There’s something in the Mumbai air

Shabnam Abdul Ghaffar Shah, 35, is wheezing. In Mumbai’s Mankhurd slum, a few hundred meters from an under-construction metro project, the air smells of soot and dust. “Everyone at home, my three children, my husband and I, have been sick for the last month. We went to the doctor. He said: ‘Hawa kharab hai(The weather is bad) ‘Cough and cold just won’t go away,’ he says, sitting just outside his one-room house, on a road where school children are running, two-wheelers honking, BEST buses trying to navigate dug-in circles and street vendors jostling for space in the same chaos. Medical expenses have now become a hassle, he says.”Kitni dawa-daru kareng? (How much will we spend on medicines?)”

About 15 km away, in Matunga district, home to several top colleges including Podar and Ruia, Khalsa College professors are worried about their students who commute by public transport and walk dusty roads to reach the campus. The construction of high-rise buildings to replace the old four-storey buildings in the region continues at full speed.

A study conducted by the Maharashtra Pollution Control Board (MPCB) to find the sources of air pollution in 10 cities in the state in 2023 showed that dust contributed to 30% of PM10 pollution in Mumbai. PM is a reference to respirable particulate matter defined by its diameter: for example 10 micrometers and 2.5 micrometers. These can enter the lungs and cause adverse health effects, both immediate and long-term, if exposure is sustained.

Mumbai’s air quality in the last three years has frequently ranged from ‘moderate’ to ‘severe’; PM2.5 and PM10 levels often exceed safe limits, increasing due to vehicle emissions, dust and winter conditions that lead to stagnant air.

Respirer Living Sciences, a climate technology start-up, released a report this year stating that Mumbai saw a 2.6% increase in PM2.5 levels from 35.2 g/m³ in 2019 to 36.1 g/m³ in 2024; This reflects the ongoing air quality challenge for India’s financial capital. He added that Mumbai has seen a significant improvement in the number of ‘good’ days, increasing from 164 in 2021 to 184 in 2024. However, the continuation of ‘moderate’ and ‘bad’ days in 2022 and 2023 drew attention to the existence of local pollution sources, especially during periods of intense construction.

Lawyer Shweta Mehta stays just 3 km away, in a neighborhood touted as the Mumbai coast’s next big hub: Wadala. Located less than 2km from New Cuffe Parade, where metro, monorail and major infrastructure projects are coming up, dust is thick in the area.

“I have been restricting my family from going out for the last few months due to poor air quality. They have lung-related ailments and I have asked them to stay at home,” says Mehta, who lives in an apartment building. She realizes that her aging parents are starting to feel frustrated and lonely as their social lives have deteriorated, but for Mehta, it’s a difficult choice.

Doctors and lawyers talking

Consultant and head of the Department of Pediatrics and Neonatology, Mahim Fortis Raheja Hospital, Dr. Asmita Mahajan thinks there should be pollution restrictions in the city. “When was the last time you saw clear skies?” he says.

Until a few years ago, we were seeing a seasonal increase in the number of children coming to the hospital with allergic respiratory conditions. “Allergic coughs take months to resolve. Symptoms are seen to flare up in children with asthma.”

Mahajan says until last year he saw two children a week with breathing problems. Now it’s up to six a week. “Especially children with asthma have repeated admissions to the hospital. Some of them also need to be hospitalized and admitted to the intensive care unit,” he says.

Pulmonologist in Mumbai, Dr. Samir Garde says that 25 years ago, the main cause of lung cancer was smoking. Many non-smokers now suffer from serious lung diseases, including cancer. He attributes one of the reasons to air pollution. He hopes the government will prioritize public health. The Bombay High Court, examining the persistent air quality issue,suo motuThe issue became aware in 2023. He launched a public interest litigation to address deteriorating air quality levels and increasing pollution from construction dust. In October 2023, the court issued detailed orders containing 28 guidelines to be implemented by the Brihanmumbai Municipal Corporation (BMC) on construction sites. These included the mandatory installation of air quality sensors and water sprinklers and the installation of covers on vehicles carrying construction materials. On 27 November this year, the court flagged a sharp drop in the air quality index (AQI) (up to 270, classified as ‘poor’) and rejected the ‘volcanic ash from Ethiopia’ theory.
amicus curiaeand senior lawyer Darius Khambata highlighted worsening air quality since 2023 and non-compliance at construction sites. Of nearly 1,000 construction sites in the city, only 400 have installed sensors mandated by the court’s earlier ruling, and 117 of them remain non-functional. Moreover, he pointed out that these sensors are not yet connected to a central monitoring system. The court stressed that Mumbai needs a sustainable plan to combat rising pollution and ordered the formation of a committee to ensure strict compliance with existing rules for construction sites. It was also stated that the previous committees had not submitted weekly compliance reports since March 2025. The new committee is expected to present its findings within a week, after which the matter will be discussed again on December 15.

