7. CONCLUSIONS AND DISCUSSION

The application of transport-transformation models involves significant uncertainties that may have implications on the confidence in model estimates and on their use in the assessment of possible alternative scenarios in a regulatory framework, for example, with respect to control strategy selection for decreasing pollutant levels. Hence, it is important to address these uncertainties. However, the main limitations in performing comprehensive uncertainty analyses of transport-transformation models are the associated cost and effort, and the increased data needs for characterizing uncertainties in inputs. Clearly, there is a need for methods that can reduce the cost and effort associated with uncertainty analysis of transport-transformation models.