In the past two days, Colaba and Mazagaon in south Mumbai have emerged as the most polluted localities. File Pic
Despite marginal improvement Mumbai's AQI continued to remain in the poor category with figures of 201 on November 17.
Incidentally, the city recorded its second warmest November morning in 10 years with the minimum nighttime temperature on Wednesday touching 26.5 degrees Celsius.
According to experts, increasing heat and humidity have been the key drivers behind Mumbai’s ongoing pollution. And sea salt may be responsible for high AQI in south Mumbai.
On November 15, Colaba's AQI was even worse than that of Delhi. It registered air quality of 345 as compared to the national capital's 331.
Sachin Panwar, an independent air quality expert, said, 'Mumbai experiencing high humidity and slow, landward winds from the sea, the conditions are perfect for sea salt to become aerosolised, or airborne. Since the particles are very tiny, air quality monitors will detect them and reflect a higher AQI,' reported Hindustan Times.
Panwar further added, 'Sea salt is a chemical compound. In areas where there is a lot of traffic we usually see the presence of other compounds like sulphur oxides and benzene, which is present in the vehicular exhaust. In the presence of humidity and heat, salt will react with these other pollutants to form secondary compounds in the air. If wind speeds are slow, these secondary pollutants will accumulate and add to the pollution load.'
However, with the unseasonal light showers on November 17, the AQI of Mumbai is expected to improve.
India Meteorological Department (IMD) has predicted heavy rains with strong winds in the upcoming days. This is not only expected to bring down the heat and humidity but could also play a role in improving the city's air quality.
Meanwhile, Of the world's top 10 cities with the worst air quality, three -- Delhi, Kolkata and Mumbai, are in India, data from air quality and pollution city tracking service from IQAir, a Switzerland-based climate group showed. While Delhi's Air Quality Index (AQI) at 556 made it to the top of the list, Kolkata and Mumbai recorded an AQI of 177 and 169, respectively, at fourth and sixth position, on the list.
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_d.jpg "Sachin Panwar, an independent air quality expert, said, 'Mumbai experiencing high humidity and slow, landward winds from the sea, the conditions are perfect for sea salt to become aerosolised, or airborne. Since the particles are very tiny, air quality monitors will detect them and reflect a higher AQI,' reported Hindustan Times.")
