Every year 3.3 million people worldwide die prematurely because of ambient air pollution. This number is significantly higher than those dying of AIDS/HIV or Malaria. Especially large cities, such as Beijing, Delhi, Mexico City or São Paulo, are known for their high air pollution levels. Locals and tourists now have access to information about the quality of air in their city. World Air Quality (Index), an online-based map, makes it possible to track current air data for over 5,900 cities around the globe. You can jump in between the cities of the world and, for example, thus compare the sulphur dioxide content of Mumbai in India with Johannesburg in South Africa.
Possibly up to 6.6 million yearly deaths from 2050 due to air pollution levels

A team of scientists, engineers and designers has developed a world map which indicates air pollution levels of cities. Air quality of a measuring station is indicated within the world map through a classification number and a colour-coded category based on the Air Quality Index (AQI) by US Environmental Protection Agency (EPA). After choosing a specific measuring station, more precise data appear.

Data regarding particulate matter pollution such as PM2.5 and PM10, nitrogen dioxide (NO₂), sulphur dioxide (SO₂) and carbon monoxide (CO), as well as the outside air temperature, air pressure, humidity and wind conditions, are displayed once a measuring point is chosen. The map is automatically updated. Apparently it only shows air data which has been collected through official measurements. Amateur measurements are not taken into account.

Currently the world map is not completed. Africa, large parts of Asia and South America report few or no air pollution levels for cities. Even regions with many measuring points, such as East Asia, Europe and North America, still show some gaps. How current the stated data is also depends from city to city and can vary by several days.