WEDNESDAY, Sept. 16, 2026 (HealthDay News) — Air pollution could be keeping you up at night, robbing you of sleep, a new study says.

Data gathered by the popular Sleep Cycle app shows that snooze-depriving coughs increase with levels of particle air pollution, even if pollution levels are under exposure limits, researchers reported recently in the journal Communications Health.

“This suggests that there may be no such thing as a safe threshold for exposure to air pollution, although our research is purely observational,” senior researcher Cecilia Mascolo said in a news release. She is a professor of mobile systems at the University of Cambridge in the U.K.

“However, people may wish to consider how they might mitigate their own exposure to air pollution, by using masks or air filters, for example,” she said.

The Sleep Cycle app collects and analyzes nighttime sounds like breathing, snoring or coughing to track sleep quality, researchers explained.

Particle pollution can penetrate deep into the lungs, causing irritation of the airways, researchers noted.

“Everyone coughs from time to time, but coughing, whether it’s a one-off or more persistent, is a sign of irritation or inflammation in the lungs,” lead researcher Tong Xia, an assistant professor at Tsinghua University in Beijing, said in a news release. “A cough could be a sign of something that hasn’t become chronic yet, but might in future.”

For the new study, researchers analyzed sound samples taken from 32 cities in 12 countries over about 500 days, and compared nighttime coughs to local air quality readings. Data from tens of thousands of users was included.

“The dataset from Sleep Cycle is really valuable, because the app is widely used worldwide,” Mascolo said. “Most public health studies only have data from one country, so having a dataset of this size gives it much more power.”

Results showed that when pollution levels rose by 10 micrograms of particulate matter per cubic meter, there was a 2.4% increase in nighttime coughing.

Healthy air quality standards in the United States call for an annual average of no more than 9 micrograms per cubic meter, according to the Environmental Protection Agency (EPA).

Even accounting for the annual flu season, a strong link remained between daytime pollution levels and nighttime cough frequency, researchers said.

“I was surprised we could still see the signal at all,” Tong said. “I thought that adding in the confounding factor of flu season would make the link in the data disappear, but it didn’t.”

More information

The U.S. Environmental Protection Agency has more on particle pollution.

SOURCE: University of Cambridge, news release, Sept. 15, 2026