Smog Engulfs Mumbai As Air Quality Worsens, Civic Body Plans GRAP-4 Measures

Mumbai witnessed a thick blanket of smog on Tuesday as citywide air-quality readings surged into poor and severe categories, prompting the Brihanmumbai Municipal Corporation (BMC) to step up emergency measures. The civic body warned it may invoke the strictest controls under the Graded Response Action Plan (GRAP).  

Visibility on the waterfront and across major arterial roads was markedly reduced through the morning and into the evening, with residents reporting burning eyes and breathing discomfort. Real-time monitoring services showed overall city AQI figures fluctuating in the unhealthy-to-severe range. Several monitoring stations recorded readings well over 300 at times, driven largely by high PM2.5 and PM10 concentrations.  

Officials said Mazagaon, Deonar, Chakala (Andheri East), and parts of the central and eastern suburbs were among the worst hit. Mazagaon alone recorded AQI levels above 300 on multiple days this month, and several locations exceeded 200 - thresholds that put them in the "poor" to "very poor" categories. 

In response, the BMC has reinstated ward-level enforcement teams, set up flying squads to check polluting activities and warned that GRAP-IV restrictions, which include halting construction and other dust-creating operations, will be invoked if high readings persist.  

The civic body has activated an emergency pollution plan and is considering targeted construction bans and other controls in the worst-affected wards.

Mumbai, Maharashtra: A dense layer of smog blanketed the city, with the Air Quality Index (AQI) soaring to 239 pic.twitter.com/hjIFSMplGR

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"We will attempt positive intervention first, like misting, cleaning, and action against polluting bakeries and units, before imposing blanket halts, but stricter measures like construction bans are on the table if air quality does not improve," a BMC official said. 

Causes And Contributing Factors

Environmentalists pointed to a mix of local and regional contributors, such as ongoing construction and road dust, emissions from vehicles and diesel generators, industrial emissions in peripheral zones such as Mahul, and meteorological conditions including cooler nights and light winds that trap pollutants near the surface. Experts have highlighted the broader role of increased fossil-fuel power usage linked to heavy electricity demand from data-centres in and around the city's industrial belts.  

Health Impact And Advisories

Public-health warnings accompanied the high readings. Experts note that PM2.5 levels observed in recent days are much higher than the World Health Organization's guideline. It poses elevated risks for children, the elderly and people with respiratory or cardiovascular disease; short-term symptoms include coughing, throat irritation and exacerbation of asthma. 

The municipal corporation and health departments advised residents to limit outdoor exertion, use masks where necessary, and keep windows closed during peak pollution hours. Use of air-purifiers was recommended indoors for households in worst-hit areas. 

November has seen a steady deterioration in air quality after spikes during the festival season and a month of elevated construction activity. Meteorologists said that light winds and temperature inversions are expected to persist for the next 48-72 hours, raising the prospect of continued poor dispersion of pollutants unless significant emission reductions occur. Civic officials said they will monitor readings hourly and reassess the need for GRAP-IV curbs if AQI remains high.