It’s no secret: when having fun with a delicious piece of fish or a platter of seafood, we devour not only useful omega-3 acids and vitamin D. In addition to these advantages, there are less appetizing elements – countless micro- and nanoplastics.
Amélie Châtel, Provided by the writer
These plastic particles, measuring lower than 5 millimeters in size, enter our oceans through human waste and enter the food chain. According to Ifremer’s studyThere are roughly 24,400 billion microplastics floating on the ocean surface. These molecules are present in all marine life, from microalgae to fish, which occupy the higher levels of the food chain. This phenomenon not only threatens marine ecosystems, but additionally raises concerns about potential threats to human health.
What exactly can we learn about the accumulation of those pollutants in marine organisms and the risks they pose to human health?
Well, Bertold Jensen/Unsplash, CC BY-NC-SA
Micro- and nanoplastics: an invisible threat
Since the Fifties, plastic production has increased exponentially, reaching 58 million tons in Europe only in 2022. This has led to the creation of giant amounts of waste.
Over time, wind, waves, sunlight and microorganisms break down larger plastic waste into microplastics (1-5 mm) and nanoplastics (smaller than 100 nanometers), which now pollute all parts of the environment, including air, soil and water.
(There are already over 120,000 newsletter subscriptions. Sign up today to higher understand the world’s most vital issues.)
The process by which these plastics accumulate in organisms at various levels of the food chain is known as “bioaccumulation”.
Alice Vidal, Provided by the writer
Research from our laboratory reveals that in aquatic environments, micro- and nanoplastics are consumed by a wide selection of species – from microalgae at the base of the food chain to top predators resembling eels.
Impact on marine life
Such consumption has serious consequences. Studies show that microplastics may cause toxic effects on marine animals.
In mussels, for instance, microplastics can clog the digestive system, activate immune responses, cause DNA damage, and disrupt the expression of genes mandatory for various cellular functions.
The severity of those effects relies on the size, composition, degree of degradation and harmful chemical additives that plastics may contain.
Plastics often contain large amounts of phthalates, which disrupt the functioning of the endocrine system. These chemicals can disrupt the endocrine system, posing a risk not only to marine life, but potentially to humans as well.
Risks to human health
Plastics ingested by marine animals inevitably find yourself in our food.
Amélie Châtel, Provided by the writer
Frequent seafood consumers are estimated to ingest hundreds of microplastic particles annually. Although research into the exact effects on human health is ongoing, some disturbing hypotheses have emerged.
Once in the human body, these particles may cause damage similar to that observed in fish.
Studies on human cells indicate this micro- and nanoplastics may cause interference cellular functions in a fashion similar to the effects seen in marine organisms. Scientists are particularly concerned about the toxic effects of plastic additives.
Additionally, micro- and nanoplastics can act as carriers of pathogens or bacteria, potentially increasing the risk of infectious diseases.
The urgent need to address the bioaccumulation of plastics in the food chain can’t be overemphasized. By taking quick motion to reduce plastic use and improve recycling technologies, we are able to slow the progression of the environmental and health crisis.
