Prenatal exposure to chlordecone, gestational weight gain, and birth weight in a Guadeloupean birth cohort

Chlordecone determination in serum by LC-MS/MS and the importance of low limit of detection

Chlordecone is an organochlorine insecticide that has been used intensively from 1973 to 1993 in the French West Indies banana fields to control root borers. This use has resulted in persistent pollution of soils and waters, and people have been and are still exposed mainly through food. Epidemiological studies showed that this exposure is associated with health disorders, including prostate cancer, prematurity, cognitive or motor development. The measurement of chlordecone in serum is considered as the best surrogate, though no clear and definitive cut-off value has been established. This renders necessary the development of analytical methods with the lowest limit of detection as possible. While most published methods have utilized GC-MS or GC-MS/MS, in the present study we report an LC-MS/MS method based on a simple QuEChERS salts extraction. The whole procedure was validated according to ISO 15189 requirements and reached LOD and LOQ values of 0.007 and 0.02 µg/L, respectively. It was applied to more 10 000 serum samples of French Indies inhabitants. More than a half had a concentration below 0.1 µg/L and more than one third of them exhibiting a concentration below 0.05 µg/L. The capability of this LC-MS/MS method to detect very low concentrations highlights its utility in exploring the health impact of chlordecone.

Prenatal and childhood chlordecone exposure, cognitive abilities and problem behaviors in 7-year-old children: the TIMOUN mother-child cohort in Guadeloupe

BACKGROUND

Chlordecone is a highly persistent organochlorine insecticide that was intensively used in banana fields in the French West Indies, resulting in a widespread contamination. Neurotoxicity of acute exposures in adults is well recognized, and empirical data suggests that prenatal exposure affects visual and fine motor developments during infancy and childhood, with greater susceptibility in boys.

OBJECTIVE

To assess the associations between pre- and postnatal exposures to chlordecone and cognitive and behavioral functions in school-aged children from Guadeloupe.

METHODS

We examined 576 children from the TIMOUN mother-child cohort in Guadeloupe at 7 years of age. Concentrations of chlordecone and other environmental contaminants were measured in cord- and children's blood at age 7 years. Cognitive abilities of children were assessed with the Wechsler Intelligence Scale for Children-IV (WISC-IV), and externalizing and internalizing problem behaviors documented with the Strengths and Difficulties Questionnaire (SDQ) completed by the child's mother. We estimated covariate-adjusted associations between cord- and 7-years chlordecone concentrations and child outcomes using structural equations modeling, and tested effect modification by sex.

RESULTS

Geometric means of blood chlordecone concentrations were 0.13 µg/L in cord blood and 0.06 µg/L in children's blood at age 7 years. A twofold increase in cord blood concentrations was associated with 0.05 standard deviation (SD) (95% Confidence Interval [CI]: 0.0, 0.10) higher internalizing problem scores, whereas 7-years chlordecone concentrations were associated with lower Full-Scale IQ scores (FSIQ) and greater externalized behavioral problem scores. A twofold increase in 7-year chlordecone concentrations was associated with a decrease of 0.67 point (95% CI: -1.13, -0.22) on FSIQ and an increase of 0.04 SD (95% CI: 0.0, 0.07) on externalizing problems. These associations with Cognitive abilities were driven by decreases in perceptive reasoning, working memory and verbal comprehension. Associations between 7-year exposure and perceptive reasoning, working memory, and the FSIQ were stronger in boys, whereas cord blood and child blood associations with internalizing problems were stronger in girls.

CONCLUSIONS

These results suggests that cognitive abilities and externalizing behavior problems at school age are impaired by childhood, but not in utero, exposure to chlordecone, and that prenatal exposure is related to greater internalizing behavioral problems.

Health Effects of Pesticide Exposure in Latin American and the Caribbean Populations: A Scoping Review

BACKGROUND

Multiple epidemiological studies have shown that exposure to pesticides is associated with adverse health outcomes. However, the literature on pesticide-related health effects in the Latin American and the Caribbean (LAC) region, an area of intensive agricultural and residential pesticide use, is sparse. We conducted a scoping review to describe the current state of research on the health effects of pesticide exposure in LAC populations with the goal of identifying knowledge gaps and research capacity building needs.

