By the first week of November, New Delhi’s air quality index was 472, high enough to affect healthy people while having a serious impact on those with existing conditions. In some areas of the city, the reading exceeded 800, according to the Delhi Pollution Control Committee, a regulatory body. Experts say exposure to low air quality levels increases the risk of respiratory infections, heart disease and lung cancer. In response to the poor air quality, Delhi officials ordered the closure of primary schools and reduced outdoor activities for older students from Nov. 4 to 9. A government vehicle sprinkles water to control air pollution in New Delhi last month.

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