27 Feb ’25

PolarQuest scientist participates in Plastic Treaty to end global plastic pollution

Stefano Aliani, Senior Scientist at the Institute of Marine Science (ISMAR) of Lerici, Italy, and PolarQuest scientist, was involved in the activities of the 2024’s Plastic Treaty convention in Busan, where scientists, policymakers and politicians met to establish the strategy to combat global plastic pollution. He describes some of the current challenges related to microplastics research, debunks some environmental myths and highlights how PolarQuest’s past and future missions have significantly contributed — and will continue to contribute — to advancing our knowledge on plastic debris in the Arctic and Atlantic oceans.

Plastics is a wicked problem: innumerable complex independent factors come into play. There is no one single best solution.”

In November 2024, you participated in the 2024 Plastic Treaty. Since when are you a member of it?

Already in 2022, the United Nations Environment Assembly called for an international treaty to find solutions to limit plastic pollution to the minimum. I have since the beginning been involved in bringing my scientific expertise on plastic pollution through the International Science Council, a scientific NGO.  

What was the outcome of the 2024 Plastic Treaty?

Many solutions were discussed. The UN’s plan to eliminate single use plastic production by 2050 is ambitious, but we are determined to go towards this direction. Countries with contrasting interests come together to find common solutions, and this is challenging like any other diplomatic exercise.  As a scientist, my role was to analyse different scenarios, and present the consequences that we would have to face if we chose one path rather than the other. 

So you present policy makers with predictive models. What is the most promising one?

Plastics is a wicked problem: innumerable complex independent factors come into play. There is no single best solution. A mixture of different initiatives depending on the geopolitical scenario is probably the most efficient way to solve the plastic problem. Anyways, limiting the plastic production at its source, as opposed to recycling it, is a better and more radical solution. At the same time, it pressures industries to seek plastic alternatives, whose production requires significant energy and releases greenhouse gases that accelerate climate change. The problem is infinite, but we need to act quickly. This is why the Plastic Treaty will meet again in 2025 to continue negotiations.  

We look forward to seeing what practical regulations come out of it. You are also a member of the PAME and AMAP working groups of the Arctic Council, both dedicated to ecological problems of the Arctic. What kind of work do you do with them?

The Arctic serves as a striking example of dynamic interaction between science and policy. Decision-making in the region is highly effective in identifying, communicating, and addressing challenges, with policies on waste management and energy use guided by scientific data. In 2018, PolarQuest was among the first expeditions to provide the Arctic Council with valuable data on the Arctic. Today, numerous initiatives contribute to this effort, yet it remains a privilege to have been among the pioneers of this collaboration.

Why is the Arctic a good place to study climate change?

The Arctic is changing more rapidly and dramatically than any other region on Earth. Continuous monitoring is essential to ensure we respect planetary boundaries. Among these boundaries, alongside climate change, is pollution. Exploring these remote landscapes is crucial, as satellites cannot always reach them. It is well established that plastic debris tends to accumulate in zones of oceanic convergence and divergence. Of particular interest is the area where glaciers melt, creating a temperature gradient between ice and water. This could be a hotspot for microplastic accumulation, warranting further study. Beyond our previously published book chapter [1], I am still analyzing data collected during the PolarQuest’s 2018 expedition to identify Arctic pollution trends.

“The Arctic serves as a striking example of dynamic interaction between science and policy.”

On this note, let’s talk about your involvement in PolarQuest expeditions. 

I met Paola Catapano around 20 years ago on a boat during an expedition in the Antarctic. I then met her again in 2015, and she told me about her future plans to sail the Arctic. I had already worked a lot on data taken on boats, so I was able to advise her on the scientific methodology to follow in order to study microplastics. 

What was the objective of the microplastics research?

The research plan was carried out with a level of knowledge from 10 years ago, focusing on the hot topics of the time, which were centred around the presence of plastic and microplastic in the environment. We basically wanted to determine whether plastic was present in the Arctic – because we didn’t know. Nobody had ever collected samples north of the northern coast of Svalbard.  Some hypotheses and numerical models existed, but real data was lacking. PolarQuest was an opportunity to explore these areas and investigate plastic presence at latitudes where no one had ever been before. 

Why was there no data on the Arctic regions until 2018?

To study the presence of plastic in water either you need to take samples, or use satellites and drones to sample larger areas. The samples can be macroplastic pieces, or microplastics traces, detected with a 300-micron mesh size plankton net or through vacuum filtration techniques. No scientists had ever collected such samples at those latitudes before, due to the remote and harsh environments. 

What did you find during the PolarQuest 2018 expedition?

We found a lot of plastic at the northermost latitude ever researched, 82° 07’ N. Macroplastics, and microplastics.

What are the characteristics that differentiate all the kinds of plastics?

Plastics are synthetic polymers derived from petroleum or natural gas, consisting of long-chain molecules made up of hundreds to thousands of repeating units known as monomers. In water samples, approximately 200 different polymers are typically found, though there are likely more types, as industries do not always disclose the technical specifications of the plastics they produce. Plastic becomes microplastics at a size of 5 mm. Anything below 20 microns is instead classified as nanoplastics. For reference, a red blood cell is about 7.5 microns in diameter. That means nanoplastics can be as small as two or three red blood cells lined up side by side. Given that red blood cells are among the smallest components of human blood, nanoplastics are extremely dangerous as they can easily enter the body and lodge themselves between red blood cells, macrophages, and other immune system cells. At sizes below one micron, nanoplastics can cross cell membranes and physically damage the cell, or trigger cellular mechanisms that we still understand very little about. Moreover, these polymer particles can carry pollutants on their surface, effectively acting as vectors for contamination. Recent studies have detected microplastics—and even nanoplastics—not only in drinking water but also in beer, blood, placentas, and breast milk [2]. Essentially, they are everywhere. Nanoplastics have become a fundamental part of our environment, to the extent that no matter where you analyze a sample, you will likely find synthetic polymers.

