Wehner et al. (2009) have conducted particle (7–400 nm) emission factor estimations behind AZD4547 diesel passenger car as well as a gasoline passenger car, under urban traveling conditions. These parameters have values of 1.66 × 1014 particles/km·veh for diesel passenger cars and 1.73 × 1012 particles/km·veh for gasoline passenger cars, respectively.
Based on the above emission factors, we carried out PNC computation for a specific day with wind direction perpendicular to street canyon. Traffic count has been taken manually and fleet's composition constituted of ~ 95% gasoline and ~ 5% diesel passenger cars. This fleet composition corresponds to the years before 2012 when the circulation of diesel private vehicles in Athens was banned.
In this study we tried to characterize the influence of UFP emissions from traffic on population exposure by applying the intake fraction approach. We calculated the intake fraction of UFPs for residents, pedestrians and office workers in a street canyon, in central Athens urban area, Greece. Our case study shows an application of intake fraction, not limited to large areas but referred to a micro scale urban level. Recently, the necessity for high resolution intake fraction estimates near the emission sources has been pointed out (Lobscheid et al., 2012). We applied a three dimensional CFD model based on real measurements for the simulation of UFP levels indoors and outdoors. We used infiltration factors calculated for the under study area, to evaluate the indoor UFP levels attributable to outdoor emissions.