The pollution of seas, air and floors by microplastics has already been researched. It is far less known how much of the even smaller nanoplasty in the environment is present. Now a first systematic sampling in the North Atlantic shows that it even makes up the lion’s content of the marine plastic pollution less than a micrometer small plastic particles. The researchers determined nanoplastic concentrations of 5.5 milligrams per cubic meter in deep water to 25 milligrams per cubic meter in the coastal surface water. Overall, they appreciate the total amount of nanoplasty in the North Atlantic at 27 million tons- that is more than previously assumed for the entire micro and macroplasty of the Atlantic. The nanoplastic problem could therefore be much larger than before.
Plastic particles below a diameter of a micrometer are nanoplasty. These particles are so small that they penetrate cells and can accumulate in tissues. In addition, nanoplasty is also more chemically reactive than the microplastics up to a few millimeters. It is therefore considered potentially particularly harmful to health and environmentally harmful. In addition, nanoplasty is easily distributed with the wind and can accompany the dust and organic particles of all kinds. But how great the pollution of the environment is through nanoplasty is largely unknown. “This knowledge gap exists because it is very difficult to identify and analyze nanoplasty in environmental samples,” explain Sophie Ten Hietbrink from the University of Utrecht and her colleagues. With common analysis methods, it was almost impossible to distinguish the tiny particles from natural particles and to determine their composition and quantity.
Sample analyzes once across the North Atlantic
So far, this has also been unknown whether and how much nanoplasty was swimming in the oceans- earlier surveys only recorded micro and macroplasty. That has now changed. Ten Hietbrink and her team used a new method to track down and measure nanoplasty in sea water samples. To do this, first filter all particles larger than one micrometer from the samples. “By drying and heating the remaining material, we were able to measure the characteristic molecules of different types of plastic in the laboratory in Utrecht using the mass spectrometry,” explains Ten Hietbrink. Specifically, the team used a combination of proton transfer reaction mass spectrometry (PTR-MS) with thermal desorption (TD). “Since each polymer creates its own chemical fingerprint, identity and concentration can be determined very well,” explains co-ortor Dušan Materić from the Helmholtz Center for Environmental Research in Leipzig.
For their rehearsal, the researchers drove with the Dutch research ship Pelagia across the North Atlantic – from the coastal European mainland pelf to the open Atlantic to subtropical North Atlantic vertebrae, a flow system of the North Atlantic. They took water samples from different sea depths from the surface water at twelve places up to ten meters deep to the deep water around 30 meters above the sea floor. “With the data of these measuring points, we can make statements about the vertical and horizontal distribution of nanoplasty in the North Atlantic,” says Materić.
Nanoplasty everywhere
The analyzes showed nanoplasty in sea water in all twelve measuring points of the North Atlantic. The nanoplastic concentration in surface water and in the coastal areas on the European continental Schelf was particularly high. “This is because nanoplasty comes from the atmosphere on the surface of the sea and on the other hand, that a lot of plastic is entered over the estimation areas of rivers,” explains Materić. With an average of 25 milligrams per cubic meter of sea water, the coastal sea water contained around 1.7 times as much nanoplasty as the water in the north atlant’s coast. Another focus of the contamination lies in the subtropical flow vertebrae of the North Atlantic- a sea area in which there is also a lot of micro and macroplasty. There, the team found an almost twice as high nanoplastic concentration in water from a thousand meter depth as outside the flow gyrus – an average of around 13.5 milligrams per cubic meter compared to 7.5 milligrams.
The most common plastic varieties in marine nanoplasty were polyethylenterephthalate (PET), polystyrene (PS) and polyvinyl chloride (PVC)- all frequent plastics, which consist, for example, single and reusable plastic bottles, foils or one-way drinking cups and one-time cutlery. PET nanoparticles were even detectable up to a depth of 4500 meters. However, it was surprising that some frequent plastic varieties were missing: Ten Hietbrink and their colleagues could not demonstrate polyethylene (PE) and polypropylene (PP) at any measuring point. These plastics are used, for example, in garbage bags and plastic bags, which often end up in the oceans as plastic waste. “There is a lot of PE/PP microplasty on the surface of the sea, but we did not find any PE/PP nanoparticles that could have arisen, for example, as a result of solar radiation or abrasion through the waves,” says Materić. The researchers suspect that these plastics are changed so much when decaying molecular that their analysis method can no longer recognize them. It would also be conceivable that this nanoplasty binds particularly strongly in organic or mineral particles in the sea water and thus remained undetected in the samples.
More nanoplasty than other plastic waste
Based on its measurement data, the research team has calculated how much nanoplasty as a whole could exist in the North Atlantic. The result: This part of the ocean alone could contain around 27 million tons of nanoplasty- this is more valued for the entire Atlantic than before with micro- and macroplastics. “A shocking crowd,” says Ten Hietbrink. This shows that the entire pollution of the oceans with plastic is more serious than previously assumed, explains the team. Because nanoplasty has not yet been included in these projections. The new measurement data also suggest that nanoplasty could even make up the lion’s share of the total plastic pollution of the oceans. “This estimate shows that more plastic in the form of nanoplasty in this part of the ocean floats as larger micro or macroplastic particles in the Atlantic or even in all world’s oceans!” Says senior author Helge Niemann, from the Royal Dutch Institute for Marine Research.
According to the research team, the extent of the nanoplasty contamination in the sea is a reason for concern. “It is already known that nanoplasty can penetrate deeply into our body. It has even been proven in the brain tissue,” says Niemann. “Since we now know that these nanoparticles in the ocean are omnipresent, it is also obvious that they penetrate the entire ecosystem-from bacteria and other microorganisms to fish and top predators like us humans.” What consequences this has for the marine living environment must now be researched. At the same time, the researchers also advocate more effective combating the flood of plastic: “Nanoplasty that is already in the sea can never be removed,” says Niemann. “An important message from our study is therefore: at least we have to prevent the pollution of our environment with plastic.”
Source: Sophie Ten Hietbrink (University of Utrecht) et al. Nature, DOI: 10.1038/S41586-025-09218-1
