Early this year, gynaecologist Dr Nikita Kulkarni began coughing every time she stepped out of her home in Mulund, an eastern suburb in Mumbai. Initially, she did not think much of it.

But then she began coughing indoors, with the intensity always aggravating when she stepped out. Towards the end of January, she suddenly felt breathless on her way to work. Her husband, a pulmonologist, had her admitted to a hospital. She took eight days to recover.

Thirty years old and in otherwise good health, she was diagnosed with asthma, a condition in which the airways narrow, making breathing difficult. Kulkarni now needs an inhaler regularly.

“She had an allergic tendency before, but no respiratory illness. This is a first,” said her husband Dr Tarang Kulkarni. He has an inkling of what may have caused her illness.

The residential society in Mulund where they live is surrounded by the construction sites of three high-rises while Metro work is underway on the road outside. A sewage line, too, is under repair close by. The result is a thick blanket of haze since December.

“Dust exposure has risen,” said Tarang Kulkarni. In February, Mulund’s air quality index crossed 500, which is categorised as “hazardous”. Local legislator Mihir Kotecha arranged for water sprinklers on roads around the society to settle the dust. For perspective, Delhi’s air quality crosses these air quality index limits as winter smog sets in during October and November.

A high-rise being constructed near the home of Nikita and Tarang Kulkarni in Mulund. Credit: Special arrangement.

Since January, on 70 of 73 days, Mumbai’s air quality index ranged from poor to severe – between 200 and 400, according to data from AQI India. On most days, it hovered at over 150. An air quality index of 50 or less is considered good and 51 to 100 moderate.

Meteorologist Gufran Beig, project director of System of Air Quality Forecasting and Research said that between November and February, he had observed 70 days when the air quality was poor or very poor in Mumbai, compared to 28 such days in the previous year. “This is a 150% rise in days when air quality was bad,” he said.

Doctors said that the high levels of air pollution in Mumbai, since at least November, are driving up cases of respiratory illnesses in the city.

In the last three months, several cases of cough and wheezing that Tarang Kulkarni has treated among patients from Thane and Ghodbunder, north of Mumbai, are linked to either homes near a construction site or daily exposure to vehicular pollution. Pollution, he said, has caused respiratory illnesses to surge. “I am hoping as summers peak, pollution levels will subside,” he said.

Physicians and pulmonologists told Scroll that while flu and respiratory infections are common in this season, they are seeing more such cases in the out-patient departments. Some of these patients are also being hospitalised, such as Nikita Kulkarni, who was administered a high dose of steroids to reduce inflammation in her lungs. Apart from the inhaler, she now also uses a three-ply mask regularly.

The inhaler has its own set of side effects: it causes tremors in her hand, making it difficult to perform surgeries. “She takes inhaler after surgery is complete,” Tarang Kulkarni said. But that comes with a risk of attacks of breathlessness halfway during a surgery.

According to Dr Alpa Dalal, head of pulmonary medicine at Jupiter Hospital, a temporal correlation shows that pollution has exacerbated respiratory infections – the increase in air pollution has been followed by a noticeable rise in related illnesses. Mumbai has not seen such severe pollution before, she said. Pulmonologist Dr Jignesh Patel too said that the combination of dust, pollution and viruses have increased respiratory infections in Mumbai.

Pollution aids virus spread, infection

Particulate matter, or polluted particles with a diameter of 10 microns (PM10) that hang in the air, is usually caused by dust from construction sites, landfills, wildfires and industrial operations. Such particulate matter can enter the upper respiratory tract. Particulate matter of 2.5 to 5 microns is caused by the combustion of wood or diesel, and can easily enter the lungs.

Dalal, the doctor at Jupiter Hospital, said that PM2.5 and PM10 damages the epithelial cells in the lungs. These cells serve as a protective lining in the lungs, help clear particulate matter and generate an immune response. Damage to the epithelial cells exposes the lungs, allowing viruses direct access into the respiratory system.

“It makes a person more susceptible to viral infection,” Dalal said.

Viral droplets can latch onto particulate matter and thus remain suspended in polluted air for longer. “This allows the infection to spread to a wider population,” she said. Since January, Dalal has been treating 200-300 patients for respiratory concerns every month, 10% of whom require hospitalisation.

