Spatial Variations in PM10 and Heavy metals concentrations in four Prime activity-driven locations in Ibadan, Nigeria

Godson Ana(1),Tolu Odeshi(1), Mynepalli Sridhar(1) and A. Abimbola(2)

University of Ibadan, Nigeria

     Abstract Number: 655
     Last modified: May 14, 2010

Abstract
Respirable suspended particulate matter (PM10) and adsorbed heavy metals have been implicated as public health hazards yet information on their spatial variations is scanty in the developing countries. In our study we assessed the variations in levels of PM10 and some toxic heavy metals in selected prime locations in Ibadan, Nigeria. The PM10 was collected purposively from four activity areas namely high traffic intersect at Ojoo(OJ); commercial market in Bodija(BM), industrial estate at Oluyole(OL) and the University of Ibadan(UI),which served as the control area. A calibrated gravimetric sampler was used to collect the particulate samples during two peak periods in the day: 6-8a.m and 12-2p.m for one week according to standard methods. Data was compared with National guideline limits(NGL).The filter paper obtained from the particulate sampling was analysed for heavy metals such as Cr, Fe, Ni, Cu and Pb using ICPMS according to standard methods. Data analysis was done using descriptive statistics, ANOVA and Spearman-rank correlation tests. The mean morning and afternoon particulate concentrations in microgram per cubic meter were 286.0 ±102.0 and 370.3±139.0 (OJ), 342.39 ± 122.45 and 502.0 ± 39.9(BM), 220.9±74.6 and 418.6 ±156.8 (OL) respectively when compared with 220.6±69.9 and 294.1±38.4 at UI. All the afternoon PM10 concentrations were higher than the NGL daily limits of 250 (p<0.05).The concentration of heavy metals in milligrams per cubic meter were: Cr 0.85(BM),0.75(OJ),0.7 (OL) and 1.25(UI);Fe was 250 (BM), 510 (UI), 210(OL) and 385 (OJ);Ni was 0.3(BM), 0.3(OJ), 0.3(OL) and 0.45(UI); Cu was 1.6(BM), 1.44(OJ),0.55(OL) and 1.0(UI); while Pb was 5.72(BM), 2 (OJ),1.5 (OL) and 2.42 (UI).There was a strong positive correlation between the metals and PM10 concentrations (p<0.05).The highest particulate matter concentration was recorded in the market area with Fe being the most predominant metal and this suggested that the pollution sources wer mainly of anthropogenic origin.