Few Mumbai citizens can be seen on the streets wearing masks. Fewer seem concerned about air pollution. “It’s not as bad as Delhi,” most say, and inevitably draw attention to the winds that blow in from the Arabian Sea. The feeling that Mumbai is better than landlocked cities wins.

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

In December, temperatures dropped in the city but pollutants remained trapped in the atmosphere. The overall air quality index was reported to be 267, as bad as the world’s most polluted city, Delhi. This comparison, however, do not always tell the complete story. “AQI is simply a tool that makes it easier for people to understand the quality of air in terms of good, poor or hazardous,” said Ronak Sutaria, the founder of Urban Sciences, which focuses on realtime data monitoring.



Most scientific papers and studies, including the annual reports of the Maharashtra Pollution Control Board, analyse the components in the air that are invisible to the naked eye: sulphur dioxide, nitrogen oxides and particulate matter. In its 2017-’18 report, for instance, the board presented the “annual average concentration of all the parameters analysed at its two locations” in Mumbai: Sion and Bandra. In both places, sulphur dioxide concentrations were within the limit but that of nitrogen oxides and particulate was worryingly high.

Experts particularly dread 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 an increased risk of mortality from non-communicable diseases.

India is a routine underperformer on most global scales even though its standards are lower than some international measures. For instance, the World Health Organisation’s safe annual mean for particulate matter is 10 microgram per metre-cube, while the Indian standard is 60 microgram per metre-cube. Nonetheless, air pollution in all Indian cities, including Mumbai, is formidable.

A view of The Westin hotel in Mumbai's Goregaon East, clouded by pollution. Credit: Swaraj Shetty/Citizen Matters

City of smoke

In a 2016 study, the System of Air Quality Weather Forecasting and Research, a project of the Indian Institute of Tropical Meteorology, Pune, which generates data to determine the air quality index in Mumbai at 10 locations, identified sector-wise causes for air pollution in the city. 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 the Ujjwala Yojana] has performed much better than Mumbai in reducing dependence on biofuels,” said Gufran Beig, the project director at the research programme.

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 only 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,” he said. “It might settle soon, but the road is never free of vehicles.”

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, said transportation expert Ashok Datar, is terrible for the environment. “When you’re forced to stop and start or drive slowly in first gear, you keep the engine idling,” he said. “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 the vehicle. When hundreds of vehicles move like that, it creates localised high particulate pollution, much higher than the dust.”

Good air days

Pollution gets accumulated because of stagnant winds. When 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 explained. “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 the 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.

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 depend on its lofty winds. It will take 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 said. “But the government is building more roads, flyovers and cutting the trees.”

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

In 2017, Anil Galgali, an activist, filed an RTI asking how many trees the city’s municipal corporation had cut in the past three years. The answer revealed that at 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 2,700 trees at Mumbai’s Aarey area for a metro shed, it faced staunch resistance. Presently, the High Court has restrained the Brihanmumbai Municipal Corporation 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 have propelled governments to take some action. In April, for instance, the Maharashtra Pollution Control Board submitted a plan to the Central Pollution Control Board listing measures that included “adopting the most advanced emission standard for automobiles, daily pollution checks for vehicles and increasing 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 corporation 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 state board. In another instance, the Maharashtra Board filed a police complaint against the corporation when it did not comply with its order to shut down a garbage station in Gorai in Mumbai.

Indeed, regardless of its role as an agent, it is 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. The System of Air Quality Weather Forecasting and Research has signed a memorandum of understanding with the municipal corporation, under which it submits air quality data to the municipal corporation. The corporation then releases an environment assessment report based on this data. However, no environment assessment report was released in 2017-’18.

Many air quality stations will have to be built to understand the air quality of a city as vast as Mumbai. Sutaria explained 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. “People write to the Central Pollution Control Board for remedy, which is a crazy way of working,” he said. “Civic bodies can play a big role here, but the role municipal corporations play in mitigation is not clear to anyone.”

While the central pollution board 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.

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

One of the ways he suggested is for corporations to “develop their own Environmental Management Systems in coordination with state pollution control boards”. It’s these systems by a municipal corporation that can better understand the city-specific causes of pollution.

It is 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 about air pollution action plans in Maharashtra. The board responded, “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 Central Pollution Control Board.” But till April 2019, no plan was forthcoming.

Toothless tigers

Ironically, the Centre released a National Clean Air Programme 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 remain elusive until 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 remains 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 municipal corporation that sanctioned the cutting of trees in Aarey, a green belt in Mumbai, even as they spoke of “green development”.

Mitigation efforts around air pollution in Mumbai, and by extension in Maharashtra, are symbolic. At best, redressals involve the court where the National Green Tribunal or other central agencies impose steep fines on BMC or the Maharashtra Pollution Control Board – 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.

This article is part of a series produced under the Citizen Matters – Sustainable Cities Reporting Fellowship, supported by Climate Trends, and first appeared on the Citizen Matters website.