Features

doi:10.1038/nindia.2011.108 Published online 22 July 2011

What's ailing our lungs?

Lungs give us life. We pollute them in return! Changing environmental conditions and unchanging human habits make lungs the most commonly diseased organs. Pawan Dhar reviews the work of Pune-based Chest Research Foundation to outline emerging lung conditions and ways to prevent them.

Historically, human lungs have hosted diseases like tuberculosis, pneumonia and other respiratory tract infections. Now, gen next diseases and lifestyle-linked problems such as asthma and chronic obstructive pulmonary disease (COPD) have arrived with a bang. Worse, these diseases of epidemic proportions have already overtaken classic infective conditions of the lung.

In 2009, a group of researchers at the Chest Research Foundation in Pune, India established an organic link between indoor air pollution and the occurrence of COPD. Prior to this, the scientific and clinical community attributed the etiology of COPD only to smoking and environmental conditions. COPD is a chronic progressive inflammatory disease of the airways and lung tissue causes huge disability and deaths, and this is estimated to increase by 160% over the next couple of decades.

Among all the non-communicable diseases, chronic respiratory conditions account for the biggest health burden in India — more than cardiovascular disease, diabetes and cancer. An estimated 60 million people suffer with Asthma and COPD in India alone! Despite this huge health burden, there is little India-specific knowledge on the origin and progression of this condition. India contributes 0.5% of the total medical knowledge in the world, and out of this only 2% is accounted for research in respiratory medicine.

India's understanding of asthma and COPD comes largely from western medical literature. Given that we live in a very different environment, have different socioeconomic factors and eat food different from the west, we need India-specific data to encounter this threat. In other words, India urgently needs a respiratory research revolution.

Sundeep Salvi

In 2002, Sundeep Salvi set up the Chest Research Foundation (CRF) in Pune with funding from Cipla Pharmaceuticals Ltd to bridge this gap and generate India-specfic knowledge on Asthma and COPD. In a pioneering work, Salvi and colleagues Bill Brashier, Sneha Limaye and Rahul Kodgule reported an almost two-fold increase in the prevalence of asthma among children during the last five years of school. Excess consumption of paracetamol during first 6 months of life was also shown to increase the risk of developing asthma when the child grows up to be six or seven years old.

The team further found that exposure to diesel fumes, mosquito coils and incense stick fumes also increased the risk of asthma. Other risk factors for childhood asthma could be family history, caesarean delivery, absence of exclusive breast feeding during the first 6 months, damp walls at home harbouring different species of fungi and resident smokers.

The festival of lights Diwali was also found to contribute significantly to the risk. The researchers measured levels of sulphur dioxide, a strong respiratory irritant, in the air during Diwali to find it 200-times higher than the WHO-prescribed safety limit. Not surprisingly, the incidence of cough increased by 30% and breathlessness and wheezing by around 10%.

In another first, CRF recently reported that cell/tissue damage in the lungs of traffic policemen and bus drivers was equivalent to the effect produced by cigarette smoking. They recommended consumption of antioxidant boosting foods to reduce lung damage caused by air pollution.

Salvi's earlier research in UK on the effects of air pollution on human lungs, with a particular emphasis on diesel exhaust, has received high global citation. CRF is now collaborating with Imperial College of London and Johns Hopkins University to go deeper into the understanding of asthma and COPD for early prevention and cure. The foundation has also been creating awareness among doctors, health care providers, policy makers and public to stop the growing menace of chronic lung diseases.

Despite such huge impacts on health and economy (asthma and COPD are estimated to cause losses of over Rs 40,000 crore every year), the lung remains a badly neglected organ. They provide the human body with 420 litres of oxygen every day, for which they work hard to pull in 10,000 litres daily.

In a healthy individual, the lungs use only 10% of their requirement. Although 90% backup is good in a way, it also means that one would not notice any significant disability until it's too late.


References

  1. Salvi, S. et al. Chronic Obstructive Pulmonary Disease in non-smokers. Lancet 374, 733-743 (2009) | Article | PubMed | ISI |
  2. The Global Burden of Disease, WHO (2008)
  3. Nongkynrih, B. et al. Current status of communicable and non-communicable diseases in India. J. Assoc. Physician I. 52, 118-123 (2004)
  4. Dandona, L. et al. The lack of public health research output from India. BMC Public Health 4, 55 (2004) | Article | PubMed |
  5. Salvi, S. et al. Acute inflammatory responses in the airways and peripheral blood after short-term exposure to diesel exhaust in healthy human volunteers. Am. J. Respir. Crit. Care Med. 159, 702-709 (1999) | PubMed | ISI |