Response of a grassland ecosystem to air pollutants. V. A toxicological model for the assessment of dose–response relationships for air pollutants and ecosystems

The principles of the interaction between gaseous air pollutants and ecosystems are investigated using a pharmacokinetic model. This model illustrates the importance of pollutant flux determinations by measurements and/or by modeling in order to provide a description of the adequate dose entity. It serves as a mechanistic base for the present discussion of flux-based versus concentration-based air quality guidelines. Consequently, the results obtained from chamber experiments can only be transferred to ambient conditions, if the function relating fumigation concentrations to absorbed fluxes is established. Adequate dose–response relationships for airborne pollutants and plant/soil systems presuppose a combination of flux measurements, free-air exposure systems and Soil-Vegetation-Atmosphere Transfer models.