NEW DELHI — As air pollution shot up to dangerous levels across India on Friday, underscoring an already dire public health crisis, a crowd descended on a small shop in New Delhi for a novel solution: a 15-minute hit of clean oxygen.

At Oxy Pure, a self-styled “oxygen bar,” customers strapped tubes to their noses and inhaled scents of lavender, lemongrass or spearmint. In the absence of other options, Lisa Dwivedi, a Ukrainian living in the city, said she came to the bar because she was fed up with having itchy eyes, a runny nose and a swollen throat.

“I don’t know if it’s psychological, but it makes me feel good to know I am inhaling pure oxygen, if only for 15 minutes,” she said.

The air pollution crisis in India has become so severe that officials in the capital declared a public health emergency earlier this month, when levels of deadly particulate matter rose a few dozen times above what the World Health Organization considers safe.