Choking back exhaust fumes, 22-year-old Rihana Saif stands at a traffic signal in India's capital New Delhi, holding a sign mounted on a bamboo stick imploring motorists to turn their engines off.
The city has been facing one of its worst spells of air pollution in years, caused by a combination of traffic, factories, construction dust and the widespread burning of agricultural waste in neighbouring states.
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Doctors and environmentalists also say the smog is exacerbating the health effects of a third wave of coronavirus infections.
"Sometimes it feels like my eyes are burning, standing in the pollution for so long," Saif said, barely audible over the roar of traffic.
Saif is one of more than two thousand people in the city's Civil Defence force, which supports the capital's frontline emergency services, deployed to the "red light on, vehicle off" scheme.
Paid a monthly salary of around $300, they have also been deployed in coronavirus quarantine zones in recent months.
Introduced in October, the Delhi government this week extended the initiative to the end of the month, with Saturday's Diwali festival likely to lead to a further surge in pollution.
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Residents are expected to set off huge amounts of firecrackers, despite a ban on their sale in the region surrounding the capital.
Authorities have also experimented with "smog guns" that mist the air, in an attempt to tamp down clouds of toxic dust.
But pollution in some areas of the capital is still more than eight times the World Health Organization's permitted limit.
The Delhi government has said the traffic campaign is to raise awareness about pollution, and turning off engines is voluntary.
Many motorists leave their engines idling, shaking their heads in disbelief when asked if they think the scheme will help.
"It's a waste of public money," said 62-year-old N.S. Rathur, a thin rag covering his mouth as he waited on his motorcycle. "There's no difference at all."
This story has been published from a wire agency feed without modifications to the text.