METHODS

We searched PubMed and SciELO for epidemiological studies on pesticide exposure and human health in LAC populations published between January 2007 and December 2021. We identified 233 publications from 16 countries that met our inclusion criteria and grouped them by health outcome (genotoxicity, neurobehavioral outcomes, placental outcomes and teratogenicity, cancer, thyroid function, reproductive outcomes, birth outcomes and child growth, and others).

RESULTS

Most published studies were conducted in Brazil (37%, n = 88 ) and Mexico (20%, n = 46 ), were cross-sectional in design (72%, n = 167 ), and focused on farmworkers (45%, n = 105 ) or children (21%, n = 48 ). The most frequently studied health effects included genotoxicity (24%, n = 62 ) and neurobehavioral outcomes (21%, n = 54 ), and organophosphate (OP) pesticides were the most frequently examined (26%, n = 81 ). Forty-seven percent (n = 112 ) of the studies relied only on indirect pesticide exposure assessment methods. Exposure to OP pesticides, carbamates, or to multiple pesticide classes was consistently associated with markers of genotoxicity and adverse neurobehavioral outcomes, particularly among children and farmworkers.

DISCUSSION

Our scoping review provides some evidence that exposure to pesticides may adversely impact the health of LAC populations, but methodological limitations and inconsistencies undermine the strength of the conclusions. It is critical to increase capacity building, integrate research initiatives, and conduct more rigorous epidemiological studies in the region to address these limitations, better inform public health surveillance systems, and maximize the impact of research on public policies. https://doi.org/10.1289/EHP9934.

Prenatal and childhood exposure to chlordecone and adiposity of seven-year-old children in the Timoun mother-child cohort study in Guadeloupe (French West Indies)

BACKGROUND

Exposure to persistent environmental organic pollutants may contribute to the development of obesity among children. Chlordecone is a persistent organochlorine insecticide with estrogenic properties that was used in the French West Indies (1973-1993) and is still present in the soil and the water and food consumed by the local population. We studied the association between prenatal and childhood exposure to chlordecone and the adiposity of prepubertal children.

METHODS

Within the Timoun Mother-Child Cohort Study in Guadeloupe (French West Indies), 575 children had a medical examination at seven years of age, including adiposity measurements. A Structural Equation Modeling approach was used to create a global adiposity score from four adiposity indicators: the BMI z-score, percentage of fat mass, sum of the tricipital and subscapular skinfold thickness, and waist-to-height ratio. Chlordecone concentrations were measured in cord blood at birth and in the children's blood at seven years of age. Models were adjusted for prenatal and postnatal covariates. Sensitivity analyses accounted for co-exposure to PCB-153 and pp'-DDE. Mediation analyses, including intermediate birth outcomes, were conducted.

RESULTS

Prenatal chlordecone exposure tended to be associated with increased adiposity at seven years of age, particularly in boys. However, statistical significance was only reached in the third quartile of exposure and neither linear nor non-linear trends could be formally identified. Consideration of preterm birth or birth weight in mediation analyses did not modify the results, as adjustment for PCB-153 and pp'-DDE co-exposures.

CONCLUSION

Globally, we found little evidence of an association between chlordecone exposure during the critical in utero or childhood periods of development and altered body-weight homeostasis in childhood. Nevertheless, some associations we observed at seven years of age, although non-significant, were consistent with those observed at earlier ages and would be worth investing during further follow-ups of children of the Timoun Mother-Child Cohort Study when they reach puberty.

Inverse probability weighting to handle attrition in cohort studies: some guidance and a call for caution

BACKGROUND

Attrition in cohort studies challenges causal inference. Although inverse probability weighting (IPW) has been proposed to handle attrition in association analyses, its relevance has been little studied in this context. We aimed to investigate its ability to correct for selection bias in exposure-outcome estimation by addressing an important methodological issue: the specification of the response model.

