The European Citizen Science Association Conference 2022 took place from 5 to 8 October 2022 in Berlin under the cross-cutting theme of Citizen Science for Planetary Health. One major concern for planetary health is global plastic pollution, which has exceeded the save operating space for humanity as part of the planetary boundary for novel entities.

Against this background, more and more legislation has been adopted in the past years to address the plastic pollution problem. One of these policies is EU Directive 2019/904 on the reduction of the impact of certain plastic products on the environment. This directive targets several single-use plastic items most commonly found at European beaches. Therefore, Directive 2019/904 is often referred to as Single-Use Plastics Directive.

In her presentation, titled "Evaluating environmental policies with citizen science data? An example from the Plastic Pirates investigating plastic pollution of rivers", Linda Mederake (Ecologic Institute) presented an approach to evaluate the Single-Use Plastics Directive with the help of citizen science data. The results of a scenario analysis based on sampling data of the citizen science youth project “Plastic Pirates” as well as data from three other sampling protocols for coastal litter indicate the possibility for moderate improvements with regard to litter quantities. However, many sources of riverine litter are not sufficiently addressed by the Directive, such as cigarette butts and plastic packaging of snack products.