Modelling heavy metal fluxes from traffic into the environment.
A new method is presented which allows emissions of traffic into the environment to be described as a function of road distance. The method distinguishes different types of emissions (runoff, spray and drift), which are determined by measurements and mass balances of a specified road section. The measurement of two-dimensional pollutant concentrations in the road shoulder is an important part of the method. In a case study performed at Burgdorf, Switzerland, the method was applied to the determination of the spatial distribution of heavy metal emissions. The results show that between 36 and 65% of the heavy metals Cd, Cr, Cu, Pb and Zn are present in runoff and spray and between 35 and 64% are dispersed diffusely in the environment (defined as drift). The runoff infiltrates into the vegetated road shoulder up to a distance of approx. 1 m from the road. The distribution of spray shows a maximum at 1 m and decreases steadily up to a distance of 5 m. This information can serve as a basis for the quantitative evaluation of road-runoff treatment scenarios. Although the results of the Burgdorf study are case-specific, several general guidelines for the reduction of traffic-related emissions can be derived from it.
Eawag: Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland. michele.steiner@eawag.ch
Michele
M
Steiner
Markus
M
Boller
Thorsten
T
Schulz
Wouter
W
Pronk
D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis*; D008962:Models, Theoretical; D013557:Switzerland; D014186:Transportation; D001335:Vehicle Emissions / Q000032:analysis*
D000393:Air Pollutants; D019216:Metals, Heavy; D001335:Vehicle Emissions