Évaluation du risque chimique dans l’environnement marin : exemple d’application aux installations industrielles du Nord-Cotentin

In the context of the European legislation on chemicals (existing, new chemicals and biocides) a risk assessment for the environment and human health is performed. A technical guidance document (TGD), in support of Commission Directive 93/67/EEC on risk assessment for new notified substances and Commission Regulation (EC) No1488/64 on risk assessment for existing substances has been developed in 1996 and was recently adapted for the marine environment. The methodological concept is based on the relation between a value representing the contamination level of a chemical substance in the environment (exposure assessment) and a value representing its effects on the environment (effects assessment). The exposure value is expressed as PEC for “Predicted Environmental Concentration” and the effect value is defined as the PNEC, for “Predictive No effect Concentration”. The risk characterisation is represented by the value of the PEC/PNEC ratio. The recent adaptation of the technical guidance document lead to two different aquatic assessments: one for the inland compartment and one for the marine compartment. This adaptation was conducted during two years and is the result of the co-operation of the European Commission and the OSPAR Convention. The main adaptations of the document to the marine environment concern the dilution rate in the water compartment, the behaviour of the substances, biodegradation, the local and regional exposure assessment scenario, effects assessment and secondary poisoning. A specific part dealing with PBT substances (Persistent, Bioaccumulable and Toxic) was also added. The initial concept of the guidance was however the same as for the inland environment. The document was used in the context of a specific study in France: “Environmental risk assessment of chemical releases of nuclear installations in Nord-Cotentin, France”. The chemical releases of industrial sites were mainly composed of metals and a few organic chemicals. The releases of 27 substances in the marine environment were assessed. Limits and uncertainties of the methodology were underlined regarding, in particular, the determination of PNEC and the lack of ecotoxicological data for the marine environment.