Characterization of Emission Factors from Fossil Fuel and Biomass Combustion Sources in Eastern Africa
THEOBARD HABINEZA, Albert A. Presto, Allen Robinson, Carnegie Mellon University
Abstract Number: 36
Working Group: Urban Aerosols
Abstract
Anthropogenic emissions in Africa are diverse and evolving due to new emerging sources. Quantifying emission factors (EFs) is essential to reduce uncertainties in regional and global circulation models representing air pollution in this data-scarce region. We conducted tailpipe measurements (81 vehicles) and chamber experiments to quantify EFs for diesel and gasoline trucks, as well as solid biomass energy sources (specifically charcoal). Using a carbon mass balance approach, we quantified EFs by vehicle age (very old, old, new), type (heavy-duty trucks, light-duty trucks, passenger cars and Two wheels motorcycles), Euro category (Euro 1–5), along with charcoal and wood combustion emissions for fine particulate matter (PM2.5) mass, SO2, CO, CO2, NOx, and black carbon. Very old vehicles (manufactured before 2000) showed 2.97 times higher PM2.5 and 1.2-times higher BC emissions than new ones (manufactured after 2015), with heavy-duty vehicles reporting the highest EFs. Light-duty passenger cars exhibited the highest mean CO₂ emissions and lowest CO and NOx emissions. A factor or 2.3 between Euro five and Euro 1 vehicle category. Vehicle maintenance indicators (CO/CO₂ > 0.005) showed 47% of vehicles poorly maintained, dominated by older and very old models. Furthermore, 20% of vehicles accounted for ~65% of total CO emissions, while the cleanest 40% contributed <10%. The updated emission factors are compared to global databases (EDGAR v6.1, DACCIWA) and show substantial regional differences. This highlights the need for Africa-specific EFs to improve model-based assessments of air pollution and associated health impacts in the region.