If you are one of the 3.9 billion people around the World living in a city, the air in your lungs is very likely hurting you.

More than 80% of those who live in cities with more than 100,000 that monitor air pollution are exposed to air quality levels that exceed WHO limits.

98% of cities in low- and middle-income countries have heavily polluted air, while only 56% of cities in high income countries do.

Over 54% of the World’s population lives in urban areas. This number is expected to rise 66% by 2050, so urban air quality is a pressing issue for governments around the World.

Most air pollution is not caused by the actions of individuals, so air quality control is an issue of government regulation.

When governments step up and take responsibility, cities can increase their air quality relatively quickly.

More than 50% of the cities in high-income countries and 33% of the cities in low- and middle-income countries reduced their air pollution levels by more than 5% in five years.

An alarming 7 million people die each year from air pollution. More than 90% of these pollution-related deaths occur in low- and middle-income countries, mainly in Asia and Africa.

New Delhi as the World‘s most polluted big city. Other polluted megacities, with populations over 14 million, include Cairo; Dhaka, Bangladesh; Mumbai, India; and Beijing.

Many of the World’s megacities exceed WHO’s guideline levels for air quality by more than five times.

The air quality in India is so bad, its the equivalent of smoking 44 cigarettes a day. India has 14 of the 15 top polluted cities in the World. 

Designers and engineers are racing to come up with all kinds of air-purifying solutions. One of the most impressive ideas so far can be found in Milan, Italy.

Bosco Verticale (Vertical Forest) is the concept of residential high-rises packed with greenery, which can help cities build for density while improving air quality.

The science is simple: trees are the cheapest and most efficient way to absorb carbon dioxide.

The 20,000 trees and plants across this pair of towers can transform approximately 44,000 pounds of carbon dioxide into oxygen each year.