Sequestration of chlordecone in the porous structure of an andosol and effects of added organic matter: an alternative to decontamination

Abstract

The context of this study is the pollution of soils and water by a persistent organo‐chlorinated insecticide, chlordecone, in a tropical environment. The application of chlordecone to control the banana black weevil has led to continuing diffuse pollution of soils, and to its being a source of contamination for cultivated plants, as well as for terrestrial and marine ecosystems. Chlordecone is toxic and stable and is considered to be a persistent organic pesticide. Consequently, the amounts of chlordecone that could migrate through the environment and contaminate agricultural products need to be controlled. We measured the impact of two composts (5% weight) on chlordecone sequestration in andosols. To this end, we first characterized the transfer of chlordecone from soil to water, and then its transfer from soil to plants. After 3 months of maturation, soil‐water and soil‐plant transfers were reduced by a factor of from 3 to 10. We also showed that adding compost to contaminated soils increases chlordecone sequestration because it leads to changes in soil microstructure in the form of pore collapse and closure of the fractal structure of the allophane content.

Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils

“…This K oc value is consistent with the reported range in the literature of 2500 to 20,000 cm 3 g -1 (Woignier et al, 2012) and indicates that CLD sorption on the soil is mainly controlled by hydrophobic interactions with soil organic carbon (Cabidoche et al, 2009;Levillain et al, 2012;Li et al, 2012), while inorganic soil components like clay minerals play a relatively minor role, which produces a limited mobility of CLD in soils (Fernandez-Bayo et al, 2013a;. The sorption of SDZ in the same (Kaldenkirchen-Hülst) soil was described in an earlier study (Zarfl, 2008 (Kasteel et al, 2010).…”

Compost addition reduces porosity and chlordecone transfer in soil microstructure

“…We have already demonstrated the efficiency of compost addition in reducing chlordecone transfer from the soil to water (Woignier et al 2012b). After 90 days of maturation of the organic amendment, chlordecone content of water leached through amended andosol was 20 % of the chlordecone content in the water leached through control andosol.…”

“…After 90 days of maturation of the organic amendment, chlordecone content of water leached through amended andosol was 20 % of the chlordecone content in the water leached through control andosol. Moreover, adding organic matter decreased the capacity of plants to take up chlordecone: compared with the transfers of chlordecone in the control soils, transfers were 7 % for radish, 23 % for lettuce, and 51 % for cucumber in the soils with added organic matter (Woignier et al 2012b).…”

Ultra-trace quantification method for chlordecone in human fluids and tissues

“…Extraction of the fatty content is performed by binary solvent mixtures, e.g. toluene/ethyl acetate (1:3, v/v), followed by petroleum ether/fuming sulfuric acid [9], hexane/acetone (85: 15, v/v) [15], dichloromethane/acetone (50:50, v/v) [16] or by pressurized liquid extraction with hexane/dichloromethane/methanol (5:2:1, v/v/v) [17]. Clean-up is made either by liquid/liquid washing of the organic layer with sodium hydroxide, followed by sulfuric acid [15] or Florisil ® purification [16].…”