Traffic air pollution and urban sustainability: an assessment of strategic road intersections in Owerri urban, Nigeria

Abstract

An assessment of the ambient air quality in selected road intersections in Owerri Urban, Southeastern Nigeria was carried out. Random sampling of 5 air pollutant species: NO2, CO, SO2, and PM 2.5 and PM 10, from 4 major points coded SP1 to SP4 were carried out daily, morning, afternoon and evening sections for 14 days in the dry season. The levels of each air pollutant species were determined in-situ using standard sampling devices. The coordinates of the sampled locations were recorded using GPS equipment. The results obtained revealed elevated levels of pollutants in all the selected intersections. NO2 ranged between 0.055-0.089 ppm, CO ranged between 0.70-12.70 ppm, SO2 ranged between 0.47-0.86 ppm, PM 2.5 ranged between 0.008-0.027 ppm whereas PM 10 ranged between 0.019 - 0.067 ppm in all the locations. SO2 level at SP1 (0.47±0.15), SP2 (0.86±0.21), SP3 (0.71±0.06), and SP4 (0.74±0.13) were found to be above the National Ambient Air Quality Standard (NAAQS) and Federal Ministry of Environment (FMEnv) limits. PM (2.5 & 10) was concentrated in SP4 whereas elevated levels of CO and SO 2 were observed at SP3 and SP2. SP3 was observed to have elevated levels of NO2. Changes could be attributed to high density of vehicles observed during peak hours and the presence of building clusters. The selected road intersections may not be safe due to cumulative impacts to various socio-economic and health effects triggered by prolonged exposures. Greening approach towards low-carbon cities and urban sustainability becomes essential.

Keywords

• air quality
• road intersection
• owerri urban
• southeastern nigeria