Institut national de l‘environnement industriel et des risques (INERIS), Parc Technologique ALATA, BP 2, 60550 Verneuil‐en‐Halatte <roseline.bonnardineris.fr>
We have used a simple, conservative model, written in Excel, to calculate exposure by ingestion of 2,3,7,8‐tetrachlorodibenzodioxin due to atmospheric emissions from large combustion plants and their subsequent deposits. We then compared the results with those yielded by CALTOX and analyzed the reasons for the differences. In the case we studied, it was possible to obtain very similar results with both models after several changes made their underlying hypotheses comparable (using the same values for physicochemical parameters and the same exposure target characteristics, modifying one of the transfer hypotheses, and adapting the hazard quotient calculation in CALTOX). Even when the hypotheses of two models seem globally the same, specific differences can result in quite different results. For this reason, the details of the hypotheses underlying the model used should always be specified. Using a simple model can, at least in early study stages, improve the transparency of studies.