The Seine watershed covers 12% of France surface and represents one fourth of the French population, one third of its agricultural and industrial production and half of river boats traffic. Further, it can be subdivided in two parts: (i) the freshwater system (until the Poses city); and (ii) the estuarine system. Data related to contamination levels in the freshwater and estuarine water systems, the atmospheric deposition of contaminants in the watershed, as well as the agricultural land uses and human behaviours (diet, recreational activities, etc) at regional scale, were collected during the 2-FUN project.
The information provided by three research and monitoring programs ('Piren-Seine', 'Seine-aval' and monitoring network of the Seine-Normandie water management Agency) were reviewed and analysed to extract the data relevant for further health risk assessment. The analysis was based on contamination maps, temporal evolution, and the comparison with current acceptable limits in water. For case study no.2 of the project, a region situated on the Seine River watershed just downstream of Paris was selected. The region is characterized by strong industrialization and urbanization. The chemicals Benzo(a)pyrene (B(a)P) and Lead (Pb) were targeted by the case study, considering chemical exposure to humans via the ingestion of water, fish, vegetables (root, potato, and leaf ), grain, fruit, meat (beef), milk, and the inhalation of out-door air. Drinking water was assumed to be sourced from river water.
Long-term time series of B(a)P and Pb levels in river and air were reconstructed: (i) for river water, distributional methods were used to reconstruct a complete dataset considering non-detected values (that represent a significant fraction of monitored data); (ii) concentrations in air were generated by modelling tools, considering global emission at European scale. Several probability distributions for key parameters were updated with site-specific measurements.
Internal tissue concentrations of chemicals were predicted by coupling the multimedia environmental model and a generic PBPK modelling tool specifically parameterized for B(a)P and Pb. In conclusion, this case study demonstrated the feasibility of a full-chain assessment combining multimedia environmental predictions and PBPK model, including uncertainty and sensitivity analysis.
2-FUN project, newsletter 8 and newsletter 3