Mumbai holds its breath, alarm bells ring but no one’s listening

On Wednesday, as the city’s temperature soared to a four-year high for October, levels of PM10 — Particulate Matter, with a diameter of 10 microns or less (human hair is 50-70 microns) and, therefore, inhalable — crossed its levels in Delhi.

A day earlier, Mumbai’s overall Air Quality Index touched 191, way worse than Delhi’s 84. Andheri and Mazgaon touched 300 plus; Sion and Bandra Kurla Complex crossed 200 — an AQI above 200 is considered Poor, above 300 Very Poor and a serious health hazard.

These alarm bells are loud and clear and yet they have a familiar, disquieting ring.

Chronic obstructive pulmonary disease (COPD). (Credit: Amit Chakravarty)

Records analysed by The Indian Express and data obtained by the newspaper under the Right to Information Act show a pattern emerging — and hardening. Of steadily worsening air — and an action plan gathering dust severely undermining the quality of life in the country’s financial capital.

The warnings came as early as last year when several counters clocked alarm: The number of Poor air quality days in December-January 2022-23 almost doubled from the 17 in that two-month period in 2019-20.

Data from the System of Air Quality and Weather Forecast and Research (SAFAR) — under the Ministry of Earth Sciences — showed that Mumbai recorded its worst AQI last winter with the city registering Poor and Very Poor AQI on as many as 66 of the 92 days between November 2022 and January 2023 — compared to an average of 28 during those months over the previous three years.

(According to SAFAR, an AQI between 0-50 is Good; between 51-100 is Satisfactory; 101-200 is Moderate; 201-300 is Poor; 301-400 is Very Poor and beyond 400 AQI is Severe).

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As comparison, during the same 92 days, Delhi had 79 days of Poor and Very Poor AQI and as many as eight days of Severe.

That’s of little comfort, though.

For long, Delhi has held its infamous pride of place in the nation’s pollution map. But it has registered tangible progress with a well-monitored ban on open burning, mechanised road sweeping during winter months, and a Graded Response Action Plan under which a set of restrictions — bans on vehicles to curbs on construction — kick in when pollution levels reach a certain threshold.

“Delhi has a disadvantage due to its landlocked geography but Mumbai is a coastal city that enjoys a natural cleansing advantage. Stronger surface winds favour faster dispersion and wind reversal cycles of strong sea breezes sweep away air pollutants from the land. However, in recent times we see that nature can take away the blessing it bestowed,” says Gufran Beig, founder project director of Safar and chair professor at the National Institute of Advanced Studies in Bengaluru.

Changing wind patterns

Behind the recent spike in the city’s pollution cycle, Beig says, and this is what makes it so fraught, is a set of factors, local, regional and meteorological. Climate change, the dip in La Nina — the cooling of the ocean surface — and changing wind patterns have all played a role.

Over a six-year period from 2016 to 2021, a total of 14,396 individuals in Mumbai lost their lives due to COPD. (Express photo by Amit Chakravarty)

“That’s why despite Mumbai’s geographical advantage, we have seen a sharp dip in AQI (because of) natural and human factors,” says Beig. For one, over the past couple of years, the wind pattern has changed due to which the process of wind reversal is taking as many as 15 days — earlier, this used to happen every two days.

“Now, due to the delay in wind reversal, the suspended particulate matter lingers in the lower atmosphere for a longer period of time thus worsening AQI. Also, over the past few years several infrastructure and redevelopment projects have come up, due to which construction is ongoing everywhere, this has increased the proportion of particulate matter in the air, which in turn has worsened the AQI.”

Indeed, “dust arising from construction site and construction debris” has been identified as one of the top five sources of air pollution (see adjacent story) by the Brihanmumbai Municipal Corporation in its Mumbai Air Pollution Mitigation Plan released only in March this year.

The other four are: road dust and its displacement; open burning of solid waste and garbage; usage of unclean fuels in restaurants, dhabas, bakeries and roadside eateries; and a range of industries that include those using Ready Mix Concrete (RMC) plants and casting yard plants.

What this translates into is the need for what experts call a “holistic” action plan that tackles these simultaneously.

Air Quality Index (AQI). (Credit: Amit Chakravarty)

“The Union Ministry’s National Clean Air Program (NCAP) aims towards improving the current AQI standards by 20%-30% but data shows that there has been an incremental increase in PM10 components in Mumbai in just one year and this is the result of absence of a holistic policy,” says Bhagwan Kesbhat, CEO, Waatavaran Foundation, that works on hyper local projects aimed at slowing down the climate change and its impact on communities.

