HIA can be applied to large variety of topics as can be seen in previos list which is far from being complete. This relustls of course also in variety of methodologies used to perform health impact assessment. Searching the literature one can identify about 16 different models or guidances for HIA. Nevertheless, two of them seems to be crucial for developemnt of HIA and approaching some common methodology. These are the Merseyside guidelines and the 10 step risk model of the University of Bielefeld. Summary of models is given in the Developing health impact asseessment in Wales; Better Health, Better Wales brochure (20). Moreover a generla model of methodolgy is presented in this important publication as well.