Respirable particulate matter (PM10) in the environment has been associated with a number of human diseases. Tire wear particles (TWP), produced from the interaction of the pavement and the tire surface, are thought to contribute to PM10; however, airborne TWP has not been well characterized and thus associated risks are not well understood. In order to address this question, we collected PM10 samples while running passenger vehicle tires on a roadway simulator, thus simulating environmentally relevant driving conditions during TWP collection. PM10 samples were collected on mixed cellulose ester filters (MCE) and subjected to biological leaching experiments in simulated lung fluid (SLF) in order to understand bioaccessibility of metals found in TWP. The filters were incubated in SLF at 37°C for 6 days under constant agitation at 80 rpm. Leachate from the PM10 air samples were analyzed for metals content by ICP.