Unregulated Motor Vehicle Exhaust Gas Components 902116
Besides the legally controlled components carbon monoxide, total hydrocarbons, oxides of nitrogen and particulate matter (vehicles with diesel engines), there are many other components in the exhaust gas of motor vehicles, which are not explicitly controlled by law, and are therefore classified as unregulated exhaust gas components.
This does not mean that these components are not subject to environmental legislation, but rather the opposite is the case. For more than ten years, US legislation has been calling for constant proof from vehicle manufacturers that the exhaust gas treatment systems, which are built into vehicles to reduce the legally controlled emissions, do not release other (unregulated) components in such concentrations as to represent an unjustifiably high health risk.
The paper presents a summary and evaluation of the results of emission investigations on unregulated motor vehicle exhaust gas components carried out at VW on 18 VW/Audi passenger cars of model-years 1978 to 1986.
The results of these measurements serve as a basis for ascertaining the effects of the unregulated exhaust gas components on air quality. In order to do this, we have calculated ambient concentrations for both street canyons and for areas surrounding expressways, and have compared them with the corresponding health effect limit values drawn from the literature.