This report the concerns the implementation of a lung deposition model into an existing modelling system within the project Effect Models at FOI, the Swedish Defence Research Agency. In the chain Exposure-Dose-Response, dose is herein the amount of aerosol deposited in the lung. The model should be able to estimate the deposition as a function of particle size and the distribution of the deposited particles in the respiratory system. Both these two factors may have impact on the medical consequences following the exposure. Effect Models deals with scenarios including human exposures to particulate aerosols. The available human body exposure area to airborne particles is for the skin 1.5-2 m2, the gastro-intestinal 200 m2, and respiratory tract 140 m2.Adults breathe over 10 000 liters of air every day and since aerosols are rather inhaled than swallowed; the lungs are the major route of concern for atmospheric spread of toxic agents. To accurately assess health effects (the response), it is of uttermost importance to predict lung deposition in the various regions of the respiratory tract. Example of scenarios that unintentionally may produce toxic particulate aerosols include fire, leaking tanks or nuclear meltdowns. Other cases, although less common historically, include intentional atmospheric spread of chemical, biological or radio nuclear agents. It was found that the most suitable model depends on the aerosol at hand. In brief; radioactive aerosols are best modeled with the ICRP model, accurate nanoparticle deposition can be obtained with NCRP model, pharmaceutical aerosols can be evaluated with the MCNP, and several alternatives exists for research details.