On top of expensive European air purifiers, inhabitants are turning to nose filters, indoor plants and even yoga to mitigate the crisis.

But doctors say that none of it will be enough to prevent deaths in the metropolis of 20 million people battling a pollution crisis for the second year.

Some streets in the Indian capital have recorded pollution levels 40 times the World Health Organisation’s recommended safe level since Monday, with still weather and the annual post-harvest burning of crop stubble in Punjab fuelling the crisis. By mid-afternoon on Wednesday, levels had reached about 10 times the reading in Beijing, a city infamous for its air pollution.

Rickshaw drivers, street vendors and tens of thousands of homeless families endure the full force of pollution that doctors warn can do irreparable damage to the heart, brain and lungs, especially in children.

Sanjay, who like many Indians goes by one name, spends his days waiting for passengers, breathing in the poisonous mist so thick that often he cannot see the other side of the road.

“I don’t have a mask. The masks are too expensive. I have a hanky,” he said, bringing out a cotton square.

He knows however that putting the rag over his nose and mouth does next to nothing against the onslaught of fine particles – so small they bury deep in the lungs – that sear his eyes and throat.

“My eyes are fire,” he said, pulling back an eyelid to expose an irritated, bloodshot iris.

Labourer MK Sharma also cannot afford a smog mask. He thought the scarf wrapped around his face – a method favoured by motorcyclists and street workers – made things “a little better”, but he wasn’t sure.

“It is better than nothing,” Sharma said.

Rupesh Kumar paid US$4 for a cheap, poorly fitted fabric mask. It was all he could afford. “I want to save myself from Delhi,” he said.

Nearby, affluent Delhi residents jostled in a long queue to a small shop selling neoprene masks, fitted with a carbon mesh designed to filter out the noxious particles.

Panic rose from the crowd as the vendor lowered the shutters, announcing most sizes had sold out.

“Oh my goodness, you’re finished? This is a catastrophe,” said Sue, an expatriate woman who declined to give her second name, her young daughter by her side.

Those lucky enough to secure a mask ripped open the packaging and immediately put it on their children.

One elderly Indian woman looked distressed upon learning a mask cost 2,500 rupees, roughly US$40. “This is really too much. I cannot deal with this,” she said, shaking her head.

At a nearby shop, office worker Apurva, covering her mouth with her sleeve, bought two air purifiers to complement the one already at home.

“Every room needs one because it is that crazy,” she said, referring to the high-end machines, which between US$150 and US$1,000.

Many joggers and dog walkers in Delhi’s Lodhi Gardens park appeared unfazed, joining the overwhelming majority of residents battling on without masks.

Children played cricket, couples canoodled and men read newspapers in smog so thick that the park’s ancient Islamic monuments were barely visible in the gloom.

One snowy haired retiree taking a daily walk said he did not worry about the danger for his health because he did not have asthma.

“I can walk without a mask. I am not troubled by this weather,” said Rammi Bakshi, reflecting a common belief that the winter smog is seasonal.

At India Gate, a towering monument that was also barely visible, Pushkal Rai scoffed at suggestions the smog would halt his cricket match.

“We’re spiritual guys, we love yoga, meditation, and this will remove [the pollution] from our body,” he said, adding sugar cane also helped clean the lungs of contaminants.

“We are Indians, we never worry about such kind of things here.”

Additional reporting by Bloomberg