The Comisión Ambiental de la Megalópolis (CAMe) announced on Wednesday, April 2, 2025, that it has lifted Phase 1 of the environmental contingency due to ozone in the Valley of Mexico. This decision came after almost two days of heightened ozone levels that posed health risks to residents.
As of 17:00 hours on April 2, the CAMe reported that hourly ozone concentrations had dropped below the established limits set in the Atmospheric Environmental Contingency Program. "The latest information from meteorological models indicates that the displacement of the high-pressure system towards the Gulf of Mexico allowed for a significant decrease in atmospheric stability over the Metropolitan Zone of the Valley of Mexico," the CAMe stated in a press release.
The high-pressure system's movement facilitated moderate winds from the south, accompanied by strong gusts, which helped disperse the accumulated ozone particles. This change in weather conditions was crucial in alleviating the environmental crisis that had gripped the region.
With the suspension of the contingency measures, the double "Hoy No Circula" program, which restricts vehicle circulation based on license plate numbers, will also be lifted for Thursday, April 3. However, the usual restrictions will remain in effect for vehicles with hologram 1 and 2, green stickers, and plates ending in 1 and 2.
During the contingency, the CAMe had advised residents to avoid outdoor activities, especially between 13:00 and 19:00 hours, due to the adverse air quality conditions. Vulnerable groups, including children, the elderly, pregnant women, and individuals with respiratory or cardiovascular diseases, were particularly urged to stay indoors during this period.
In addition to lifting the contingency, the CAMe expressed gratitude to the public for adhering to health protection recommendations and emission reduction measures during the crisis. The agency, along with the Secretariat of Environment and Natural Resources, will continue monitoring air quality and weather conditions closely.
Despite the lifting of the contingency, residents are encouraged to remain vigilant regarding air quality. The CAMe recommends using the Aire app or following official channels for real-time updates. Furthermore, the agency has requested the public to postpone the use of solvents, promote teleworking, and refuel their vehicles outside of peak hours to continue reducing emissions.
The recent environmental contingency was triggered by a high-pressure system that led to stable atmospheric conditions, allowing pollutants to accumulate in the air. This situation was exacerbated by low humidity and weak air circulation, combined with intense solar radiation during the day.
As of now, the air quality in the Valley of Mexico has improved significantly, moving away from critical levels. The CAMe's decision to lift the contingency reflects a positive shift in environmental conditions, allowing residents to resume normal activities without the added burden of pollution-related restrictions.
Moving forward, the CAMe will remain proactive in addressing air quality issues and will implement necessary measures to prevent future environmental contingencies. The collaborative efforts between the CAMe, local governments, and the community will be essential in maintaining a healthier environment for all.
The public is reminded that breaking the vehicle restriction program can result in fines equivalent to 20, 25, or 30 times the current Unit of Measurement and Update. Vehicles violating the restrictions may be immobilized and taken to an impound yard until the fines are paid.
As the situation continues to evolve, the CAMe emphasizes the importance of public cooperation in maintaining air quality standards and protecting the health of all residents in the Valley of Mexico.
