An Expert Discusses the True Impact of Microplastics on Human Health

It’s well-known that enjoying a tasty fish fillet or a seafood platter provides essential nutrients like omega-3s and vitamin D. However, these meals often come with an unwelcome side: numerous micro- and nano-plastics.

Plastic particles smaller than 5 millimeters find their way into oceans through human waste, infiltrating the food chain. An Ifremer study estimates about 24,400 billion microplastics float on the ocean’s surface.

A Growing Threat to Ecosystems and Human Health

These particles are present in all marine organisms, from microalgae to top-of-the-chain fish, posing threats to marine ecosystems and raising alarms about their potential impact on human health.

What do we currently understand about how these pollutants accumulate in marine life and the risks they may pose to humans?

Plastic production has surged dramatically since the 1950s, with Europe alone producing 58 million tonnes in 2022, resulting in vast quantities of waste.

From Waste to Widespread Pollution

Larger plastic waste gradually breaks down into microplastics (1–5 mm) and nanoplastics (smaller than 100 nanometers) due to exposure to wind, waves, sunlight, and microorganisms. These tiny particles now pollute every part of the environment, including air, soil, and water.

The accumulation of these plastics in organisms at various levels of the food chain is called “bioaccumulation.”

Our laboratory’s research shows that in aquatic ecosystems, micro- and nano-plastics are consumed by a variety of species, ranging from microalgae at the bottom of the food chain to top predators such as eels.

The ingestion of microplastics has significant consequences. Research indicates that these particles can have toxic effects on marine animals.

In mussels, for example, microplastics can obstruct digestive systems, trigger immune responses, cause DNA damage, and disrupt the expression of genes vital to various cellular functions.

The Complex Impact of Size, Composition, and Chemical Additives

The impact depends on factors such as the size, composition, level of degradation, and harmful chemical additives present in the plastics. Many plastics contain high concentrations of phthalates, known endocrine disruptors that can interfere with hormonal systems, posing threats not only to marine organisms but also to human health.

Plastics consumed by marine animals ultimately enter the human food chain.

Frequent seafood eaters are estimated to consume thousands of microplastic particles each year. While the exact health effects on humans remain under study, some concerning possibilities have emerged.

Once inside the body, these particles may cause harm similar to that observed in fish. Research on human cells suggests that micro- and nano-plastics can disrupt cellular functions, mirroring effects seen in marine life. Scientists are particularly worried about the toxic effects of plastic additives.

Moreover, micro- and nano-plastics can serve as carriers for pathogens or bacteria, potentially heightening the risk of infections.

Addressing plastic bioaccumulation in the food chain is a pressing issue. Swift measures to reduce plastic use and enhance recycling technologies are crucial to slowing this growing environmental and health challenge.

Read the original article on: Science Alert

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