The infamous post-Deepavali pollution spike has kept its annual rendezvous with Delhi, masking the Indian capital's landmarks behind a pall of smog, reducing the sun to a pale orb and forcing residents into coughing fits for several days now.
The severity of the pollution since Oct 28 forced the Delhi state government to declare a rare public health emergency on Friday, a day recorded as the most polluted in around two years with an average air quality index (AQI) of 484.
AQIs between 401 and 500 are classified as severe and fall in the worst category in India's air quality index. The average AQI yesterday afternoon was 410.
The state government attributed the decision to impose an emergency to "non-tolerable levels of air pollution making Delhi a gas chamber". It ordered all schools in Delhi to be shut until Tuesday, and began distributing five million face masks to schoolchildren in the city.
Residents have been advised to avoid personal exposure to the polluted air and construction activities have been halted, also until Tuesday. From tomorrow, the city will introduce a temporary scheme - until Nov 15 - that allows cars with odd and even number plates on to the roads on alternate days in a further bid to cut traffic pollution.
Besides vehicular and factory emissions, the toxic smog that hangs over Delhi, as well as its suburbs, is a mix of construction dust, lingering emissions from the Deepavali fireworks and farm fires in adjoining states.
The contribution of stubble burning to the recent pollution spike has also risen significantly - the government-run System of Air Quality and Weather Forecasting And Research (Safar) attributed 15 per cent of the PM2.5 levels in Delhi to external bio-mass burning last Monday, a figure that rose to 44 per cent on Thursday. It is expected to abate early next week.
Ms Rinku Singh, a 45-year-old Delhi resident who has been on medication for allergy due to pollution for the last two years, told The Sunday Times that the recent spike has left her with a burning sensation in her throat and nostrils.
"My voice has changed since Deepavali and I become breathless even while walking inside the house," she said. "I now avoid going out but for my job," Ms Singh added, urging the authorities to stop the farm fires and ban firecrackers entirely on Deepavali.
According to Safar, the PM2.5 level in Delhi at noon yesterday was 285, more than 10 times the World Health Organisation's daily average safe limit of 25 micrograms per cu m. These particles can seep into the lungs and the bloodstream, causing premature deaths.
A recent Delhi-based hospital study analysed lung cancer operations over the past 30 years and found that nine out of 10 cases in 1988 affected smokers. But last year, the ratio was evenly split between smokers and non-smokers.
Air pollution is not confined to the capital; urban agglomerations across India are also saddled with foul air. Fifteen of the world's 20 most-polluted cities are in India, according to the IQAir AirVisual 2018 World Air Quality Report released in March.
But public and institutional apathy still hobbles the anti-pollution drive.
Face masks remain a rarity as morning joggers go on with their daily regimen. A literature festival took place as usual at an outdoor venue over the weekend. Bangladeshi cricketers were spotted practising with their masks on ahead of a match with the Indian team in Delhi yesterday. And the federal government organised a run to celebrate the 144th birth anniversary of independence-era leader Sardar Vallabhbhai Patel last Thursday, with several children running in the toxic air.