Cognitive, visual, and motor development of 7-month-old Guadeloupean infants exposed to chlordecone.

BACKGROUND: The insecticide chlordecone was extensively used in the French West Indies to control banana root borer. Its persistence in soils has led to the widespread pollution of the environment, and human beings are still exposed to this chemical. Chlordecone has been shown to impair neurological and behavioural functions in rodents when exposed gestationally or neonatally. OBJECTIVES: The aim of the study was to evaluate the impact of prenatal and postnatal exposure to chlordecone on the cognitive, visual, and motor development of 7-month-old infants from Guadeloupe. METHODS: Infants were tested at 7 months (n=153). Visual recognition memory and processing speed were assessed with the Fagan Tests of Infant Intelligence (FTII), visual acuity with the Teller Acuity Card, and fine motor development with the Brunet-Lezine. Samples of cord blood and breast milk at 3 months (n=88) were analyzed for chlordecone concentrations. Postnatal exposure was determined through breast feeding and frequency of contaminated food consumption by the infants. RESULTS: Cord chlordecone concentrations in tertiles were associated with reduced novelty preference on the FTII in the highly exposed group (ß=-0.19, p=0.02). Postnatal exposure through contaminated food consumption was marginally related to reduced novelty preference (ß=-0.14, p=0.07), and longer processing speed (ß=0.16, p=0.07). Detectable levels of chlordecone in cord blood were associated with higher risk of obtaining low scores on the fine motor development scale (OR=1.25, p<0.01). CONCLUSION: These results suggest that pre- and postnatal low chronic exposure to chlordecone is associated with negative effects on cognitive and motor development during infancy.

Dietary exposure of 18-month-old Guadeloupian toddlers to chlordecone.

Chlordecone is an organochlorine insecticide used in the French West Indies until 1993. Toddlers are expected to be differently exposed than older children and adults. The dietary exposure to chlordecone of 18-month-old Guadeloupian toddlers was assessed through different scenarios depending on whether the subjects live on a soil-contaminated place or not and on their supply habits. Food contamination data came from the RESO study performed in 2005-2006. Consumption data derived from a dietary survey conducted in 2005-2008. Results were compared to those of other age groups. Chronic dietary exposures to chlordecone were estimated in a range of 0.018-0.051 µg/kg bw/day (P95: 0.044-0.096) for toddlers living in a non contaminated area and between 0.045-0.078 µg/kg bw/day (P95: 0.110-0.144) for toddlers living in a contaminated area. The probability of exceeding the chronic health-based value of 0.5 µg/kg bw/day was null. These results suggest that 18-month-old toddlers are less exposed than groups aged over 3 years old. This can be explained by their consumption pattern mostly based on milk and fruits, which are not highly contaminated by chlordecone. The acute health-based value of 10 µg/kg bw/day could be exceeded when consuming of highly contaminated taros, showing the importance of regulatory maximum limit.