Emergency Declared as Smog Chokes Parts of India and Pakistan

The authorities in New Delhi closed schools and urged people to stay indoors as toxic smog, which has plagued neighboring Pakistan for weeks, choked India’s capital in what officials called a medical emergency.New Delhi and the surrounding metropolitan area, home to about 55 million people, had the world’s worst air pollution on Monday, according to IQAir, a Swiss company that measures air quality.The reading on its index rose to over 1,600.Anything above 301 on that index is considered hazardous, potentially leading to severe eye and throat irritation and serious heart and lung conditions.

The U.S.Environmental Protection Agency essentially considers anything beyond 500 to be off the charts.“All of North India has been plunged into a medical emergency,” Atishi Marlena, the chief minister of Delhi, said on Monday, adding that many cities were “reeling under severe levels of pollution.”The same pollution has enveloped parts of Pakistan, where the authorities have banned most outdoor events, canceled most classes and told some workers to stay home.Parts of northern India and Pakistan experience severe air pollution each year in the late fall, as farmers burn straw left over from their rice harvests to make room for new planting.

But even for a region with cities that regularly top the list of the world’s most polluted, the air quality readings this year have been dire.For weeks, Punjab, the largest province of Pakistan, has experienced some of the worst air pollution on record, surpassing 1,000 on IQAir’s index for the first time earlier this month.Punjab, which borders India, began closing some schools two weeks ago.It enacted more measures in the following days and asked workers to stay at home last week.

It has also banned outdoor events and most construction activity, and it has closed parks, playgrounds and monuments.The authorities there declared a health emergency on Friday, warning of an “unprecedented rise” in the number of patients wit...