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Road traffic is one of the main causes of poor air quality in European cities. The air pollution burden due to road traffic in a street canyon consists of shares from local traffic and contributions of vehicles driving elsewhere in the city as well as elsewhere on a larger scale. Are electric vehicles a solution for air quality problems in cities? Do they reduce noise levels in street canyons significantly? The aim of this sensitivity study is to investigate the regional and local effects of electric vehicles on noise and air quality taking possible effects of additional electricity production into account. Focus of the present study lies for air quality on the regional scale in North Rhine-Westphalia and the overall effect in some selected street canyons, to be more precise the annual average PM10 and NO2 concentrations. A sensitivity study using the chemistry transport model EURAD and a screening model for street canyons was carried out. The influence on noise levels was analysed based on measurements of vehicles at different speeds. It turns out that road traffic has a significant impact on the regional air pollution levels. Furthermore it is shown that the reduction potential is bigger for NO2 than for PM10. With regard to EC limit value compliance a major share of electric vehicles could be a solution for the NO2 problems in moderately polluted street canyons. One of our findings is that if the additional electricity need causes additional emissions these counteract the possible reduction, especially for PM10. The noise reduction potential of electric vehicles is only significant for vehicles moving at low speeds.

Two commonly used models to assess air pollution concentration for investigating health effects of air pollution in epidemiological studies are Land Use Regression (LUR) models and Dispersion and Chemistry Transport Models (DCTM). Both modeling approaches have been applied in the Ruhr area, Germany, a location where multiple cohort studies are being conducted. Application of these different modelling approaches leads to differences in exposure estimation and interpretation due to the specific characteristics of each model. We aimed to compare both model approaches by means of their respective aims, modeling characteristics, validation, temporal and spatial resolution, and agreement of residential exposure estimation, referring to the air pollutants PM2.5, PM10, and NO2. Residential exposure referred to air pollution exposure at residences of participants of the Heinz Nixdorf Recall Study, located in the Ruhr area. The point-specific ESCAPE (European Study of Cohorts on Air Pollution Effects)-LUR aims to temporally estimate stable long-term exposure to local, mostly traffic-related air pollution with respect to very small-scale spatial variations (≤100 m). In contrast, the EURAD (European Air Pollution Dispersion)-CTM aims to estimate a time-varying average air pollutant concentration in a small area (i.e., 1 km2), taking into account a range of major sources, e.g., traffic, industry, meteorological conditions, and transport. Overall agreement between EURAD-CTM and ESCAPE-LUR was weak to moderate on a residential basis. Restricting EURAD-CTM to sources of local traffic only, respective agreement was good. The possibility of combining the strengths of both applications will be the next step to enhance exposure assessment.