This report presents a comparison of two Gaussian atmospheric dispersion models widely used in France to estimate public exposure to emissions from stationary sources of pollutants: ADMS and ARIA Impact. The methodology was chosen from the perspective of a model user. With this in mind, the comparison was conducted using a real-world scenario—the dispersion of dioxin and furan emissions from a household waste incineration plant—and utilized measurements taken in the soil near the facility. This study shows that the discrepancies observed between the atmospheric dispersion modeling results from these two models have multiple explanations. Differences in the calculation equations contribute to these discrepancies, particularly regarding deposition results, which represent the primary route of exposure for populations to organic pollutants. Another explanation, related to the model interfaces that determine their application, is also significant. Finally, the uncertainty of the input parameters for the models, particularly regarding dioxins and furans, has a major influence on the observed discrepancies between the model results. Comparisons of the modeling results with soil measurement data allow for the relativization of the uncertainties associated with modeling relative to those associated with measurement. These comparisons underscore the importance of acquiring knowledge about the initial state of the environment prior to the construction of any industrial facility in order to understand exogenous inputs to the studied source. This report also offers practical recommendations for users of both models. (R.A.)