Déchets et microplastiques : comprendre et agir face à une pollution mondiale

• Plastic materials have become indispensable in our daily lives. They are found in packaging, clothing, household appliances, cars, buildings… This widespread adoption has been accompanied by a sharp increase in global production, which has grown 266-fold since 1950 to reach 400.3 million tonnes in 2022 (source: Plastics Europe), roughly equivalent to the total weight of all humanity. The main user sectors are packaging (the primary market), followed by construction and automotive. • According to Plastics Europe data, France is the 3rd largest plastic consumer in the European Union with approximately 5 million tonnes per year (2021), behind Germany and Italy.

• The treatment of plastic waste presents two major problems: • a constantly increasing waste volume: in France, only 21% of plastic waste was recycled in 2022 (23% for packaging), 51% was incinerated with energy recovery and 28% was sent to landfills (source: Plastics Europe). Worldwide, of the 353 million tonnes of plastic waste produced, 9% was recycled, 19% incinerated and nearly 50% ended up in controlled landfills. The remaining 22% was abandoned in nature, burned in open fires or dumped in illegal landfills (source: OECD); • microplastic pollution: large plastic waste, called macroplastics, gradually degrades due to sunlight, heat, friction or microorganisms. They then break into small pieces called secondary microplastics, measuring less than 5 millimetres. Other microplastics, known as primary, are directly produced by certain human activities: tire wear on roads, paint residue, sewage sludge or synthetic fibres released when washing clothes. Very light, these microplastics can be transported by air or water over long distances. They then accumulate in soils, rivers, oceans and can persist for several centuries in the environment.

• In the air, very fine plastic particles (less than 20 micrometres) were found in 2021 at high altitude in the Pyrenees. They came from distant regions such as Africa, North America or the Atlantic Ocean, transported by wind (source: Nature journal). • In soils, a 2020 study of 33 agricultural sites in France showed that 3 out of 4 (76%) contained plastic fragments. These plastics, mostly found in major crops, were mainly composed of polyethylene and polypropylene. • Regarding water, there is no yet regular monitoring of microplastics in watercourses or precise regulations for bottled water, although studies show their presence, but European and national laws aim to reduce and ban single-use plastics (source: IGEDD). • Analyses carried out in groundwater by the National Institute of Industrial Environment and Risk (Inéris) revealed between 77 and 520 plastic fragments per litre of water. This shows that even soils are not sufficient to filter the smallest debris (from 25 to 350 micrometres), which can reach groundwater reserves.

• On French beaches, most plastic collected consists of fragments too damaged to be identified, as well as single-use items, such as packaging or disposable utensils. Between 2020 and 2022, the number of plastic waste observed varied by area: an average of between 209 and 894 items was counted per 100 metres of beach. Mediterranean beaches were the most affected. • At sea, large quantities of plastics have also been observed. According to a scientific report by Ifremer and Cedre, between 2015 and 2022: • in the Mediterranean, an average of 39 floating plastic items per square kilometre were counted, compared to less than one in other areas; • on the seabed, density varied between 68 and 510 items per square kilometre; • for floating microplastics, concentrations ranged from 17,000 to 88,000 fragments per square kilometre, with the highest levels in the Mediterranean.

Plastic pollution has effects on animals. Many species can swallow pieces of plastic or become trapped in waste such as nets or bags.

In humans, several studies have detected microplastics in lungs, blood and faeces. We therefore know they can enter our bodies, but their effects on health are still poorly understood.

• Since the 2020s, laws and measures have begun to be put in place to limit plastic pollution: • in France, the AGEC Act (Anti-waste for a Circular Economy) aims to end single-use plastic packaging by 2040; • in Europe, the Zero Pollution plan banned the sale of several single-use plastic items, such as straws or disposable cutlery. The European Union has also set targets for 2030: 50% reduction in plastic releases into the sea compared to 2016 and 30% reduction in microplastic leakage. In accordance with the Basel Convention, the export of dangerous or difficult-to-recycle plastic waste is now prohibited to non-OECD member countries;

at the international level, the United Nations are working on the development of a treaty to reduce plastic pollution. Initially scheduled for the end of 2024, an agreement has not yet been reached and negotiations continue.