METHODS

A simulation study compared the IPW method with complete-case analysis (CCA) for nine response-mechanism scenarios (3 missing at random - MAR and 6 missing not at random - MNAR). Eighteen response models differing by the type of variables included were assessed.

RESULTS

The IPW method was equivalent to CCA in terms of bias and consistently less efficient in all scenarios, regardless of the response model tested. The most effective response model included only the confounding factors of the association model.

CONCLUSION

Our study questions the ability of the IPW method to correct for selection bias in situations of attrition leading to missing outcomes. If the method is to be used, we encourage including only the confounding variables of the association of interest in the response model.

Visuospatial processing and fine motor function among 7-years old Guadeloupe children pre- and postnatally exposed to the organochlorine pesticide chlordecone

BACKGROUND

Chlordecone is an organochlorine that was largely used as an insecticide to control a species of root borers, the Banana weevil (Cosmopolites sordidus), in the French West Indies, Guadeloupe and Martinique. Its molecules have been shown to be very persistent in the environment as pollution in soils leading to contamination of water sources and foodstuff will last for several decades. Our team previously reported associations between prenatal chlordecone exposure and poorer fine motor development at two points in time during infancy.

OBJECTIVE

To document whether effects of prenatal exposure to chlordecone previously reported persists until middle-childhood, and whether deleterious effects are observed in domain of visual processing. Associations with postnatal exposure and sex-specific vulnerabilities were also investigated.

METHODS

We examined 410 children from the TIMOUN mother-child cohort in Guadeloupe at 7 years of age. Concentrations of chlordecone and other environmental contaminants were measured in cord- and children's blood at age 7 years. Fine motor function was assessed using the Bruininks Oseretsky Test of Motor Proficiency Second Edition (BOT-2). The Computerized Adaptive Testing System (CATSYS) was used to evaluated postural hand tremor, while non-verbal visuospatial processing was measured using the Stanford Binet copying (S-B copying) test. We used adjusted multiple linear regressions to test the relationship between children's scores and both continuous and categorical blood chlordecone concentrations, adding child sex as a moderator in continuous models.

RESULTS

Cord chlordecone concentrations are associated with a regular frequency pattern of subtle hand tremors in both hands, and not related to visual processing and fine motor precision. Chlordecone concentrations in blood sample collected at testing time are associated with poorer visual processing when copying geometric figures, but not significantly related to poorer fine movement precision in tasks requiring pencil, scissors and paper. No sex-specific vulnerability was reported in any of the outcomes.

CONCLUSIONS

These results at school aged expand those previously reported in the same cohort during infancy at age 7- and 18 months, and corroborate the negative effects of chlordecone exposure on fine motor function in absence of intoxication. Our results support the need to continue public health efforts aimed at reducing exposure especially among women of child bearing age and young children.

Development and Application of Molecularly Imprinted Polymers for the Selective Extraction of Chlordecone from Bovine Serum

The widespread use of chlordecone (CLD), an organochlorine pesticide, until the 1990s to protect banana crops in the French West Indies led to significant pollution of water and soil and, subsequently, of bovine intended for human consumption. Carcasses are submitted to official controls based on perirenal fat CLD determination. In order to allow for pre-slaughter controls, a selective analytical method based on a molecularly imprinted polymer (MIP) associated to the LC/MS-MS method was developed to determine the level of CLD in bovine serum that can be collected before slaughter. Different synthesis conditions were therefore assayed by varying the nature of the monomer and of the porogen, and the most promising MIP in terms of selective retention for CLD (extraction recovery close to 100%) was completely characterized by solid-phase extraction (repeatability of the extraction procedure, of the synthesis, and of the cartridge filling) in pure medium. The capacity of the MIP was determined at 0.13 µmol g−1 of MIP. After application of a spiked bovine serum sample on the MIP, the selective retention was maintained (87 and 21%, respectively, on the MIP and on the corresponding non-imprinted polymer). Moreover, extraction on the MIP led to a cleaner extract compared to those issued from a conventional C18 sorbent.

