Hundreds Hospitalized in Pakistan’s Largest Province as Pollution Worsens

The authorities in Pakistan’s largest province told half the work force to stay at home and extended school closures for another week as record-breaking smog choked the region and strained hospitals.

“This is a critical situation,” Marriyum Aurangzeb, a senior minister in Punjab Province, which includes Lahore, said at a news conference on Wednesday. New measures aimed at fighting the heavy smog will affect more than 70 million people in four divisions of the province.

Lahore, home to 13 million people and the country’s second-largest city, recorded an Air Quality Index of over 1,000 on Sunday morning, according to IQAir, a Swiss air quality technology company. Anything above 301 on the index is considered a hazardous situation that can cause severe eye and throat irritation and serious heart and lung conditions. The U.S. Environmental Protection Agency considers anything beyond 500 as off the charts.

Sunday was the first time the index for Lahore exceeded 1,000, prompting the authorities to close all primary schools for a week. On Wednesday, the city recorded a reading of 1,165.

Lahore regularly tops the list of the world’s most polluted cities, according to IQAir, which last year ranked Pakistan among the four countries with the worst air pollution on earth. The World Bank has said that air pollution shortens the average life expectancy of Pakistanis by 4.3 years and leads to economic losses equivalent to about 6.5 percent of the economy.

On Tuesday, more than 900 people were admitted to hospitals with respiratory problems, Ms. Aurangzeb said, adding, “If you don’t want to become one of them, for God’s sake, stay at home.”

Additional measures announced on Wednesday included advising residents to wear face masks in