Diseases caused by pollution killed more than 9 million people in 2015, 16 percent of all deaths worldwide. That’s three times more deaths than from AIDS, malaria, and tuberculosis combined, and 15 times more than from wars and other violence.

If those figures surprise you, it might be because your first thought is that pollution means dirty air. Or you may think of contaminated water. In reality, pollution is both those things and much more, and only now is the first global effort to assess all forms of it finally calculating those sobering numbers.

Between productivity losses and health care, pollution costs some $5 trillion a year, more than 6 percent of global economic output. That’s just from tallying what’s known. The vast majority of the more than 140,000 chemicals and pesticides that have entered the environment since 1950 remain largely untested, but could pose a threat. Pollution, as epidemiologists understand it today, is any substance in the air, water, or soil that can harm human health.