EVALUATION OF ELEMENTAL CONTAMINATION LEVELS IN GROUNDWATER AND SOIL NEAR ANTHROPOGENIC SITES IN IBADAN, NIGERIA

Abstract

Waste disposal is a major challenge confronting and threatening the environment globally. Heavy metals can be found in almost all planetary surroundings, such as dumping sites and biological activities. Contaminated soil and groundwater with these metals have turned into a serious issue for the residents and agricultural experts in Ibadan, because of the damage and havoc caused to human life and agricultural products. The five different samples were obtained from different groundwater and soil sites and then analyzed for elementals: Cadmium (Cd), Manganese (Mn), Nickel (Ni), Chromium (Cr), Zinc (Zn), Cobalt (Co), and Lead (Pb); after acid digestion using Atomic Absorption Spectrophotometer, while physicochemical parameters (pH and conductivity) were also determined in soil and water samples. The samples of soil were taken in triplex at 15 cm intervals in depth, while the samples of water were collected from different hand-dug wells below 15 m deep. The following ranges results (in mg/kg) were obtained for soil samples: Pb (0.04-0.08); Cr (0.05-0.08); Cd (0.02-0.05); Zn (0.54-4.49); Co (0.04-0.07); Mn (0.03-0.06) and Ni (0.06-0.13); while the pH ranged from (7.6-8.5); conductivity (406-683) uS/cm. The following values of results (in mg/L) were obtained for water samples: Pb (0.01-0.03); Cr (0.02-0.04); Zn (0.6-1.1); Co (0.01-0.04); Mn (0.01-0.06) and Ni (0.02-0.03), but Cd was not found, while pH ranged from (6.3-6.9) and conductivity (264-607) uS/cm. The concentrations of Mn, Ni, and Pb in groundwater collected from Sango and Moniya were above the WHO/SON permissible limits. The results revealed that the concentrations of Ni, Co, Pb, Cr, and Cd in soil were above the WHO\SON acceptable bounds. Also, Mn and Zn were lower than the bound.