Microplastics found in glacier ice

Tiny pieces of plastic are present even in the ice of "pristine" glaciers.....
11 May 2021

Interview with 

Ella Gilbert, University of Reading

PLASTIC-POLLUTION

A discarded plastic bottle on the seashore

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Since the 1950s, when it first entered the mainstream, the world has been hooked on plastic; and now we produce hundreds of millions of tonnes of the stuff each year. Whilst its resilience and stability make it attractive as a material, the fact that it’s so long-lived and does not readily break down, means it accumulates in the environment. And often it takes the form of tiny particles, called microplastics, which are formed when bigger pieces of plastic break apart. In recent years scientists have become increasingly alarmed about the build-up of these microplastics in the oceans where they can concentrate chemical toxins in animals’ bodies. Now a team from Iceland have found them in a new place we hadn’t expected: in glaciers. They’re literally coming down in the last shower and becoming embedded in the ice, where they can change its properties. Reading University climate scientist Ella Gilbert, who wasn’t involved in the study herself, took Chris Smith through the new findings…

Ella - These researchers were looking for the influence of microplastics, so teeny tiny particles of plastic, in ice, rather than in oceans, which we typically think about or in food chains.

Chris - Where were they looking?

Ella - So they looked in this very remote, pristine glacier in Iceland. And to do this, they were looking at snow samples that they collected in this glacier.

Chris - Why did they choose the location that they did?

Ella - Well, the idea of this is that it is extremely remote. So it's mostly untouched by human activity. It's not likely to have been contaminated by anyone traipsing up there or any tourism, anything like that. So it does give you a good indication of how environmental processes, in their sort of natural, pristine state, are influencing and transporting microplastics to this really remote region.

Chris - And when you say transporting microplastics, what did they actually measure then? What did they collect?

Ella - So they drilled down or collected kind of cores, so tubes of snow and ice from the surface, which give you an indication of what's been trapped in the snow and the rain that's fallen over the last several months. And they analyse this in the lab and they found lots of different microplastic particulates that indicates that those plastics came from somewhere.

Chris - Where from?

Ella - They don't know 100%, but they're pretty sure it's to do with atmospheric transport. The process that they suggest is that these plastics that have been broken down, for example, in the ocean or in river systems or something like this that, have been transported in the process of evaporation from the sea or the river, formed into clouds, transported to Iceland, and then they've fallen in the snow and rain. It shows you how connected every different element of our planet is. Whether that means that you can get plastics in the ocean breaking down and then ending up all the way almost at the poles is quite mind-boggling.

Chris - How much plastic did they find?

Ella - I can't actually tell you the numbers. They did find a considerable amount, and they are very small particles, but it just demonstrates the pervasive nature of these particles.

Chris - And presumably if it's landing as snow, that snow is destined to become part of the glacier because it will pack down and join the mass of ice that's there, which means these plastic particles are going to end up lodged in the ice.

Ella - Precisely. They will become inevitably part of the glacier, and eventually will end up back in the sea again as part of the kind of natural cycle of glaciers and ice sheets and ice shelves. What's interesting, and perhaps very worrying, is that the placement of these particles in the glacier can actually start to influence the glacier. And that's quite an interesting insight that I hadn't personally, before I read this study, actually considered.

Chris - In what way will they change the glacier?

Ella - Because pristine ice and snow behaves in a specific way, if you add something else, say it could be rock, it could be plastic in this case, it changes the way that the ice absorbs energy, absorbs radiation from the sun. And that influences how the ice melts. It influences how the ice behaves, how it moves. And this effect on the macro scale can actually have an influence on the melting of the glacier, for example. And now that's not completely clear from this paper, there's mostly a speculation, but if it did increase the amount of melting that occurred, then that could potentially contribute to sea level rise, which of course is a worrying consequence.

Chris - And what's the take home message do you think? I mean, to a person who's interested in how climate works and studies it professionally like you, what do you take away from this?

Ella - The main thing that I'm taking away from this is the demonstration of how connected our planet is. It shows you how something that ends up in the ocean, which could be hundreds of thousands of miles away, and then ends up all the way at the poles, accumulating in a glacier, it's not exactly what you imagine when you throw your non-reusable plastic bottle into landfill is it.

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