Trace metals concentration assessment in urban particulate matter in Yenagoa and its environs

Abstract

This study was conducted to investigate the distribution and correlation of selected trace elements (Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in Yenagoa, Bayelsa State and its environs. Air particulate matter was collected gravimetrically at five stations (using a high volume portable SKC air check MTXSidekickair sampler (Model: 224-52MTX). The total suspended particulate matter samples were extracted in nitric acid and hydrochloric acid mixture, followed by the quantification of the trace elements by flame Atomic Absorption Spectrophotometric (AAS) method (Model: AA 6600, GBC Avanta PM AAS). The estimated elemental data were then subjected to a set of Multivariate statistical analysis and evaluated for their mutual variations in the urban particles. The concentrations of trace elements (μgm^-3) found in the particulate matter were in the order of Ca>Fe>Zn>Ni>Pb> Mn>Cu>Cd>Co>Cr. On the average, the correlation of the trace elements of the study area shows strong correlations between Pb-Ni, Fe-Mn, Co-Ni, Zn-Pb, with correlation coefficients of 0.767, 0.595, 0.508, and 0.791 respectively. Principal component analysis revealed that major sources of trace metals in ambient air of the study areas were mainly emissions from automobile exhaust, industrial emissions and gas flaring.

Keywords: Particulate matter, trace elements, enrichment factor, toxic