The following post is one of a series spotlighting research presented at the  in Rome, Italy (13-17 May 2018).

A guest post by Ana Marta Gonçalves, Nelson Abrantes, Alice Horton, and Claus Svendsen

Plastics are an indispensable component of our daily lives due to their wide applications. As a consequence of improper handling or disposal, plastics may become dispersed in terrestrial and aquatic (water and sediment) systems, with rivers potentially transporting microplastics (MPs) to marine systems. The accumulation of plastics in these systems constitutes an emerging scientific and societal issue due to their ubiquity, high persistence and potential to cause ecological effects.

Photo by Ana Marta Gonçalves

Microplastics, which are plastics < 5 mm, are a group of particles that differ in physico-chemical properties (e.g., size, shape, color, density, and polymer type). They are of particular concern because they can derive from a variety of sources and can accumulate to reach high concentrations within the environment. As a modern, populous society, we rely heavily on the preservation of aquatic environments as resources for both agriculture and drinking water. Accumulation is especially likely within the continental environment due to the proximity to areas where (micro)plastics are manufactured and used, with direct inputs from point sources. The factors influencing fate, behavior, and effects of particles are complex and can rely on a combination of environmental and biological interactions. The form in which plastics enter the environment will have a significant influence on their behavior. Physical, chemical, and biological degradation will lead to the creation of microplastics from larger plastic items, in addition to microplastics input directly via sewage and runoff.

The results of several studies are in most cases not comparable due to the application of different methods of sampling, processing and analysis. Precise analytical tools such as Fourier transform infrared spectroscopy (FTIR) and thermal desorption gas chromatography mass spectrometry (TED-GC-MS) allows us to identify the types of polymers and detect polymers’ masses in samples, and thus allow us to infer their potential for interactions with, and toxicity to, organisms. It will be important to standardize methodologies for monitoring MP contamination in different systems and emission from urban areas, so we can also determine the potential impacts on adjacent environmental compartments. Moreover, interactions of MPs with different chemical stressors may also potentiate several effects on different levels of organization (from the molecular level to the whole ecosystem scale), a topic of emerging concern and receiving growing interest. Although measurements and monitoring data are indispensable, modeling tools are potentially suitable to simulate the distribution and effects of (micro)plastics. These issues: fate, monitoring, and effects of (micro)plastics in freshwater and terrestrial systems, were discussed at the SETAC Europe Annual Meeting and the session summary will be fully reported in the SETAC Globe.