Comparative Analysis of Air Quality in Different Markets of Owerri Metropolis in Relation to Vehicular Emission

This study evaluated the concentrations of various air pollutants, including Carbon Monoxide (CO), Hydrogen Sulphide (H2S), Carbon Dioxide (CO2), Volatile Organic Compounds (VOCs) and Nitrogen Dioxide (NO2), originating from vehicular emissions. In addition, the ambient air particulate matter (PM2.5 and PM10) levels were measured across seven market sites in Owerri. These markets were chosen due to their high congestion during the day, attributed to dense vehicular traffic, residential buildings, and human activities. Measurements were conducted over three-hour periods in the morning (6:00 a.m.-9:00 a.m.) and evening (4:00 p.m.-7:00 p.m.), which are peak times for human and vehicular movement. The results indicated that the highest H2S concentration (0.04-0.54 ppm) was found at Orji market, well below the AEGL-3 limit of 33 ppm. CO2 levels peaked at 1027-1088 ppm at Relief market, exceeding the ambient standard of 314 ppm, while the lowest levels (810-960 ppm) were recorded at Obinze Market. NO2 concentrations were highest (0.132-0.20 ppm) at Orji and Relief markets, surpassing the NAAQS limit of 0.100 ppm. The highest CO concentration (14-15.5 ppm) was observed at Relief market, below the NAAQS limit of 35 ppm. VOC levels were highest (0.8-1.0 mg/m³) at Obinze Market, exceeding the permissible target value of 0-0.75 ppm. PM2.5 and PM10 concentrations were highest at World Bank Market (0.40-0.50 mg/m³), exceeding the NAAQS and WHO standards of 0.15 mg/m³. The study concludes that vehicular emissions and human activities significantly contribute to air pollution in the environment. Atmospheric conditions such as temperature, dew point, humidity, wind pressure, and wind speed were also analyzed.