Risk assessments for microplastic within reach

Researchers of Wageningen University & Research now provide the first mathematical framework to assess the risks of microplastic particles. So far, studies comparing the exposure and effects of microplastic particles have compared apples and oranges. This is because two microplastic particles are never the same, and the methods used to measure exposure and effects are all different. They use different types of microplastics, all of which are very different from the mixtures we are exposed to.

In their recent paper Bart Koelmans and colleagues discuss and summarize ways to solve all these misalignments using mathematical approaches that are new to microplastic research. This provides a way to represent all of this data as just apples so that they can be compared in a consistent risk characterization.

An important element of the new approach is that microplastics should no longer be regarded as a material that can be characterized as separate categories of sizes, shapes or polymers. Instead, the researchers describe microplastics as a continuum of properties. If the particles occur in large numbers, and they do, those properties are best described with mathematical distributions. And if you know the distributions, you can align all kinds of data between studies, which is a huge improvement.

Risk assessment of microplastic

The new method provides a valuable tool to assess the risk of this new contamination. Until now, the method has been used by the authors’ team to assess risks for surface water and freshwater sediments on a global scale, with a risk for a few percent of the locations worldwide. In California, the new methods have recently been applied to derive standards for microplastics in the marine environment and in drinking water in a regulatory setting. Results are expected early 2022.

Wur.nl