…With a lump in her throat, Sujata accompanied Rajesh on the trek through the hallways of the All India Institute of Medical Sciences in Delhi. With the bitter taste of cleaning and antiseptic fluids, hospitals are often despondent places, more so in a country where poverty is entrenched. Sujata was clinging on to whatever hope she could muster, but that too collapsed when the doctor informed them of what she had suspected. An X-ray test had revealed a large tumour in his lung.
‘How could it even be possible,’ Sujata thought, ‘he does not even smoke.’ But it was too late. The cancer was Stage IV by the time the diagnosis had been made. It had already spread beyond his lung. What followed were weeks of long absences from home, trips to the hospital, extreme weight changes and that hairless head. The most comforting part of the day for Sujata was when she sobbed herself to sleep every night.
The final few days went by quickly, even as the phases of deterioration made it seem like years had passed. First came the wheelchair, following which Rajesh lost his ability to sit and eat by himself. A young man rotting away while his wife watched helplessly. This was not what she had signed up for. The disease went on to consume his life, her love—and bankrupt the young family in the process…
That air pollution causes cancer is now a foregone conclusion among scientists, even as they continue studying the specific nature of the impact. As recently as in 2013, the World Health Organization’s (WHO) International Agency for Research on Cancer concluded that particulate pollution causes lung cancer after reviewing several of the latest studies that were conducted on very large samples, consisting of hundreds of thousands of people around the world.
Air pollution consists of several unwanted constituents, key among them being particulate matter, which is a mix of solid and liquid particles. These particles are made up of various components, including organic chemicals, metals, soil, acids and dust particles. This particulate matter has various sources, including vehicles, power plants, construction sites, forest fires, cooking stoves, manufacturing industrial units and even natural sources such as volcanoes.
Of such particulate matter, the ones that are of most concern to us are what are known as PM2.5 and PM10. The PM here stands for particulate matter, and the 2.5 and 10 here refer to the size of the particles in microns. Human hair is 50–70 microns wide and fine beach sand about 90 microns. PM10 particles in the air are therefore about one-fifth or one-seventh as small as the width of human hair, while PM2.5 is as small as one-twentieth of a human hair in width. PM2.5 particles are so small, they are invisible to the naked eye. There are finer particles still, called ultra-fine particles, which are PM0.1, that is, 0.1 microns in width. If you look out on a summer day and see a clear sky, it does not mean that air pollution levels are low. They could still be critically high— you’re just not able to see it.
Our body has evolved natural defences to filter out dust that keeps us healthy. However, these fine particles are too small to be restricted by these defences. When inhaled, they bypass the natural defences by just flowing through our natural filters without restriction, much like oxygen molecules that the human body needs. While all particles pose a risk to human health, PM0.1 is the most dangerous, as it is small enough to enter the bloodstream by passing through the lung tissue. Unlike larger particles, the human body cannot cough or sneeze such particles out.
Cancer, however, is not the only possible outcome of exposure to pollution. Studies involving tens of thousands of people have proven the link of air pollution to depressive and cognitive disorders, neuro-degenerative illness, brain ischemia, heart rate variability, heart attacks, strokes, congestive heart disease, thrombosis, lung inflammation, worsened asthma and several other conditions. Importantly, pollution leads to increased mortality among infants, miscarriage, foetal growth problems and low birth weight…
Excerpted and edited from The Great Smog of India (Penguin Random House India) by Siddharth Singh
