As monsoon tapers, AQI levels in the city begin to rise

“In the past 24 hours, the entire city of Mumbai has seen more than 50% increase in the PM2.5 levels as compared to the prior week. Colaba has reported the highest increase in PM2.5 at 81%,” said Ronak Sutaria, founder and CEO of Mumbai-based climate tech startup Respirer Living Sciences

Mumbai: With the monsoon beating a formal retreat later this month, air pollution levels in the city have started spiking again. The 4pm air quality bulletin released by the Central Pollution Control Board (CPCB) on Wednesday recorded an Air Quality Index (AQI) of 101 based on a reading of 24 out of 30 air quality monitoring stations. In contrast, the AQI on October 1 stood at 66. In Navi Mumbai too, AQI levels rose to 109 at five out of eight stations on Wednesday, compared with the AQI of 97 (7 out of 8 stations) the previous day.

Mumbai, India – Oct 02, 2024: Haze engulfs the city skyline, in Mumbai, India, on Wednesday, Oct 02, 2024. (Photo by Bhushan Koyande/HT Photo)

As per guidelines, an AQI below 50 indicates good air quality, 51 to 100 indicates satisfactory, whereas 101 to 200 indicates moderate air quality.

“In the past 24 hours, the entire city of Mumbai has seen more than 50% increase in the PM2.5 levels as compared to the prior week. Colaba has reported the highest increase in PM2.5 at 81%,” said Ronak Sutaria, founder and CEO of Mumbai-based climate tech startup Respirer Living Sciences.

According to analysis by Respirer Living Sciences, between September 25 to September 30, the average of 25 stations reporting PM2.5 was 12.23 micrograms per cubic meter with the highest level of 27.26 micrograms per cubic meter at Shivajinagar Mumbai–BMC monitor. Between October 1 and 9pm October 2, the average of 25 stations reporting PM2.5 was 36.67 micrograms per cubic meter, which is three times the level reported in last five days.

The India Meteorological Department has not yet announced the withdrawal of the monsoon from the state. As on Wednesday, southwest monsoon withdrew from most parts of northwest India and some parts of Central India.

The absence of rain in the city for 24 hours ending Wednesday 8.30am resulted in an increase in both day and night temperatures. The maximum temperature recorded at Santacruz was 1.2 degrees above normal at 33.5 degrees Celsius while the minimum temperature recorded at 5.30am was 2.5 degrees above normal at 27.4 degrees Celsius. Relative humidity levels dropped from a high of 90% at 8.30am to 76% at 5.30pm.