Air pollution spiked after the Trump administration stopped embassy monitoring

Smog mixed with a thick layer of clouds covers the Metro Manila skyline in the Philippines, on August 27, 2026. Photo by Melvin James Urubio/NurPhoto/via Getty Images hide caption

Growing up in Shanghai in the early 1990s, Eric Zou remembers the air.

"I lived a couple of miles next to a chemical plant and it was just really bad, really foggy," he says. "It's the middle of the day, but you can't see the sun."

Intensive industrial activity blanketed many cities in China during the 1990s and 2000s with extremely hazardous air . But Zou, now an environmental economist at the University of Michigan, says that many people didn't really understand this smog as air pollution, or something that could harm them.

"When you have a big smog event, people often talk about that as fog, they think it was just like bad weather," says Zou. One big key to changing that sentiment, he says, was information initially provided by the United States.

In 2008, U.S. officials installed an air quality monitor on the embassy in Beijing and began making the information public. Over time, that helped spur demand for cleaner air, says Zou. "Once you have pollution information, it tends to be that it actually helps people to realize, 'Oh I actually value air quality.' "

Since 2008, the State Department's monitoring initiative expanded to more than 80 embassies and consulates. Research suggests that monitoring contributed to measurable improvements in air quality, especially across many low- and middle-income countries with limited monitoring systems of their own.

But in March 2025, the Trump administration shuttered that program, citing monetary costs. Research out this week suggests the move had health costs for the people living in those countries. Over the several months following the shut-down, air pollution levels measured via satellite increased by 24 - 33%, researchers reported Monday in the journal PNAS .