HEAVY METAL STATUS IN SOILS AND FLUTED PUMPKIN LEAF (Telfairia occidentalis) AROUND A DUMPSITE

ABSTRACT

Dumpsites are threats to water and soil quality when rainfall percolates through wastes leaching out a variety of substances such as heavy metals and other toxic materials. The study examined the heavy metals status in soils and fluted pumpkin leaf grown around Oto – fure dumpsite in Ovia North East local government area of Edo state, Nigeria. Soils and fluted pumpkin leaf samples were collected at the dumpsite, 60m and 120m away from the dumpsite in three replicates, making a total of 9 soil and 9 fluted pumpkin samples. The soil samples were analyzed for some physical and chemical properties using standard laboratory procedures and some selected heavy metals such as Ni, Pb, Co, Cr, Se and Cd were analyzed using DTPA – TEA extraction method, while fluted pumpkin leaf samples were analyzed for same selected heavy metals using di – acid digestion method. The results show that heavy metals content in soils around the dumpsite are generally below critical toxicity levels and decreased with increased distance from the dumpsite except Ni, Co and Cd. Mean values of 3.13, 1.28 and 1.61 mg/kg were obtained for Ni at dumpsite, 60m and 120m away from the dumpsite respectively. Co had mean values of 0.03, 0.11 and 0.06 mg/kg at dumpsite, 60m and 120m away from the dumpsite respectively. Cd had mean values of 0.01 and 0.004 mg/kg at dumpsite and 120m away from the dumpsite respectively, but was below detectable limit at 60m away from the dumpsite. The result also shows that heavy metals content in fluted pumpkin leaf grown around the dumpsite contained elevated levels of Ni and Co exceeding permissible limits and posing potential health risks to consumers as reported in literatures. Ni had values of 31.50, 13.00 and 12.50 mg/kg at dumpsite, 60m and 120m away from the dumpsite respectively. Co had values of 1.21, 1.59 and 1.16 mg/kg at dumpsite, 60m and 120m away from the dumpsite respectively. It could be concluded that the fluted pumpkin leaf is contaminated with Ni and can pose a risk to food safety and human health through the consumption of the fluted pumpkin grown around the dumpsite studied.