Chlordecone in basal trunk wood of native trees growing in abandoned banana plantations in Guadeloupe, France

Abstract

Chlordecone (CLD), used to control the Cosmopolites sordidus banana weevil and released from polluted banana plantations, continues to contaminate ecosystems in the French Caribbean. Edible plants have been actively studied for risk prevention, but trees have not, even though they could play a significant role in future remediation strategies. CLD contents were analysed in 24 pioneer trees belonging to 13 species found in abandoned banana plantations in Guadeloupe, at three contaminated sites on Nitisols (Site 1) and Andosols (Sites 2 and 3). Wood samples were taken from each tree in the basal part of the trunk and the soil at its foot and their CLD content was measured by the analytical laboratory for the Drôme département (26) in Valence, France. Mean CLD contents in the top 30-centimetre soil layer from sites 1, 2 and 3 were 2,543 ± 702, 5,251 ± 1,102 and 875 ± 865 µg/kg dry soil respectively. Of the trees, 96% were contaminated. The CLD content in trees growing on Nitisols (3,406 ± 1,658 µg/kg dry wood) was at least 5 times higher than in trees growing on Andosols (299 ± 314 and 226 ± 378 µg/kg), but no clear relationships were found with soil CLD contents. Calculations of available CLD dissolved in the soil liquid phase using equations and soil datasets in the literature showed higher available CLD contents in Nitisols than in Andosols and a linear relationship between CLD available in soil and concentrations of CLD in wood, regardless of the type of soil. Trees growing on Nitisols are the plants most highly contaminated by CLD of all the plants in which this compound has been studied so far. With a plant-to-soil bioconcentration ratio around 150 l/kg, the consistent CLD uptake efficiency of the trees needs to be taken into account in further research for CLD remediation.