01:06 Toxic Foam, Deadly Smog Plague India’s New Delhi During Hindu Holiday Thousands of people flocked to a polluted Yamuna River covered with toxic foam for the Hindu religious celebration of Chhath Puja in New Delhi, India.

At a Glance Officials institute measures aimed at reducing pollution levels, which have hit a three-year high.

The air quality index in New Delhi has topped dangerous levels.

One official called the city a "gas chamber" because of the pollution. Smog blanketing India's capital got so bad over the weekend that pilots couldn't see to land their planes at New Delhi's international airport.

Officials declared a public health emergency, and schools and colleges have been ordered to remain closed this week , according to CBS News.

Private cars can only be on the road on alternate days. Cars with odd-number license plates may drive on odd dates while even-numbered plates are allowed on even-numbered dates, the Associated Press reported.

"I have a headache every day I wake up. It's suffocating to breathe sometimes. And inflammation in the nostrils and all. And eyes also. Like it kind of burns ," Ankusha Kushi, a student, told the AFP news agency.

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Pollution levels have reached a three-year high. The air quality index in some parts of Delhi hit 900 on Sunday , the Guardian reported. At 7 a.m. Monday, Delhi's overall AQI was "severe" at 708 , according to India Today. An AQI between 0-50 is considered "good," 51-100 is "satisfactory."

Much of the smog is caused by farmers in neighboring states of Punjab and Haryana burning off the stubble and crop waste left after the harvest.

Delhi Chief Minister Arvind Kejriwal said last week that the city had been "turned into a gas chamber due to smoke from crop burning ," CNN reported. Fireworks set off during Diwali, the Hindu festival of light, add even more smoke to the air, and calmer winter winds do not clear the air very well.

Scattered rainfall expected Thursday could help wash away the pollutants , BBC.com reported.

At a hearing Monday about the pollution, India's Supreme Court said, "Delhi is choking every year and we are not able to do anything. Every year this is happening and this continues for 10 to 15 days, this is not done in civilized countries. Right to life is most important."

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/IndiaAir2.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/IndiaAir2.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/IndiaAir2.jpg?v=ap&w=980&h=551 800w" > A man crosses a street in smoggy conditions in New Delhi on Monday, November 4, 2019. Millions of people in India's capital started the week choking through "eye-burning" smog, with schools closed, cars taken off the road and construction halted. (Jewel Samad/AFP via Getty Images)

“I have been driving ... on Delhi roads for the last three years and every year this time after Diwali, Delhi becomes like this,” Sachin Mathur, an auto-rickshaw driver in northwest Delhi, told the Guardian.

“I am suffering from a throat infection and my eyes are burning. The pollution means I do not get many passengers, so going to a doctor is not affordable.”