Microplastic pollution is commonly associated with the ocean where it has been widely studied, but new research shows that these tiny particles can also be found in the air, even in the Yukon.
A team of researchers from Yukon University is monitoring the amount of microplastics deposited from the atmosphere into the air around Whitehorse over the past two years.
To do this, they constructed metal containers, similar to fly traps, and filled them with ultra-purified water. When tiny particles fall from the atmosphere and into the container, they are trapped in the water.
Microplastic collectors, meeting international dustfall collection standards, were placed at four locations around Whitehorse and exchanged monthly to obtain continuous data.
The researchers then filtered the water using a micrometer fiberglass filter. After visually counting the microplastics under a microscope, they were able to estimate the amount of microplastics deposited in different areas of the city.
This study makes Whitehorse one of the only cities in the world where atmospheric microplastic deposition is measured. The study is currently undergoing a peer review process.
Microplastics “in everything, basically”
John Postma, the study’s lead author and a professor of math, physics and statistics at Yukon University, said he decided to work on the study because very little research has been done on microplastic pollution. atmospheric.
“There has been a lot of media coverage and scientific publications about microplastic pollution in the oceans and in water supplies,” Postma said.
“But everywhere humans looked, we found microplastics. On top of mountains, on the bottom of the ocean, in our rivers, in our guts, in our cells, in everything, basically.”
According to Postma, airborne microplastics take many forms and come from many different sources, but discarded plastic waste is a key contributor. Since plastic biodegrades very slowly, it simply breaks down into smaller pieces that can be carried around by air currents.
Once in the atmosphere, microplastics can travel long distances. Microplastic fibers have been found in the most remote environments of the world.
Postma suspects that about a quarter to half of the microplastics his team captures are produced by the city of Whitehorse.
Janice Brahneya Canadian microplastics researcher not involved in the study, said cities produce a lot of microplastics, but these plastic particles don’t necessarily reach the atmosphere because buildings can block wind currents.
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Brahney also said the method used by Postma and his team shouldn’t be seen as a way to measure the amount of microplastics in the air. Rather, his method measures the deposition of these particles from the air.
“Whether a particle that’s in the air settles or not, has a lot of variables associated with it — particle size, density, wind conditions and things like that,” Brahney said.
She said deposition data is still very useful for studying the movement of different atmospheric components in the Earth’s environment.
How microplastics end up in the atmosphere
Brahney, an associate professor of watershed science at Utah State University, was originally another study who investigated sources of airborne plastic and how plastic entered the atmosphere.
Brahney used available information on the sources and amounts of microplastics, as well as samples the team collected from 11 remote wild sites, to understand how microplastics enter the atmosphere.
She and her team found three main ways this happened.
“In the terrestrial environment, we found that highways were the most important mechanisms,” she said.
“The friction of car tires on the road surface produces the energy needed to move dust through the atmosphere. There is a lot of dust and debris on the surface of a highway, including lots of tiny bits of microplastics.”
Another way microplastics end up in the atmosphere is through the movement of ocean waves. Microplastics floating on the surface of seawater can end up in the atmosphere when the waves bubble and bubble.
The third way microplastic particles ended up in the atmosphere was through agriculture. Agricultural soils tend to be high in microplastics as more farmers use plastic mulch and water containing plastics from sewage treatment plants.
Brahney said she was “really happy” to see the Yukon University study measure microplastic deposition in Whitehorse.
“We just need, as a research community, a lot more information.”
Postma and Brahney said the long-term health effects of breathing microplastics are unknown.
Postma hopes to expand the measurement of microplastic deposits to other Yukon communities.
“It is an inexpensive, low-maintenance microplastic collection system that can be used in remote areas,” he said.