ABSTRACT
Air pollutants from motor vehicles come from the exhaust pipe, fuel tank, canister and carburettor. Exhaust pipe emissions come from fuel combustion in the engine. Evaporative emissions occur while the vehicle is moving, standing or refuelling. The principal health-related pollutants include CO, NOx, sulphur oxides, sulphurous and sulphuric acids, reduced sulphur compounds, particulate matter, and aromatic hydrocarbons (HC) such as benzene, toluene, ethyl benzene, the xylenes and the trimethylbenzenes (Atkinson, 1988). Lead (Pb) is a pollutant when it is added to fuel to improve engine performance. Ozone is a secondary air pollutant created in the atmos phere through a photochemical process that involves NOx, reactive non-methane hydrocarbons and volatile emissions.
