Air pollution is killing on average 4,000 people in China a day, according to a new study published Thursday. It is the first such piece of research to draw from newly released official air quality figures from the country.

The study, published in the online peer-reviewed journal PLOS One from the Public Library of Science, was carried out by physicists at the University of California, Berkeley, and found that around 1.6 million people in China die each year from heart, lung and stroke problems caused by air pollution. Tiny particles, known as PM2.5s, associated with the burning of coal, were the main pollutants.

The study's lead author, Robert Rohde, told the Associated Press that 38 percent of the Chinese population lives in an area with a long-term air quality average that the U.S. Environmental Protection Agency calls "unhealthy."

"It's a very big number," Rohde said, adding, “nearly everyone in China experiences air that is worse for particulates than the worst air in the U.S."

China pollution People do morning exercises on a polluted day in Jiaozuo, Henan Province, March 16, 2015. Photo: Reuters/China Daily

China gets about 64 percent of its primary energy from coal, according to National Energy Administration data, cited by Bloomberg. In recent years, Chinese authorities have, amid increasing public pressure, acted to curb pollution by adopting air quality standards, installing pollution monitoring stations and making plans to shutter some of its most polluting coal power plants, replacing them with cleaner ones.

“This is a concern that is uppermost on all people’s minds,” Premier Li Keqiang said, at an annual meeting at the National People’s Congress in March when asked about environmental reforms, the New York Times reported. “But the progress we have made still falls short of the expectation of the people. … We’re determined to carry forward our efforts until we achieve our goal.”

The new study comes amid increasing concern about the impact of air pollution from China in the U.S. A study, published this week in the journal Nature Geoscience, found that ozone has been making its way from China to the western U.S. The pollutant's presence was so extensive that it had offset about 43 percent of the region's efforts to reduce ozone emissions, the study found.