Microplastics are found almost everywhere. Scientists at UGent and VITO developed a way to monitor even the smallest particles.

Ubiquitous microplastics

Microplastics -very small particles of plastics- do not only occur in inhabited environments, but also in snow in the polar regions, for example, suggesting that they can be transported through the atmosphere over long distances and possibly can also be inhaled.

Equally alarming is the observation that these microplastics also occur in many, possibly even all, foods and our drinking water and that they (at least the smaller specimens) are absorbed into the body during digestion.

Monitoring the occurrence of these microplastics and thorough evaluation of their possible effect on different ecosystems and especially on human health is more than appropriate. But that is precisely where the problem lies, because there are as yet no methods for easily characterizing such particles, especially the very small variety. After all, the smallest fraction of microplastics often (also literally) slips through the net during current monitoring. Since the smallest fraction of plastic contributes proportionally the most to the number of particles, we now only see the tip of the plastic iceberg in terms of the actual number of particles.

New method

A team of researchers from Ghent University (UGent) and VITO has now demonstrated that ICP mass spectrometry or shorter, ICP-MS, a technique used to determine the content of (heavy) metals in all kinds of samples, can also be used for the characterization of small microplastics.

Based on this technique, the research team developed a method with which they can measure the number of polystyrene particles present in an artificial water sample and determine their size to at least 1 µm.

Further research is of course still required in order to be able to use this method routinely. For example, the researchers point out the need to develop a suitable sample preparation to separate microplastics from organic particles of natural origin (of vegetable or animal origin) and the need to further optimise the technique so that particles smaller than 1 µm (nanoplastics) can also be detected.

Although further research is therefore necessary, this development is seen as a breakthrough. After all, this approach has the potential to provide the necessary information for environmental and health studies, but also makes it possible to carry out such analyses fairly quickly.

Huge quantities of microplastics

The presence of small plastic particles in several, if not all, environmental compartments has recently become a regular feature of the media. The term ‘microplastics’ is used to refer to these small plastic fragments. The presence of these microplastics is the result of the immense and worldwide use of plastic as a disposable material.

In 2017, it was calculated that in the period between 1950 and 2015, approximately 6300 million tonnes of plastic waste was generated, most of which ended up in landfills or in the natural environment. Through fragmentation and degradation, this plastic waste is transformed into a multitude of ever smaller particles (e.g. one plastic particle of 1 mm has the same volume as 1 000 000 particles of 1 µm). Although there is as yet no generally accepted definition, microplastics are generally used for particles smaller than 5 mm in size. A distinction is often still made between large (5 mm – 1 mm) and small (1 mm – 0.001 mm or 1 µm) microplastics. For particles smaller than 1 µm one speaks of nanoplastics.

Source press release: ugent.be

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