Hundreds gathered in the Indian capital of New Delhi on Sunday to protest against a rising public health crisis brought on by air pollution, demanding government action.

Riot police dispersed the protesters and detained dozens, saying they did not have the right to demonstrate at the symbolic India Gate plaza.

Opposition leaders criticized the detention of peaceful protesters, with leading opposition figure and member of the National Congress (INC) Rahul Gandhi, stressing that "the right to clean air is a basic human right." 

New Delhi's air quality index stood at around 344 by Monday morning, a "severe" level according to the World Health Organization's recommended exposure limits. India Today recorded the index being as high as 390 on Sunday.

Hazardous air quality peaks ahead of winter in New Delhi

A metropolitan region of about 30 million residents, New Delhi frequently ranks among the world's most polluted cities.

Air pollution in India's capital routinely rises to dangerous levels ahead of the winter months, as construction dust, engine exhaust and smoke from burning fields create a thick haze, bringing on lung and heart conditions, eye and throat irritations, headaches, skin discomfort, and coughing.

"Year after year, it is the same story but there is no solution," lawyer Tanvi Kusum told the French AFP news agency. "We have to build pressure so that the government at least takes up the issue seriously."

Over the weekend, air pollution levels spiked to "severe" and "hazardous" levels in parts of the wider region, as India's National Air Quality Index (NAQI) reported. These levels are categorized as posing "serious" health risks to people with preexisting conditions.  

What is the Indian government's response to the poor air quality?

In line with a Graded Response Action Plan (GRAP), Delhi officials have responded by strictly controlling dust at construction sites, restricting the use of diesel generators and engines, and even making attempts to induce rain with cloud seeding.

A higher escalation of GRAP restrictions would bring construction to a near halt and require most schools to close, moving classes online. Officials have been mulling the decision but have yet to enforce it.

The ruling Bharatiya Janata Party (BJP) has stated it will "continue every possible effort to rid us of pollution."

The majority of the world's most polluted cities are in India, according to a report by Switzerland-based air quality monitoring database IQAir released earlier this year.

A study by the Lancet Planetary Health suggested links between long-term exposure to air pollution and approximately 1.5 million deaths per year in India.

On Sunday, protester Namrata Yadav told the AFP news agency she had come to demonstrate out of fear for her future.

"I am here because I don't want to become a climate refugee," she said.

Edited by: Rana Taha