Large-scale separation of gram-level tire and road wear particles from road dust

Separation approaches have been developed to isolate tire and road wear particles (TRWPs) from environmental media, demonstrating their potential in providing representative test materials for TRWPs studies. However, the achievable mass of TRWPs and the broader applicability of the method have yet to be verified. This study aims to determine whether separation methods can acquire gram-scale TRWPs from various road dust samples. A large-scale dust separation protocol incorporating two-stage density separation and software-assisted TRWPs selection was adapted from existing methods. Twenty-five road dust samples from various road types and regions in a megacity were collected and processed using this protocol. The selected particles were identified as TRWPs using SEM-EDX, FTIR, and Py-GC–MS. Gram-scale yields (>1.0 g TRWPs per kg dust) were achieved at 44 % of sampling sites. Additionally, we proposed three recommended road dust sampling locations and estimated that collecting 1.3–2.3 kg of dust from these sites would yield one gram of TRWPs. This is the first demonstration that gram-level TRWPs can be reliably obtained from field dust, enabling environmental fate studies. Future research should focus on the standardization of environmental TRWPs as test materials.