Risks of dietary exposure to chlordecone in the French Caribbean
What is chlordecone and what are its health effects?
Chlordecone is an organochlorine pesticide that was used from 1972 to 1993 in the banana plantations of Martinique and Guadeloupe to combat the banana weevil, a serious insect pest for this crop.
This substance is toxic to humans. Toxicological studies on animal models and epidemiological studies have shown adverse effects on the nervous system, reproduction, the hormonal system and the functioning of certain organs (liver, kidney, heart, etc.). In 2021, ANSES concluded that there was a probable causal relationship between prostate cancer and exposure to pesticides in general, and chlordecone in particular.
Where is chlordecone found?
Near the areas where this pesticide was used over the twenty-year period, chlordecone has contaminated soil, river water and the marine environment. It can therefore be found in certain plant and animal products, as well as in spring water that has not been treated with activated carbon. Many local foods (primarily fish, crustaceans, molluscs and eggs from backyard poultry flocks) may be contaminated, particularly in areas known to be affected due to the former presence of banana plantations.
Chlordecone has not been detected in air. Diet therefore remains the main route of exposure for the populations of Guadeloupe and Martinique.
Which populations are exposed to chlordecone in the French Caribbean?
In the Kannari study conducted by ANSES and Santé Publique France in 2013–2014, chlordecone was detected in more than 90% of individuals in the general population. The study showed that the vast majority of banana plantation workers in the French Caribbean were exposed to chlordecone during the period when this pesticide was used. According to Santé Publique France, there has been a decline in internal chlordecone contamination for most of the population since 2003, but these contamination levels remain high for certain categories of people.
According to the Kannari study, the populations most exposed to chlordecone are:
- in general, people living in areas known to be contaminated;
- consumers of freshwater fish, or of seafood products acquired from recreational fishing or via informal channels;
- consumers of poultry and eggs from domestic flocks in areas known to be contaminated;
- consumers of root and tuber vegetables from family gardens in areas known to be contaminated.
What foods contribute most to exposure?
The ChlorExpo study published by ANSES in 2026 reassessed dietary exposure to chlordecone in the populations of Guadeloupe and Martinique by combining dietary intake data from the Kannari study with recent data on contamination levels in foods as consumed. These data were obtained through a food sampling campaign designed to reflect the population’s actual eating habits as closely as possible, taking account of their preferences regarding food sourcing, preparation and cooking.
The results from ChlorExpo confirm that the foods contributing the most to exposure are:
- in Guadeloupe, sea fish and eggs for children, and sea fish, crustaceans and molluscs, as well as freshwater crustaceans, for adults;
- in Martinique, freshwater crustaceans, eggs and sea fish for children, and freshwater crustaceans for adults.
How can dietary exposure to chlordecone be limited?
Consumption of certain food products from informal supply channels (home-grown produce, gifts, purchases from roadside stalls, recreational fishing) leads to greater exposure than that associated with food obtained from formal channels (supermarkets, markets, grocery stores, professional fishers and farmers).
In 2021, around 75% of respondents to the ChlorExpo survey reported that they sourced the majority of their food through formal channels.
In 2007, ANSES issued the following recommendations to limit dietary exposure to chlordecone and reduce the health risks:
- Limit the consumption of fishery products acquired through short supply chains (recreational or subsistence fishing or purchases from roadside vendors) to no more than four times a week;
- Do not consume freshwater fishery products from areas where fishing is prohibited by prefectural order;
- Limit the consumption of roots and tubers from family gardens in areas known to be contaminated to no more than twice a week. On the other hand, unlimited amounts of any fruit from family gardens can be consumed.
In 2022, three-quarters of people in the French Caribbean followed these recommendations.
The 2026 findings of ChlorExpo suggest that these recommendations could be relaxed, particularly with regard to the consumption of tubers. This should be confirmed by the forthcoming reassessment of the health risks.
In addition, ANSES stresses the importance of limiting the contamination of food produced in gardens, especially eggs. For this, it recommends increasing membership and participation in the JAFA family garden programmes run by the Regional Health Agencies. This programme offers to carry out free tests to verify the levels of chlordecone in soil and foodstuffs, including eggs. These tests are used to provide personalised advice on suitable farming practices for family gardens. Good practices include isolating animals from contaminated soil as much as possible and giving them uncontaminated feed.
What are blood chlordecone levels?
These relate to the concentration of chlordecone measured in blood at a given time. The value of this measurement indicates recent exposure to chlordecone.
If chlordecone is found in the blood, it does not necessarily mean that a person is sick or likely to become sick. It is evidence of exposure to chlordecone. Actions to reduce this exposure are necessary, especially if the measured level exceeds the risk thresholds.
To understand the risks associated with chlordecone exposure, other parameters should be taken into account such as the duration, level or source of exposure.