Correlation between endemic chlordecone concentrations in three bovine tissues determined by isotopic dilution liquid chromatography-tandem mass spectrometry

Chlordecone (CLD) is an organochlorine pesticide widely used from the 1970s to the 1990s in the French West Indies that induced long-term pollution of the ecosystem. Due to involuntary soil ingestion, some species bred in open-air areas can be contaminated. As CLD is distributed in various tissues depending on the breeding species, this study focuses on the distribution of CLD in bovines. For this purpose, three tissues, i.e. fat, muscle, and liver, from 200 bovines originating from Martinique and Guadeloupe were sampled in 2016 to determine their endemic contamination levels. Analyses were performed with the official method for veterinary controls, isotopic dilution liquid chromatography-tandem mass spectrometry, which has been fully validated and which reaches a limit of quantification of 3 μg.kg^-1 fresh weight (fw). Irrespective of the matrices, CLD was detected in 68% of samples (404 samples above the LOD) and quantified in 59% of samples (332 samples above the LOQ). Regarding contamination levels, the liver had a broader range of concentrations (LOQ up to 420.6 μg.kg^-1 fw) than fat (LOQ up to 124.6 μg.kg^-1 fw) and muscle (LOQ up to 67.6 μg.kg^-1 fw). This confirms the atypical behaviour of CLD compared to other persistent organochlorine pollutants. Statistical processing demonstrated a correlation between CLD concentrations among the three studied tissues. The CLD concentration ratios were 0.54 for muscle/fat, 3.75 for liver/fat, and 0.14 for muscle/liver.

Relationship between Prenatal or Postnatal Exposure to Pesticides and Obesity: A Systematic Review

In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health.

In Utero Chlordecone Exposure and Thyroid, Metabolic, and Sex-Steroid Hormones at the Age of Seven Years: A Study From the TIMOUN Mother-Child Cohort in Guadeloupe

BACKGROUND

Chlordecone is an endocrine-disrupting chemical with well recognized estrogenic and progestagenic properties. This organochlorine insecticide was extensively used in the French West Indies from 1973 to 1993 to control the banana root borer. Due to its poor degradation in the environment, permanently polluted soil is responsible for the current contamination of the food chain and human beings. We aimed to examine the relationship of in utero exposure to chlordecone and thyroid (thyroid stimulating hormone [TSH], free tri-iodothyronine [FT3], free thyroxine [FT4]), metabolic (insulin growth-factor 1, leptin, adiponectin), and sex-steroid (dehydroepiandrosterone [DHEA], total testosterone [TT], dihydrotestosterone [DHT], estradiol [E2]) hormone levels in children at the age of seven years who participated in TIMOUN, an ongoing birth cohort in Guadeloupe.

METHODS

Chlordecone concentrations were measured in cord-blood at delivery. Thyroid, metabolic, and sex-steroid hormone levels were determined in the blood of children at seven years of age. Associations between in utero chlordecone exposure and hormone levels at seven years of age were assessed by multiple linear or logistic regression, controlling for confounding factors.

RESULTS

Among the study population (210 boys and 228 girls), chlordecone and hormone measurements were available for 124 boys and 161 girls. We found the third quartile of in utero chlordecone exposure relative to the lowest quartile to be associated with elevated TSH levels in girls and elevated DHEA, TT, and DHT levels in both sexes. Complementary non-linear analysis (spline regression) confirmed a significant non-linear trend for TSH in girls and DHEA and DHT in boys.

CONCLUSION

In utero chlordecone exposure was associated with elevated levels of selected thyroid (TSH) and sex-steroid (DHEA, TT, and DHT) hormones at seven years in a non-monotonic dose response (inverted U) relationship. The implications for future health and reproductive function in puberty and adulthood should be determined.

