Other compounds must also be monitored. It is not clear that the substances now measured are the most appropriate to serve as indicators of health impacts or air quality. Export of gases and aerosols from Mexico City over a broader region may be important for climate. CO 2 is important with respect to global warming but no measurements exist for Mexico City. Little is known about the export of aerosols, how they evolve during transport.
Some studies indicate that particles are larger at the top of the boundary layer.
In particular, aerosols might affect the stratification of the boundary layer, decreasing vertical transport and therefore decreasing transport out of the basin. Regarding the interactions between particles and ozone, aerosols may decrease the radiation flux and therefore decrease ozone formation. The speciation of hydrocarbons is essential for photochemical modeling. The speciation of hydrocarbons emitted from refueling differs from speciation emitted in exhaust emissions. Studies carried out by Dr. G. Ruiz Suarez and others also show naphthalene, contrary to common wisdom, and higher concentrations of light aromatics in PM 2.5 .