Work carried out by Inserm researchers shows that postnatal exposure to chlordecone reduces the IQ of children by 0.64 points for a doubling of the level of exposure.
In study published on Monday, a team of international researchers, some of whom are attached to Inserm, investigated the effects of pre- and postnatal exposure to chlordecone on the cognitive and behavioral abilities of West Indian children.
Chlordecone is an insecticide, used in the West Indies from 1973 to 1993 to fight against the banana weevil, an insect that ravages crops. But through its massive use, the toxic product has gradually contaminated the soils and rivers of the West Indies. So much so that the populations have in turn been poisoned, by consuming contaminated food.
A total of 576 children from Guadeloupe took part in the study. The “work shows that this exposure is associated with lower scores on tests for evaluating cognitive abilities and behavioral disorders”, indicates Inserm in a press release.
A study conducted on 576 children
Chlordecone is now recognized as an endocrine disruptor, neurotoxic, toxic for reproduction and development, and also carcinogenic, underlines Inserm. Previous studies in animals had shown that exposure of females to the pesticide resulted in “neurobehavioral and learning disorders in the litter”.
This new study shows this time the ravages of chlordecone in children exposed at a young age, even in the womb of their mother. To assess their contamination, the concentration of chlordecone in the blood of the umbilical cord, as well as in the blood of 7-year-old children, was measured. As for intellectual abilities, they were measured via the children’s verbal comprehension, their speed of information processing, their working memory and their perceptual reasoning.
The mothers were also questioned to find out if they measured behavioral difficulties in their children.
Dramatic results
The results are alarming. They report a 3% increase in so-called internalized behavioral difficulties, such as emotional or relational difficulties in the children studied, the overwhelming majority in girls.
Same dramatic observation for the intellectual abilities of children: “decrease of 0.64 IQ point for a doubling of the level of exposure”, reports Inserm. Before adding: “This is reflected, especially in boys, by a decrease in indices assessing perceptual reasoning, working memory and verbal comprehension”.
Inserm concludes in its press release that “exposure to chlordecone during periods of in utero development or during childhood is associated with a decrease in intellectual abilities and an increase in behavioral difficulties”.
An investigation closed without follow-up
Last January, the Paris prosecutor’s office signed a dismissal order as part of the investigation into the large-scale poisoning of the French West Indies with chlordecone.
The two instructing magistrates had recognized a “health scandal”, as well as an “environmental attack whose human, economic and social consequences affect and will affect for many years the daily life of the inhabitants”. However, they had advanced the difficulty of collecting evidence.