Microlitter Quality assurance and Quality control approaches to enable the comparability of data in European Seas

Microlitter (incl. Microplastics) is ubiquitous in all environmental compartments and monitoring data are needed to support policy processes. Therefore, besides availability of guidance for monitoring, analysis and data treatment, there is need to establish large scale agreed provisions for quality control and quality assurance, also to be documented as metadata. There are currently no harmonised QA/QC protocols or methods implemented in the collection and analysis of microlitter, that would allow the collection of comparable and reliable data. Although the application of QA/QC procedures in microlitter studies is becoming more frequent, proficiency testing and interlaboratory schemes are currently not implemented for evaluating the performance and calibration of laboratories. Therefore, QA/QC best practices are urgently needed to ensure the validation of microlitter measurements and to produce more accurate data. The European Marine Strategy Framework Directive (MSFD) Technical Group on Marine Litter (TG ML), together with the scientific community is currently evaluating the available approaches and options to validate and check microlitter samples based on references materials, proficiency and interlaboratory testing for in-house calibrations, checks and external validation. Furthermore good practices for avoiding contamination during sampling and analysis processes to support harmonised microlitter monitoring in European Seas and the implementation of the MSFD are being compiled. Also see: https://micro2024.sciencesconf.org/569298/document