In 2014, the World Health Organization reported that New Delhi was one of the most polluted cities in the world, with dangerous levels of fine particulate matter pollution, known as PM2.5. Ever since, New Delhi has been synonymous with hazardous air quality.

Over the last few years the air quality levels in one of the world’s fastest growing metropolises have ebbed and flowed, but for the most part New Delhi’s pollution levels remain higher than most cities across the world.