Air pollution now kills more people than cigarettes, according to recent research published in the European Heart Journal.

A new study led by the Max Planck Institute for Chemistry suggests that air pollution is responsible for nearly 9 million premature deaths each year – almost double the number previously estimated.

Past studies have estimated the number of extra deaths globally to be 4.5 million, however, a new approach has shown that air pollution could be responsible for as many as 8.8 million extra deaths. In Europe alone, it’s believed around 790,000 people die prematurely due to poor air quality.

“To put this into perspective, this means that air pollution causes more extra deaths a year than tobacco smoking, which the World Health Organization estimates was responsible for an extra 7.2 million deaths in 2015,” study co-author Professor Thomas Münzel, from the Department of Cardiology at the University Medical Centre Mainz in Germany, said in a statement.

“Smoking is avoidable but air pollution is not.”

So, how come these new statistics vary so massively from previous estimates? The new method has taken a multi-faceted look at the issue by combining data on levels of air pollution in different countries, the health impacts of pollution, and numerous factors related to the studied populations, such as population density, age, and health care quality. 

Most pollution-related deaths in Europe, somewhere between 40 to 80 percent, were related to cardiovascular diseases, such as heart attacks and stroke. Air pollution can affect your heart and blood circulation in a number of ways, primarily by damaging the walls of your blood vessels and causing them to become narrower. It can disrupt the normal electrical functioning of your heart and make your blood more prone to clotting.

The new study mainly looked at the effects of PM2.5 particles, the researchers say. These are microscopic particles, smaller than 2.5 micrometers or 0.0025 of a millimeter, that can penetrate deep into the lungs and enter the circulatory system. Many dangerous PM2.5s are emitted during the combustion of fuels, such as vehicle exhausts, wood burning, industrialized agriculture, and the burning of fossil fuels. Based on these new findings, the team suggests the World Health Organization (WHO) should change its guidelines regarding safe PM2.5 levels.

"Since most of the particulate matter and other air pollutants in Europe come from the burning of fossil fuels, we need to switch to other sources for generating energy urgently," said Professor Jos Lelieveld, of the Max Planck Institute for Chemistry. "When we use clean, renewable energy, we are not just fulfilling the Paris Agreement to mitigate the effects of climate change, we could also reduce air pollution-related death rates in Europe by up to 55 percent."