For example, there are several areas across Kalyan, Navi Mumbai, Bhiwandi where open burning of garbage and scrap happens at a massive scale. “The particulate matter often drifts towards Mumbai due to air movement and, in return, plays havoc with the AQI. Issues like these can only be addressed when all agencies would work together,” said Kesbhat.

Over the next days and weeks, The Indian Express will report on each aspect of Mumbai’s air pollution crisis and the possible solutions and interventions needed.

One imperative that is likely to drive change, experts agree, is the public health cost of pollution.

Warning bells sounded

Nothing moves the needle more effectively than a city and its residents suffering in hospital wards, say experts. “That affects our children, our loved ones…that’s the alarm bell that’s heard the loudest. That was heard in Delhi and that needs to be heard in Mumbai. This needs awareness on a scale that we have never seen,” said a senior official.

A local train is seen running amid hazy conditions. (Express photo by Amit Chakravarty)

One of them ringing a bell regularly is renowned pulmonologist and epidemiologist, Lancelot Pinto at Hinduja Hospital.

When AQI hits 300, as it did in several areas in Mumbai this week, indicating a PM2.5 level of 120, it implies that the air quality at this level carries a health impact equivalent to inhaling the particulate matter from about 5-6 cigarettes each day, says Pinto.

“Of even greater concern is the exposure of school children to this air quality (akin to smoking 5-6 cigarettes each day) particularly while their developing lungs remain vulnerable. This carries the potential for serious consequences, including the risk of respiratory diseases in their future,” adds Pinto.

Data obtained from BMC by The Indian Express under the Right to Information Act reinforces this concern: the steady uptick in casualties — an average of six a day — to Chronic Obstructive Pulmonary Disease. COPD is a common lung ailment that hinders airflow and can lead to lung damage or phlegm congestion, causing breathing difficulties.

Over a six-year period from 2016 to 2021, a total of 14,396 individuals in Mumbai lost their lives due to COPD. Additionally, during the same period, records show, 1,220 people in Mumbai passed away from bronchitis, and 6,757 deaths were attributed to asthma, with 619 of these occurring in the M East ward, which encompasses Govandi. This area faces elevated air pollution levels due to the presence of Asia’s oldest dumping yard in Deonar.

Climate change, the dip in La Nina — the cooling of the ocean surface — and changing wind patterns have all played a role in the change on the city’s pollution cycle. (Express photo by Amit Chakravarty)

That’s not all.

Mumbai has witnessed a gradual rise in lung cancer fatalities from 621 in 2009 to 923 in 2021, reflecting a 48.6% increase over 12 years. Daksha Shah, the BMC’s executive health officer, told The Indian Express that mortality figures for 2022 are currently under scrutiny.

In hospital after hospital, there are reports of a rising curve when it comes to asthma and respiratory illnesses. For example, records from Sion Hospital show asthma-related admissions going up, from 62 in 2018 to 86 in 2022. Dr Sanggita Checker, a Consultant Chest Physician at Wockhardt Hospitals, says that each winter, when reduced wind speed causes pollutants from construction sites and traffic to accumulate in the air, there is a surge in the number of patients with comorbid conditions like asthma, COPD, and bronchitis.

Prolonged exposure and respiratory health

Air pollution worsens the issue as PM2.5 particles bypass natural nose and respiratory defences.

“Micro air pollutants, such as PM2.5, deeply penetrate the respiratory system. These fine particles reach the alveoli where gas exchange occurs. They trigger inflammation, oxidative stress, and damage to lung tissues. Prolonged exposure can lead to chronic respiratory ailments, worsen existing conditions, and increase the risk of lung infections, ultimately compromising respiratory health,” said Dr Jalil Parker, pulmonologist at Lilavati Hospital. “PM2.5 can thus access internal organs, posing a significant threat.”

Global studies have observed associate air pollutants with lung cancer. The PM2.5 can induce mutations in normal cells, potentially leading to cancer. Regions with elevated air pollution exhibit a greater prevalence of lung cancer in non-smokers compared to areas with lower pollution levels.

Dr Sewanti Limaye, director of oncology and precision medicine at Sir HN Reliance Hospital, cites a recent UK study involving approximately 45,000 individuals that revealed a link between dust particles larger than 2.5 microns and a particular lung cancer type driven by specific EGFR gene mutations.

Said Limaye: “This mutation is present in 25% of lung cancer cases in India, predominantly affecting non-smokers.”