The study estimated that 2.1 million deaths each year are linked with fine particulate matter, tiny particles that can get deep into the lungs and cause health problems.
Exposure to particle pollution has been linked with early death from heart and lung diseases, including lung cancer, the researchers said; meanwhile, concentrations of particulate matter have been increasing due to human activities. The study also found that 470,000 deaths yearly are linked with human sources of ozone, which forms when pollutants from sources such as cars or factories come together and react. Exposure to ozone has been linked to death from respiratory diseases.
Most of the estimated global deaths likely occur in East and South Asia, which have large populations and severe air pollution, said study researcher Jason West, an assistant professor of environmental sciences at the University of North Carolina at Chapel Hill.
“Air pollution is an important problem. It’s probably one of the most important environmental risk factors for health,” West said. The study suggests that improving air quality around the world would increase life expectancy for some, he said.
While some studies have suggested that climate change can make air pollution more deadly, the new study found that climate change had only a small effect on air pollution-related deaths.
Pollution and climate interact in several ways. Climate-related factors such as temperature and humidity can affect the reaction rates of particles in the air, which in turn determine the formation of pollutants; additionally, rainfall can affect accumulation of pollutants, the researchers said.
However, in the researchers’ analysis, changes in climate were linked with just 1,500 yearly deaths from ozone pollution, and 2,200 yearly deaths from fine particulate matter.
In some areas, such as Beijing, breathing in the poor quality air can be as damaging as smoking two packs of cigarettes a day, even more so for children. The number of respiratory diseases worldwide has skyrocketed and more and more children are forced to live with asthma, many cases of which are severe.