More than one million deaths worldwide were attributable to the burning of fossil fuels in 2017, according to a new study. More than half of those deaths were attributable to coal.

Researchers from around the world comprehensively examined the sources and health effects of air pollution—not just on a global scale, but also individually for more than 200 countries.

Pollution is at once a global crisis and a devastatingly personal problem. Satellites analyze it, but PM2.5—tiny particles that can infiltrate a person’s lungs—can also sicken a person who cooks dinner nightly on a cookstove.

“PM2.5 is the world’s leading environmental risk factor for mortality. Our key objective is to understand its sources,” says Randall Martin, professor in the energy, environmental, and chemical engineering department in the McKelvey School of Engineering at Washington University in St. Louis.

Martin jointly led the study with Michael Brauer, a professor of public health at the University of British Columbia. They worked with specific datasets and tools from the Institute for Health Metrics and Evaluation at the University of Washington, the Joint Global Change Research Institute at the University of Maryland, and Pacific Northwest National Laboratory, as well as other researchers from universities and organizations across the world.

Read the full article about fossil fuel-related deaths in 2017 by Brandie Jefferson at Futurity.