Metal pollution and health risk assessment of soil within an urban industrial estate, southwest Nigeria.

Abstract

This paper assessed metal contamination associated with industrial activities around Agbara Industrial Estate, Southwest, Nigeria. Thirty soil samples collected within the estate were analysed using Inductively Coupled Plasma Atomic Emission Spectrophotometry ICP-AES. The results showed that the concentrations of Mo, Ag, Cr, Ni, Cu, Pb, Zn, As, Sb, Bi, Cr, Tl, Se, Hg and Cd were higher than their background values as contained in Average Crustal Values (ACV). An evaluation of the contamination factor showed that soil samples had suffered low to moderate contamination with respect to Cu, Mn, Mo, Ag, Cd, Cr and Bi, low to considerable contamination with respect to Pb, and Th and low to very high contamination with respect to Zn, Sc, Se and Sb. The degree of contamination ranged from 2.18 to 234.28 which indicated low to high degree of contamination. The toxic elements posed between low to high risks on the environment based on the potential ecological Risk Index (RI). The soil samples with the high risks were those closed to the industrial wastewater dumpsite. The total chronic hazard quotient index (THI) of oral exposure to soil contamination in the study area ranged between 2.81 and 134.89 for children, and 1.73 and 14.06 for adults. All the samples gave THI values above 1 which depicted great potential hazard for both young and old. The critical factor for THI in both adults and children for the study area were due to exposure to Pb, Mn, Zn and Cr.

Keywords: Soil, Risk, Metals, Environment, Assessment, Industrial Estate