Investigation of the pollutant load of artisanal-refined gasoline in the Niger Delta region of Nigeria and its implications on air quality

Abstract

In order to examine the gaseous pollutants generated by artisanal refined gasoline and the contribution to air pollution associated with such combustion in the Niger-Delta region of Nigeria, this study collected a sample of indigenously refined gasoline product each from thirty (30) different randomly selected artisanal camps in the Niger-Delta region and subjected all the collected samples to combustion. Fifty (50) ml of each gasoline sample was combusted at controlled conditions, and the concentrations of gaseous emissions from the process were measured using a combustion emission analyser. Pollutants characterised by the Department of Petroleum Resources which include sulphur dioxide (SO2), carbon monoxide (CO), oxides of nitrogen (NOx), hydrocarbons (HC) and carbon dioxide (CO2) were characterised. The average concentrations of the emissions were 211.50 mg/m3, 7.18 mg/m3, 17.51 mg/m3, 3011.33 mg/m3, and 500.39 mg/m3 for CO, NOx, SO2, CO2, and HC respectively. The concentrations of SO2 and NOx measured were within the Federal Environmental Protection Agency (FEPA) set limits for combustion emissions from stationary sources but breached World Health Organization (WHO), World Bank and Environmental Guidelines and Standard for Petroleum Industry in Nigeria (EGASPIN) set limits. The concentrations of CO and HC exceeded FEPA, WHO, World Bank and EGASPIN set limits and hazardous on Air Quality Index (AQI) classification. Elevated concentrations of CO and HC in the atmosphere pose a major threat to ambient air quality and human health, especially in locations where artisanal-refined fuel is predominantly utilised. Associated risks include poor visibility, occurrence of acid rain, blood poisoning and cancer-related diseases. In addition to these effects are the worsening global warming crises associated with CO2 emission, a major product of fossil fuel combustion.