ic, and glass. Processing these materials involves a variety of heavy metals, toxic chemicals, chlorinated solvents, and ozone depleting chemicals. The largest contribution to non-hazardous waste among the life-cycle stages is mining waste associated with energy generation and iron ore production. The residue from auto shredding operations is the second largest contributor.
             Beside the painting and coating operations, the metal casting operations are the main manufacturing operations where air emissions occur. Approximately 56% of all releases and transfers originate from the painting and coating operations. (Porter 52) Furthermore, the paint shop is the main consumer of primary energy within the manufacturing process. The largest solid waste streams generated by an automobile assembly plant are wastewater treatment sludges, waste oil, plant trash, and scrap metal.
             Naturally, the use of an automobile accounts for approximately 80% of the total primary energy use of the life cycle of an automobile. This estimation is made after taking exhaust into account. Most of the CO2 and CO emissions are released during the utilization. VOC emission during the use of the automobile (exhaust and evaporation) is greater than what is generated in any other life-cycle stage.
             Environmental impacts in the retirement stage consist of waste produced during different retirement processes. Energy depletion results from these activities. The impact depends on what materials the vehicles are made from and the means by which the vehicles are produced. When the material that the vehicle is made of changes, a difficult issue comes about. On the one hand, the use of more light-weight material such as plastics improves fuel efficiency and reduces air emissions. On the other hand, design changes that increase the amount of plastics result in lower levels of recylcability. Lighter vehicles use less fuel and therefore create less of the greenhouse gas...