Estimation of motor vehicle toxic emissions in the metropolitan area of Mexico city

The contribution of gasoline-powered vehicles to air toxic emissions in the Metropolitan Area of Mexico City (MAMC) is not well established. The MAMC has particular geographic conditions such as being in a valley at high alti tude (2280 m above sea level) and has a very old and technologically hetero geneous vehicular fleet. Toxic compounds emitted by the exhaust of motor ve hicles (e.g., benzene, 1,3-butadiene, formaldehyde, and acetaldehyde) were estimated. In this work, tests using Mexican gasolines in a vehicular fleet representative of the MAMC (ca. 1999) were carried out. As a comparison, s ome tests were done using an American gasoline (Federal Reformulated Gasoli ne, RFG-1) in a representative fleet of vehicles operated in Mexico.