Flu viruses, meanwhile, are getting stronger and are immune to antibiotics. “Upper respiratory infection is so severe [that] people are losing their voice texture for 30-45 days,” said pulmonologist Dr Jalil Parkar, attached with Lilavati Hospital. “They can’t speak properly.”

Parkar’s patients suffering from coughing are not responding to the usual line of treatment of paracetamol and cough syrups. “We use steroids sparingly. But now we are forced to use it. Nothing else is working,” said Parkar.

Mumbai’s surge in air pollution levels comes at a time when the H3N2, an influenza type A virus, has been circulating across India. It is currently the dominant flu virus circulating which causes common cough and cold symptoms.

Since January till March 10, there have been 451 confirmed cases of the H3N2 virus, of which 58 have been reported from Maharashtra. In Mumbai, data from the civic body shows four people are presently hospitalised due to H3N2. The number may be indicative of a larger pool since many patients do not get tested and seek symptomatic treatments, said physician Dr Siddharth Lalitkumar.

Since last week, states have begun reporting deaths suspected to be linked with the H3N2 virus – two each in Maharashtra, Kerala, Punjab and Haryana and one each in Karnataka, Tamil Nadu and Gujarat.

Sarojini Dhotre who was hospitalised for an H3N2 infection. Her doctor said air pollution aggravated her cough and caused breathlessness. Credit: Scroll Staff.

Adding to effect of emissions

Mumbai’s high air pollution levels are also exacerbating the health effects of emissions from landfills and other pollutants. Sunil Kailash, 63, who is currently admitted in Lilavati Hospital, was hospitalised after he was found coughing every few minutes. Close to his home in Deonar is a sprawling landfill where harmful emissions mix with the already polluted air.

“We keep our windows closed,” said Sneha Kailash, his wife. Pulomonoligst Parkar of Lilavati Hospital, who is treating Sunil Kailash, said constant coughing has led to bronchial spasms, or swelling in the bronchial tube, most likely caused by a combination of pollution and a viral infection.

In Govandi, bordering the landfill, Nafees Ansari has also been suffering from coughing fits. The 42-year-old lives a kilometre away from a biomedical waste plant. Local residents have held protests demanding that the plant be relocated and say its poisonous discharge is adding to the existing pollution.

When Ansari began coughing, he first had himself tested for tuberculosis, worrying that the infectious disease, rampant in the settlements around, had got hold of him too. After testing negative, he visited a local physician. “Whenever the coughing fits intensify, I start antibiotics and cough syrup,” he said. Ansari has relied on these medications to control his coughing for three months now.

Faiyaz Shaikh, president of the non-profit Govandi New Sangam Welfare society, said residents have begun monitoring air quality using sensors on their terraces. On March 3, the sensors showed that PM10 particles were at 249 micrograms per cubic metre air. The normal range is 50 micrograms per cubic metre air, or µg/m3 . PM 2.5 particles were 152 µg/m3, against a normal range of 15 µg/m3 or less.

Pollution mitigation

In March, the Brihanmumbai Municipal Corporation announced a series of pollution control measures. It identified construction and road dust, vehicular pollution, waste burning and industrial pollution as major pollutants. The civic plans to set up 14 smog towers, each 30-feet-tall, to cleanse ambient air.

But experts have said there are multiple problems with this solution.

According to Abhijit Chatterjee, associate professor at Bose Institute, under the Centre’s Department of Science and Technology, scientific evidence shows that smog towers have a limited effect. “[They are] only effective in cleaning the indoor air where the amount of air driven is minimal and released back in a small and closed space like a room,” said Chatterjee. “It is absurd to think that these systems could be effective on a city level.”

Dr KV George, senior principal scientist at the National Environmental Engineering Research Institute, said, “Even if the towers operate at more than 100% efficiency, they will not be able to purify the ambient air due to its scale.”

For now, residents seem to have returned to masking. Anil Navandar, secretary of the Maharashtra State Chemists and Druggists Association, said that in February and March, chemists have observed a 25% increase in the sale of masks. While in Delhi, middle-class residents turned to air purifiers, Mumbai has not yet reached that stage – yet.

Haze obscures a view of Mumbai's skyline in Worli. Credit: Scroll Staff.

This reporting was supported by a grant from the Thakur Family Foundation. Thakur Family Foundation has not exercised any editorial control over the contents of this article.