Risk assessment and source identification of heavy metal contamination by multivariate and hazard index analyses of a pipeline vandalised area in Lagos State, Nigeria

摘要

Petroleum contamination is a significant contributor of elevated level of toxic heavy metals, which are of great concern to human health, due to their non-biodegradable nature. Agaye community has experienced frequent gasoline spills due to pipeline vandalisation, resulting in the contamination of soil and water sources. The concentrations of metals (Cd, Cr, Cu, Mn, Ni, Pb, V and Zn) in groundwater, surface-water and soil were determined from a total of 216 samples acquired bi-monthly for two years by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) to evaluate the impact of oil spills. Multivariate analyses using principal component analysis (PCA) and duster analysis (CA) were also used to study the interactions between metals and identify the possible sources of contamination. The concentrations of heavy metals in soil and water samples (surface and groundwater) were in deueasing order of Mn Ni Zn Cu V Cr Pb Cd and Ni Zn V Cu Mn Pb Cr Cd respectively. Ni concentration ranged from 0.42-8.05 mg kg(-)(1). and 0.10-2.85 mg L-1 for soil and groundwater respectively. Ni and V were more enhanced (P 0.05) in soil samples. This study showed that there was significant relationship between elevated levels of Cr, Cu, Ni and Zn and oil spillage, due to petroleum spills and that residents were vulnerable to and at greater risk of non-carcinogenic hazards if they consumed groundwater. Multivariate analyses showed significant anthropogenic intrusions of two diagnostic heavy metals (Ni and V) for petroleum contamination in the soils and water sources. (C) 2018 Elsevier B.V. All rights reserved.