A recent, comprehensive study has revealed that nanoplastics—often under-represented in both research and policy contexts—may be the dominant form of marine plastic pollution in the North Atlantic. The study, conducted by researchers from the Netherlands and Germany with financial support from the European Research Council (ERC), provides staggering data: the mass of these invisible particles may far exceed the combined quantity of macro- and microplastics.
Plastics found in the environment are categorized by their size. While macroplastics refer to pieces larger than 5 millimeters across, and despite the lack of a formal definition, particles measuring less than 1 micron (0.001 millimeters) are conventionally called nanoplastic particles. These extremely tiny particles are sometimes specifically manufactured, but far more commonly, they are generated as larger plastics break down—for example, through incidental tyre wear, washing of synthetic fabrics, or the degradation of plastic waste exposed to sunlight and physical abrasion.
The European Union is committed to tackling plastic pollution through its plastics strategy, adopted in 2018 as part of the circular economy action plan. However, due to the prevailing difficulties in reliable detection and standardized measurement of nanoplastics, EU policy currently addresses them as a fraction of microplastics, unless explicitly stated otherwise.
Research Methodology: 12 Sites and 3 Water Depths
The research team collected water samples from 12 different locations across the North Atlantic, ranging from the subtropical gyre to the southern North Sea. Measurements were taken at multiple depths at each station:
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In the mixed layer (within 10 meters of the surface)
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In the intermediate layer (at a depth of 1 kilometer)
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In the bottom layer (within 30 meters of the sea floor)
During the processing of the samples, particles smaller than 0.001 millimeters were analyzed using a mass spectrometry technique, which provided precise data on the type and quantity of the plastics.
Concentrations and Primary Plastic Types
The results showed that significant quantities of nanoplastics were present at all locations and at all depths:
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The highest average concentration was measured in the near-surface mixed layer: 18.1 milligrams per cubic meter (mg/m³).
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This value fell to 10.9 mg/m³ in the intermediate layer, and further to 5.5 mg/m³ in the bottom layer.
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In shallower coastal shelf areas, the concentration in the mixed layer reached 25.0 mg/m³, supporting the observation that nanoplastics can enter the ocean from the land via rivers, directly from the coast, or even transported over long distances through the air.
The vast majority of the detected nanoplastics belonged to three types: PET (polyethylene terephthalate), PS (polystyrene), and PVC (polyvinyl chloride). However, their distribution was uneven. At the intermediate depth of 1 km, locations within the subtropical gyre contained 2.5 times the concentration of PET compared to locations outside the gyre, while PVC and PS showed no significant difference. PET concentrations remained relatively constant at all depths, whereas the levels of the other plastic types decreased markedly, reaching only minimal levels in the bottom layer.
Staggering Estimates: 15.20 Megatonnes of Nanoplastics
The researchers compared the concentrations found in open ocean locations (away from the coastal shelves) with existing models for macro- and microplastics. Based on their data, they estimated the total mass of nanoplastic particles in the mixed layer of the North Atlantic (between latitudes 8.5° N and 55° N):
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Using figures from inside the gyre, they estimated 15.20 Megatonnes (Mt) of nanoplastic.
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Using figures from outside the gyre, the estimate was 11.73 Mt.
These figures stand in dramatic contrast to a recent study that estimated the total mass of macro- and microplastics in the exact same layer at a mere 0.31 Mt inside the gyre and 0.05 Mt outside it. The researchers highlight that their results suggest nanoplastics—previously excluded from such estimates—contribute significantly more to the total mass of plastic in the ocean than macro- and microplastics combined, underlining an urgent need for further research into their dynamics and ultimate effects.
Official Source and Reference:
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Original Official EU Source (European Commission, DG Environment): Do nanoplastic particles make up the majority of North Atlantic plastic pollution?