It has been said that "
Mexico City’s air has gone from among the world’s cleanest to among the dirtiest in the span of a generation."
[4] Historic air pollution episodes of the 1950s led to acute increases in
infant mortality.
[5] Connections have also been found between air pollution and
school absenteeism among children in Mexico City,
[6] between air pollution and
heart rate variability among the elderly in Mexico City,
[7] and between urban air pollutants on emergency visits for
childhood asthma in Mexico City.
[8]