The Environmental Commission of the Megalopolis (CAME) announced on Wednesday, March 19, 2025, that Phase 1 of the environmental contingency is still in effect across the Metropolitan Zone of the Valley of Mexico due to high concentrations of ozone continuing to pose significant health risks to residents. The air quality in Mexico City is currently assessed as ranging from "bad to very bad," primarily attributed to intense solar radiation and weak winds that persist in the region.
Amid these adverse conditions, which have been exacerbated by a stable atmospheric system bringing little moisture, the CAME issued a series of precautions aimed at protecting public health. Authorities urge the population, particularly vulnerable groups such as children, the elderly, and individuals with respiratory or cardiovascular conditions, to avoid outdoor activities between the hours of 1:00 PM and 7:00 PM, when pollutant levels peak.
In a communication released at 3:00 PM on March 19, CAME confirmed that despite efforts to curb pollution since the previous day, pollution levels have not decreased sufficiently to lift the contingency measures. The report further stated that the influence of a high-pressure system across central Mexico is contributing to poor air circulation, which facilitates ozone formation and leads to an accumulative effect on air quality.
As part of the ongoing contingency, vehicle restrictions are in place from 5:00 AM to 10:00 PM. Specific limitations apply to vehicles with verification hologram 2, which are completely forbidden from circulating, as well as vehicles with verification hologram 1 ending in odd digits (1, 3, 4, 5, 7, 9) and 00 or 0 with red stickers ending in 3 or 4. Moreover, gas stations in the area have been ordered to reduce their operational capacity by 20%, while the Miguel Hidalgo refinery near Tula will operate at no more than 75% capacity, ensuring a significant labor reduction in industries reliant on combustion.
In light of these regulations, the CAME has released additional recommendations to the public. These include avoiding the use of tobacco indoors and refraining from using aerosols, paints, and any products that emit solvent fumes. Residents are advised to minimize their water and energy consumption during the contingency by adhering to shorter showers and utilizing covered cooking pots.
Authorities are keenly watching future developments and public health advisories regarding the Doble Hoy No Circula program, which is implemented to manage the number of vehicles on the roads and mitigate pollution levels. The officials are expected to issue further guidance after another assessment scheduled for 8:00 PM on March 19, 2025.
This announcement follows a prior environmental contingency measure activated on February 26, 2025, due to record-high ozone concentrations that reached 157 parts per billion in Tlalnepantla, prompting immediate action to protect vulnerable populations.
The current situation demonstrates the ongoing challenge faced by authorities in dealing with air quality crises exacerbated by urbanization and high vehicle density. Mexico City consistently ranks among the worst in global air quality metrics according to the IQAir platform due to its heavy traffic and other pollution sources.
As discussions about Mexico's air quality continue to evolve, the public is encouraged to stay attentive to further announcements from the CAME, as changes may occur quickly depending on meteorological conditions.
With the high-pressure system forecasted to shift, potentially allowing for better airflow and humidity levels, the next days will be crucial for air quality improvements. Forecasts indicate that conditions may change, leading to a reduction in atmospheric stability and an overall improvement in air quality as early as March 20, 2025. Meteorologists predict the introduction of moderate humidity and cloud cover will aid in reducing ozone buildup.
The persistence of environmental contingencies in Mexico City underscores the critical need for ongoing monitoring and effective public communication strategies to ensure that residents' health remains a priority amidst fluctuating air quality challenges.
