Environmental Effects of Vehicle Exhausts, Global and Local Effects : A Comparison between Gasoline and Diesel

Abstract: Since 1970, vehicle’s exhaust pollutions have received increasing attention as a source of air pollution at both local (human health concerns) and global (global warming) scales. This study mainly discusses diesel and gasoline vehicles because, today, over 90% of vehicles on the road use gasoline and diesel fuels. The major concerns of gasoline exhaust contaminants are carbon monoxide (CO), hydrocarbon (HC), carbon dioxide (CO2) and polycyclic aromatic hydrocarbons (PAHs); the major concerns of diesel exhaust emissions contaminants are nitrogen oxides (NOX) and particulate matter (PM). The aim of this study is mainly to compare gasoline and diesel fuels, and to determine which fuel and its developed forms are less harmful to humans, and which are most suitable for the natural environment at both a local and global level. The results show that burning gasoline fuels will emit less PM and NOX emissions than burning diesel fuels, but it will generate about 50% more CO2 than diesel fuels, and it also emit about ten times more CO, PAHs and around five times more HC than diesel fuels; burning diesel fuels will produce less CO2 emissions than gasoline fuels, but will emit around ten times more NOX and PM than gasoline fuels. Consequently using a gasoline car in urban areas might help to reduce the human health effects; using a diesel car on motorways or in rural areas might help to reduce the greenhouse gas (GHG) emissions and minimize the global warming effects. Biofuels, biodiesel and ethanol, have the potential to minimize the vehicle exhaust emissions and adverse effects. Nonetheless, there are still many debatable issues around biodiesel, such as insufficient fuel supply and health concerns (especially, ultrafine particles (UFPs)). In the future, there remains a need to continue the further studies of vehicle exhaust emissions, and to improve the understanding of all vehicle exhaust emissions and all of their impacts, especially the vehicle exhaust health research.