data points

This month, BMC Commissioner Bhushan Gagrani announced Project MANAS to set up a hyperlocal sensor-based ambient air quality monitoring system in collaboration with IIT Kanpur.

“Even when the monitors are installed, what are you going to do? Don’t we already have enough air quality data?” says Rakesh Kumar, president of the nonprofit Indoor Environmental Foundation and former director of the Council for Scientific and Industrial Research National Environmental Engineering Research Institute (CSIR-NEERI). He says that the real problem is not the lack of data to measure the air quality in the environment, but the translation of this data into action.

He also points out that the data is general. “Let’s talk about the transportation sector. There is a mix of different models of vehicles. Out of 100 vehicles on the road, 50-60 are regularly on the road. Some are there for construction activities: vehicles carrying materials and debris. They go to different construction sites. This is the data we need,” he says.

He adds that it is necessary to get into detailed data on road movement. He said the immediate ban on all construction activities and Phase III of the Phased Response Action Plan. and IV. He thinks that applying curbs overnight as part of their phases are instantaneous reactions. “Some information is missing. It’s not going to come from ambient air quality measurement,” he says. Tuhin Banerji, former scientist at CSIR-NEERI and current coordinator of the non-profit International Center for Climate and Sustainability Action, thinks the government knows the solutions but is not willing to invest in them. “Everyone just talks about monitoring. Nobody is doing anything about removing these pollutants. There are molecular filters that can selectively remove pollutants from the atmosphere,” he says.

He lists interventions such as electrostatic precipitators to remove particulate matter; WAYU (wind augmentation cleaning unit), an outdoor air purification device developed by CSIR-NEERI to combat air pollution in high-traffic areas; and Techno Green Yuka Yantra, a patented solution for air quality. He also complains about the “lack of bureaucratic will” to implement these.

People walk in Girgaon Chowpatty as the city skyline appears shrouded in smoke on December 5, 2025. | Photo Credit: Emmanual Yogini

Environmentalists accused authorities of hiding important data on air quality. Sumaira Abdulali has been monitoring air quality for years. As part of its awareness campaign, it had been publishing data on PM2.5 levels every day for more than a year. Then, suddenly in May this year, PM2.5 data was not available on the Central Pollution Control Board’s (CPCB) Sameer app, which provides real-time updates on AQI and other parameters.

“All indicators were red until May 2025. PM2.5 level was even seen in Kandivali in April this year.” [a Mumbai suburb] 434 is well above the red zone,” says Abdulali. He conveyed the issue of not being able to find data to the authorities, asked questions for a while, but said that he did not receive an answer.

“We know that PM2.5 is more dangerous. The structure of your nose can stop PM10. However, PM2.5 particles go to your lungs. They can cause all kinds of problems such as cough, wheezing. Long-term exposure can cause cancer,” says Banerji.

When asked why PM2.5 data is no longer available on the Sameer app, MPCB officials said the data is checked by the CPCB. “You will have to ask them,” says MPCB Joint Director (Air) Satish Padwal. “There needs to be one monitoring center per 10 lakh population. Currently, there are excess stations in Mumbai,” he adds. Sameer app shows that 23 out of 30 stations are active.

Gagrani agrees that air quality is a critical public health and management priority.

“321 facilities have been given a work stoppage notice. We carry out road irrigation, fogging, field visits and encourage furnaces to switch to clean fuel,” he says.

But experts say mist spraying doesn’t work to reduce air pollution. BMC has deployed 94 flight crews to ensure strict compliance with 28 rules formulated for construction sites. BMC Additional Municipal Commissioner Ashwini Joshi says show notices have been issued for the bullet train project and Dharavi redevelopment project.

vinaya.deshpande@thehindu.co.in