Study: Water treatment significantly reduces level of microplastics in drinking water

The findings, presented in the 2025 Report on Microplastics Monitoring in Croatian Water Supply Systems, underline the importance of continued investment in public water supply infrastructure and water treatment technologies.

Conducted by the “Josip Juraj Strossmayer“ Water Institute and submitted to the Croatian Institute of Public Health (HZJZ), the study is the first systematic national survey of its kind in Croatia and places the country among the first EU member states to implement monitoring under the new European framework for microplastics in drinking water.

The research covered representative water supply systems across Croatia, including groundwater sources, karst springs, rivers and reservoirs. Samples were collected at water sources, after treatment and within distribution networks, providing new insight into the movement of microplastics from source to tap.

While detailed results are still undergoing expert verification, the study confirms that water treatment substantially reduces microplastic content.

Researchers say the findings reinforce confidence in Croatia’s public water supply system, which remains among the highest-quality in Europe.

The Institute noted that microplastics have been detected worldwide in water, food, air and even the human body, making monitoring increasingly important for both environmental protection and public health. The new methodology also enables data comparisons across EU member states and lays the groundwork for a future European monitoring system.

The study used the Institute’s TinyTrap sampling system and Raman microspectroscopy, one of the most advanced analytical techniques available for microplastics detection.