3Mexico City, Mexico

Mexico City has long been associated with poor air quality, primarily due to its geographic location in a valley that traps smog and pollution.  

The city is plagued by traffic congestion, industrial emissions, and pollution from surrounding areas. Although measures have been taken to improve air quality, such as restricting vehicle use and promoting cleaner energy sources, air pollution remains a persistent issue. Additionally, the city’s waste management system is overwhelmed, resulting in frequent illegal dumping of waste, further degrading the environment.