Few citizens in Mumbai are seen wearing a mask outdoors; fewer are actively concerned about air pollution. “It’s not as bad as Delhi”, most say, and inevitably point to the winds that blow from the surrounding sea. The murky, grey and polluted water might make them reconsider their statement, but the feeling that Mumbai is better than the northern landlocked cities wins.

But when winter arrived last year, the sea winds failed Mumbai.

In the month of December, temperatures dropped in the city but pollutants remained trapped in the atmosphere. The overall air quality index (AQI) was reported to be 267, as bad as the world’s most polluted city, Delhi. Comparisons between AQIs, however, do not always tell the complete story. Ronak Sutaria, Founder, Urban Sciences, says, “AQI is simply a tool that makes it easier for people to understand the quality of air in terms of good, poor or hazardous.”

All scientific papers and studies, including the Maharashtra Pollution Control Board’s (MPCB) annual reports, analyse those components in the air that are invisible to the naked eye: sulphur dioxide (SO2), nitrogen oxides (NOx) and Particulate Matter (PM10). In its 2017-18 report, for instance, MPCB presented the “annual average concentration of all the parameters analysed at its two locations” in Mumbai: Sion and Bandra. In both places, SO2 concentrations were within the limit but that of NOx and PM10 were worryingly high.

Anyone in the know particularly dreads particulate matter in the air because this pollutant is small enough to surge towards the lungs and cause health ailments such as lung cancer. A substantial body of evidence also links it to many adverse health effects, including diminished lung function, acute and chronic respiratory symptoms (such as asthma, cough and wheeze), and increased risk of mortality from non-communicable diseases.

India routinely underperforms on most global scales, so even if WHO’s safe PM10 annual mean is 10 μg/m3, Indian standard is 60. Even by those standards, air pollution in all Indian cities, including Mumbai, is formidable.

A view of The Westin Mumbai Garden City in Goregaon East, clouded by the pollution in the air. Pic: Swaraj Shetty

City of Smoke

In a 2016 study, System of Air Quality Weather Forecasting and Research (SAFAR), a project of the Indian Institute of Tropical Meteorology, Pune, which generates data to determine AQI in Mumbai at 10 locations, identified sector-wise causes for air pollution in Mumbai. Emissions from industries and power plants, biofuels, transportation and suspended dust were apportioned.

The findings surprised many. While emissions from industries and power plants remained the major cause at 35.82%, biofuel emissions came a close second. Poverty creates conditions conducive to pollution and the report confirmed that biofuel burnt in Mumbai’s slums for household purposes was contributing 27.05% to the pollution.  “Delhi (under Ujjwala Yojana) has performed much better than Mumbai in reducing dependence on biofuels,” Dr. Gufran Beig, the Project Director at SAFAR, says.

Another widely held belief is that Mumbai’s construction dust contributes heavily to pollution but Beig adds that construction dust, contained by green curtains around under-construction buildings, is a minor cause. About 21.2% of pollution is due to the suspended dust that rises from unpaved roads. “As a vehicle speeds on this road, the dust rises. It might settle soon, but the road is never free of vehicles,” he says.

In the past five years, Mumbai has seen a 56% rise in vehicular population, and the linear, island city has no way around traffic jams. Traffic, says transportation expert Ashok Datar, is tragic for the environment. “When you’re forced to stop and start, or drive slowly in first gear, you keep the engine idling. At that time, exhaust from the engine goes up seven-eight times and the pollution naturally goes up several times. There is a great surge in the exhaust irrespective of the type or quality of vehicle. When hundreds of vehicles move like that, it creates localised high particulate pollution, much higher than the dust.”

Yet, sometimes, Mumbai experiences good air days. How is that?

Pollution gets accumulated because of stagnant winds. When the winds are light, pollution remains suspended and we inhale it. Any place requires wind to push whatever is locally created. “In Mumbai, there is a wind reversal that takes place every four-five days,” Beig explains, “so when winds are coming from the seaside towards the land, it sweeps away all the pollutants and replaces the polluted air with clean air.”

Naturally, there’s also a reversal. Whenever wind blows from the land to the sea, the pollutants get accumulated again. The pendulum of pollution continues but since Mumbai is surrounded by water on three sides, the wind reversal is higher as compared to, say, a city like Delhi.

Pollution hangs heavy on those days when the landward winds from the sea slow down. Pic: Christian Haugen/Flickr

But when temperatures drop like they did last winter, warmer air is held above the cooler air, and the decreased wind speed stops pollutants from being flushed out. When this happens, even a coastal city like Mumbai cannot remain dependent on its lofty winds, but looks forward to efficient governance and reforms to tackle the pollution problem at a systemic level.

Citizens, however, cough in response.

