On March 11, the Valley of Mexico experienced its fourth environmental contingency of the year as air quality deteriorated due to elevated levels of pollutants. The authorities monitor air quality indicators, focusing on PM2.5 and PM10 particles across various analysis stations in the region. This situation has generated concerns about public health and necessitated immediate actions from local government to address air quality issues.

By 8:00 AM on March 11, the only analysis station reporting 'bad' air quality was located in Villa de las Flores, State of Mexico. Other areas including Tlalnepantla and Gustavo A. Madero reported 'acceptable' air quality levels, while districts like Tláhuac and Nezahualcóyotl maintained 'good' levels. The contrasting air quality readings across various locations highlight the varying impacts of pollution in the metropolitan region and raise questions about the effectiveness of local policies on air quality management.

These conditions have led to the implementation of vehicle circulation restrictions under the 'Hoy No Circula' program, specifically for vehicles that do not meet certain environmental criteria. The local government is closely monitoring the situation to determine the necessary actions to protect public health in light of the ongoing air quality issues, illustrating the challenges faced by urban areas in mitigating environmental impacts while balancing transportation needs.