Out-Door Air Pollution Levels in Vehicular-Traffic Junctions in Nsukka Metropolis, Enugu Metropolis and Awgu Semi-Urban Area in Enugu State, Nigeria

摘要

Studies were carried out to investigate the outdoor air pollution levels in vehicular traffic junctions in the major cities of Nsukka, Enugu and semi-urban area of Awgu all in Enugu State, Nigeria using standard analytical procedures. PM _( 2.5 ) was collected using Envirotech air sampler, APM 550 and analyzed gravimetrically. Other determined air pollutant gases such as SO _( 2 ) , NO _( 2 ) , O _( 3 ) and CO were analyzed using colorimetric techniques. The mean hourly traffic density in the vehicular traffic junctions in Nsukka metropolis, Enugu metropolis and Awgu w ere 2015, 2873 and 587 respectively. The mean range of values of PM _( 2.5 ) , NO _( 2 ) , SO _( 2 ) , O _( 3 ) and CO in vehicular traffic junctions within the investigated environments w ere 1.67 - 12.16 μg/m ~( 3 ) , 3.72 - 23.83 μg/m ~( 3 ) , 2.96 - 30.09 μg/m ~( 3 ) , 5.45 - 66.54 μg/m ~( 3 ) and 1.18 - 15.17 ppm respectively. The mean levels of the determined air pollutants in the air around vehicular traffic junctions in Nsukka metropolis, Enugu metropolis and Awgu semi-urban area differed significantly. The mean levels of PM _( 2.5 ) , and CO in the air around vehicular traffic junctions in Enugu metropolis and CO in the air around traffic junctions in Nsukka metropolis were above the recommended permissible limits. Traffic density was therefore seen as the single most important factor contributing to the varying air pollution levels observed in the investigated environments.