MONDAY, Aug. 14, 2017 (HealthDay News) -- High levels of air pollution can harm heart health, but air purifiers may protect against the threat, according to a small study from China.
The study included 55 healthy college students who used real or fake air purifiers in their dormitory rooms. Researchers measured the students' indoor and outdoor exposure to fine particulate matter (PM2.5), a component of air pollution emitted from vehicles, factories, power plants, fires and smoking.
Exposure to high PM2.5 levels increased students' stress hormones and triggered metabolic changes that may increase heart disease risk, the researchers said.
Using air purifiers reduced indoor levels of PM2.5 by an average 82 percent and led to short-term declines in stress hormone levels. After 24 hours of air purifier use, PM2.5 levels were within the World Health Organization's safe range, the study found.
The findings were published Aug. 14 in the journal Circulation.
"Although we found significant health benefits with air purifiers, the actual health protection people could get from air purifiers in real living conditions is still not well-determined," study author Dr. Haidong Kan said in a journal news release. Kan is a professor of environmental health sciences at Fudan University in Shanghai.
He noted that this was a small study, and it's not clear whether the results would apply to other countries, because pollution levels in China are much higher than in places such as the United States or Europe.
"Future studies should examine whether the health benefits from short-term air purification can improve long-term health, and whether these findings are also found in people who live in low pollution areas," Kan said.
The American Lung Association has more on air pollution.