The 10 most polluted cities in the world

Six of the world’s most polluted cities are in India, according to the latest World Air Quality Report. New Delhi’s air quality continues to deteriorate, making it by far the world’s most polluted capital city. While the city is home to some of the country’s best-known landmarks, including the India Gate and Parliament Building, it is often hard to look past the smog that blankets New Delhi. The worst-ranked city on the list – Ghaziabad – is a Delhi suburb, followed by Hotan in China and Gujranwala and Faisalabad in Pakistan, respectively. Published by IQAir AirVisual, the index lists six Indian cities in the world’s top 10 most polluted cities. All cities in the worst 10 list have unhealthy or very unhealthy levels of air quality. The increasing presence of vehicle emissions was one of the main factors contributing to the rising levels of pollution. In China, rapid industrialisation results in intense levels of air pollution that present serious social, economic and political problems. In Pakistan and India, high population density means heavy traffic on the roads. As a result, the heavy use of fuel-powered vehicles, including cars, rickshaws and lorries, adds to harmful emissions. The latest findings were based on air quality data from public monitoring sources. The cities were ranked based on the presence of fine particulate matter (PM) in the air. The most harmful kind, called PM2.5, contains particles with a diameter less than 2.5 micrometres (more than 100 times thinner than a human hair). They are tiny enough to enter the bloodstream through the lungs. The World Health Organisation estimates that about seven million people die every year from exposure to fine particles in polluted air. Air pollution can cause diseases such as stroke, heart disease and lung cancer.

The 10 most polluted cities in the world

Indian cities have the worst air quality, causing untold health problems for their huge populations