Rising levels of air pollution all over the world increase the chance of people dying early, a sweeping new study shows. In Australia, which historically has low air pollution, an increase in soot air has led to a sharp increase in the number of deaths.
More air pollution means more deaths, even at low levels of air pollution and short exposures to it, according to the study, which measured particles and daily deaths in 652 cities in 24 countries over 30 years. It is the largest international study on the short-term effects of air pollution on death conducted to date and published in The New England Journal of Medicine.
Much research already exists on how this type of pollution makes people sick. Inhale particles from dust, ash and the burning of fossil fuels and can damage the heart and lungs. It has been linked to chronic lung and heart problems, as well as premature death. Today's study highlights that even low levels of particles can be dangerous.
The results are particularly resonant now, as the Amazon rainforest burns at some of the fastest speeds ever recorded in the country
Today's study showed that death rates rose sharply as air pollution did – a daunting result, especially in Brazil, which only ranked second to Australia in increased mortality. In Brazil, the Amazon rainforest is currently burning at some of the fastest speeds ever recorded in the country. And these forest fires generate particles. Smoke from the fires was so heavy that it darkened the sky in the city of São Paulo. Brazilian President Jair Bolsonaro has promised to open the Amazon to agribusiness and mining interests, making it vulnerable to people who cut and burn to clear land.
To determine the deaths were actually early, researchers compared daily mortality levels during the study period. Compared to daily death rates in the beginning, deaths increased on days when air pollution increased.
If you look at the percentages, the increases seem small. For all causes of death, mortality across the board increased 0.44 percent when the amount of coarse particulate matter increased slightly. For fine-grained particles, which are smaller and can enter the deep lungs upon inhalation, mortality increased by 68 percent as concentrations increased. But less than 1 percent of the global population is still millions of people.
"If we look at a population of one million people in a city, well over 1 percent is significant and it can affect many people," says Eric Lavigne, co-author of the study The Verge . Lavigne is a professor at the University of Ottawa and a senior epidemiologist for Canada's Public Health Agency.
Some countries in the analysis, such as the United States, have already taken measures to keep air pollution in check; nevertheless, they saw higher levels of death as pollution increased. This means that there is still plenty of room for improvement. "We can still have consequences for public health by becoming cleaner than we already are," said John Balmes, spokesman for the American Lung Association, who teaches at the University of California at San Francisco and Berkeley.
Balmes adds, "A relatively small risk affecting the entire population can be as important in public health as a stronger risk factor not everyone experiences [like smoking]."