The fumes of burning rubbish, a major source of pollution that goes unchecked, undermine the Arvind Kejriwal government’s odd-even road rationing formula to reduce air toxicity.

Penalties to offenders in the past year — north and south municipal corporations’ 26 challans and their east counterpart’s 191 — show how much importance is given to the green watchdog in New Delhi that the World Health Organization (WHO) ranks as the world’s worst city for air pollution.

The National Green Tribunal had banned in April 2015 the practice of burning leaves and trash in the city — a ritual followed almost religiously in the absence of a robust garbage disposal system and a strict monitoring system.

Delhi’s never-ending stream of traffic contributes 8% to air pollution in summer, which is just 1% higher than the burning of garbage, an IIT-Kanpur study found.

Smoke from leaf and trash burning releases PM10, a coarse particle that can embed deep in the lungs. Studies have shown PM10 leads to respiratory and heart problems, especially in children.

“We regularly monitor leaf burning to curb the practice,” North Delhi municipal commissioner PK Gupta said.

A civic official defended the relatively low compliance, saying garbage is burnt mostly before dawn or after sunset.

Another official said wood and leaf piles were burnt by poor people to keep warm in winter. “These people can’t pay the lowest fine amount, which is Rs 5,000.”

But at the root of such man-made emissions is the lack of an effective waste management system.

Errant municipal employees find it easy to burn garbage, mostly of biological origin — from horticulture waste to food — than taking the rubbish to dumping sites.

“Sanitation workers, especially those on contract, indulge in this practice on the sly. It becomes hard for enforcement officials to catch them because they escape after lighting the waste,” said an official.

Green activist demanded more accountability, saying burning does not make the waste disappear but transforms it into a formidable pollution problem.

“It requires vigilance to catch offenders. Communities should be involved to ensure the burning doesn’t happen in their neighbourhood … the municipal agencies must work to provide a solution to the problem of waste disposal,” said Anumita Roy Chowdhury, executive director of the Centre for Science and Environment (CSE).

Often residents were clueless about a garbage fire until smoke enters their homes.

“In such a scenario, the sanitation staff, local officials and even residents must be held responsible to ensure accountability,” said Bharti Chaturvedi of Chintan, an NGO.