Gas flaring attendant impacts of criteria and particulate pollutants: A case of Niger Delta region of Nigeria

Abstract

Gas flaring operations as experienced in the Niger Delta region (NDR) of Nigeria are characterized with the release of gases, particulates, noise and heat that have adversely affected both human and environment. The purpose of this paper was to conduct an inventory of pollutants (NOx, SOx, CO, NMVOC, PM2.5, and organic carbon (OC)) released over half a century in order to assess the environmental health risk of the region. Data on volumes of gas flared in the country and emission factors of pollutants sourced from literature were used in carrying out emission inventory from 1965 to 2015. The air quality index (AQI) of NOx, SOx, CO and PM2.5 was estimated while the relative uncertainties associated with the emissions were obtained using Analytica® (4.6). The result showed that of the 1.78 × 1012 m3 of gas produced for a period of 51 years, 822.02 × 109 m3 utilized and 917.17 × 109 m3 were flared. Estimated total amount of 1.13 × 106, 5.10 × 106, 1.46 × 106, 1.05 × 104, 6.56 × 105 and 8.90 × 104 tons of NOx, CO, NMVOC, SOx, PM2.5, and OC, respectively, were emitted due to flaring. Relative uncertainties linked to the pollutants ranged from −99.53% to 335.02%. The environmental health risk assessment as indicated by the AQI showed that the emissions of NOx and PM2.5 were hazardous, CO was unhealthy and SOx was good. Statistical analysis on PM2.5 estimated in this study and life expectancy in NDR showed that both data are significant and statistically independent with a correlation coefficient of 0.6717. The implementation of sustainable development goals and other international initiatives aimed at reducing gas flaring in the NDR will ensure the well-being and livelihood of the inhabitants as well as the environment. Keywords: Gas flaring, Emissions, Air quality index, Niger Delta region, Air pollution, Health risk