Record of trace organic contaminants in a river sediment core: from historical wastewater management to historical use

Thomas Thiebault (1, 2) , Fabrice Alliot (1) , Thierry Berthe (3) , Hélène Blanchoud (1) , Fabienne Petit (3) , Elodie Guigon (1)

1 METIS - Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols
2 EPHE - École Pratique des Hautes Études
3 M2C - Morphodynamique Continentale et Côtière

Some trace organic contaminants (TrOCs) can be considered as ubiquitous contaminants since the 1950s, and the study of their historical distribution within river sediments allows us to better understand the temporal variation of the chemical quality of sediments, and make assumptions about the most insightful forcings impacting these distributions. In this study, the occurrence of 41 TrOCs of various classes (i.e. pharmaceutical products and pesticides) was studied in a sedimentary core sampled in a disused dock along the Seine River, France. This core covers a 60 year-long period between 1944 and 2003, and 23 TrOCs were detected at least once. Their concentrations mainly ranged between 1 and 10 ng g-1 within the core, except for tetracycline that exhibited higher concentrations (~hundreds of ng.g-1). The dating of the core, based on previous studies, enabled the characterization of the changes since 1945, potentially impacted by (i) the sewer connectivity, (ii) the upgrading of wastewater treatment technologies, (iii) historical modifications in the use of each TrOC, and (iv) the sedimentary composition. In every case the deepest occurrence of each TrOC in the core matched its market authorization date, indicating the potential of TrOC to be used as chronomarkers. This study also reveals that the recent upgrading of wastewater treatment technologies within the 2 watershed decreased the concentrations of each TrOC, despite an increase in TrOC diversity in the most recent years.

Mots clés: Sediments; Wastewater treatment; Trace Organic Contaminants; Pharmaceuticals; Pesticides

Domaines: Géochimie; Environnement et Société; Interfaces continentales, environnement; Chimie organique

Thomas Thiebault, Fabrice Alliot, Thierry Berthe, Hélène Blanchoud, Fabienne Petit, et al.. Record of trace organic contaminants in a river sediment core: from historical wastewater management to historical use. Science of the Total Environment, 2021, 773, pp.145694. ⟨10.1016/j.scitotenv.2021.145694⟩. ⟨insu-03134012⟩