LAHORE, Pakistan — For nearly two weeks, Lahore, Pakistan’s second-largest city, has been like one huge airport smokers’ lounge. But Abid Omar’s jaw still dropped on Wednesday, when he checked the air-quality monitor he had installed to track the city’s appalling pollution.

It said that levels of the dangerous particulates known as PM2.5, small enough to penetrate deep into the lungs and enter the bloodstream, had reached 1,077 micrograms per cubic meter — more than 30 times what Pakistan’s government considers the safe limit.

“You can see and smell the smoke all day; you can actually touch the filth,” said Amna Manan, a 26-year-old manager for a multinational company in Lahore, a city of 11 million. “Half the time, I’m scared to breathe in.”

While Delhi’s air quality has generated headlines worldwide in recent days, experts say the air in Lahore rivals the Indian capital’s for toxicity. The problem is not limited to the city; in 2015, according to a World Health Organization estimate, almost 60,000 Pakistanis died from the high level of fine particles in the air, one of the world’s highest death tolls from air pollution.