Delhi recorded the highest Air Quality Index (AQI) among five major metropolitan cities ahead of Diwali, with a reading of 175, according to the latest available figures as of October 28.
Bengaluru followed with an AQI of 156, narrowly ahead of Chennai, which recorded 155. Mumbai reported the lowest AQI among the five cities at 124, following a brief period of poor air quality.
The readings highlight differences in air pollution levels across India’s major urban centres as the country approaches Diwali. The festival period can bring additional pollution from firecrackers, adding to existing emissions from vehicles, industries and other sources.
A comparison of pollution levels in Delhi and Mumbai on October 28 showed significantly higher concentrations of particulate matter in the national capital.
According to the Indian Institute of Tropical Meteorology’s Delhi air quality early warning system, elevated pollution levels were recorded across several monitoring stations in the capital.
The concentration of PM2.5 stood at 193.41 micrograms per cubic metre in Delhi, compared with 152.11 micrograms per cubic metre in Mumbai. Meanwhile, PM10 levels in Delhi were recorded at 168.79 micrograms per cubic metre, against 126.93 micrograms per cubic metre in Mumbai.
PM2.5 refers to fine particulate matter that can penetrate deep into the lungs and pose risks to human health. PM10 consists of inhalable particles that can affect the respiratory system.
With Diwali approaching, air quality remains a concern in major Indian cities, particularly Delhi, where existing pollution sources could combine with festival-related emissions to further deteriorate air quality.