New Delhi: Delhi overtook Lahore in Pakistan to become the world’s most polluted major city on Friday, as hazardous air quality and dense smog reduced visibility across the national capital.
According to Swiss air quality monitoring group IQAir, Delhi recorded an Air Quality Index (AQI) of 334, placing it at the top of its global ranking of major cities. India’s Central Pollution Control Board (CPCB), meanwhile, recorded a higher AQI of 403 and classified the air quality as ‘severe’.
The difference in the readings is due to the distinct AQI scales and calculation methods used by IQAir and Indian authorities.
Dense Smog Reduces Visibility Across Delhi
Thick smog covered several parts of the capital, with vehicles moving through low-visibility conditions on major roads. Videos shared by news agency ANI showed cars and motorcycles navigating the haze, while street lights appeared obscured by the pollution.
Delhi’s air quality typically deteriorates during the winter months, when colder and heavier air traps pollutants closer to the ground.
Vehicle emissions, construction dust and smoke from stubble burning contribute to the seasonal pollution problem across northern India and neighbouring Pakistan.
What Do Delhi’s AQI Readings Mean?
Under the Indian AQI classification, a reading between 401 and 500 falls in the ‘severe’ category. Such conditions can affect healthy people and pose serious health risks to those with existing respiratory or cardiovascular conditions.
IQAir uses a different scale, which is why its reading of 334 was described as ‘hazardous’ in the report, while the CPCB classified its reading of 403 as ‘severe’.
The two figures should therefore be understood within their respective monitoring systems rather than compared directly.
