Abstract

Traffic source emission inventories for the rapidly growing West African urban cities are necessary for better characterization of local vehicle emissions released into the atmosphere of these cities. This study is based on local field measurements in Yopougon (Abidjan, Cô te d&rsquo Ivoire) in 2016 a site representative of anthropogenic activities in West African cities. The measurements provided data on vehicle type and age, traveling time, fuel type, and estimated amount of fuel consumption. The data revealed high traffic flow of personal cars on highways, boulevards, and backstreets, whereas high flows of intra-communal sedan taxis were observed on main and secondary roads. In addition, the highest daily fuel consumption value of 56 L· day&minus 1 was recorded for heavy vehicles, while the lowest value of 15 L· 1 was recorded for personal cars using gasoline. This study is important for the improvement of uncertainties related to the different databases used to estimate emissions either in national or international reports. This work provides useful information for future studies on urban air quality, climate, and health impact assessments in African cities. It may also be useful for policy makers to support implementation of emission reduction policies in West African cities. Document type: Article

Abstract

Large-scale use of leaded gasoline was an important source of the neurotoxin lead in the European environment. After a sequence of regulations on the allowed gasoline lead content and, eventually, a ban on the use of lead additives in gasoline, road transport was no longer considered a source of atmospheric lead. Currently a discrepancy exists between measured atmospheric lead concentrations and model-predicted concentrations, suggesting that lead emissions to the atmosphere may be underestimated. Recently it was suggested that lead emission from unleaded gasoline combustion is still an important source and may (partly) fill the gap between modelled and observed atmospheric lead concentrations. In this paper we assess the plausibility of the latter suggestion by following various emission estimation methodologies. The uncertainty of lead emissions from road transport is further reduced by chemical analysis of fuel samples. The result of our assessment is that lead from road transport fuel combustion is not the missing lead source needed to fill the gap between modelled and observed lead concentrations. Road transport is still a source of lead through brake wear and a small contribution from exhaust emissions but this contributes no more than 5-8% of the EU25 total emission. © 2009 Elsevier B.V. All rights reserved.