Experts are calling the situation in New Delhi a major public health emergency. (Reuters photo)

Highlights Thick toxic smog enveloped New Delhi for a second straight day

Chief Minister Arvind Kejriwal called the capital a 'gas chamber'

Mr Kejriwal blamed the pollution on farmers in the neighboring states

Thick toxic smog enveloped New Delhi for a second straight day Wednesday, forcing schools to shut down, halting traffic on highways and sending residents scurrying to buy air purifiers and filtration masks.Chief Minister Arvind Kejriwal called the capital, home to about 20 million people, a "gas chamber" as his government sought meetings with adjoining states to address the issue.By mid-afternoon, the deadly level of carcinogenic pollutants in Delhi's air was roughly 10 times the reading in Beijing, a city globally infamous for its air pollution. Experts are calling the situation in Delhi a major public health emergency."The situation as it exists today is the worst that I have seen in my 35 years staying in the city of Delhi," said Arvind Kumar, a lung surgeon at Sir Ganga Ram Hospital. "As a doctor, I have no problem saying that the situation today is a public health emergency. If you want to protect people, we should be ordering the evacuation of Delhi. Closing down all schools. Closing down all offices."Kejriwal blamed the pollution on farmers in the neighboring states of Haryana and Punjab for burning crop residue, an annual tradition to clear fields that combines with vehicle and industrial emissions, as well as road and construction dust.A day earlier, a senior member of Prime Minister Narendra Modi's ruling BJP blamed the pollution partly on Kejriwal's "failure to maintain" working relationships with nearby chief ministers, one of whom belongs to the ruling BJP.Shikha Gupta, 32, an IT professional, has kept her children and elderly parents inside and has stopped taking her morning walks. "I just stepped out of my office a couple of minutes ago and my eyes are burning already," she said.The levels of the deadliest, tiny particulate matter known as PM 2.5, which lodge deep in a person's lungs, soared on Tuesday to 726, according to a U.S. embassy monitor.World Health Organization guidelines suggest exposure to levels of about 10, while anything less than 50 is considered healthy and levels above 300 are considered "hazardous." At 2 p.m. Wednesday, Beijing had a level of around 76 while pollutants in Delhi's air measured 833.The organizers of an international half marathon scheduled for the 19th said they are holding the race but are constantly monitoring the situation. To minimize the impact of pollution, the organizers will wash the entire 21-kilometer course with effluent water mixed with salt, according to a statement.The Supreme Court last month slapped a ban on selling fireworks ahead of Diwali in an attempt to reduce pollution levels.Jai Dhar Gupta, who sells the pollution-filtering Vogmask brand of facemasks in India, is dealing with a sudden deluge of orders. He said demand shot up 3,000 percent starting Sunday, as the pollution began to worsen."Corporates and institutions like schools are placing bulk orders suddenly," he said. "The sad part is that people don't take the polluted air threat seriously until they 'see' it."Mr Kejriwal has blamed farmers in Haryana and Punjab for burning crop residue, an annual tradition to clear fields that combines with vehicle and industrial emissions, as well as road and construction dust, for Delhi's pollution.A day earlier, a senior member of the BJP blamed the pollution partly on Mr Kejriwal's "failure to maintain" working relationships with nearby chief ministers - ML Khattar, who heads Haryana, is from the BJP.Anumita Roychowdhury, executive director of research at advocacy group Centre for Science and Environment, said this year has seen fewer polluted days than last year. She blamed westerly winds for bringing crop smoke, while easterly winds reduced temperature and trapped fumes.

Last year, NASA satellite imagery showed thick plumes of smoke rising across north India and covering Delhi -- similar to when the agency tracked fires from Indonesia's Sumatra, which regularly drift over and pollute Singapore."During winters, the pollution problem is always atmosphere driven," Roychowdhury said. "The important thing now is what can be immediately done."