Catch me if you can: Microplastics hidden in plain sight

Microplastic (MP) pollution is widely recognised as a pressing environmental issue, yet certain major sources remain under-addressed. This paper focuses on three significant but often overlooked contributors: paint particles, textile fibres, and tire wear particles (TWP). Together, these sources account for over 25 % of global MP emissions, nearly 3 million tonnes annually, yet they are rarely singled out in research or regulation. Each presents unique analytical and regulatory challenges due to their complex compositions, diffuse emissions, and strong ties to daily life. We enumerate current knowledge on their environmental pathways, emission estimates, and detection methods, highlighting the need for multi-method analytical approaches to overcome sampling and identification limitations. Monitoring remains constrained by technical barriers, particularly for pigment interference in paint particles, fibre contamination, and the heterogeneous nature of TWP. Despite their significant impact, policy responses remain limited. The current draft of the Global Plastics Treaty acknowledges these sources under the general MP category but lacks specific measures. Effective mitigation will require enhanced regulatory frameworks, product redesign, expanded Extended Producer Responsibility (EPR), and greater investment in innovation. Moreover, system-level interventions, societal and behavioral changes, such as improved public transport can help reduce TWP at source. In addressing these "hidden in plain sight" pollutants, this paper calls for coordinated national and global action to reduce their release and integrate them into broader MP policy agendas. Only through such targeted efforts can we ensure these overlooked pollutants no longer escape meaningful regulation and environmental accountability. • Three unintentionally released microplastics account for 25 % of global emissions. • Neglected in many studies due to their complexity. • National and global actions are needed to reduce microplastic release.