Exposure to polluted air, water and soil caused nine million premature deaths in 2015, according to a report published Thursday in The Lancet.

The causes of death vary — cancer, lung disease, heart disease. The report links them to pollution, drawing upon previous studies that show how pollution is tied to a wider range of diseases than previously thought.

Those studies observed populations exposed to pollutants and compared them to people not exposed. The studies have shown that pollution can be an important cause of diseases — many of them potentially fatal — including asthma, cancer, neurodevelopmental disorders, birth defects in children, heart disease, stroke and lung disease.

The nine million figure adds up to 16 percent of all deaths worldwide, killing three times more people than AIDS, tuberculosis and malaria combined. Pollution is responsible for 15 times more deaths than wars and all other forms of violence.

“No country is unaffected,” the report notes. But 92 percent of those deaths occurred in low- and middle-income countries.

“Pollution in rapidly developing countries is just getting worse and worse and worse. And it isn’t getting the attention it deserves. It needed to be rigorously studied,” says Dr. Philip Landrigan, pediatrician and professor of environmental medicine and global health at the Icahn School of Medicine at Mount Sinai. He is the lead author of the Lancet Commission on Pollution and Health along with Richard Fuller, president of Pure Earth, which works to clean up pollution in poor countries.

We talked with Landrigan about the commission’s findings.

Why do this study now?

The issue has come of age. Richard Fuller and I have worked in environmental health for a long time. Richard works with USAID and counterparts to clean up hazardous waste. I’m a pediatrician studying effects of pollution on health. We have deep roots in this area. We wanted to rigorously study the problem and marshal the evidence. We brought in these authors with a range of expertise to work on a report to try to translate science into policy. We wanted to look at disease, but also the intersection of pollution with economics and social injustice.