La Megalopolis Environmental Commission (CAMe) has decided lift the environmental contingency The atmospheric ozone pollution alert in the Valley of Mexico was lifted after a clear improvement in air quality was observed during the afternoon. The extraordinary measures, which primarily affected mobility and outdoor activities, were lifted at 18:00 PM.
This change of scenery comes after a day marked by the contingency phase 1The restrictions, which had been activated the previous day due to high ozone levels recorded in the metropolitan area, aimed to reduce the population's exposure to polluted air and minimize health risks.
Why is the environmental emergency being suspended in the Valley of Mexico?
As detailed by CAMe in several statements, the decision to suspend the contingency is based on a Favorable weather conditionsFrom 16:00 PM onwards, a decrease in atmospheric stability and an increase in wind were recorded over the Valley of Mexico, which favored the dispersion of pollutants.
Air quality monitoring systems indicated that, thanks to that increased ventilationOzone levels began to decline steadily. By 18:00 PM, the stations were already reporting hourly concentrations within the values ​​permitted by regulations, which opened the door to lifting phase 1.
Forecasting models also indicate that high-pressure system affecting the center of the country It will move away from the region in the coming hours. This system had caused moderate to strong atmospheric stability, little wind, and intense solar radiation in recent days—a combination that favors the formation and accumulation of surface ozone.
With the weakening of that deadlock situation, it is expected better conditions for the dispersion of pollutants the following day, which reduces the risk of a recurrence in the short term of the pollution spikes that led to the activation of the contingency.
CAMe emphasizes that the suspension is carried out under the protection of the Programs to Prevent and Respond to Atmospheric Environmental Contingencies current in Mexico City and the State of Mexico, which set the thresholds and technical criteria to activate and deactivate these alerts.
How did phase 1 of the contingency affect the population and traffic
Phase 1 of the ozone contingency plan was launched on Thursday, after ozone was detected. high levels of formation and accumulation of this pollutant at a large number of stations in the Atmospheric Monitoring System. The situation was considered serious enough to trigger specific road traffic restrictions.
During the hours that the contingency was in effect, movement was restricted vehicles with holograms 1 and 2especially those with certain final license plate digits, as well as some cars with hologram 0 and 00 depending on the sticker color and license plate ending. The idea was to quickly reduce the emissions of ozone precursors, such as nitrogen oxides and volatile organic compounds from traffic.
In addition to restrictions on private cars, the authorities recommended to the public Avoid civic, cultural, sporting and recreational activities outdoorsespecially during peak sun hours. Special emphasis was placed on protecting children, the elderly, pregnant women, and patients with respiratory or cardiovascular diseases.
Among the guidelines disseminated were specific tips such as avoid intense outdoor exerciseReduce outdoor exposure time, do not smoke —especially indoors— and limit the use of solvent-based products, such as aerosols, paints, air fresheners or waterproofing agents, which also contribute to the formation of tropospheric ozone.
At the same time, the Government urged the population to adopt small daily changes to lower domestic emissions: shorter showersCooking with covered containers or moderating the use of private vehicles when possible, measures that, although they may seem minor, add up on a metropolitan scale.
End of the contingency: what happens to the Hoy No Circula program
With the announcement of the lifting of the contingency, CAMe specified that the Extraordinary traffic restrictions are lifted From 18:00 PM. This means that the additional restrictions applied during phase 1 no longer apply to the following day.
The program for Saturday, January 10th No Circulation Today it starts working again under its ordinary guidelinesThat is, without the extensions typical of a poor air quality episode. The hours of operation for the scheme remain from 5:00 a.m. to 22:00 p.m.
In those areas, Vehicles with hologram 2 are not allowed to circulateThis also applies to cars with a "1" hologram sticker whose license plate ends in an odd number, according to the usual rules. Those who violate these regulations face fines and the possible impoundment of their vehicle.
The program includes different exemptions for certain types of vehiclesCars with valid "Exempt", "00" or "0" holograms are exempt from the restrictions, a category that mainly includes... hybrid, electric vehicles or those that demonstrate lower pollutant emissions.
Essential services are also excluded, such as ambulances, fire units and patrol carsas well as school transport with proper authorization. People with disabilities can use their vehicles without limitations provided they carry the corresponding identification, and certain services are included in the exemption. federal public passenger transport with valid permits.
In the case of cars with license plates from states other than Mexico City, State of Mexico, Hidalgo, Morelos, Puebla, Querétaro and Tlaxcala, the regulations state that They are not subject to the programunless their owners have permanent residence in the metropolitan area. Furthermore, vehicles that have a active tourist pass They can circulate normally on the days established by said permit.
Air quality monitoring and lessons for other cities
Following the lifting of phase 1, CAMe, the Ministry of Environment and Natural Resources, and the environmental authorities of Mexico City and the State of Mexico have insisted that they will remain vigilant in the face of any change in atmospheric conditions. The goal is to react quickly if a new spike in pollutants such as ozone or particulate matter (PM2.5) is detected.
The public can consult at any time the AIR AND HEALTH Index through the official portal (www.aire.cdmx.gob.mx) and the AIRE mobile application. These tools allow users to know, almost in real time, the level of pollution in different areas of the metropolis and offer specific recommendations according to each air quality range.
So far this year, the Valley of Mexico has already faced several significant pollution episodesThis included a previous alert related to PM2.5 particles associated with the use of fireworks and the burning of materials and fuels during festive celebrations. That alert was also deactivated within a few hours, once particle levels dropped to acceptable values.
This type of event serves as a reminder for both Mexico and other large urban areas of Europe and SpainIn these regions, episodes of high pollution from nitrogen dioxide, fine particulate matter, or ozone are relatively frequent. Cities like Madrid, Barcelona, ​​Milan, and Paris apply similar protocols: traffic restrictions, health recommendations, and temporary measures to reduce emissions when certain thresholds are exceeded.
The experience of the Valley of Mexico reinforces the idea that the combination of temporary restrictions, transparent information, and changes in habits It can help overcome isolated episodes of poor air quality. However, health and environmental experts insist that the fundamental solution lies in structurally transforming mobility, the energy model, and urban design.
Following the lifting of the contingency measures in the Valley of Mexico, the remaining scenario is that of a city gradually recovering its daily activity and its normal circulation patternBut at the same time, it faces the fundamental challenge of permanently reducing air pollution levels. Authorities are maintaining vigilance and urging citizens not to let their guard down, adopting more sustainable habits that, both in Mexico and in major Spanish and European cities, can make the difference between breathable air and an environment that jeopardizes public health.
