MEXICO CITY (AP) – Choking smog returned to the skies of Mexico City this week at levels not seen in more than a decade, prompting fears of more eye-watering days to come as efforts to curb pollution run afoul of the courts and the realities of life.
The haze that shrouded the second-largest city in the Western Hemisphere for four days never reached the worst periods in the 1980s and 1990s, but ultimately resulted from the fact that there are still too many cars on the crowded streets.
“You have to recognize that we are doing better, but it’s still not ideal,” Javier Riojas, a specialist in environmental sustainability at the Universidad Iberoamericana, said Friday.
Authorities declared the city’s first Phase 1 pollution alert since 2005 on Monday due to high ozone levels blamed on a thermal inversion, which traps airborne contaminants from releasing upward into the atmosphere. Mexico City typically sees its worst air smog during the winter-spring dry season when warm, still air settles in the high-altitude basin ringed by volcanic mountains.
At one point on Monday, the pollution index edged past 200 – double the level considered acceptable but far short of the record of 398 set in March 1992.