Soil thresholds and a decision tool to manage food safety of crops grown in chlordecone polluted soil in the French West Indies.
Due to the persistent pollution of soils by an organochlorine, chlordecone (CLD also known as Kepone©) in the French West Indies, some crops may be contaminated beyond the European regulatory threshold, the maximum residue limit (MRL). Farmers need to be able to foresee the risk of not complying with the regulatory threshold in each field and for each crop, if not, farmers whose fields are contaminated would have to stop cultivating certain crops in the fields concerned. To help farmers make the right choices, we studied the relationship between contamination of the soil and contamination of crops. We showed that contamination of a crop by CLD depended on the crop concerned, the soil CLD content and the type of soil. We grouped crop products in three categories: (i) non-uptakers and low-uptakers, (ii) medium-uptakers, and (iii) high-uptakers, according to their level of contamination and the resulting risk of exceeding MRL. Using a simulation model, we computed the soil threshold required to ensure the risk of not complying with MRL was sufficiently low for each crop product and soil type. Threshold values ranged from 0.02 μgkg-1for dasheen grown in nitisol to 1.7 μgkg-1for yam grown in andosol in the high-uptake category, and from 1 μgkg-1for lettuce grown in nitisol to 45 μgkg-1for the leaves of spring onions grown in andosol in the medium-uptake category. Contamination of non-uptakers and low-uptakers did not depend on soil contamination. With these results, we built an easy-to-use decision support tool based on two soil thresholds (0.1 and 1 μgkg-1) to enable growers to adapt their cropping system and hence to be able to continue farming.
Cirad, UPR fonctionnement agroécologique et performances des systèmes de culture horticoles (HortSys), F-97285, Le Lamentin, Martinique, France. Electronic address: florence.clostre@cirad.fr.
Florence
F
Clostre
Cirad, UPR Agroécologie et intensification durable des cultures annuelles (Aida), F-34398 Montpellier, France.
Philippe
P
Letourmy
Cirad, UPR fonctionnement agroécologique et performances des systèmes de culture horticoles (HortSys), F-97285, Le Lamentin, Martinique, France; Cirad UR HortSys, F-34398 Montpellier, France.
Magalie
M
Lesueur-Jannoyer
D000383:Agriculture / Q000379:methods; D007631:Chlordecone / Q000032:analysis*; D018556:Crops, Agricultural / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D003661:Decision Support Techniques; D059022:Food Safety / Q000379:methods*; D007306:Insecticides / Q000032:analysis*; D008962:Models, Theoretical; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014900:West Indies
D007306:Insecticides; D012987:Soil; D012989:Soil Pollutants; D007631:Chlordecone
Crop uptake; Decision support tool; Food contamination; Persistent organic pollutant; Soil contamination threshold