Improved specificity of radiological assessment models leads to better planning for emergency response and long term agricultural counter measures, particularly in developing countries, through the development of generic data as well as those more relevant to local conditions. In addition, more precise information on environmental parameters may be used when setting limits for authorized discharges from nuclear installations. This publication summarizes the results of a Coordinated Research Project initiated in cooperation with the International Union of Radioecologists (IUR) to address this need for improved specificity.