27 million tons of nanoplastics found in North Atlantic, Dutch researchers say

An estimated 27 million tons of nanoplastic particles are suspended in the North Atlantic Ocean, according to research published in Nature by scientists from the Royal Netherlands Institute for Sea Research (NIOZ) in Texel. The study reveals that these microscopic particles—smaller than 1 micrometer in diameter—are present at concentrations far exceeding those of larger plastic debris.

Researchers conducted sampling at 12 locations across the North Atlantic during a November 2020 expedition aboard the research vessel Pelagia. Samples were collected at three depths: near the surface at 10 meters, at 1,000 meters, and approximately 30 meters above the seafloor. The sites included five in the North Atlantic subtropical gyre, four in open ocean, and three along the European continental shelf.

Helge Niemann, professor and one of the study’s authors, emphasized the scale of the pollution: “This estimate shows there is more plastic in the form of nanoplastic particles in this part of the ocean than there is micro- or macroplastic floating in the Atlantic or even all the world’s oceans,” Niemann told NOS.

Using thermal-desorption proton-transfer-reaction mass spectrometry, the team identified nanoplastics composed mainly of polyethylene terephthalate (PET), polystyrene (PS), and polyvinylchloride (PVC). These materials were measured at average concentrations of 18 milligrams per cubic meter, translating to the 27 million-ton estimate in the upper layers of the ocean.

Sophie ten Hietbrink, a master’s student who contributed to the research, described the findings as alarming. “A shocking amount,” she told NOS. “But with this, we finally have an important answer to the paradox of the missing plastic,” referring to the long-standing question of why so much of the plastic produced globally has never been recovered.

Samples showed higher concentrations of nanoplastics at the surface, though researchers detected particles even in deep water and near the seabed. “At the surface, we found more nanoplastics than on the bottom,” Niemann told NOS. “That was expected because plastic often enters the sea via rivers or the air. But it is unpleasant to see that even in mid-water layers and on the seabed, nanoplastic is still present. The pollution is spread throughout the entire ocean.”

Dušan Materić, an environmental analytical chemist at the Helmholtz Centre for Environmental Research in Leipzig and co-author of the paper, explained to NOS that nanoplastics behave differently from larger particles. Their movement is dominated by Brownian motion—a random, jittery motion caused by collisions with water molecules—which prevents them from simply sinking.

One unexpected observation was the absence of polyethylene (PE) nanoplastics in the samples, despite evidence that PE is commonly released into the environment. Materić said, “We faced a big mystery. The fragments probably transform into something else or might fall to the sea bed. This suggests that PE nanoplastic cycling in the ocean follows some unusual pathway.”

Researchers caution that the ecological and health consequences could be severe. “It is already known that nanoplastics can penetrate deep into the human body,” Niemann told NOS. “They are even found in brain tissue.”

Given their size and distribution, these particles are impossible to remove from the ocean. “The nanoplastics that are here now, you will never clean up,” Niemann added. “An important message of this research is that we must at least prevent further pollution of our environment with plastics.”