Focus Model for megacities? Mexico City cleans up its air.

As people around the world celebrate Earth Day, Mexico City may serve as an unlikely environmental example for cities in developing countries suffering poor air quality.

By , Contributor

Eduardo Verdugo/AP

Mexico City was once known for its smoggy landscape with industrial eyesores such as the 18 de Marzo Refinery spewing ozone-forming emissions such as sulfur dioxide. The cloud of contaminants hanging over the capital played into an apocalyptic reputation for pollution, crime, and overpopulation; and it fueled urban myths, like the one about birds dropping dead mid-flight because of the poor air quality.