Environmental authorities in Mexico City and the State of Mexico have activated Phase 1 of an atmospheric ozone contingency in the Valley of Mexico metropolitan area.
The measure was triggered Saturday afternoon after ozone levels reached 163 parts per billion at the Faculty of Higher Studies Acatlán station in Naucalpan, State of Mexico, according to official reports. That reading placed air quality in the “very poor” category, posing health risks particularly for children, the elderly and individuals with respiratory or cardiovascular conditions.
Officials cited a persistent anticyclonic system over central Mexico, intense solar radiation and the onset of a heat wave as key factors contributing to ozone accumulation. The atmospheric stability limited pollutant dispersion, whereas high temperatures and sunlight accelerated ozone formation.
As part of emergency actions, a double “Hoy No Circula” vehicle restriction will be enforced Sunday from 5:00 a.m. To 10:00 p.m. The following vehicles will be prohibited from circulating:
- Vehicles with hologram 2
- Vehicles with hologram 1 ending in 2, 4, 6, 8 or 0
- Vehicles with hologram 0 or 00, yellow sticker, ending in 5 or 6
- Vehicles without hologram, foreign vehicles, temporary permits or license plates consisting only of letters
- 50% of LP gas delivery vehicles without dry valves and even-numbered license plates
The contingency marks the fifth environmental alert of the year in the Valley of Mexico. Authorities urged the public to limit outdoor activities, especially during peak sunlight hours, and to use public transportation or carpooling alternatives where possible.
