, Federal Polytechnic, P.M.B 001, Nasarawa, Nigeria BL Gav Department of Chemistry, Federal University of Agriculture P.M.B 2373, Makurdi, Nigeria Correspondence BW Tukura Department of Chemistry, Nasarawa State University, Keffi Nigeria Assessment of heavy metal contaminants of used engine oil around automobile workshop in Nasarawa local Government area, Nasarawa state, Nigeria BW Tukura, PC Madu, Y Usman and BL Gav Abstract The study was carried out on assessment of heavy metal contaminants of used engine oil around automobile workshops in Nasarawa Local Government Council, Nasarawa State, Nigeria. Samples of Soil, water, fluted pumpkin leaves, spinach and used engine oil were collected from selected mechanic workshops within the Nasarawa Local Government Area for both rainy and dry seasons were analyzed for heavy metal concentrations. These samples were subjected to analysis for eight elements; Co, Zn, Cd, Cu, Ni, Mn, Cr and Pb using Inductively Coupled Atomic Absorption Spectrophotometer. The results of the analysis carried out for both rainy and dry seasons showed clearly that there is more concentration of the heavy metals analyzed in the dry season than that of the rainy season. The result also shows that apart from the mechanic workshop, some of the metals have high concentrations in some control samples. The results of the analysis showed that most of the heavy metals examined in some samples were above the World Health Organization limit for human consumption. Keywords: Heavy metals, used engine oil, automobile workshop, soil, water, Amaranthus Habridus Introduction The increase in population worldwide has led to a high level of industrialization and urbanization which in turn have led to environmental pollution arising from the indiscriminate discharge of industrial effluents. These effluents may contain most common heavy metals, such as Hg, Zn, Cu, Co, Pb, Cr (Madu et al., 2007) [12] . It is known that pollution through heavy metal has become increasingly more in recent years, not only because people are more sensitive on this subject but also because the amount of pollution has increased markedly. There is need for research and public information on these metals, otherwise unknown dangers may create irreparable environmental damage. Since 1999, thousands of cars, Lorries, motor cycles are coming into Nigeria and the number of mechanic villages are increasing at a very high rate and consequently the amount of used automotive oil being disposed everyday has equally increased (Madu et al.,2007) [12] . Waste automotive oil can be defined as oil that has picked up foreign substances, or contaminants. This can occur before, during or after use (CCME, 2002). Waste automotive oils collect contaminant in many ways depending upon the original use of the oil. In general, waste automotive oils contain oxidation products, sediments, water and metallic particles resulting from machinery wear. In addition to these, waste automotive oil also contains gasoline fuels, organic and inorganic chemicals used in oil additives and metals which were present in gasoline and transferred to the crankcase during combustion (Adebayo et al., 2004) [1] . Lead is the principal metallic contaminant found in waste automotive oils being present in amounts which sometimes exceed one percent by weight (Olonisakin et al., 2005) [14] . Heavy metals are natural components of the earth crusts. They are stable and persistent environmental contaminants of coastal waters and sediments. Since they cannot be degraded or destroyed to a small extent, they enter our bodies via food chain, drinking water and air (Lawrence, 1990) [9] . Examples of heavy metals include mercury (Hg), cadmium (Cd) Arsenic (Ar) chromium (Cr) Lead (Pb) Nickel (Ni) Zinc (Zn), and Selenium (Se). Interest in metals like Zinc, Copper, Iron and Selenium which are required for metabolic activity in organisms lies in the narrow path between their essentiality and toxicity. Other heavy metals like lead, cadmium and mercury may exhibit extreme toxicity even at low levels under certain