Plastic and oceans

The annual global production of plastic exceeds 450 million tons, and plastic pollution is now found in significant quantities in all regions of the world, including the most remote areas of the planet. Plastic degrades at sea into microplastics and nanoplastics, a group of heterogeneous particles varying in size, shape, color, chemical composition, and density. Some of the more significant environmental impacts of plastic litter include entanglement, ingestion, transfer of chemical contaminants, and long-range transport of species. Plastic litter has detrimental effects on human health but also affects some specific sectors of the economy, such as tourism and fisheries, as well as risks to navigation. The management of plastic pollution is exceptionally complex and requires an integrated approach encompassing scientific, legislative, economic, and social aspects. In addition to reduction measures based on improving the circularity of the economy, recycling, water purification, selective cleaning, and education, several global initiatives established a legal framework in which states must take management measures to achieve a better state of the environment. More studies are needed to understand plastic's degradation processes and determine impacts, such as the transfer of chemical contaminants to organisms, the leaching of additives, and the role of plastic debris as a vector for transporting pathogens and hitchhiking species. Established harmonized methodologies, based on sound scientific techniques and sampling strategies for assessing macro-, micro-, and nanoplastics in the environment, remain a critical step. Besides the consideration of more optimized monitoring, analytical methods also need to be improved to better characterize and quantify small-sized particles.