Mumbai recorded the cleanest air day of this year on Wednesday, with the air quality index (AQI) value of 13, which falls in the ‘good’ category. The city owes this rare phenomenon to its geographical location of being surrounded by ocean on three sides, leading to stronger winds, experts said. The higher the AQI value, the greater the level of air pollution and health concerns.
On Thursday, Mumbai recorded an AQI of 22, while Delhi recorded 52. According to SAFAR, the AQI of Mumbai will continue to remain in the ‘good’ category for the next two days.
As per data from the System of Air Quality and Weather Forecasting and Research (SAFAR) last week, on June 14, the city had recorded the AQI of 14. On September 4, 2019, it had touched a record low of 12, making these among the lowest AQI recorded since the monitoring began in 2015.
The project director of SAFAR, Gufran Beig said, “As a rare phenomenon, Mumbai records very low AQI, mostly below 15 (very clean air), during initial monsoon days as compared to other regions in the country like Delhi, Pune, Ahmedabad, where there are land to land winds.” He said the winds on the coast are stronger and faster.
Moreover, such low AQI in Mumbai is mostly expected during the initial days after monsoon has set in over the country, because the winds in the coastal areas pick up pace significantly during this period, added Beig.
Comparing the AQI of Delhi, he said, “The lowest AQI Delhi can record, even in its heaviest monsoon, is around 30 as it is surrounded by land and it can never come down to below 15 like Mumbai. So we can say that Mumbaikars are blessed to have such a phenomenon due to which we can breathe clean and fresh air during the initial monsoon season.”
There are six AQI categories, according to SAFAR, namely ‘good’ (0 to 50), ‘satisfactory’ (50 to 99), ‘moderate’ (100 to 199), ‘poor’ (200 to 299), ‘very poor’ (300 to 399), and ‘severe’ (400 to 500). Each of these categories is decided based on the ambient concentration values of air pollutants and their likely health impact.