Development and characterisation of a nanostructured hybrid material with vitamin B12 and bagasse-derived activated carbon for anaerobic chlordecone (Kepone) removal

Intensive use of the chlorinated pesticide chlordecone from the 1970s to 1993 to prevent crop damage in banana plantations of Guadeloupe and Martinique led to diffuse pollution of soils and surface waters, affecting both fauna and human beings in the contaminated areas. Since 2001, drinking water production plants have been equipped with filters containing activated carbon that must be treated after saturation. The objective of this work is to produce a hybrid material composed of activated carbon and vitamin B12 (VB12) for the degradation of chlordecone (CLD). The preparation of such a hybrid material is carried out by non-covalent fixation to achieve an eco-friendly solution for the serious environmental problem of contamination by chlorinated pesticides. It is thus proposed to degrade CLD by a physico-chemical treatment allowing salvage of the catalyst, which is adsorbed on the carbon surface to generate less waste that is inexpedient to treat. Activated carbon (AC) is produced locally from available sugarcane bagasse subjected to phosphoric acid activation. The main characteristics of this material are a major mesoporous structure (0.91%) and a specific (BET) surface area ranging from 1000 to 1500 m² g^-1. The experimental results showed that BagP1.5 has a high adsorption capacity for VB12 due to its large surface area (1403 m² g^-1). The binding of VB12 to the bagasse-derived AC is favoured at high temperatures. The adsorption is optimal at a pH of approximately 6. The maximum adsorption capacity of VB12 on the AC, deduced from the Langmuir model, was 306 mg g^-1, confirming the high affinity between the two components. The hybrid material was characterised by FTIR, Raman, X-ray fluorescence spectroscopy and SEM analysis. CLD removal by this hybrid material was faster than that by VB12 or BagP1.5 alone. The CLD degradation products were characterised by mass spectrometry.

Early exposure to food contaminants reshapes maturation of the human brain-gut-microbiota axis

Early childhood growth and development is conditioned by the consecutive events belonging to perinatal programming. This critical window of life will be very sensitive to any event altering programming of the main body functions. Programming of gut function, which is starting right after conception, relates to a very well-established series of cellular and molecular events associating all types of cells present in this organ, including neurons, endocrine and immune cells. At birth, this machinery continues to settle with the establishment of extra connection between enteric and other systemic systems and is partially under the control of gut microbiota activity, itself being under the densification and the diversification of microorganisms’ population. As thus, any environmental factor interfering on this pre-established program may have a strong incidence on body functions. For all these reasons, pregnant women, fetuses and infants will be particularly susceptible to environmental factors and especially food contaminants. In this review, we will summarize the actual understanding of the consequences of repeated low-level exposure to major food contaminants on gut homeostasis settlement and on brain/gut axis communication considering the pivotal role played by the gut microbiota during the fetal and postnatal stages and the presumed consequences of these food toxicants on the individuals especially in relation with the risks of developing later in life non-communicable chronic diseases.

Natural Chlordecone Degradation Revealed by Numerous Transformation Products Characterized in Key French West Indies Environmental Compartments

Production and use of the insecticide chlordecone has caused long-term environmental pollution in the James River area and the French West Indies (FWI) that has resulted in acute human-health problems and a social crisis. High levels of chlordecone in FWI soils, even after its ban decades ago, and the absence of detection of transformation products (TPs), have suggested that chlordecone is virtually nonbiodegradable in the environment. Here, we investigated laboratory biodegradation, consisting of bacterial liquid cultures and microcosms inoculated with FWI soils, using a dual nontargeted GC-MS and LC-HRMS approach. In addition to previously reported, partly characterized hydrochlordecones and polychloroindenes (families A and B), we discovered 14 new chlordecone TPs, assigned to four families (B, C, D, and E). Organic synthesis and NMR analyses allowed us to achieve the complete structural elucidation of 19 TPs. Members of TP families A, B, C, and E were detected in soil, sediment, and water samples from Martinique and include 17 TPs not initially found in commercial chlordecone formulations. 2,4,5,6,7-Pentachloroindene was the most prominent TP, with levels similar to those of chlordecone. Overall, our results clearly show that chlordecone pollution extends beyond the parent chlordecone molecule and includes a considerable number of previously undetected TPs. Structural diversity of the identified TPs illustrates the complexity of chlordecone degradation in the environment and raises the possibility of extensive worldwide pollution of soil and aquatic ecosystems by chlordecone TPs.

