Activated carbon, a useful medium to bind chlordecone in soil and limit its transfer to growing goat kids

Abstract

Chlordecone (Kepone) (CLD) is a highly persistent pesticide which was extensively used in the French West Indies; high levels of CLD can still currently be found in large agricultural areas. As CLD transfers from soil to animals mainly via involuntary ingestion, the consumption of foodstuffs derived from animals raised in contaminated areas may significantly contribute to exposure of humans to CLD. The present study was designed to test the efficacy of two different activated carbons (ACs) sources in limiting CLD transfer from soil to animal. Three soils (ASs) were prepared according to the OECD guideline 207. One standard soil (SS) lacking AC, and two modified preparations of SS supplemented with 2% coconut-based activated carbon (ORBO), SSO or with 2% lignite-based one (DARCO), SSD. All three soils were spiked with 10 μg of kepone per g of dry matter and aged for three weeks. This study involved 15 goat kids randomly assigned to the 3 experimental groups (n = 5/group), which were fed the experimental matrices at an exposure dose of 10 μg CLD per kg of body weight per day. After 21 d of oral exposure, CLD in adipose tissue and liver were analysed by LC-MS-MS. A significant decrease of 63.7% and 74.7% of CLD concentrations in adipose tissue and liver, respectively, were obtained from animals exposed using SS containing DARCO as compared to those receiving only SS. Decreases in CLD levels of 98.2% (adipose tissue) and 98.7% (liver) were obtained for animals exposed using SS containing ORBO. This study leads us to conclude that (i) the presence of AC in CLD-contaminated soil strongly reduces CLD bioavailability, and (ii) the efficacy depends on the nature and characteristics of the AC used.

Amendment of soil by biochars and activated carbons to reduce chlordecone bioavailability in piglets

“…This contrast with relative bioavailability and availability data obtained from ACs which displayed a clear reduction of CLD transfer. This result is in accordance with previous data obtained with the same soil and for different organic pollutants (Delannoy et al, 2014a, Delannoy et al, 2014b and CLD (Yehya et al, 2017). One main explicative hypothesize should be that the 700 °C pyrolysis process is not enough to achieve the quality of porosity needed to bound CLD and limit its subsequently its availability.…”

“…. In the present paper the bioavailability was assessed in a relative way as a reference matrix (standard soil) was used and set to be 100% transferred to animal Bouveret et al, 2013, Delannoy et al, 2014a, Littell et al, 1997 This assumption was made 1) to compare soil with and without organic matter and biochars or activated carbon to finely assess the sequestration of each media and 2) such matrix is known to possess the same behaviour than contaminated feed Bouveret et al, 2013, Yehya et al, 2017 which was used to assess the toxicity of those molecules in numerous studies in organic contaminant. By this way, the exposure assessment obtained from the relative bioavailability assay could be compared to the known hazard of those pollutants.…”

Reduction of chlordecone environmental availability by soil amendment of biochars and activated carbons from lignocellulosic biomass

“…6 and 7). This result is in accordance with previous data obtained within OECD soil and for different organic pollutants (Delannoy et al 2014a;Delannoy et al 2014b) and CLD (Yehya et al 2017). It indicates that the pyrolysis process on its own is not sufficient to reach an adequate basal porosity quality and a total surface area which would be needed to bound CLD and consequently to reduce its environmental availability.…”

In vitro and in vivo assessment of a CLD sequestration strategy in Nitisol using contrasted carbonaceous materials

“…The current reference analytical method (French Ministry of Agriculture, 2015) was applied to control CLD in liver against the maximum residue levels established in European regulation (Commission of the European Communities, 2008). This methodology is described elsewhere (Yehya et al, 2017) and was performed by a COFRAC accredited laboratory (Labocea, Quimper, France).…”

“…To limit transfer to plant, compost amendment of CLD-contaminated soils displayed a reduction of transfer to plants by a factor of 3 to 10 compared to non-amended soils (Woignier et al, 2012). Activated carbons (ACs) amendment showed also a reduction up to 90% in nonphysiological based in vitro environmental availability assays (Ranguin et al, 2020) or 95% in in vivo relative bioavailability assays using spiked OECD artificial soils (Delannoy et al, 2019;Yehya et al, 2017). To date, no data are available concerning the sequestration potential of ACs in an historical Antillean contaminated soil using a combination of physiological based in vitro and in vivo assays.…”