Urbanisation and modernisation have begun to claim their pound of flesh. Mumbaikars now easily contract respiratory infections as the city’s teeming millions have done enough to raising its air pollution levels. Ignoring the symptoms may prove fatal, finds Somita Pal

Suhasini Parekh recoils in fear each time someone around her fails to sneeze into a handkerchief. "I had one of my worst experiences with common cold last year and it all started with a sneeze," explains the 24–year–old resident of Borivli. "I was first treated for common cold. But within a few days, I developed chest congestion, whooping cough and wheezing. It was a viral infection."

Although she recovered in two weeks, the symptoms have resurfaced every month since then. "Doctors blame my low immunity [against viral infections], but I have observed an increasing number of colleagues and relatives with similar symptoms."

No more seasonal Parekh’s fear of letting down her guard is justified. A sneeze is no longer regarded as a mere defence mechanism of the body. Doctors blame the rising number of cases of respiratory infections/diseases on the declining quality of air.

The latest environment status report of the Brihanmumbai Municipal Corporation states that Borivli is one of the six areas in the city which have seen a sharp rise in the number of air pollutants, like sulphur dioxide, nitrogen dioxide, suspended particulate matter and ammonia.

"The poor air quality is affecting everyone. Upper respiratory tract infections, which used to be seasonal, now crop up regularly throughout the year. Two out of every 10 Mumbaikars suffer from some form of a respiratory infection or disease," says Dr Jalil Parker, renowned chest physician from the Lilavati Hospital. Upper respiratory infections include rhinitis, sinusitis, laryngitis, epiglottitis, otitis media (inflammation of the middle ear) and croup (a respiratory condition usually triggered by an acute viral infection).

Sinusitis – an infection caused by a pathogenic microorganism (virus, bacterium or fungus) growing within the sinus (the hollow, air–filled cavity that leads to the mouth) – has become the most common and fastest–growing upper respiratory infection, says Dr Asha Pherwani, a specialist in asthma and allergic treatment at PD Hinduja Hospital. "Sinusitis is a co–morbid condition for asthma and many people who suffer from sinusitis and allergic cold are now being diagnosed with asthma."

She projects that there are over a million Mumbaikars in various stages of asthma today. "The number of people complaining of respiratory problems has been increasing every year. Earlier, we used to ask such patients if they had a history of allergies. But now, we first check whether they stay near a massive construction site. Interstitial lung diseases, which were earlier found only in factory workers who inhaled a lot of dust, are also becoming common."

Conducive environs The Association of Otolaryngologists of India says Mumbai alone has 1.5 million people suffering from chronic sinusitis. Till about five years ago, say doctors, only seven to eight people out of 100 upper respiratory infection cases suffered from sinusitis. Today, at least half of those with respiratory problems are diagnosed with sinusitis.

Patients with an upper respiratory infection cannot afford to treat it lightly since it may lead to a lower respiratory infection like bronchitis or pneumonia.

"Airborne infections thrive in Mumbai’s climatic conditions. The city is crowded and is very humid, which help bacteria and viruses grow. Also, people have a poor sense of hygiene, their lives are stressful and their immunity is low. This makes airborne infections resurface throughout the year," explains Dr Om Shrivastav, infectious disease expert at Jaslok Hospital.

He warns that poor air quality can lead to the development of serious infections, which may even turn fatal. He adds that with the exception of tuberculosis, airborne infections influenzas A and B as well as swine flu pose the biggest threat to Mumbaikars. Statistics show that the mortality rates of influenzas A and B are 4% and 1%, respectively.

"Influenza, combined with upper respiratory infections, is getting more and common," says Dr Pratit Samdhani, consulting physician at Jaslok Hospital and Breach Candy Hospital. He points fingers at the ‘mall culture’ in the city, which encourages people to gather around in big numbers in air–conditioned environments, which aid the spread of infections, for such a trend. Dr Khusrav Bajan, consulting intensivist at PD Hinduja Hospital, agrees. "Infections spread in public places. Many people lack a basic sense of hygiene. Sneezing and coughing without a handkerchief or spitting on the road is still common. Ninety per cent of airborne infections are related to upper respiratory problems and they spread through such a conducive atmosphere. Quite a few people with an upper respiratory infection end up needing intensive care unit treatment if their condition is not addressed at its onset."

Dr Parker says the frequency, the severity of cough and cold and the duration of an infection have gone up. "Now, even after completing an antibiotic course, along with cough syrups, symptoms persist for 10–15 days. Population explosion, migration, low immunity and associated illnesses like diabetes and hypertension has changed the dynamics of upper respiratory diseases, which used to be seen only at the beginning of winter and monsoon."

Price to pay Although cases of airborne diseases in Mumbai have been increasing through the year, not much research has been done to find their causes. Studies conducted abroad show that vehicular and industrial sectors are the main sources of air pollution. The problem of urban air pollution is nearing a crisis of sorts at many cities in developing countries.

Dr Vijay Yewale, convenor of an immunisation committee, says, "We are paying the price of urbanisation and industrialisation. Respiratory ailments recur when temperatures fluctuate and pollution levels soar. Almost 20–25% of patients who have been treated [for respiratory infections] come back with the same symptoms."

Children, pregnant women, senior citizens, diabetics, those suffering from hypertension and ones who take immunosuppressants are more vulnerable to airborne infections. "A long–term exposure to air pollutants such as nitrogen dioxide and suspended particulate matter can cause reduced lung growth in children. The effects are more pronounced in areas with higher air pollution. "Most of the children have hypersensitive airways. This makes them prone to developing a respiratory ailment," warns Dr Yewale.

The good news is that people with even the mildest of symptoms of flu have now begun to come forward to get themselves tested, thanks to awareness created following endemic diseases, like the swine flu outbreak in the city in 2009, says Dr Bajan.