Physicists at the University of California, Berkeley, calculated that about 1.6 million people in China die each year from heart, lung and stroke problems because of incredibly polluted air, especially small particles of haze.
Earlier studies put the annual Chinese air pollution death toll at 1 to 2 million, but this is the first to use newly released Chinese air monitoring figures.
Study lead author Robert Rohde said that 38 percent of the Chinese population has a long-term air quality average that the U.S. Environmental Protection Agency calls "unhealthy." He said coal is the chief polluter.
The study was released Thursday.