Key facts
- IQAir ranked Delhi first among major cities at 10:35 a.m. (0505 GMT) on November 7, with a US air quality index reading of 581.
- Lahore in neighboring Pakistan ranked second on IQAir's list with a reading of 285, about half Delhi's level.
- India's Central Pollution Control Board put Delhi's air quality index at 363 at 10 a.m. on November 7, in the very poor category.
- Local media, citing official data, said Friday's air quality in Delhi was the worst pre-Diwali air in eight years.
Delhi was the world's most polluted major city on the morning of November 7, according to Swiss group IQAir's live ranking, as the Indian capital faced severe pollution forecasts a day before Diwali, the Hindu festival of lights.
IQAir ranked Delhi first among the world's major cities at 10:35 a.m. (0505 GMT), with a US air quality index reading of 581. Lahore in neighboring Pakistan ranked second at 285, about half Delhi's level. IQAir's reading, based on concentrations of air pollutants, is not directly comparable to India's official index, which uses a different scale and methodology.
India's Central Pollution Control Board put Delhi's air quality index at 363 at 10 a.m. on November 7, in the very poor category. Local media, citing official data, said Friday's air quality in Delhi was the worst pre-Diwali air in eight years.
India has ordered schools in and around Delhi to offer online classes and encouraged people to work from home ahead of Diwali on November 8, which is usually marked by the widespread use of firecrackers that further worsen the air quality.
Pollution is an annual problem in many parts of northern India from the onset of winter, as cold, heavy air traps vehicle emissions, construction dust and smoke from crop-waste burning.