Contamination of free-range ducks by chlordecone in Martinique (FrenchWest Indies): A field study
The former use of chlordecone (CLD) in the French West Indies has resulted in long-term pollution of soils and subsequently of food chains. In contaminated areas, free-range ducks used to control weeds in orchards may be exposed to CLD through polluted soil ingestion. The question arises whether they may be consumed. Muscovy ducks were raised on a guava orchard planted on a soil moderately contaminated (410 ?g CLD/kg dry matter). Duckswere raised indoor up to 6 weeks of age and allowed to range freely outdoors thereafter. Twentynine females were sequentially slaughtered by groups of 2 to 5 ducks, after 4, 16, 19, 22 or 26 weeks spent in the orchard or after 16-17 weeks in the orchard followed by 3, 6 or 9 weeks in a closed shelter for depuration. CLD concentration increased from258 to 1051, 96 to 278, 60 to 169 and 48 to 145 ?g/kg fresh matter (FM) as the exposure through grazing increased from 4 to 22 weeks, in liver, abdominal fat and leg with and without skin, respectively. Eggs collected in the orchard contained up to 1001 ?g CLD/kg FM. All these values exceeded the MaximumResidue Limit (MRL) of 20 ?g/kg FM. CLD concentration in all tissues was divided by around 10within the 9-week confinement period. Despite this quite rapid decontamination, it is estimated that 12-13 weeks would be required to achieve the MRL in liver and in eggs, and 5-6 weeks in leg muscle. Such durations would be too long in practice. Thus, the consumption of products from free-range ducks should be avoided, even in areas mildly contaminated with CLD.