A new estimate suggests that land-based sources release 600 quadrillion microplastics into the atmosphere each year.
By KR Callaway edited by Claire Cameron
Microplastics travel by air and sea and appear even in remote areas.
Ben Stansall/Getty Images
Join our community of science lovers!
Microplastics are omnipresent, found everywhere on Earthfrom the Sahara Desert to patches of Arctic sea ice. Yet despite the ubiquity of these plastic particles, scientists have struggled to determine exactly how much there is in our atmosphere.
Now a new estimate published in Nature suggests that terrestrial sources releasing approximately 600 quadrillion (600,000,000,000,000,000) microplastic particles into the atmosphere each year, around 20 times more than the number of particles brought by the oceans (around 26 quadrillion).
The median concentration of microplastics is 0.08 particles per cubic meter (m3) on earth and 0.003 particles per m3 above the sea, according to the study.
On supporting science journalism
If you enjoy this article, please consider supporting our award-winning journalism by subscribe. By purchasing a subscription, you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
These estimates are between 100 and 10,000 times lower than previous accountings of atmospheric microplastics – a gap that, according to the researchers behind the new study, highlights the need for better overall measurements of these pollutants.
“We knew that the uncertainties in existing emissions estimates were very large,” says Andreas Stohl, lead author of the study and an atmospheric scientist at the University of Vienna. “They’re even still large after our study, but we could at least reduce the range of uncertainty, particularly in the importance of land versus ocean emissions.”
A microplastic is a plastic particle whose size is between one micron and five millimeters. Easily swept by wind and carried long distances by water, these tiny particles are also extremely difficult to detect and almost impossible to remove from the environment.
Previous estimates have focused on accounting for microplastics generated by human activity or directly measuring their concentration in the air in a given area. But these measurements vary widely: along the southeast coast of China, for example, atmospheric microplastics estimates varied from 0.004 to 190 particles per m3. To try to get a more global estimate, Stohl and his team compiled 2,782 measurements collected at 283 sites around the world.
The researchers hope the findings will serve as a basis for future studies of global microplastic levels, including new measurements that can account for even smaller particles than they did.
It’s time to defend science
If you enjoyed this article, I would like to ask for your support. Scientific American has been defending science and industry for 180 years, and we are currently experiencing perhaps the most critical moment in these two centuries of history.
I was a Scientific American subscriber since the age of 12, and it helped shape the way I see the world. SciAm always educates and delights me, and inspires a sense of respect for our vast and magnificent universe. I hope this is the case for you too.
If you subscribe to Scientific Americanyou help ensure our coverage centers on meaningful research and discoveries; that we have the resources to account for decisions that threaten laboratories across the United States; and that we support budding and working scientists at a time when the value of science itself too often goes unrecognized.
In exchange, you receive essential information, captivating podcastsbrilliant infographics, newsletters not to be missedunmissable videos, stimulating gamesand the best writings and reports from the scientific world. You can even give someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you will support us in this mission.