What is ANSES doing about chlordecone?
For many years, the Agency has been involved in assessing the risks posed by chlordecone for the French Caribbean population.
Definition of reference values
In 2021, the Agency proposed new, more protective toxicity reference values (TRVs) following the publication of new scientific studies.
- The chronic external toxicity reference value
This is the amount of chlordecone ingested daily via food over a long period of time below which the risk of adverse effects in the population is considered negligible. This value is defined on the basis of toxicological and epidemiological studies.
In 2021, ANSES recommended lowering the external TRV from 0.5 to 0.17 µg per kilo of body weight per day. This new TRV takes into account the most recent studies suggesting toxic effects on reproduction in rodents exposed to moderate doses of chlordecone.
- The chronic internal toxicity reference value
This is the concentration of chlordecone in blood below which, over a long period of time, the risk of adverse effects in the population is considered negligible. As with the chronic external TRV, if this value is exceeded on a long-term basis, the risk of adverse effects in the population cannot be ruled out.
This value is used to interpret the results of campaigns to measure internal concentrations in the population. The internal TRV has been set at 0.4 µg of chlordecone per litre of plasma. ANSES reiterates that the chronic internal TRV is in no way an indicator of a person's health status and cannot therefore be used to interpret a measurement of blood chlordecone levels or guide an individual's medical follow-up.
These TRVs are tools for analysing data on dietary exposure and internal concentrations in the population. They provide an estimate of the proportion of the population that is overexposed and can be used to identify at-risk consumption profiles, i.e. people who, because of their dietary habits, have excessively high exposure to chlordecone. This is useful for identifying which foods are most problematic, which contribute most to high exposure, and therefore which ones should be the focus of special attention.
Assessing the risks associated with chlordecone
Using the toxicity reference values (TRVs) developed in 2021, ANSES carried out a risk assessment in late 2022.
The experts compared the TRVs with the data on blood chlordecone concentrations and dietary exposure from the Kannari study (2013-2014). They found that part of the French Caribbean population is at risk of exceeding the toxicity reference values for chlordecone. Thus, 14% of people in Guadeloupe and 25% of people in Martinique had concentrations above the internal chronic TRV. Efforts therefore need to be stepped up to reduce people's exposure.
In 2023, Santé Publique France launched the second edition of the Kannari study (Kannari 2) in order to measure contamination of the adult and child populations of Martinique and Guadeloupe with chlordecone and other environmental contaminants.
Measuring food contamination and estimating dietary exposure
In addition to the campaigns to analyse chlordecone levels in food (in particular the annual monitoring and control programmes led by the Directorate General for Food), in 2024, ANSES proposed a specific methodology for monitoring changes over the years in chlordecone contamination in the food products on the market that contribute most to exposure.
The ChlorExpo study, published in 2026, estimated dietary exposure to chlordecone while taking account of food sourcing, preparation and cooking habits. It found that the foods contributing most to exposure were fishery products, as well as eggs for children. The study also found that the most widely used cooking methods in the French Caribbean had no significant effect on chlordecone levels. The new contamination data obtained through the ChlorExpo study will be used to reassess the health risks associated with exposure to chlordecone in food and update the consumption recommendations.
Specific research work on chlordecone
ANSES’s Laboratory for Food Safety carries out various research and reference work on chlordecone. In recent years, it has focused on the distribution of the compound in bovine tissues (muscle, fat, liver, blood serum) and the development of more sensitive and rapid methods for analysing chlordecone and chlordecol (its main metabolite) in foodstuffs of animal and plant origin. In particular, the laboratory analysed all the samples from the ChlorExpo study (2026).
In addition, researchers have studied the effects of different meat and offal preparation processes on chlordecone and chlordecol contamination. They found that cooking in a microwave oven led to greater reductions. The laboratory also used high-resolution mass spectrometry techniques to identify and measure organochlorine compounds associated with chlordecone that have rarely been considered despite being found in products formerly sold on the market as well as in various foods.
In collaboration with the Laboratory for Food Safety, a team from the ANSES Lyon Laboratory specialising in the study of neurodegenerative diseases is also carrying out research on the effects of chlordecone on the brain.
Link between occupational exposure to chlordecone and prostate cancer
As part of its expert appraisal tasks on occupational diseases, the Agency has studied the links between exposure to pesticides – including chlordecone – and prostate cancer. In July 2021, it concluded that there was a probable causal relationship between chlordecone and the risk of prostate cancer. This conclusion was mainly based on the findings of the Karuprostate study, and on toxicological and mechanistic data demonstrating a plausible role for chlordecone in the process of prostate carcinogenesis.
Following its expert appraisal, an occupational disease table was created for the agricultural social security scheme for prostate cancer related to pesticide exposure. This table enables prostate cancer associated with chlordecone exposure to be officially recognised as an occupational disease.