By Marie DeNoia Aronsohn
The ubiquitous nature of microplastics is stunning. These tiny bits of plastic — which can wash out of our clothing, facial exfoliants, and other products, or come from the breakdown of larger plastic items — are everywhere. They are in the oceans and rivers, fish and soil, and even in the atmosphere. And they are not going anywhere. Plastic never biodegrades — it just breaks down into tinier pieces of plastic. That means all of the plastic we’ve ever created on Earth still exists. Even if it’s been recycled, it’s still here.
New and developing research at Columbia University’s Lamont-Doherty Earth Observatory suggests microplastics are turning up even in the most remote and essentially untouched areas of the planet, coming to rest in places like Greenland and Antarctica, transported by snowfall. This discovery has sparked a line of inquiry and a new citizen science project called PlastiX-Snow. The project will start in New York state, but is expected to expand. It is an outgrowth of the X-Snow Project, which has recruited volunteers to study how climate may be affecting the distribution of snowfall, and the structures of individual snowflakes.
“We’d been doing microplastic research in the Hudson River. I wondered if there was any research on microplastics being disseminated by snow in different areas around the world,” explained Laurel Zaima, project collaborator and Lamont education program assistant. “Turns out there’s not much research on that. So, that was when we were thinking we could do a citizen science project where people from all over the country can collect snowfall, and then we can melt it and analyze it at the labs in Lamont to see how much plastic is in the snow.”
To test the concept, Lamont glaciologist Marco Tedesco, working with contacts in Aspen, Colorado, obtained two large mason jars of melted snow. Together with Joaquim Goes — a Lamont microbiologist with a specialized microscope — Tedesco and Zaima found the samples were indeed heavily contaminated with microscopic plastic particles.
“This tells us that even if you don’t have local pollution that’s impacting an area, it doesn’t mean pollution doesn’t exist there,” said Zaima. “These plastic fibers and fragments are so small they can be atmospherically transported to a new pristine area and then fall as snow, so that even areas untouched by humans can be polluted.”
However, there is much still to explore and understand about how much plastic is falling with the snow, and where and how the microplastics get into the snow. Tedesco noted that winds could be transporting the plastic particles and depositing them onto the snow in these remote places. He also theorized that the plastic particles could be so small that they act as nuclei for water molecules to wrap around, getting built-in to the snow before it falls. Thus, it is especially important that the scientists gather fresh snowfall that has not had periods of exposure to wind-driven microplastics or contaminants.
The PlastiX-Snow citizen science project requires a sophisticated process that involves teaching participants the methods to discover microplastics from snowfall in their local area. Citizen scientists will work with specially designed snow collectors, a filter syringe to isolate the microplastics, and a fluorescent light and filter to illuminate the microplastics under a USB microscope. Glass vials are provided to citizen scientists to send snowmelt samples to Lamont for intensive analysis involving the high-powered microscope. More details are available on the PlastiX-Snow website.
Tedesco and Zaima are also planning to expand their research to look for plastic in lake sediment cores, which hold a record of Earth’s past climate and weather, collaborating with Lamont’s Billy D’Andrea, an expert in this area. They want to dig deeper, to get the best possible idea of how pervasive plastic pollution is now and has been.