As rainfall diminished, Mumbai experienced a notable decline in air quality on Friday, with the Air Quality Index (AQI) surpassing 100 for the first time this post-monsoon season, resulting in a haze enveloping the city.
By Friday afternoon, the overall AQI reached 111, with 10 out of 20 active monitoring stations reporting ‘moderate’ air quality, as per data from the Central Pollution Control Board (CPCB). The highest levels were recorded in Worli at 178, followed by Colaba at 143, Deonar at 141, and Mazgaon at 138. PM2.5 and PM10 emerged as significant pollutants at these sites.
This decline in air quality follows four months of generally satisfactory conditions, with AQI levels typically remaining below 100 from June to September. The frequent rainfall during this period helped clear out dust and other suspended pollutants. With the reduction in rainfall, experts indicated that shifts in wind patterns, combined with drier weather, contributed to the increase in pollution levels.
Experts speaking to The Indian Express noted that the recent rise in pollution was not solely due to a lack of rainfall. They pointed out that clockwise winds from inland areas were also bringing dry air and dust from the north.
In response to the worsening air quality, the Brihanmumbai Municipal Corporation (BMC) has implemented new standard operating procedures (SOPs) to address pollution at the ward level.
Each civic ward is tasked with identifying at least ten pollution hotspots, which will include significant construction sites, infrastructure projects, open areas where waste is burned, debris dumping locations, and congested traffic zones. An officer will be designated for each hotspot to monitor air quality and ensure appropriate measures are executed.
Monitoring teams at the ward level are instructed to inspect a minimum of two construction sites daily.
A civic official stated, “Demolition sites must ensure proper barricading, cover debris with tarpaulin or green cloth, and implement continuous misting to control dust.”
Developers and contractors are also accountable for cleaning roads adjacent to construction activities. Projects covering up to 4,000 square meters will need to clean roads up to 100 meters; those ranging from 4,000 to 10,000 square meters must extend up to 200 meters; and projects exceeding 10,000 square meters will require cleaning up to 500 meters on either side.
The BMC’s action plan outlines escalating measures in response to rising pollution. Should the AQI exceed 200, authorities may initiate comprehensive cleaning, road washing, water spraying, and misting, alongside stricter actions against open waste burning.
If the AQI remains above 300 for three consecutive days, activities contributing to pollution within a two-kilometer radius of the relevant air-quality monitoring station may be halted.
The civic body also plans to conduct a post-monsoon cleanup campaign during the first two weeks of October, aimed at removing sludge, mud, and accumulated dust from roads, including major thoroughfares, medians, junctions, and road edges.
Civic authorities mentioned that roads could be washed using recycled water or fine water spraying as required.
According to CPCB standards, an AQI of 0-50 is categorized as ‘good’, 51-100 as ‘satisfactory’, 101-200 as ‘moderate’, 201-300 as ‘poor’, 301-400 as ‘very poor’, and above 400 as ‘severe’.
