The dwindling air quality in Delhi has come as a rude shock this year. There is a sense that the capital city of India is in the throes of an undeclared air emergency.

To give a perspective of how bad the air quality is due to an increase in PM2.5 levels, read what Siobhan Heanue has to say: "I use an app that converts the air quality to an equivalent number of cigarettes. Anyone in Delhi now might as well be smoking 33 cigarettes a day. Imagine knowing your children are smoking more than a pack a day. Cos here, they are. Eyes water, everyone coughs and chokes. Kids and outdoor workers are worst affected, their health seriously compromised."

Charles Onyango-Obbo says, "India air pollution reported at “unbearable levels”. Last week, New Delhi recorded an Air Quality Index (AQI) of 999, beyond which reading is not possible – that’s 16 times worse than the prescribed level."

The government authorities have issued an advisory to residents, asking them to step out only if necessary. The quality of air is "morbid" out there.

Meanwhile, River Yamuna stands covered by foam that looks like "candyfloss".