As pollution levels fall, Mexico City's residents breathe cleaner air - and a sigh of relief.
Not even a decade ago, the atmosphere surrounding Mexico's capital was so toxic that birds died midflight and many of the city's residents were forced to walk the streets in surgical masks. But today, things are looking brighter: The skies are sometimes blue, and the volcanic range that rings the city has reemerged from the haze.
"We're in the best position we've ever been in," says Luis Roberto Acosta, director of Mexico City's International Environmental Monitoring Institute (SIMA), confirming that the skies are clearing above North America's largest city.
On Oct. 15, this city will mark two straight years without a smog emergency, something that would have been unthinkable a decade ago.
Mexico City is reaping the benefits of seeds planted in 1986. Then, the government began to heed local and international alarm bells about the worsening situation. It established greenbelts, phased out leaded gasoline, introduced emission standards for vehicles, and passed legislation to pull cars off the streets and shut factories when pollution levels reach dangerous heights.
Thanks to those efforts, the key pollution index, which measures the amount of poisonous ozone gas in the air, has fallen from an average of 211 points in 1991 to 104 so far this year. But, says Mr. Acosta, "better doesn't mean good." He worries that after 15 years of slow but steady improvement, a sense of crisis could be lost. "We've become desensitized. By North American standards, the air here is still terrible."
Despite the drop in the ozone count, Mexico City's average remains nearly double that of the most polluted US cities, where any reading above 100 would be considered a public health crisis.