Contamination of free-range ducks by chlordecone in Martinique (French West Indies): A field study

Abstract

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 (410μg CLD/kg dry matter). Ducks were raised indoor up to 6weeks of age and allowed to range freely outdoors thereafter. Twenty-nine females were sequentially slaughtered by groups of 2 to 5 ducks, after 4, 16, 19, 22 or 26weeks spent in the orchard or after 16–17weeks in the orchard followed by 3, 6 or 9weeks in a closed shelter for depuration.CLD concentration increased from 258 to 1051, 96 to 278, 60 to 169 and 48 to 145μg/kg fresh matter (FM) as the exposure through grazing increased from 4 to 22weeks, in liver, abdominal fat and leg with and without skin, respectively. Eggs collected in the orchard contained up to 1001μg CLD/kg FM. All these values exceeded the Maximum Residue Limit (MRL) of 20μg/kg FM. CLD concentration in all tissues was divided by around 10 within the 9-week confinement period. Despite this quite rapid decontamination, it is estimated that 12–13weeks would be required to achieve the MRL in liver and in eggs, and 5–6weeks 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.