People commute on a motor-cart on a smoggy morning in New Delhi, India, November 5, 2018.

Women receive treatment for respiratory issues at a hospital in New Delhi, India, November 2, 2018.

A woman waits to receive treatment for respiratory issues at Ram Manohar Lohia hospital in New Delhi, India, November 5, 2018.

Residential buildings are seen shrouded in smog in New Delhi, India, October 30, 2018.

People wait to receive treatment at a hospital in New Delhi, India, November 2, 2018.

Residential buildings are seen shrouded in smog in Noida on the outskirts of New Delhi, India, November 5, 2018.

The Humayun's Tomb is seen shrouded in smog in New Delhi, India, October 29, 2018.

An under-construction building is shrouded in smog in New Delhi, India, November 1, 2018.

A man crosses a road next to Indian Defence Ministry and Home Ministry buildings on a smoggy morning in New Delhi, India, November 5, 2018.

India's presidential palace Rashtrapati Bhavan is seen shrouded in smog in New Delhi, India, November 5, 2018.

Image used for illustrative purpose. India Gate is shrouded in smog as people participate in 'Run For Unity' to mark the 143rd birth anniversary of Sardar Vallabhbhai Patel, one of the founding fathers of India in New Delhi, India, October 31, 2018.

A church is shrouded in smog in New Delhi, India, November 1, 2018.

People commute on a smoggy morning in New Delhi, India, November 5, 2018.

Indira Gandhi International Airport is seen shrouded in smog in New Delhi, India, October 30, 2018.

People pass by an installation of an artificial model of lungs to illustrate the effect of air pollution outside a hospital in New Delhi, India, November 5, 2018.

Residential buildings are seen shrouded in smog in New Delhi, India, October 30, 2018.

People receive treatment for respiratory issues at a hospital in New Delhi, India, November 2, 2018.

A bird flies past the Humayun's Tomb shrouded in smog in New Delhi, India, October 29, 2018.

A temple is shrouded in smog in New Delhi, India, November 1, 2018.