Gaseous air pollutants emissions from ota industrial estate in Ogun state, Nigeria

Abstract

The interest in monitoring air quality status of Ota industrial estate was aroused by undesirable rapid corrosion of residential roofing sheets in the vicinity of the estate. This study aimed at assessing the air pollution status around Ota industrial estate situated in Nigeria by determining the levels of NOx, CO, and SO₂ weekly for a  period of one month. The assessment was done during the daytime at one hourly basis using standard methods of analysis. The concentrations of NOx, CO and SO₂ were determined by colorimetric method. Traffic density   data reported in this study was obtained by manual count. Average levels of 33.3±4.7 μg m^-3 , 246±32 μg m^-3  and  15.6±5.3 μg m^-3 were obtained for NOx, SO₂ and CO, respectively. Level of NOx in the area was below the  national guidelines stipulated by the National Ambient Air Quality Standard (NAAQS) and that of US National  Ambient Air Quality guidelines. Carbon monoxide level was not above the air quality limit of 11400 μg/m³ , while that of SO₂ was above the limit set by FEPA. Thus, the atmospheric air at the industrial estate is potent to  have deleterious effect on human health on account of SO₂ concentration. A strong positive correlations (p=  0.05) were observed among NOx, CO and traffic density. In addition to diesel powered vehicles and fuel combustion in the industries, vehicles plying the estate roads contributed to the emission of NOx and CO.

Keywords: Nitrogen oxides; Sulphur dioxides; Carbon monoxide; Respiratory health; Automotive exhaust.