Delhi was the world's most polluted major city on Saturday morning, according to IQAir, a Swiss air quality monitoring group.
BW Businessworld reported this.
The ranking came as pollution levels worsened ahead of Diwali, which falls on Sunday.
At 10:35 am, IQAir gave Delhi a US Air Quality Index (AQI) reading of 581.
However, its scale differs from India's official AQI, so the two numbers cannot be compared directly.
India's Central Pollution Control Board (CPCB) recorded Delhi's AQI at 363 at 10 am.
That places the city in the "very poor" category.
Graphic: News Anek, from the facts in this report
Local media, citing official data, said Friday's air was the worst in the run-up to Diwali in eight years.
Key points
- IQAir ranked Delhi the world's most polluted major city on Saturday morning.
- Official CPCB data put Delhi's AQI at 363, in the "very poor" category.
- Stage III of GRAP is in force across Delhi-NCR from Friday.
- Schools up to Class V have moved to hybrid mode.
What is GRAP Stage III, and what does it mean?
The Commission for Air Quality Management (CAQM) invoked Stage III of the Graded Response Action Plan (GRAP) on Friday, November 6.
It took effect immediately.
The decision followed a review of pollution levels and weather forecasts from the India Meteorological Department and the Indian Institute of Tropical Meteorology.
Non-essential construction and demolition work is now banned across the region.
BS-III petrol and BS-IV diesel four-wheelers face restrictions in Delhi and nearby districts, including Gurugram, Faridabad, Ghaziabad and Gautam Buddha Nagar.
Residents have been advised to use public transport, avoid unnecessary travel and limit time outdoors.
Why are schools and offices changing how they work?
Authorities have asked schools to hold classes up to Class V in hybrid mode. Students can attend in person or join online.
The aim is to limit children's exposure to polluted outdoor air.
The government has also encouraged employees to work from home where possible.
An earlier order allowed offices to run with 50 per cent physical attendance from November 5 to November 20.
Environment Minister Manjinder Singh Sirsa warned on Friday that falling wind speeds could worsen pollution.
He asked residents to cooperate with the restrictions.
What did the Supreme Court say about the problem?
On Friday, the Supreme Court said vehicle emissions are a major cause of pollution in Delhi-NCR.
A bench headed by Chief Justice of India Surya Kant raised concern about bumper-to-bumper traffic.
The bench also questioned whether repeated restrictions work.
It said more orders may not tackle the underlying causes, and stressed public awareness and changes in behaviour.
Explainer
What happened before
- Earlier, a preventive order allowed government and private offices to run with 50 per cent attendance from November 5 to November 20.
- On Friday, November 6, CAQM invoked Stage III of GRAP across Delhi-NCR with immediate effect.
- The same day, the Supreme Court questioned how well existing restrictions were working.
Why it matters
Poor air affects schools, offices and daily travel for people across Delhi-NCR.
What to watch next
- The reports do not say when the Stage III restrictions will end.
