Mumbai Becomes India’s Most Polluted City; QAir Ranks City 5th Globally

SHARES Mumbai has been ranked the fifth most polluted city in the world and the most polluted in India , according to global air quality monitoring platform iQAir. The city recorded an Air Quality Index (AQI) of 152 on Thursday, October 15, with ground-level ozone identified as the primary pollutant.

The rise in pollution comes amid unusually hot and humid weather following a rain-deficient monsoon and the early withdrawal of seasonal rainfall.

Mumbai has experienced three of its hottest days in at least a decade this month, with maximum temperatures rising 4–5°C above normal on several occasions.

Atmospheric scientist Gufran Beig, chair professor at the National Institute of Advanced Studies (NIAS), Indian Institute of Science (IISc), has linked the prevailing conditions to an El Niño-like climate pattern, high temperatures and reduced wind speeds.

Weaker winds can limit the dispersal of pollutants, allowing them to accumulate closer to the ground. Ground-level ozone can also increase during hot, sunny weather when nitrogen oxides and volatile organic compounds react in the presence of sunlight.