摘要: Publisher Summary This chapter presents an overview on the different concepts how to evaluate exposure and impact assessment models. Furthermore, approach is outlined applied by which reliability of results with respect their valuation at European scale shall be assessed. The discusses approaches for evaluation results. One way subdividing validation process into components (a) operational or whole model validation, (b) theoretical conceptual validity, (c) data only can validated whereas theory cannot. A thorough in-depth presented external cost would constitute a major task in its own right. Therefore, more semi-quantitative followed chapter. purpose Impact Pathway Approach provide estimates that are specific human activity, it single collective/societal activity. supports decision-making conducting cost-benefit analyses policy options. focuses costs resulting from health impacts because indirect decision-support Union level and/or member countries including acceding (potential) accession countries.