Particulate emissions from burning transportation fuels are increasingly implicated in human illness and death. In 2010, the California Air Resources Board estimated that 9,000 Californians die prematurely each year because of exposure to particulate matter. Previous studies have shown that exposure to motorists can be up to 10 times higher than ambient particulate concentrations.

Currently, the assessment of public exposure to particulate emissions is based on data from fixed monitoring sites or temporarily and spatially averaged emission data. That creates a problem because the sites are too sparsely located to accurately measure particulate variations on highways for the former case and spatial and temporal changes are not considered for the latter case, said Jung.

Jung’s research will attempt to quantify the highest potential exposure to particulate matter during the daily commute, enabling a better assessment of the public’s exposure to particulate emissions on highways focusing on probing temporal and spatial variations of particulate matter on highways.

Following the principles of fluid dynamics and particle formation, local conditions along highways can create hot spots of particulate concentration, Jung said. This phenomenon is impacted by such things as particle nucleation, traffic variables and weather conditions.

The researchers will install mobile particle measuring systems and use telematics developed at the center for simultaneous measurement of particle concentrations, engine parameters and GPS data. The team will also make use of the Comprehensive Modal Emissions Model developed at Center for Environmental Research and Technology for comparison.

In addition to enhancing the performance of such models, precise understanding of the mechanisms of particle matter exposure could affect future designs of highways, vehicles and air handling systems and form the basis on how to space out particulate monitoring along freeways, Jung said.