ENVIRONMENTAL IMPACT ASSESSMENT OF PETROL AND GAS FILLING STATIONS ON AIR QUALITY IN UMUAHIA, NIGERIA

This study investigated pollutants emissions from filling stations and their impact on the air quality. Gas monitors were employed to identify the different pollutants present in the ambient air of the study areas. The results showed that the most prominent pollutants present in the ambient air are the volatile organic compounds followed by methane, then carbon monoxide. Measurements were taken at the controls at distances between 20 to 200m.The pollutants concentration recorded at the study areas showed that the level of pollutants exceeded the FEPA air quality guidelines. There are few exceptions in pollutants like the particulate matter which was found to be at concentrations within the FEPA limits. Regression analysis of the pollutants at the controls showed that only the volatile organic compounds and methane are the only significant pollutants present in the ambient air primarily because of the presence of the filling stations. These two pollutants showed a strong negative correlation with distance from the study area. While the regression curve for the volatile organic compounds (VOCs) shows a nearly perfect curve with exponential functions as its regression equations, that of methane is linear. Specifically, both VOCs and methane have a correlation coefficient (R) that is above 0.9 for the study areas. Hence a conclusion was drawn from the findings that the primary pollutant to consider when building filling station are the VOCs and methane and that the minimum safe distance to site a filling station is a distance of 80m away from residential areas.