Yes the air in Delhi is a Disaster.
The pollution & uncontrolled trash burning accompanied by a foggy climate with extreme heat/cold seasons all contribute. It is a very real and complex problem and the people & the Govt. of India & Delhi have not done nearly enough to tackle this.
None of this is a secret. People have been screaming about this for the past innumerable years, it is featured in the frickin Wiki about Delhi.
But you gotta wonder about the priorities of the author. He brought a sick asthmatic child to a City known for its horrible air quality. What the f* was he thinking?
Then he writes a rambling article decrying the open defecation & air quality (mixing two tangentially related issues) after his son has an entirely predictable attack. A bad parent and a worse author, playing off the sympathy factor to decry known evils after putting his child in this situation himself.