Air Pollution Is Killing Millions More People Than We Thought

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Scientists believe air pollution could be causing millions more deaths than previously estimated. Getty Images

Air pollution could be killing 8.8 million people worldwide each year—almost double the figure previously thought, that's according to the authors of a study, who said heir findings highlighted the "urgent and important" need to tackle the issue.

Deaths caused by air pollution appear to have overtaken those caused by smoking, according to a study published in the European Heart Journal. In 2015, air pollution was thought to be responsible for 8.79 million deaths, compared with the 7.2 million caused by tobacco smoking, the study—which focused on Europe—found.

An additional 790,000 deaths in Europe were likely caused by air pollution, with between 40 to 80 percent of those associated with cardiovascular disease, according to the study. Fine particulate matter could be shaving 2.2 years off the life of the average European, likely due to a combination of densely populated areas and poor air quality, the authors of the study warned.

Fine particulate matter, known as PM2.5, is the term used to describe tiny specs measuring 2.5 micrometers or smaller that can be breathed into the body. It can come from sources such as burned fossil fuels and biomass, as well as dust. A strand of human hair is around 30 times larger than the biggest piece of PM2.5.

Being exposed to excess levels of fine particle matter is thought to impact the blood vessels, and in turn raise the risk of conditions like heart attacks and failure, as well as stroke, the authors said. Air pollution is therefore an underappreciated threat to health, eclipsed in the public imagination by better-known factors such as smoking and poor diet, the authors argued.

Politicians and policymakers should move to replace fossil fuels with clean, renewable energy, which "could substantially reduce the loss of life expectancy from air pollution," the authors wrote. That includes committing to the promises laid out in the Paris Climate Agreement, which Donald Trump controversially withdrew the U.S. from in 2017.

Past research indicated air pollution caused 4.5 million deaths annually worldwide. To calculate the new estimate, the researchers used an updated technique for modeling data to investigate how outdoor sources of air pollution affect death rates in Europe.

Professor Jos Lelieveld of the Max-Plank Institute for Chemistry in Mainz and the Cyprus Institute Nicosia, who co-authored the study, told Newsweek: "New data have become available for both low and high concentrations of fine particulate matter (PM2.5), indicating that the hazardous health impacts of PM2.5 are much larger than assumed previously."

"We had not anticipated such a large increase," Lelieveld said.

However, he acknowledged the study was limited because was difficult to link particles in the air to specific sources, which are needed to understand how to reduce pollution.

Commenting on air pollution more generally, Lelieveld said: "Even though the limits for air pollution in the USA are stricter than in Europe, the health impacts are still significant, also at lower concentrations.

"We hope to show that it is urgent and important to further reduce fine particulate matter in ambient air. The main message is that PM2.5 air pollution is a health risk factor that is comparable to other main risks such as hypertension, diabetes and tobacco smoking," he said.

Francis Pope, a professor of atmospheric science at the University of Birmingham, U.K., who was also not involved in the research, also told Newsweek the findings had some limitations. "The study looks at modeled outdoor air pollution, but most of us live our lives indoors for much of the day," he said.

"Some estimates suggest we spend less than 10 percent of our time outdoors. Hence, we need to know much more about our indoor exposure to air pollution to be able to completely model the burden of air quality upon human health."

Audrey de Nazelle, from the Center for Environment Policy at Imperial College London who did not work on the research, told Newsweek: "We know this is undeniably a major problem that needs to be tackled urgently, and this paper is just one more proof of that.

"Hopefully, the clear message of air pollution surpassing tobacco smoking as a killer will help mobilize citizens and politicians to change the vision of cities so that streets become places where people can easily, safely and comfortably walk, cycle, take public transport and interact with each other, and where children can play."

Pope said those who are concerned about their exposure to air pollution can change their densely.

"In urban areas, air pollution varies both through time and space. For example, traffic rush hours, with associated pollution, are at well-defined times in most cities. By changing our behavior, we can try to minimize our exposure to air pollution by avoiding areas and times with high air pollutant concentrations," he said.

"Even better would be for policymakers to make roads a lower source of pollution in the first place by encouraging lower and non-polluting forms of transport."