“We found a lot of plastic at the northermost latitude ever researched, 82° 07’ N. Macroplastics, and microplastics.”

How fast does macroplastic become microplastic? When a plastic bag is dispersed into the environment, for example, does it stay intact for millennia?

The life of a plastic bag in an open environment is much shorter than what we used to believe in the past. And this is not for the best. Ultraviolet radiation, temperature fluctuations, and mechanical abrasion (such as waves grinding plastic against sand and rocks) break it down into microplastics relatively quickly depending on where it ends up. Moreover, certain animals, such as birds, unintentionally contribute to the production of microplastics by ingesting plastic debris. So in the end, while the bag may disappear, the plastic polymers themselves remain in the environment indefinitely.

In the 80s the global plastic production was around 60 million metric tons per year. Today it is around 500 million [3]. If it keeps growing at a steady rate until mid-century it will hit around 700 million metric tons per year. Is it true that there will be more plastic in the waters than fish [4]?

The figures on plastic growth are right, keeping in mind that this increase is driven by population growth and by changes in consumption patterns. The environmental impact of a single person in 2020 is far greater than that of someone in 1980, simply because plastic is now used in almost every aspect of modern life. The claim about fish should be interpreted with caution. More importantly, a study published in Nature [5] found that the total mass of human-made materials—plastics, concrete, metal, and other synthetic products—has now surpassed the total biomass of all living organisms on Earth. This means that artificial matter has outpaced natural matter. And this is the proven, tragic fact, more than the plastic to fish ratio. 

“…the total mass of human-made materials—plastics, concrete, metal, and other synthetic products—has now surpassed the total biomass of all living organisms on Earth. This means that artificial matter has outpaced natural matter.”

 

Are there more ‘plastic facts’ that should be taken with a grain of salt?

Another widely circulated misconception is the idea of the ‘Great Pacific Garbage Patch‘ as a solid island of plastic debris. In reality, it’s not a walkable landmass but rather a massive accumulation of plastic particles dispersed throughout the ocean.

Talking about Ocean Garbage Patches. What are your future plans with PolarQuest?

In the central regions of each of the world’s major oceans, massive vortices form due to the planet’s shape and variations in rotational velocity. Already in the 90s captain Charles Moore, while traveling from California to Hawaii, noticed an accumulation of plastics on the ocean surface. This took the name of ‘Pacific Garbage Patch’. Since him, many others have studied it, namely the Algalita Marine Research Foundation is very active in the field. On the contrary, we have really scarce data on the Atlantic, and since PolarQuest’s next mission will be sailing on the Atlantic coasts, and eventually crossing the Atlantic, I would like to collect some data on the Atlantic Garbage Patch: which polymers constitute it, what is the plastics’ size, age, origin and persistence in the marine environment. Another mystery is that there is an imbalance between the amount of plastic that is produced on a global scale and the amount of plastic waste that is found in the environment every year. This imbalance accounts to around two orders of magnitude, a figure that cannot be ignored. Pacific studies have discovered that, over time, plastic sinks. When it sinks, it is hidden under water. 

A sort of plastic dark matter…

Yes, and the research in this field is at its infancy; the European Space Agency (ESA), for instance, is expected to develop specialized sensors to put on satellites for plastic detection, but such technology is still beyond the current state of the art. One promising avenue of research involves small surface (capillary waves or windrows) —small surface ripples that behave differently in the presence of floating objects. By analyzing these wave modifications, researchers could theoretically infer the presence of marine plastics. However, field verification remains essential, requiring direct exploration of these remote oceanic regions. I look forward to collaborating with PolarQuest on disclosing some oceanic secrets. 

[1] Aliani, S., Casagrande, G., Catapano, P., & Catapano, V. (2020). Polarquest 2018 Expedition: Plastic Debris at 82°07’ North. In M. P. Collares-Pereira, M. C. Cunha, & R. Freitas (Eds.), Mare Plasticum – The Plastic Sea (pp. 89–116). Springer International Publishing. https://doi.org/10.1007/978-3-030-38945-1_5 

[2] Landrigan, P. J. et al. The Minderoo-Monaco Commission on Plastics and Human Health. Annals of Global Health, 89(1), 23. https://doi.org/10.5334/aogh.4056 

[3] Villarrubia-Gómez, P. (2023, November 10). The bumpy road towards a global plastics treaty. Stockholm Resilience Centre. https://www.stockholmresilience.org/research/research-news/2023-11-10-the-bumpy-road-towards-a-global-plastics-treaty.html

[4] Padilla-Vasquez, D. (2024, May 1). Protect Our Planet from Plastic Pollution: 5 Things to Know. United Nations Foundation. https://unfoundation.org/blog/post/protect-our-planet-from-plastic-pollution-5-things-to-know/

[5] Elhacham, E., Ben-Uri, L., Grozovski, J., Bar-On, Y. M., & Milo, R. (2020). Global human-made mass exceeds all living biomass. Nature, 588(7838), 442–444. https://doi.org/10.1038/s41586-020-3010-5 

Interview by Elena Gazzarrini.

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