Delhi overtakes Lahore as world's most polluted major city
Delhi overtook Lahore in Pakistan to become the world's most polluted major city on Friday, as air quality reached hazardous levels and thick smog blanketed the capital, reducing visibility across the city of 20 million people.
According to Swiss air quality monitoring organisation IQAir, Delhi's Air Quality Index (AQI) stood at 334 on Friday, categorised as "hazardous", making it the most polluted global major city. IQAir's hourly data showed that Delhi's AQI had dropped to 208 at 11.30 a.m. local time (0630 UTC). At that time, Lahore was ranked seventh among the world's most polluted major cities, with an AQI of 155.
India's official Central Pollution Control Board, however, recorded the AQI higher at 403 and rated it "severe." The difference between the Indian and Swiss readings is caused by the fact that the two use different AQI scales and methodologies to calculate and categorise air pollution levels. An AQI reading up to 50 is considered good with little or no health risk.
Visibility in Delhi was significantly impacted as a thick layer of smog enveloped the city. Videos from news agency ANI showed cars and motorcycles emerging from dense smog, while it also appeared to obscure street lights on the city's main roads.
In many parts of northern India and Pakistan, pollution poses a seasonal problem as the cold, heavy air of winter traps vehicle emissions, construction dust and smoke from agricultural burning.