Gulshan Mistry, a resident of Borivali in Mumbai, is asthmatic and often finds it difficult to breathe on crowded roads in the city. “We should be investing in public transportation systems and increasing the green cover,” he says, “but the government is building more roads, flyovers and cutting the trees.”

In 2017, Anil Galgali, an activist, filed an RTI asking how many trees the BMC had cut in the past three years. The answer revealed that almost seven trees a day, a total of 7,842 trees, were cut on private property between 2014 and 2016. The everyday tree felling can be missed but when the municipal corporation set in motion a plan to cut 2700 trees at Mumbai’s Aarey area for a metro shed, it faced staunch resistance. Presently, the High Court has restrained BMC from cutting trees in Aarey.  

Lack of Planning

In the past two or three years, however, residents around Maharashtra have become conscious of pollution and that has propelled governments to take some action. In April, for instance, MPCB submitted a plan to the Central Pollution Control Board (CPCB) whose measures included “adopting the most advanced emission standard for automobiles, daily pollution checks for vehicles and increasing the tree cover.”

But the plan in itself is not reassuring. There has been a clear lack of coordination between the state pollution control board, which has the primary responsibility of monitoring and solving the crisis of air pollution, and implementing agencies such as the city’s municipal corporation.

The BMC works as an agent of the state. The municipal body, for instance, asked a bakery in the city to move to eco-friendly options or risk closure only after it was directed to do so by the MPCB.  In another instance, MPCB filed a police complaint against BMC when it didn’t comply with the MPCB’s order to shut down a garbage station in Gorai in Mumbai. Indeed, regardless of its role as an agent, it’s the municipal corporation itself that often contributes to pollution by allowing solid waste to pile at the city’s landfills where its combustible nature leads to thick blankets of smoke over the city for days.

The exact role that a municipal corporation can play in mitigating air pollution is unclear. The Air (Prevention and Control of Pollution) Act, 1981 grants it no power. SAFAR has signed an MoU with BMC, under which it submits air quality data to the municipal corporation. The BMC then releases an environment assessment report based on this data [however, no environment assessment report was released in 2017-18].

Numerous air quality stations are required to understand the air quality of a city as vast as Mumbai. Sutaria explains that “Mumbai, like any other urban city, has microclimates.” As there is no single air quality condition around the city, mitigation will have to depend on local hotspots. But, Sutaria adds, “People write to CPCB for remedy, which is a crazy way of working. Civic bodies can play a big role here, but the role municipal corporations play in mitigation, is not clear to anyone.”

While we know that the CPCB is responsible for the supervision and coordination of the overall environmental management system in the country, specific regional issues are resolved by state pollution control boards. But within a particular state, the source and sector of pollution can vary, and so must solutions.

Dr Pallav Purohit, of International Institute for Applied Systems Analysis (IIASA), Austria says, “In megacities like Mumbai, municipal corporations lack authoritative responsibility and institutional capacity. It is important to strengthen them to effectively formulate and implement policies.”

One of the ways he suggests is for corporations to “develop their own Environmental Management System (EMS) in coordination with state pollution control boards”. It’s this EMS by a municipal corporation that can better understand the city-specific causes of pollution.

It’s possible that policy makers understand that the top-down approach in air pollution mitigation is faulty, but there has been no effort to legally tie up the loose ends. In 2017, an RTI query asked the Central Pollution Control Board (CPCB) about air pollution action plans in Maharashtra. CPCB responded that “Cities such as Mumbai, Pune, Amravati, Aurangabad, Kolhapur, Jalna and Latur have been requested to revise their action plans; resubmit it to their state government and CPCB,” but till April 2019, no plan was forthcoming.

Toothless Tigers

Ironically, the centre released a National Clean Air Programme (NCAP) with a focus on cities, even though city governments have no power to take any decisions regarding air quality. Comprehensive and smoothly implementable solutions will be elusive till the role of municipal corporations, along with provisions for financial autonomy, are clearly defined.

But no political party, not even the party ruling Mumbai’s municipal corporation for around three decades, has said anything about it. Treating air pollution as a national emergency was part of Congress’ manifesto, but Shiv Sena is mum. For the 2017 BMC elections, the Sena had promised the “conservation of the green cover and biodiversity of Aarey,” but it was the Sena-led BMC which sanctioned the cutting of trees in Aarey, a green belt in Mumbai, even as they continue to talk of “green development”.

Mitigation efforts around air pollution in Mumbai, and by extension in Maharashtra, are symbolic. At best, redressals involve the court where National Green Tribunals or other central agencies impose steep fines on BMC or MPCB—an act that can be described as a comical, namesake extraction of funds from powerless taxpayers, which changes nothing on the ground, or in the air.