Each winter, 15% of the patients with moderate to severe breathing problems at the department of pulmonary medicine at the All India Institute of Medical Sciences (AIIMS) are healthy persons with no diagnosed respiratory illness.
"We notice a sharp increase in respiratory and cardiac cases within 24 to 48 hours whenever there is an increase in pollution levels, especially during winters," says Dr Randeep Guleria, professor and head, department of pulmonary medicine and sleep disorders, AIIMS.
Air pollution not just causes lung cancer but also wrecks havoc with people’s cardio-pulmonary system, which involves the heart and the lung. To provide clinching evidence of how poor air quality affects health of people, Dr Guleria is spearheading a study to track the hazards of air pollution.
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Though it is too premature to talk about the findings, Dr Guleria acknowledges that it does establish a direct correlation between rising pollution levels and immense stress on the heart and the lung.
Air pollution is the fifth largest killer in India, causing 620,000 premature deaths, said the Global Burden of Disease Report released in 2013.
"Air-pollution is as bad for the heart as smoking — in patients with cardiac history, symptoms become worse and for a healthy young person it is a high-risk factor," says Dr KK Talwar, director - cardiology, Max Healthcare.
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The World Health Organisation has classified air pollution as a Class-1 carcinogen because it is directly linked to lung cancer.
Apart from the heart and the lungs, doctors warn against equally serious side-effects of air pollution on the reproductive system, eyes, bones and even causing mutation in certain genes.
Over the last five years, not only are more people reporting symptoms but the the duration and severity of symptoms has also seen a rise.
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"Mild health gains of improved air quality after CNG was introduced in Delhi in 2002 have been negated in the last five years. With the rising vehicles on the roads, the pollution levels are significantly higher.
Delhi now needs an on-going plan to curb pollution, as short-term ones are redundant," Dr Guleria added. Long-term effect causes irreversible damage.
"There is a rapid decline observed in the lung capacity and lung function of people living in heavily polluted cities like Delhi.
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It is almost like smoking—a person may have never smoked but his or her lungs are like that of a heavy smoker," said Dr Guleria.