The Scheldt: hotspot for microplastics

Plastic bottles sometimes cause pollution even before they are made. The pellets that are used as raw material are being found in the Scheldt, even deep inland. Hanne Diels from the University of Antwerp (Faculty of Science) is investigating how they find their way there and continue to drift around.

 

Plastic pellets are small plastic granules measuring between two and five millimetres in size. ‘Just about anything we buy that is made of plastic comes from those pellets,’ explains Hanne Diels, a PhD biology researcher at the University of Antwerp. ‘The Port of Antwerp is one of Europe’s largest plastic hubs. Pellets are produced, packaged, repackaged and transported there. At every stage of that process, pellets are lost unintentionally.’

 

Plastic that keeps circulating

‘Those tiny particles fall into the category of microplastics. They are larger than the invisible microplastics that are attracting so much attention, because we ingest them every day through water and food. They are no less relevant, however, because once they enter the environment, they remain there, and smaller particles gradually break away from the pellets.’

The results reveal that pellets accumulate in specific areas along the river. The places where plastic ends up are determined by vegetation, rocks, river bends and even wind direction. ‘Anything that makes a bank rougher helps the pellets stay in place more easily.’

 

From the stomach to the bloodstream

Although the pellets themselves are quite large, they do sometimes end up in animals’ stomachs. ‘In a pilot study conducted by the research group, we found pellets in the stomachs of baby birds. That means that parent birds saw them as food,’ she notes.

 

Even more problematic is what happens when pellets break down. Through the microscope, Diels can see how they crack and shed small fragments. ‘Each pellet releases thousands of tiny particles: microplastics and nanoplastics, which can subsequently be absorbed into the blood vessels and tissues of humans and animals. They can sometimes contain harmful substances, such as plasticisers or UV filters.’

Awareness and behaviour

‘We do not yet know the exact impact this has on our health, but various studies have reported links to disruptions in the gut microbiota and chronic inflammation, as well as to hormonal and reproductive problems,’ Diels explains. ‘Furthermore, toxic substances can attach themselves to these particles and thus infiltrate the body.’

 

According to Diels, a significant part of the solution lies in prevention. Partly as a result of new European legislation, companies are already taking various additional measures, such as extra cleaning rounds, filter systems and staff training. ‘But ultimately, a lot depends on behaviour,’ she argues. ‘Every pellet lost is one too many.’