On February 26, 2025, authorities from the Commission for Environmental Protection of the Megalopolis (CAMe) activated Phase I of the atmospheric environmental contingency due to dangerously high levels of ozone, reported at 157 parts per billion (ppb) at the Tlalnepantla monitoring station. The decision aims to protect public health and curb emissions during periods of severe air pollution.
The situation arose from meteorological conditions favorable for the accumulation of ozone precursors, exacerbated by high solar radiation and low air movement. "Today, a high-pressure system over the east of the Valley of Mexico caused light winds with variable direction, contributing to elevated ozone levels," explained CAMe officials.
To mitigate the health impacts of these pollutants, the CAMe issued multiple advisories urging residents to avoid outdoor activities and follow official guidelines aimed at minimizing exposure. This included avoiding civic, cultural, and recreational activities outside from 1 PM to 7 PM, as well as suspending any outdoor gatherings during this time.
Effective February 27, 2025, the “Doble Hoy No Circula” program was put in place. This program restricts the circulation of various vehicles within Mexico City and the surrounding Metropolitan Valley. Specifically, the following will not be allowed on the roads from 5 AM to 10 PM:
- Vehicles with verification hologram 2.
- Vehicles with hologram 1 ending with the digits 1, 2, 4, 6, 8, and 0.
- Vehicles with hologram 00 and 0 with green stickers, plates ending with 1 and 2.
- Vehicles without verification holograms, including antiquated models and those with tourist permits.
- Fifty percent of gas delivery units without disconnection valves with even-numbered license plates.
- Local and federal freight vehicles are barred from circulation between 6 AM and 10 AM, except those registered under the city’s self-regulation program.
- Taxis with verification holograms 00, 0, 1, or 2 will also be restricted during the day.
Exceptions are made for electric and hybrid vehicles, emergency service units, and vehicles driven for medical emergencies, all of whom are allowed on the roads regardless of the current restrictions. The regulations extend even to vehicles from surrounding states, which may also face restrictions if they do not carry proper verification.
CAMe has prepared specific documentation to clarify the role of vehicles with foreign license plates as many residents may be unaware of these guidelines. It was noted, "All vehicles from other states without verification holograms will automatically be treated as having hologram 2, and must comply with these restrictions," underscoring the thorough regulations planned during the environmental emergency.
With the implementation of these measures, residents of Mexico City are urged to stay informed about the air quality indices using available resources such as the “Aire” App and to adhere strictly to the outlined guidelines, particularly when engaging in any activities outdoors. The advisories aim to protect vulnerable populations, including children, the elderly, and those with pre-existing health conditions.
Significant public cooperation is deemed necessary for these efforts to succeed as the city navigates through potential health crises brought on by air pollution. The CAMe has emphasized the fact: "Community action is key to improving air quality and protecting public health during these challenging times." The urgency of continued vigilance and action during environmental contingencies could not be overstated as authorities aim to restore clean air to the city.
Mexico City faces not only the immediate challenges of pollution but also the long-term necessity for sustainable urban planning and community awareness surrounding environmental issues. The Doble Hoy No Circula is just one of several strategies being deployed to maintain air quality as the summer months approach, traditionally featuring high levels of ozone due to rising temperatures.
Authorities remain firm on their stance against complacency and urge residents to engage actively with preventive measures to encourage cleaner air and healthier lives for future generations. With the right actions, it is hoped we can move closer to achieving cleaner air quality levels and combat the adverse effects of pollution.