International Journal of Environmental Sciences

Volume 5 Issue 4 2015- January 2015    Pages: 765- 775  <<Previous    Next>>

Comparison of particulate matter levels in major urban centres in Eastern Nigeria

Author Information:

Ngele, S.O1, Onwu, F.K 2
1- Department of Industrial Chemistry, Ebonyi State University, Abakaliki, Nigeria
2- Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria.


This study investigated the particulate matter (PM) load( total suspended particulate matter (TSP) and PM of diameter ≤ ten micrometers (PM10)) in ten urban centres in South- Eastern Nigeria in the dry and wet seasons from December, 2008 to September, 2009 using particulate counter instrument. The results showed that the cities' seasonal mean TSP ranged from103.31±22.26 to1260.25±608.59 and 28.69±4.77 to 555.13±304.57 µg.m- 3 in the dry and wet seasons respectively. The corresponding range for the dry and wet seasonal means of PM10 was 14.38±3.01 to 288.06±129.79 µg.m-3 respectively. Comparatively the cities had PM load in the order: Onitsha > Aba > Umuahia > Owerri > Enugu > Nsukka > Abakaliki > Nnewi > Afikpo  > Orlu. Four cities representing 40% of the cities studied namely: Nnewi, Abakaliki, Afikpo and Orlu recorded dry seasonal mean TSP values within the WHO annual guideline limit of 150-230 µgm-3 for combined exposure to TSP and SO2 , while other cities had dry season TSP mean values above the limit. The dry seasonal mean PM10 levels in all the cities exceeded the US annual National Ambient Air Quality Standard (NAAQS) of 50 µg.m-3 .The Correlation matrix showed that the TSP seasonal means (dry and wet) correlated positively with that of the PM10 (p<0.05) while the student t-test statistics showed that the dry seasonal means (TSP and PM10) were statistically significant from that of the wet season (p<0.05). The study concluded that recording high values (which exceeded the recommended annual guideline limit) of these pollutants in these cities portends public health risk particularly to people dwelling in the affected cities.

Keywords: Ambient air, Environmental pollution, monitoring, particulate matter, South-Eastern Nigeria.


© 2015 Copyright by the authors, licensee Integrated Publishing Association.This is an open access article distributed under the Creative Commons Attribution License (3.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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