According to a new study, seven out of ten most polluted cities in the world are located in India. The study also showcase the challenges being faced by South Asia in terms of deteriorating air quality and the economic toll it's expected to take worldwide.

As per data released by IQAir AirVisual and Greenpeace, topping the list is Delhi's Gurugram with 135.8 particulate matter. It may be noted that its condition has improved from the previous year according to the report.

Along with Gurugram, the other two Indian cities on top five are Ghaziabad, Faridabad and Bhiwadi.

The index is measured by the presence of fine particulate matter known as PM2.5, a pollutant that can fester deep in the lungs and bloodstream of human beings.

Along with the figures, in a statement Yeb Sano, executive director of Greenpeace Southeast Asia was quoted saying, "This has enormous impacts, on our health and on our wallets", adding, "In addition to human lives lost, there's an estimated cost of $225 billion in lost labor, and trillions in medical costs."