A tale of two capitals fighting toxic air

Mumbai and Delhi are responding differently to the worsening air quality. Mumbai imposed GRAP IV restrictions even in neighbourhoods where the air quality index (AQI) ranged between 200 and 300, while Delhi, which recorded an AQI of 304 on Monday, continues to impose restrictions under GRAP I and II.

Last week, the Centre’s Commission for Air Quality Management (CAQM) revoked the stringent Stage III restrictions under the Graded Response Action Plan (GRAP) across the National Capital Region (NCR), citing an “improvement” in air quality. By Monday, the city slipped back into the “very poor” category.

In Mumbai, the Brihanmumbai Municipal Corporation (BMC) activated GRAP IV in several areas, including Mazgaon, Deonar, Malad, Borivali East, Chakala-Andheri East, Navy Nagar, Powai and Mulund. These zones reported PM2.5 and PM10 levels that kept AQI above 200 for sustained periods.

Under GRAP IV, the Mumbai’s civic body halted construction and dust-generating activities. BMC teams inspected 70 construction and ready-mix concrete sites across affected wards and issued notices to 53 of them for violating dust-control rules. Fifty sites received stop-work notices as part of the enforcement drive.

Alongside construction curbs, small industrial units such as bakeries and marble-cutting workshops were instructed to switch to cleaner fuels or processes. Crematoriums were also directed to use cleaner fuels.

The BMC deployed flying squads in every ward, made up of engineers, police staff and GPS-tracked vehicles, to monitor compliance.

Mumbai city has 662 AQI monitoring devices installed across construction sites, with another 251 being added. Nearly 400 devices are already linked to a central dashboard that updates air quality data in real time.

Public transport continued as usual, with more electric buses added to the fleet, and no school closures or vehicle bans were announced.

Delhi’s response remained limited even as pollution levels rose again. After lifting GRAP III, the Commission for Air Quality Management (CAQM) said it was monitoring conditions and did not reinstate any restrictions.

If GRAP III curbs were applied, Delhi would restrict non-essential truck entry and ban BS-III petrol and BS-IV diesel light motor vehicles in parts of the National Capital Region. GRAP IV involves further curbs, including online classes for students up to Class XI, work from home for private companies and reduced attendance in government offices. None of these measures are currently active. No odd-even vehicle scheme was announced, and mining and stone-crushing activities, which are banned under GRAP IV, continue in NCR.