Environmental fate of chlordecone in coastal habitats: recent studies conducted in Guadeloupe and Martinique (Lesser Antilles)

Abstract

The organochlorine pollution by chlordecone, an insecticide spread in the past in banana plantations, is now recognized as a major ecological, economic, and social crisis in Guadeloupe and Martinique Islands. Due to its physical and chemical properties, this molecule is particularly persistent in the natural environment. Volcanic soil of Guadeloupe and Martinique contain allophanes (amorphous clays), which favor chlordecone trapping due to their structure and physical properties. Thus, with this trapping ability, allophanes serve as a vector allowing chlordecone to contaminate runoff waters and, finally, the sea. In the present publication, several studies recently conducted in the Lesser Antilles have been compiled in order to evaluate the desorption of chlordecone from allophanes when arriving in the estuarine environment and to determine the transfer of chlordecone along marine trophic food webs. The experiments showed that 20% of the initial quantity of chlordecone was released from allophanes in estuarine conditions and 10% in the marine environment. These results could explain the high level of contamination found in the suspended organic matter and zooplankton in the coastal areas located downstream of the contaminated watersheds. The contamination of the marine food webs of mangroves, seagrass beds, and coral reefs is dominated by a contamination "by bath" in littoral waters containing chlordecone and by bioamplification seawards.

Evidence for extensive anaerobic dechlorination and transformation of the pesticide chlordecone (C10Cl10O) by indigenous microbes in microcosms from Guadeloupe soil

“…CLD adsorbs strongly to soils rich in organic matter, and its partitioning coefficient (log K oc ) has been reported in the range of 3.3-3.41 [1,6]. CLD is only slightly soluble in water (2.7 mg/L at pH 7 and 25˚C) [7] and tends to bioaccumulate in fatty tissues of living organisms [8,9]. CLD is also neurotoxic, immunotoxic, hepatotoxic and spermatotoxic to most living organisms [10,11].…”

“…Surface water, ground water, sediments and receiving coastal wasters have all been impacted. CLD has also been found to accumulate in animals [15][16][17] and plants used for food, including tubers and other vegetables grown in soil [18,19] as well as in marine fauna [9,20]. Effective methods to decontaminate soil and protect downgradient environments, food and water supply are clearly needed.…”

Critical care medicine in the French Territories in the Americas: Current situation and prospects

“…The FTA face infectious diseases, indigenous forms of opportunistic or tropical diseases, some chronic diseases with a genetic predisposition (sickle cell disease), environmental disaster (invasion of Sargassum seaweed), and the health consequences of specific environmental pollution (chlordecone in the West Indies, mercury in French Guiana) (19)(20)(21)(22). Monitoring and research needs are therefore important and are attractive for researchers and students.…”

Micropollutant content of Sargassum drifted ashore: arsenic and chlordecone threat assessment and management recommendations for the Caribbean

“…Concerning all the 7 sampling sites of Grande-Terre of Guadeloupe, chlordecone was never observed. Concerning Guadeloupe, chlordecone was only observed in Basse-Terre of Guadeloupe at places where contaminated watershed are known to discharge at sea(Dromard et al, 2019). In the concerned area shing and collecting seafood is restricted due to the chlordecone threat.…”