Oceans are polluted with plastic, it’s nothing new. Every day, 1000 kg of plastic waste enters the water, despite all warnings from scientists. These are mostly bigger parts of plastic, which you often see on photographs: fish in plastic, sea turtles in a plastic bag, nets and fishing lines around dolphins, seabirds suffocated in plastic, bottles washed up on coastlines, the examples are endless.
In the meantime small microplastics are found everywhere in the world, in densely populated areas up to the highest mountain tops, but also in human tissue like brains, placenta and other places.
But in July 2025 the leading scientific magazine Nature published a new shocking article. The study is about a different, hidden source of plastic waste: nanometre-scale particles which are literally everywhere, according a researcher of the Helmholtz Centre for Environmental Research in Leipzig.
The researchers took samples of the sea water on three different depts, representative for the different environment in the North-Atlantic Ocean. They took samples on 12 locations in November 2020. in the system of circular currents called the North Atlantic subtropical gyre; 4 in the open ocean; and 3 from coastal areas on the European continental shelf. On each of these locations samples were taken at 10 and 1000 metres from the surface and also on 30 metres from the bottom of the ocean. After that they were filtered out in different ways.
Three types of plastic were found: PET, polystyrene and PVC. In average concentrations of 18 milligram per cubic meter, which means about 27 million tons of nanoplastics spread over the top layer of the North-Atlantic Ocean alone, in a moderate to subtropic climate. It means that nanoplastics make out the biggest part of plastic waste in the sea. It’s estimated that about 3 million tons of plastic is floating in the oceans worldwide, exclude nanoplastics.
What’s the difference between micro and nanoplastics? Microplastics are between 1 micrometer and 5 millimetre. Nanoplastics are smaller than a micrometer or 10−6 metre or one thousands of a millimetre. As a comparison, according to Wikipedia, a human hair is between 17 and 180 micrometer.
Small particles like this are behaving differently. Gravity has no effect on them, they won’t sink to the bottom. They spread over the water column by random movement and by collisions with water molecules.
This is very bad news, nanoplastics are so small they can pass through cell walls. This means that they are already incorporated into the ocean phytoplankton. Phytoplankton serves as a base of the marine food web and are able to be transferred to other species and eventually also to humans.
Due to the large estimated numbers we should take this problem, according the researchers, very seriously. Because of the toxic potential they could become the most problematic plastic particle for life in the ocean. Time to wake up and get into action, because the way nanoplastics can infiltrate every eco system and living cell is many times worse than we know until now from microplastics and other plastic pollutions.
In August 2025 there negotiations in Geneva by the UN about plastic pollution. The use of plastic can not only be limited, but also recycling should be a lot better and more, so that less plastic gets into the environment and water. We are all responsible and we each contribute our own bit.
Source: Nature (https://bit.ly/44HJZ8k)