Seven of the top 10 most polluted cities in the world are in India, according to a new study showing South Asia's battle with deteriorating air quality and the economic toll it's expected to take worldwide. Gurugram, located southwest of India's capital New Delhi, led all cities in pollution levels in 2018, even as its score improved from the previous year, according to data released by IQAir AirVisual and Greenpeace. Three other Indian cities joined Faisalabad, Pakistan, in the top five.
