Top cleanest cities in the world

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.

Being one of the countries most deeply concerned with the environment, Canada is a country with many clean cities, such as Vancouver, Toronto and Montreal.

Why are Canadian metropolises so highly ranked? Because of their concrete policies on environmental issues that keep a good air quality; the fact that these cities have a low population density is also a helpful factor.

In Europe, the Danish Copenhagen city is among the least polluted. How do they manage to be a sustainable city?

It is a well-known place for its cycle-culture (half of its inhabitants use bicycles as a means of transport); it is officially considered the main Bike City in the world, a 390 km cycle-lane haven. Copenhagen is expected to become a zero-emission city by 2025 and its emissions decrease in 20% by 2015.

Zurich, Switzerland, is also another of the cleanest cities concerned with emission reduction.

The Spanish city Las Palmas has been described as the city with the cleanest air in all Spain, according to the World Health Organisation (WHO).

Its beach Las Canteras is also considered as one of the best urban beaches in the world. Vitoria is also considered as one of the Spanish cities with the best air quality, and was declared European Green Capital 2012.

In Latin America the Brazilian city of Salvador de Bahía is at the top of the list, followed by Ibarra, Ecuador.

Uruguay, Argentina, Paraguay and Costa Rica are the countries with the best air quality in Latin America.

Examples of clean cities in the US are Boston, Honolulu, Minneapolis, Pittsburgh and Lexington. Boston, with a population of 7,000, keeps a good air quality.

This is another case which proves that the combination of a big city and a low level of pollution is possible.

In New Zealand, a place in harmony with the environment, there is Auckland, one of the least polluted cities in the world.

It is actually one of the best recommended cities to live in in a sustainable way.

Do you know any of these cities? What other places would you include in the list?