Mumbai is slipping into another spell of deteriorating air quality as winter sets in, with the city recording some of its highest pollution levels of the season. A visible haze settled over the metropolitan region, pushing the overall Air Quality Index (AQI) to 173, which falls in the “moderate” range but masks wide variation across neighbourhoods. Several pockets reported far worse conditions, including Mazgaon, which touched an AQI of 306 and moved into the “very poor” category.
Other parts of Mumbai were not far behind. Chakala in Andheri East logged an AQI of 270, Deonar 274, Navy Nagar in Colaba 271, Malad West 224, Powai 206 and Siddharth Nagar in Worli 205. These readings place large sections of the city firmly in the “poor” band, with particulate matter rising due to a mix of local emissions, meteorological conditions and seasonal construction dust.
Under the national AQI system, air quality between 51 and 100 is considered satisfactory, 101 to 200 moderate, 201 to 300 poor, 301 to 400 very poor and anything above 400 is classified as severe. With several areas edging deeper into unhealthy categories, the city administration is preparing for more stringent interventions.
A senior civic official said the next step may be activating a higher stage of the pollution-control protocol. If the air does not improve over the next 48 hours, the government is expected to implement Stage 4 of the Graded Response Action Plan (GRAP), the most restrictive of the measures.
Stage 4 is typically invoked when air quality touches the “severe” zone and mandates a halt in nearly all construction activity. The goal is to suppress dust, which remains one of the largest contributors to PM10 and PM2.5 levels during Mumbai’s winter months. The official noted that the administration is monitoring the readings closely and is prepared to enforce the rules if conditions worsen.
Even before the possible rollout of GRAP-4, the Brihanmumbai Municipal Corporation (BMC) has begun cracking down on polluters. The civic body has issued notices to 59 construction sites and ready-mix concrete facilities ordering them to stop work because they failed to follow dust-control guidelines.
These norms include covering debris, installing barricades, deploying misting machines, and ensuring that vehicles transporting construction material are not spilling dust onto roads. Many sites were found to be operating without real-time air-quality monitoring systems, which are now mandatory for medium and large projects.
The potential shutdown will not stop at construction. Under GRAP-4, several other activities come under scrutiny. Bakeries and restaurants using wood-fired ovens would have to suspend operations to reduce emissions from biomass burning. Industrial units releasing visible smoke could be temporarily closed. Areas where open waste burning still takes place—despite prohibitions—will face immediate action.
Officials said enforcement will be strict. Violations may attract financial penalties, stop-work notices, and in serious cases, complete closure of facilities until compliance improves. The civic body is also coordinating with the Maharashtra Pollution Control Board to track emission hotspots and identify repeat offenders.
Mumbai’s worsening air quality mirrors a pattern seen across northern and western India during winter. Still, the scale of the spike this season has prompted concern among health experts, who warn that even short-term exposure to “poor” and “very poor” air quality increases the risk of respiratory problems, especially for children, senior citizens and those with asthma.
For now, all eyes are on pollution readings in the next two days. If levels continue to rise, the city may enter one of its toughest phases of pollution control in recent years, with sweeping restrictions intended to pull Mumbai back from the brink of hazardous winter air.
