Can a big city have a good air quality? Pollution in metropolises becomes worse when there is no sustainable development. Those emissions produced by factories, vehicles and other mass activities can generate high pollution levels which seriously affect their population´s health.

There are many ways to improve the air quality, such as promoting the use of low-emission public transport or sharing the same vehicle, using bicycles or controlling emissions in industrial areas, which can help a big city improve its air quality.