What's choking Delhi: Air quality remains in 'very poor' category

A layer of toxic haze lingered over the national capital on Tuesday as the city recorded its air quality in the 'very poor' category, according to the Central Pollution Control Board.

According to the Ministry of Earth Sciences' air quality monitor, SAFAR, the wind direction and wind speed were favourable for the transport of pollutants from the farm fires in Punjab, Haryana and neighbouring regions.

Here is a look at the reasons that are choking Delhi.