Traffic-Derived Particulate Matter Emissions . This study addresses particulate matter emissions from motor vehicles traveling on limited access roadways such as freeways. These reconstructed emission factors are compared to PART5, the U.S. EPA model for motor vehicle particulate matter emissions. This photograph shows MiniVol samplers deployed near an unpaved road for experiments to test the experimental method before sampling adjacent to limited access roadways. Tire Wear Contributions to Ambient Particulate Matter .
Tire wear particulate matter is generated by the movement of motor vehicles on the road.
Relatively little is known about the emission rate and size distribution of these particles which can be a source of airborne latex exposure and contribute to the overall ambient particulate matter burden. This study featured the chemical analysis of ambient particulate matter samples for benzothiazole, an organic compound used as a tracer species to quantify tire wear in particulate matter samples. Tire tread samples from a variety of tire makes and models were analyzed for the benzothiazole mass fraction. Using this mass fraction and the benzothiazole mass concentration in ambient particulate matter, tire wear mass concentrations in ambient particulate matter were estimated. Tire wear contributions to PM-2.5 were also studies at the Clayton site.