Sections of medics and environmental researchers said the ban would help curb rise in air pollution typically seen over the National Capital Region before and after Diwali as fumes from firecrackers join other air pollutants to push pollution levels beyond safe limits.

Firecrackers release sulfur dioxide, carbon dioxide, carbon monoxide and particulate matter (PM), among other compounds, that doctors say have been shown to exacerbate respiratory symptoms of asthma, chronic obstructive pulmonary disease, allergic rhinitis and lower respiratory tract infections.

Doctors caution that while exposure to high levels of air pollution can harm adults, children are likely to be affected even more. "Children's airways are small relative to body size, pollution can cause a greater compromise in air flow," said Anupam Sibal, a paediatrician and medical director at Apollo Indraprastha Hospital here.

A combination of low wind speeds and multiple sources of pollution - vehicular emissions, construction and road dust, and residues from crop-burning - have often contributed to dangerous spikes in air pollution over the NCR during November.

"We see the impacts on patients year after year - children, the elderly and people already with chronic respiratory illnesses are most vulnerable," said Vikas Maurya, head of the pulmonology department at Fortis Hospital in a northwestern suburb of Delhi. "Many of us prescribe preventive medications a few days before and after Diwali, and urge them to minimise their exposure as far as possible," Maurya said.

Conditions after Diwali last year had pushed particulate matter levels up to 10 times the safe levels, prompting the Delhi government to announce emergency measures.

The Energy and Resources Institute, a New Delhi-based research think tank, also welcomed the Supreme Court order, saying it would play a "crucial role" in reducing impacts of air pollution on human health. "This move will lower pollution levels, but stringent measures are required to address all the other major sources of pollution all year round," said Sumit Sharma, associate director at TERI.

But traders have asked the Union government to file a review petition. The Confederation of All India Traders said the ban does not prevent people from procuring firecrackers from other states and bursting them in Delhi. "This distinction of Delhi traders with the rest of India traders seems to be unjustified," the Confederation said. "Many traders (who) deal with crackers must have purchased their stocks for this Diwali by now and the ban will (cause) them huge losses."

AAP criticises ban

Delhi's ruling Aam Aadmi Party said the ban would lead to black marketing. "We can't think of celebrating Diwali without crackers. Of course, the environment needs to be clean and we need to reduce the use of crackers but a blanket ban will only lead to black marketing. Only civil engagement can bring down cracker use," party spokesman Dilip Pandey told The Telegraph.

The Delhi government is studying the verdict and is yet to respond to it.