Responsible for more premature deaths than terrorism, war, smoking, disease and natural disasters, a new study is declaring that pollution is the number one killer in the world.

Publishing their findings in the medical journal The Lancet, researchers analyzed pollution levels both indoors and out, and determined that roughly 9 million people were killed by pollution in 2015 alone — an estimated one out of six deaths worldwide.

One of the authors of the report, Karti Sandilya, explained, “Pollution threatens fundamental human rights, such as the right to life, health, well-being, safe work as well as protections of children and the most vulnerable.”

With a significant majority of the deaths occurring in developing countries, researchers are concerned that those countries aren’t more concerned and are instead prioritizing the buildup of their economies and public services than improving environmental controls.

“There is this myth that finance ministers still live by, that you have to let industry pollute or else you won’t develop," said Richard Fuller, another author of the report. "What people don’t realize...people who are sick or dead cannot contribute to the economy. They need to be looked after.”

The report also warns that the 9 million premature deaths a year figure is a conservative one and an accurate number is likely to be much higher.

Additionally, other studies have suggested that solving the issue of pollution will likely create possible solutions for other worldwide problems such as malnutrition and the rising temperature on the Earth’s surface.