Air Quality Monitoring in Uyo Metropolis, Akwa Ibom State, Niger Delta Region of Nigeria

Assessment of air quality in Uyo metropolis was carried out by monitoring levels of nitrogen (IV) oxide, sulphur (IV) oxide, hydrogen sulphide, carbon (II) oxide, ammonia, chlorine gas and suspended particulate matter at four major locations within the study area for one week. Results obtained indicated higher mean concentrations of CO, NH3 and Cl2 in the morning hours, NO2, H2S and SPM in the afternoon while, SO2 did not vary considerably between these periods. Levels of these air particulates were above their recommended standards by FEPA indicating their nuisance status. However, Air quality index classified NO2 and SO2 in the very poor class, CO in moderate class while NH3 and SPM were in the very good category. Correlation analyses showed that, NO2 and SO2 exhibited strong positive relationships with H2S, CO and Cl2. Hydrogen sulphide showed common source and strong correlation with CO, NH3 and Cl2. Carbon (II) oxide correlated positively and significantly with Cl2 and SPM while, chlorine indicated significant positive association with SPM. Principal component analysis indicated two (2) major factors with 91.39% of total variance. Factor 1 represented impacts of fuel combustion and vehicular emissions whereas; factor 2 represented influences of organic matter decomposition and petroleum processing.