[Systematic review of the impact of chlordecone on human health in the French West Indies]

INTRODUCTION

Several publications have highlighted the adverse effects of chlordecone on human and animal species. The possible long-term consequences continue to be explored as chlordecone still contaminates Caribbean soils. The objective of this literature review is to determine the long-term effects of chlordecone on human health.

MATERIAL AND METHOD

We searched for the keyword "chlordecone" on different scientific databases: Medline®, ISI Web of Knowledge, Google Scholar, EM Premium. We have enriched our research with first degree references, related articles on PubMed and grey literature.

RESULTS

Of the 192 articles analyzed, 12 responded to the impact of chlordecone on human health in the French West Indies. In obstetrics, exposure to chlordecone was associated with a lower incidence of gestational hypertension. In pediatrics, these studies have shown an association between prenatal exposure to chlordecone and increased risk of prematurity, decreased birth weight (especially when the mother gained excessive weight during pregnancy), decreased fine cognitive and motor acquisition, and changes in circulating concentrations of certain thyroid hormones. In oncology, exposure was associated with an increased risk of prostate cancer, particularly if there was a family history of prostate cancer.

CONCLUSION

While the effects of acute exposure to chlordecone at high doses are well described (Kepone Shake syndrome at the time of the Hopewell accident), the effects at environmental doses are becoming clearer even if they remain complex to identify.

Pesticides and Child's Health in France

PURPOSE OF REVIEW

The use of pesticides is predominant in agriculture, inducing environmental contamination, and has been extended to the domestic sphere. In France, > 500 pesticides were authorized for use in 2009; given their various toxicological properties, there are legitimate concerns about the possible consequences for child health. This review summarizes the recent French studies of good quality dealing with pesticides and child health.

RECENT FINDINGS

Three cohorts (mother-child, retrospective) and two case-control studies have been conducted in the last decade. Using various instruments for exposure assessment including biomarkers, they have suggested alterations of subclinical health parameters at birth, increased risk of otitis at age 2, and increased risk of several types of childhood cancer. However, there were no adverse neurodevelopmental outcomes at 6 years of age following prenatal exposure to pesticides. Both agricultural and domestic pesticides might be involved in such adverse health outcomes. Similar studies are lacking in Europe. Studies on fungicides and child health are scarce.

Gestational exposure to chlordecone promotes transgenerational changes in the murine reproductive system of males

Environmental factors can affect epigenetic events during germline reprogramming and impose distinctive transgenerational consequences onto the offspring. In this study, we examined the transgenerational effects of chlordecone (CD), an organochlorine insecticide with well-known estrogenic properties. We exposed pregnant mice to CD from embryonic day 6.5 to 15.5 and observed a reduction in spermatogonia (SG) numbers in F3, meiotic defects in spermatocytes and decrease in spermatozoa number in the first and third generation of male progeny. The RNA qRT-PCR expression analysis in F1 and transcriptomics analysis in F3 males using the whole testes revealed changes in the expression of genes associated with chromosome segregation, cell division and DNA repair. The expression of the master regulator of pluripotency, Pou5f1, decreased in foetal and increased in adult F1, but not in F3 adult testes. Analysis of histone H3K4me3 distribution revealed widespread changes in its occupancy in the genome of F1 and F3 generations. We established that 7.1% of altered epigenetic marks were conserved between F1 and F3 generations. The overlapping changes common to F1 and F3 include genes implicated in cell adhesion and transcription factor activities functions. Differential peaks observed in F1 males are significantly enriched in predicted ESR1 binding sites, some of which we confirmed to be functional. Our data demonstrate that CD-mediated impairment of reproductive functions could be transmitted to subsequent generations.