The Nord-Cotentin chemical risk assessment modeling : how ecotoxicology and radioecology can help each other ?
Céline DUFFA, Caroline RINGEARD, Laurence ROUÏL, Roseline BONNARD, Marguerite MONFORT, Karine BEAUGELIN, Laure DELERY, Catherine ROMMENS.
Congrès IUR-SETAC, Anvers (Belgique), 4-8 février 2002
The first objective of the Nord-Cotentin working Group (GRNC) was to assess the radiological risk due to past and recent discharges of the nuclear facilities of the Nord-Cotentin region of France. Now, at a second stage, the group is working on the assessment of the risk due to the corresponding chemical releases.
One step of this assessment is to build up a common tool to estimate the level of pollutants in the environment. To perform this objective, engineers and experts from environmental toxicology/chemistry and radioecology organizations are working together, within the framework of the GRNC, to model environmental dispersion and transfers and exposures to pollutants.
This paper deals with atmospheric sources of pollutants and terrestrial environmental contamination. Three specific facilities were identified as atmospheric sources of chemicals in La Hague nuclear site: the central boiler house (since 1964), the reprocessing units, UP2 and UP3 (since 1966), and the incinerator (since 1995). The list of about 30 studied chemical substances (heavy metals, inorganic and organic substances) was established on the basis of different criteria related to their emission, their potential of exposure and their toxicity. For the selected pollutants, a transfer model is developed using radioecology modeling approach, available from the previous GRNC work combined with knowledge of properties on chemicals of interest. Atmospheric dispersion, deposition on the ground, interception of pollutants by leaves (retention and translocation) and root transfer are examined just as uptake by animals. This tool will permit an estimation of concentrations of chemical pollutants that can be attributed to La Hague releases, for the main terrestrial compartments of the environment.