When calculating the immission of fine particles by road traffic in urban areas the influence by buildings can be considered using CadnaA with Option APL. The local wind fields have on enormous impact on the resulting distribution. This example shows that the maximum concentrations of fine particles PM10 are not found in the vicinity of the road crossing, but at of a building alongside of the most busy road.

CadnaA with Option APL includes the buildings as well as the terrain into the calculation of air pollutants distribution. This examples shows a highway section with the road surface below the mean terrain level and a housing areas nearby. There is also a barrier on top of the ridge alongside of the highway. Barriers are taken as buildings in CadnaA-APL as AUSTAL2000 does not consider barriers by default. The pictures illustrate the screening effect by the terrain as well as by the barrier on top.

When calculating the distribution of air pollutants at a tunnel mouth the increased emissions due to the volume shift by the vehicles inside the tunnel has to be taken into account for the exit lanes. This effect cannot be modeled by placing vertical area sources at the tunnel mouth. Therefore, the emission is distributed to several road segments for the exit lanes to cause an exponentially decreasing emission with increasing distance from the tunnel mouth. This effect is not considered for the entry lanes.

CadnaA with Option APL can be applied to calculate the distribution of air pollutants along major roads for entire cities or agglomerations based on a digital town model set up for noise modeling. CadnaA offers the possibility to perform the prognosis and the assessment of noise and air pollution by using just with the same software tool and just one town model. Besides the well-known user-friendly handling concept of CadnaA it also offers numerous assessment and output features. For calculation, the PCSP-tiles have been distributed along the axis of the main roads. The pictures show the distribution of fine particles PM10 with influence of the buildings.

In a project CadnaA with Option APL was used to predict and assess the distribution of air pollutants resulting from domestic fuel at hillside situations. The emitting stacks are modeled as point sources above roof. Here, the resulting distribution for fine particles PM10 has been calculated for two asymmetrical rows of houses on a slope of 20 degrees with an emission rate of 2 grams/hour and for a wind direction of 260 degrees at a wind speed of 1 m/s.

For modeling of the emission of industrial sources the CadnaA objects point, line, and (vertical, horizontal) area sources are used. This example shows a gravel pit modeled as an area source. The emission time series can be entered for each daily hour individually and for each pollutant. The calculation considers the influence by the terrain to assess the resulting concentrations at the houses in the vicinity.

To model industrial sources in CadnaA with Option APL the objects point, line, and area source (vertical, horizontal) are used. The calculation considers besides the hourly emission rate for each component the additional rise of the plume due to its thermal lift by entering the following parameters:

- heat flux of the exhaust gas or exhaust temperature
- exhaust velocity
- stack diameter
- liquid water content or relative humidity of the plume (when emitted via a cooling tower)

The example illustrates the NOx-distribution by three high point sources at an industrial site. The plume due to the power plant's building structure the plume is drawn to the ground on the downwind side. At this location the concentration increases considerably. The houses in the residential area cause an accumulation and an expansion of the plume perpendicular to the plume's axis.