An Assessment of the Ambient Air Quality around Major Road Intersections within Warri Metropolis

Abstract:

An evaluation of the ambient air quality of emitted gases and particles at major road junctions within Warri conurbation was carried out. The study was aimed at ascertaining if air pollution levels exceeded the acceptable limits during weekdays as well as attempt to target the root causes. Ambient air was monitored from strategic locations at eight major road junctions sparsely distributed within residential areas for in-situ measurement of NO₂, SO₂, CO and PM₁₀ concentrations. Monitoring was done consecutively for a period of two weeks at four single-carriage and four dual-carriage roads to test the contributions of traffic on air quality. The averages of the minimum and the maximum daily observations over the entire sampling period ranged between 0.02452ppm and 0.05684ppm for NO₂, while that of SO₂ ranged between 0.00564ppm and 0.05654ppm, and that of CO ranged between 0.438ppm and 4.890ppm, whereas PM₁₀ yielded 13.602μg/m³ as minimum and 122.124μg/m³ as maximum levels. As was expected, concentrations from all the single carriage roads were higher than those from the dual carriage roads owing to the heavy traffic congestions in single-lane roads. This study also revealed that only the NO₂ values obtained around Robinson plaza and Warri main market junctions were perilously close to the specified FMENV levels for hourly exposure. This being that there were rapid oxidation of NO to NO₂ from vehicular emissions. However, the presence of high levels of NO₂ is synonymous to high ground level ozone production environment, consequently, a high oxidation region of free radicals which could lead to more particulate matter formation during advection.

• Periodical: Advanced Materials Research (Volume 824)
• Pages: 650-655
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.824.650
• Online since: September 2013
• Authors: S.A. Ogunnowo, A.I. Igbafe
• Keywords: Ambient Air Quality, Gaseous Emissions, Particle Emissions, Warri Conurbation

References

[1] B. R. Gurjar, T. M. Butler, M. G. Lawrence, and J. Lelieveld, Evaluation of emissions and air quality in megacities, Atmospheric Environment, 42, (2008) pp.1593-1606.

DOI: 10.1016/j.atmosenv.2007.10.048

[2] L. E. Venegas, N. A. Mazzeo and A. L. Pineda-Rojas, Evaluation of an Emission Inventory and Air Pollution in the Metropolitan Area of Buenos Aires, National Scientific and Technological Research Council (CONICET), National Technological University, Argentina, (2010).

DOI: 10.24193/cbb.2018.22.05

[3] G. Tsilingiridis, T. Zachariadis and Z. Samaras, Spatial and temporal characteristics of air pollutant emissions in Thessaloniki, Greece: investigation of emission abatement measures, TheScience of the Total Environment, 300, (2002) pp.99-113.

DOI: 10.1016/s0048-9697(02)00170-5

[4] A. I. Igbafe, Resolving the Atmospheric Sulphur Budget Over the Elansfontein Area of the Mpumalanga Highveld, PhD thesis, University of the Witwatersrand, Johannesburg, Republic of South Africa, (2007) p.327.

[5] C. Borrego, O. Tchepel, A. M. Costa, J. H. Amorim and A. I. Miranda, Emission and dispersion modelling of Lisbon air quality at local scale, Atmospheric Environment, 37, (2003) pp.5197-5205.

DOI: 10.1016/j.atmosenv.2003.09.004

[6] T. M. Butler, M. G. Lawrence, B. R. Gurjar, J. van-Aardenne, M. Schultz and J. Lelieveld, The representation of emissions from megacities in global emission inventories, Atmospheric Environment, 42, (2008) pp.703-719.

DOI: 10.1016/j.atmosenv.2007.09.060

[7] A. D'Avignon, F.A. Carloni, E.L.L. Rovere and C.B.S. Dubeux, Emission inventory: An urban public policy instrument and benchmark, Energy Policy, 38, (2010) p.4838 – 4847.

DOI: 10.1016/j.enpol.2009.10.002

[8] H. Wang, L. Fu and Y. Zhou, Trends in vehicular emissions in China's mega cities from 1995 to 2005, Environmental Pollution, 158, (2010) p.394 – 400.

DOI: 10.1016/j.envpol.2009.09.002

[9] S.P. Beaton, G.A. Bishop and D.H. Stedman, Emission characteristics of Mexico City vehicles, Journal Air and Waste Management Association, 42, (1992) p.1424 – 1429.

DOI: 10.1080/10473289.1992.10467088

[10] O.C. Othman, Roadside levels of ambient air pollutants in Dar es salam City, Tanzania journal of natural and applied sciences, 1, (2010) pp.203-206.

[11] Y. Nishikawa and A. Kannari, Atmospheric concentration of ammonia, nitrogen dioxide, nitric acid and sulphur dioxide by passive method within Osaka Prefecture and their emission inventory, Water, Air and Soil Pollution, 215, (2010) pp.229-237.

DOI: 10.1007/s11270-010-0472-3

[12] M.F. Andrade, R.M. Miranda, A. Fornaro, Kerr, A. B. Oyama, P. A. Andre, and P. Saldiva, Vehicle Emissions and PM2. 5 Mass Concentrations in Six Brazilian Cities, Air Quality Atmosphere and Health, (2010).

DOI: 10.1007/s11869-010-0104-5

[13] B. A. Mustapha, M. Blangiardo, D. J. Briggs, and A. L. Hansell, Traffic Air Pollution and Other Risk Factors for Respiratory Illness in Schoolchildren in the Niger-Delta Region of Nigeria, Environ Health Perspect, 119(10), (2011) p.1478–1482.

DOI: 10.1289/ehp.1003099

[14] FMENV., Air Quality Guidelines and Standard in Nigeria Federal Ministry of Environment, (1991) p.56 – 63.