Natural Chlordecone Degradation Revealed by Numerous Transformation Products Characterized in Key French West Indies Environmental Compartments

Marion L. Chevallier (1) , Oriane Della-Negra (1) , Sébastien Chaussonnerie (1) , Agnès Barbance (1) , Delphine Muselet (1) , Florian Lagarde (1) , Ekaterina Darii (1) , Edgardo Ugarte (1) , Ewen Lescop (2) , Nuria Fonknechten (1) , Jean Weissenbach (1) , Thierry Woignier (3) , Jean-François Gallard (2) , Stéphane Vuilleumier (4) , Gwenaël Imfeld (5) , Denis Le Paslier (1) , Pierre-Loïc Saaidi (1)

1 UMR 8030 - Génomique métabolique
2 ICSN - Institut de Chimie des Substances Naturelles
3 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
4 GMGM - Génétique moléculaire, génomique, microbiologie
5 LHyGeS - Laboratoire d'Hydrologie et de Géochimie de Strasbourg

Production and use of the insecticide chlordecone has caused long-term environmental pollution in the James River area and the French West Indies (FWI) that has resulted in acute human-health problems and a social crisis. High levels of chlordecone in FWI soils, even after its ban decades ago, and the absence of detection of transformation products (TPs), have suggested that chlordecone is virtually nonbiodegradable in the environment. Here, we investigated laboratory biodegradation, consisting of bacterial liquid cultures and microcosms inoculated with FWI soils, using a dual nontargeted GC-MS and LC-HRMS approach. In addition to previously reported, partly characterized hydrochlordecones and polychloroindenes (families A and B), we discovered 14 new chlordecone TPs, assigned to four families (B, C, D, and E). Organic synthesis and NMR analyses allowed us to achieve the complete structural elucidation of 19 TPs. Members of TP families A, B, C, and E were detected in soil, sediment, and water samples from Martinique and include 17 TPs not initially found in commercial chlordecone formulations. 2,4,5,6,7-Pentachloroindene was the most prominent TP, with levels similar to those of chlordecone. Overall, our results clearly show that chlordecone pollution extends beyond the parent chlordecone molecule and includes a considerable number of previously undetected TPs. Structural diversity of the identified TPs illustrates the complexity of chlordecone degradation in the environment and raises the possibility of extensive worldwide pollution of soil and aquatic ecosystems by chlordecone TPs.

Mots clés: Chlordecone; persistant organic pollutant; pollution; biodegradation; structure elucidation; transformation product

Domaines: Autre; Chimie analytique; Biodiversité et Ecologie

Marion L. Chevallier, Oriane Della-Negra, Sébastien Chaussonnerie, Agnès Barbance, Delphine Muselet, et al.. Natural Chlordecone Degradation Revealed by Numerous Transformation Products Characterized in Key French West Indies Environmental Compartments. Environmental Science and Technology, 2019, 53 (11), pp.6133-6143. ⟨10.1021/acs.est.8b06305⟩. ⟨hal-02309073⟩