A host of other officials, including the chairman of the Central Pollution Control Board, were either unavailable for comment on Thursday

On Thursday in New Delhi, air pollution monitors measured levels of PM 2.5 — the small particles considered among the most dangerous for lung health — exceeding 350 micrograms per cubic meter of air. That was one of the highest levels recorded in Asia on Thursday, and twice as high as Beijing’s peak for the morning, according to a post on a Twitter account about Beijing pollution maintained by the United States Embassy there.

PM 2.5 refers to particulate matter less than 2.5 micrometers in diameter, which is believed to pose the greatest health risk because it penetrates deeply into lungs.

In Beijing, a pollution level as high as Delhi’s would most likely have caused widespread concern. But in Delhi, almost no one seemed to notice. Few people here wear the filter masks that have been appearing on the streets of Beijing, and even among the wealthy, few own air purifiers, which are used widely in East Asia, because few are even aware of the problem.

Frank Hammes, chief executive of IQAir, a Swiss-based maker of air filters, said his company’s sales were hundreds of times higher in China than in India.

“In China, people are extremely concerned about the air, especially around small children,” Mr. Hammes said. “Why there’s not the same concern in India is puzzling.”

In multiple interviews, Delhiites expressed a mixture of unawareness and despair about the city’s pollution levels. “I don’t think pollution is a major concern for Delhi,” said Akanksha Singh, a 20-year-old engineering student who lives on Delhi’s outskirts in Ghaziabad, adding that he felt that Delhi’s pollution problems were not nearly as bad as those of surrounding towns.