Toxic smog shrouds New Delhi with winter approaching

NEW DELHI: A contaminated smog blanketed New Delhi on Tuesday, pushing air quality in some parts into the "severe" category before beginning of winter, when cold air traps pollutants and spreads respiratory illnesses.

A mixture of smoke from vehicles and farm fires, construction dust are the big contributors in spiking the pollution every year in the Indian capital. 

"The outlook for the subsequent six days: the air quality is likely to be in the 'very poor' to 'severe' category," said the earth sciences ministry.

The city's overall score on an air quality index kept by India's top pollution authorities was 'very poor' at 384, the ministry added, and was likely to stay there until Thursday.

An index range of 401 to 500 falls into the 'severe' category, implying it affects healthy people, but is more serious for those already fighting disease.

Ministry data showed farm fires have increasingly swelled the pollution over the last three days, for a share of more than 23% on Monday, from about 15% on Saturday.

About a third of the city's 39 monitoring stations showed a 'severe' score of more than 400 on Tuesday, said the Central Pollution Control Board (CPCB), well short of an air quality score of zero to 50 that it rates as 'good'.

Swiss group IQAir also rated Delhi the world's second most polluted city on Tuesday, after Pakistan's Lahore, where authorities also took emergency measures in the wake of Sunday's unprecedented pollution levels.

The government in Punjab has blamed deteriorating air quality on pollution wafting in from India, an issue it has vowed to take up with its neighbour through the foreign ministry.