A new modular computational tool for estimating concentrations, exposure and risks levels due to a source of local pollution
Résumé
In France, risk assessment studies have to be conducted before the implementation or the enlargement of some new facilities and before the reuse of contaminated sites. However, the quality of prospective risk assessment studies largely depends on the relevance of the modeling tool and of the input data used in regards to the case study. The levels of predicted risk can vary of one or more orders of magnitude according to the assumptions used, as showed by various studies of intercomparison carried out by INERIS. To improve the practices and the transparency of the estimates obtained in these studies, INERIS develops and diffuses modeling tools in the framework of one's missions for the ministry in charge of the Environment. A peer-reviewed handbook, entitled 'Sets of equations for modeling exposure linked to soil contamination or emissions from an industrial facility ', is available on INERIS'website in French and at soon in English. This document presents the equations used at INERIS for estimating the media concentrations, the exposure and risk levels. It also describes the origin of these equations and underline the hypotheses on which they are built and their limits. A modeling and simulation platform based on the equations presented in this handbook has been built. The objective of this toolbox is to enable the users to design exposure models in accordance with the pathways identified for each specific site studied and to build up the models using a library containing preset modules of parameters and equations. This tool was designed to give a large flexibility to the users. The users are able to choose between various mathematical representations of some phenomena, and also to use measurement data instead of predicted values by the model at any level. The risks can be calculated with or without background concentrations. The non-carcinogenic risks can be calculated by substance and by target organs. The carcinogenic risks are calculated by the average exposure of the receptor over its whole life considering the evolution of its exposure parameters during it. The tool also enables to lead sensitivity and uncertainties analyses. One of the most important objectives during conception was to warrant the transparency of future studies. To reach this goal, on one hand, the users can view all the equations and the data used, as well all the intermediate calculations performed. On the other hand, the changes made to the default data and default calculations defined in the platform are pointed out on the screen and in the editable report. Lastly, this tool is evolutionary: new mathematical approaches and new functionalities will be added, such as the coupling with a database and a GIS.A short demonstration of the tool will be performed.