Ecodynamics of PCBs in lacustrine environments : abiotic transfers and bioaccumulation in fish

• Main Author: Masset, Thibault
• Other Authors: Laboratoire de Chimie Moléculaire et Environnement (LCME), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry ), Université Grenoble Alpes, Emmanuel Naffrechoux, Christine Piot
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2019
• Subjects: PCB; Decontamination; Lakes; Bioaccumulation; Fish; Volatilization; Décontamination; Lacs; Poissons; Volatilisation; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Arctic
• Online Access: https://theses.hal.science/tel-03574658; https://theses.hal.science/tel-03574658/document; https://theses.hal.science/tel-03574658/file/MASSET_2019_archivage.pdf

Nowadays, numerous natural or manmade chemical compounds still disseminate in our environment. Among them, Polychlorobiphényls (PCBs) are compounds produced between 1920 and 1990 for various industrial applications, today considered as ubiquitous pollutants. As 1 of the 12 Persistent Organic Pollutants (POPs) referred-to by the Stockholm Convention in 2001, they exhibit physicochemical characteristic (high environmental half-life, low degradation, semi-volatility) enabling their mobility and persistency in the environment. Moreover, they are highly toxic (classified as carcinogenic molecules by the International Agency for Research on Cancer (IARC) and, thus, responsible for many environmental and sanitary issues over the globe. Knowledge of abiotic and biotic transfers mechanisms of PCBs in perialpine aquatic ecosystems is limited. PCB ecodynamics need further investigation for a better understanding of their fate in these highly sensitive ecosystems. The main objectives of this thesis were i) to identify the main fluxes driving PCBs dynamics in perialpine lakes, ii) to evaluate appropriate models or methodologies for accurate determination of volatilization fluxes of PCB at the air/water interface and iii) to characterize environmental, trophic and physiologic factors affecting PCB contamination of fish in perialpine lakes. Lake Bourget (Savoie – France) was chosen as the study site for this work. Field sampling was performed and coupled with modeling approaches enabling to identify sediment burial and volatilization as the main mechanisms leading to the natural decontamination of the lake. Tributaries inflows were responsible for most of the PCB inputs to the lake water. An experimental device was developed for direct measurements of the volatilization flux and the results were compared with the model-based approaches currently used in the literature. Finally, bioaccumulation mechanisms of PCBs for two fish species (Arctic char and whitefish) were disentangled. Anatomic, trophic and environmental factors ...