Mumbai surpasses Delhi as the most polluted city in India

Mumbai has surpassed Delhi as the most-polluted city in India and second most polluted city globally within a week between January 29 and February 8, according to Swiss air tracking index IQAir.

Further, Lahore has been ranked as the world's most polluted city.

Saltlake city in the USA has been ranked as the city with the cleanest air in the world with a US AQI of 0, which is regarded as zero presence of pollutants in the air, followed by San Francisco with a reading of 4.

'Poor' and 'Very Poor' days in Mumbai between November and January this year were more than double than they had been the prior three winters, according to CPCB data, The Hindustan times reports. "Road or construction dust is the cause of more than 71% of the particulate matter load in Mumbai's air. Factories, power plants, airports, and waste dumps contributed in making Mumbai's air the filthiest to breathe," the report says.

The Indian Express has reported that the AQI readings of 163 is regarded as unhealthy according to the US AQI standard. However, the System of Air Quality and Weather Forecasting and Research (SAFAR), which measures India’s air pollution level under the union ministry’s earth and sciences, regards an AQI reading between 101 and 200 as moderate.

"Shame for the state’s unconstitutional government and its unconstitutional Environment Minister. What is worse - Mumbai’s AQI or Maharashtra government’s failure to take measures to control it?" Shiv Sena leader Priyanka Chaturvedi has tweeted.