OLAF -- a general modeling system to evaluate and optimize the location of an air polluting facility We propose a general modeling and optimization system for the effects of a low toxic air pollutant on the inhabitants of different land-based ecosystems. The pollution load can be traced through different ecotrophic levels, while health effects are quantified on the basis of detailed cytodynamic effects in different organs and tissues. The software package OLAF (Optimal Locating Air polluting Facilities) developed on the basis of this model does not only evaluate quantitatively the effects of a proposed decision, but uses an efficient optimization technique to optimize the location of a polluting facility with respect to the adverse effects of the total pollution load on the inhabitants of the region under consideration.