In cross-project workshops, participating experts regularly exchange ideas and information on certain interdisciplinary topics. One of these is concerned with the topic of modeling and life cycle assessment, and develops joint approaches for handling the acquired data. In this connection, the present synthesis paper also came into being, bringing together the whole area covered by the models and identifying gaps. At the beginning of the paper, the authors underline once again what the research project as a whole is all about: Microplastic in waterways is currently a topic that is attracting a great deal of attention and in which the focus is on potential risks emanating from microplastic particles. The consequence was the call for regulatory measures even though very little is as yet known about the topic. One problem according to the paper is that research has so far concentrated predominantly on marine systems and less on discharges of plastic waste from the land. These discharges are, however, now regarded as an important discharge source. This is also confirmed by work on and with the BKV model "From Land to Sea", whose approach is one of the models considered in the synthesis paper.
In the synthesis paper, readers are given a rough overview of the existing models and which areas of microplastic discharges they cover. However, say the authors, while these models may provide a good idea of how particles get into the environment and are transported in waterways, there is basically a lack of fundamentals for being able to estimate the load dynamic of soils and waters. The reason for this, they say, is firstly a lack of data and secondly, gaps in the coverage of the model structures themselves. In this respect, what is also missing is an overview of how plastics get into the waterways (at most, the authors say, selective discharges are backed with data), how they behave in the environment, what quantities remain in the environment and where, and how quickly or slowly they break down.
Against the background of the findings, the authors give, at the end of the project, an outlook of which direction they think research should be oriented. Because, in microplastic research, there is still a lack of important information for understanding the overall system and because the models will, in the foreseeable future, continue to provide only selective information, it is, they say, exceedingly important for research development to further develop the models to improve the understanding of the system. A model designed in this way could then exert an influence on the choice of suitable sampling points and how often samples should be taken. Models could also then be used for prioritizing parameters and specifically selecting analyses and tests. In addition to this coordination of data acquisition and modeling, the authors also argue in favor of an alignment to political areas of action. The models should thus help in estimating the relevance of emission sources and discharge pathways in order to derive options for measures to minimize the discharges.
Source: BMBF (November 2020)