Light- and Heavy-Duty Vehicle Emission Factors of PM Species Based on Freeway Measurements and Comparison with Tunnel and Dynamometer Studies

摘要

Numerous epidemiological studies have found positive associations between adverse respiratory and cardiovascular effects and exposure to atmospheric particulate matter (PM). In urban environments, light- and heavy-duty vehicles have become the major source of ultrafine and fine PM. Different approaches have been used to characterize vehicular emissions, including chassis dynamometer tests, roadway tunnels studies and roadside measurements. However, these methods may be limited in application in the interpretation of real-world vehicles emission factors. In the present study, a new methodology was developed for estimating fuel-based 3 emission factors for specific PM components (e.g. organic constituents, trace metals and elements, and particle number). Thus, our study provides a convenient way to derive particle emission factors that can be used to assess PM exposure from roadway emissions.