Microplastic Pollution Projects and Participatory Science

Plastics include different types of polymers, often mixed with additives which give them the desired properties (flexibility, rigidity, color, fire resistance, etc.). The diversity of properties and possible uses of plastics, combined with their strength and lightness, have made them a preferred material in many sectors (packaging, medical, construction, etc.). Their use has grown exponentially since the 1950s, today reaching 400 million tons per year. Plastics are therefore present everywhere, whether in aquatic environments or in terrestrial environments. Today, the omnipresence of plastic waste at sea and on the coast has become a subject of major public, scientific and public health concern. "Microplastic" refers to tiny plastic particles that measure less than 5 millimeters and that can be found in landfills, rivers, soils and mostly in oceans. These microplastics come from various sources such as the breakdown of larger plastic items (bags, tyres, bottles), microbeads in personal care products, and synthetic fibers from textiles. This widespread contamination rises a serious threat to marine life, ecosystems and human healthcare. Although microplastic pollution is major environmental concern, this topic is not yet included in school programs. In order to involve students to this crucial pollution problem, we are experimenting a science club with all volunteer students since September 2023. The club is part of two national participatory science projects which consist in collecting data, conducting experiments, and analyzing results and communicate with researchers. The first project has been initiated by the Tara Ocean foundation. This project is an educational operation serving education in science and sustainable development which offers students the opportunity to contribute to the inventory of plastic pollution on beaches and banks in France.The database created feeds scientific research and contributes to political decision support at different levels. We had to choose a sampling site on the banks of the Seine which has to be approved by scientists. The, we will collect plastic samples and, back at school, we will sort plastic according to their size. The data collected are used to complete a database which is freely accessible by any researcher. The second participatory project in which the club is involved is the Plastizen project, lead by the CNRS . It aims to study the fate of biodegradable plastic bags in the soil by taking into account different ecological factors (temperature, humidity, pH). Some samples of conventional plastic and biodegradable plastic are buried in the soil. pH of the soil is measured. Then, each month, the samples have to be removed, measured, pictured and the results are sent to CNRS. These two projects allow discussing the scientific contents and methodologic approach of science with the students. But we also plan to organize local cleanup events, and awareness campaigns (creation of informational posters, comic strips, ). The poster will describe the challenges of this work, the way it has been driven and the first results. The exchanges with the students and their perception of these participatory projects will be summarized and discussed.