Addressing Microplastic Monitoring Challenges in Drinking Water Resources in the Danube River Basin: Towards Standardization and Capacity Building

The presence of microplastics in drinking water has become an issue of growing concern, and there is a need for reliable and standardized methods to monitor their presence and impact. In the Danube River Basin (DRB), different countries employ a variety of instruments and approaches to deal with this challenge. Techniques such as FTIR and Raman spectroscopy are among the most commonly used due to their ability to provide detailed analysis and identification of plastic polymers. However, these methods come with drawbacks, including high costs, the need for specialized training, and their time-intensive nature. Other techniques, such as Py-GCMS and SEM, are also utilized, but their availability and application largely depend on the resources and priorities of each country. A critical issue is the lack of standardization in monitoring microplastic across the region, while some countries possess modern, state-of-the-art equipment and , experienced laboratories, others are still in the process of building their capacity. Moreover, EU countries have to comply to the directive, while non-EU countries have no strict legislative framework. Comparing the results of microplastic detection is thus challenging at the regional scale and meaningful conclusions are hard to be drawn. For this reason, there's a strong drive toward standardized protocols that could get everyone on the same page, right from sample collection to sample preparation and analysis. However, the challenge extends beyond standardization of monitoring processes. The more complex issue is how to bridge the gap between the nations with highly developed possibilities and countries which are just developing these capabilities. Collaboration is the keyword: share expertise, invest in training, and develop cheaper technologies. In the MicroDrink project, we developed the MicroDrink Knowledge Base (https://microdrink.wordpress.com/) which is an online open-access database providing comprehensive information on the existing sampling methods, analytical instruments, laboratory techniques, previous and ongoing projects, relevant legislation, guidelines, and laboratories offering microplastic analysis in the Danube region.