ChlorExpo: measuring chlordecone exposure to more closely reflect dietary habits

Chlordecone is an insecticide that was used in banana plantations in Guadeloupe and Martinique until 1993. The ChlorExpo study was launched in 2021 as part of France's Chlordecone Strategy. It follows on from ANSES’s previous work on this pesticide, which has been banned due to its toxicity but still persists in the environment. The study measured for the first time chlordecone contamination levels in food as it is produced and consumed in Guadeloupe and Martinique. 

Recent data on contamination in food as consumed

The study began with a survey of around 1500 households in the two regions on their food sourcing, preparation and cooking practices. Food samples were then taken, prepared and cooked in accordance with the survey results. 

Concentrations of chlordecone in food were then measured by ANSES’s Laboratory for Food Safety. ChlorExpo therefore examined contamination in 45 types of foods (fruit, vegetables, tubers, meat, eggs and fishery products) sourced from various supply channels (shops, markets, roadside stalls, home-grown produce, etc.).

Encouraging results on food contamination levels

The analyses carried out on the samples suggested lower levels of chlordecone contamination than had been observed in previous studies, particularly in root and other vegetables. The substance was not detected in fruit samples.

These encouraging results may be largely due to people following the recommendations on cultivation practices aimed at reducing contamination of home-grown produce under the JAFA family garden programme, run by the regional health agencies. 

Fishery products and eggs remain the foods with the highest levels of chlordecone, particularly those obtained through informal channels (home production, recreational fishing, sales from roadside stalls, gifts).

The ChlorExpo study also investigated, for the first time, the presence of chlordecol – the main metabolite of chlordecone – in foods consumed in the French Caribbean. It was detected in fewer than 3% of samples. 

New exposure data that better reflect reality 

New data from ChlorExpo on chlordecone levels in foods as consumed, together with consumption frequencies (food types and quantities) obtained from the Kannari 1 study conducted by Santé Publique France and ANSES in 2013–2014, were used to re-estimate dietary exposure to chlordecone. 

Among adults, the average exposure was 0.020 micrograms per kilogram of body weight per day (µg/kg bw/day) in Guadeloupe and 0.015 µg/kg bw/day in Martinique. For almost the entire population, the calculated exposure levels were below the chronic oral toxicity reference value updated by ANSES in 2021.

Although caution is needed when making comparisons, as the methodologies used were not the same, these exposure levels were also lower than those measured in previous studies and work carried out by ANSES. The differences between the two regions may be explained by their differing sourcing and consumption habits. 

Lower exposure via formal supply channels confirmed

The study’s findings confirmed that people who sourced their food mainly through formal channels, i.e. from supermarkets, small shops and markets, or from professional fishers and farmers, were less exposed to chlordecone than those who more often used informal channels. 

Three-quarters of the survey respondents reported that they sourced the majority of their food through formal channels, a higher proportion than in 2014. 

Fishery products the highest contributing foods

The ChlorExpo study was able to identify which foods contributed most to chlordecone exposure across the different regions and populations. 

In Guadeloupe, sea fish and eggs were the main sources of dietary exposure for children, whereas for adults, it was sea fish, molluscs and crustaceans, as well as freshwater crustaceans. 

In Martinique, children were mainly exposed through the consumption of freshwater crustaceans, eggs and sea fish, while for adults it was freshwater crustaceans.

No measured effect from the cooking method 

Another aim of the study was to determine whether the cooking method could affect the chlordecone content in food. The most common cooking methods in the French Caribbean are boiling for vegetables, simmering for meat, and poaching (blaff) for seafood. 

Measurements taken on food as consumed did not reveal any significant effect of cooking on the chlordecone content. This means that no particular cooking methods can be recommended for reducing exposure to chlordecone. 

Continue following recommendations to limit exposure to chlordecone 

Among the consumption recommendations previously issued by ANSES for limiting exposure to chlordecone, the results of ChlorExpo especially confirmed the value of:

• not consuming freshwater fishery products from areas where fishing is prohibited by prefectural order,
• limiting the consumption of certain products sourced from sea fishing,
• taking part in the JAFA programme (for owners of laying hens). This offers free soil testing and advice on how to limit contamination of eggs. 

Once the consumption frequencies have been updated by the Kannari 2 study, which is currently being finalised by Santé Publique France, ChlorExpo’s findings will be used to reassess the health risks associated with dietary exposure to chlordecone. 

This assessment will enable the recommendations for limiting chlordecone exposure to be updated, with a view to relaxing them. ANSES also recommends setting up a scheme to monitor the impact of management measures on food contamination over time.