Microplastic in soil–current status in Europe with special focus on method tests with Austrian samples

Within the last decade the production of plastic steadily increased and so did the amount of plastic waste. When bigger plastic pieces enter the environment, they are fragmented over time due to mechanical and environmental forces. The occurring and the directly released microplastic cause severe problems on soil organisms, due to alteration of physical properties and chemical interactions in the habitat. Main emissions sources of microplastic are different kinds of abrasions (road traffic, packaging, fibers of textiles during washing), waste disposal and drifts. Remains of mulching foils and protection nets spoil agricultural soil as well as the application of compost, sewage sludge and digestate, which may contain microplastic. Once released, microplastic accumulates much stronger in terrestrial than in aquatic systems. Spectroscopic, microscopic and thermo-analytical methods are commonly used to analyze microplastic in soil. The main challenges are to differentiate between soil matrix and plastic particles and to get rid of disturbing organic compounds. Unfortunately, there is no soil without plastic, no environmental blind sample to allow the finding of method limits. Inter-laboratory cooperation and data collection should allow estimation and comparison of emissions not only on European but on global scale. Investigations of Austrian samples provided a first orientation for regulations and measures to avoid further environmental pollution.