Ten Priorities for Reducing Microplastic Inputs to Freshwater and Marine Environments

Microplastics are now pervasive across environmental compartments, ingested by more than 1500 species, and detected in human tissues, yet policy responses remain fragmented and inadequate. Annual microplastic inputs to the environment are estimated at 10–40 million tonnes and are projected to double by 2040. Most governance has relied on voluntary industry initiatives, consumer behaviour change, recycling campaigns, and narrow restrictions on selected products. There is little evidence that these approaches have materially reduced microplastic pollution, and plastic production and leakage have continued to grow. With negotiations for a global plastics treaty stalled over production controls, national governments can act through existing and emerging regulatory tools. This paper identifies ten priority policy actions that target production volumes, product design standards, and point-source discharge controls rather than downstream capture alone. These priorities span wastewater and stormwater management, regulation of tyres, synthetic textiles, paints, manufactured microplastics and pre-production pellets, elimination of unnecessary single-use plastics, and limits on primary polymer production. Binding legal precedents exist in at least one jurisdiction for most of these priorities, although several have been adopted but are not yet applicable; the final priority, capping primary polymer production, is ambitious but under negotiation. After two decades of research, the sources and pathways of microplastic pollution are clear enough to regulate; what is now needed is the political will to apply the tools already available.