Charline Warembourg

Metabolomics Tools for Describing Complex Pesticide Exposure in Pregnant Women in Brittany (France)

Background The use of pesticides and the related environmental contaminations can lead to human exposure to various molecules. In early-life, such exposures could be responsible for adverse developmental effects. However, human health risks associated with exposure to complex mixtures are currently under-explored. Objective This project aims at answering the following questions: What is the influence of exposures to multiple pesticides on the metabolome? What mechanistic pathways could be involved in the metabolic changes observed? Methods Based on the PELAGIE cohort (Brittany, France), 83 pregnant women who provided a urine sample in early pregnancy, were classified in 3 groups according to the surface of land dedicated to agricultural cereal activities in their town of residence. Nuclear magnetic resonance-based metabolomics analyses were performed on urine samples. Partial Least Squares Regression-Discriminant Analysis (PLS-DA) and polytomous regressions were used to separate the urinary metabolic profiles from the 3 exposure groups after adjusting for potential confounders. Results The 3 groups of exposure were correctly separated with a PLS-DA model after implementing an orthogonal signal correction with pareto standardizations (R2 = 90.7% and Q2 = 0.53). After adjusting for maternal age, parity, body mass index and smoking habits, the most statistically significant changes were observed for glycine, threonine, lactate and glycerophosphocholine (upward trend), and for citrate (downward trend). Conclusion This work suggests that an exposure to complex pesticide mixtures induces modifications of metabolic fingerprints. It can be hypothesized from identified discriminating metabolites that the pesticide mixtures could increase oxidative stress and disturb energy metabolism.

Childhood exposure to polybrominated diphenyl ethers and neurodevelopment at six years of age.

Mixtures of polybrominated diphenyl ethers (PBDEs) are present in indoor environments. Studies of the developmental effects of exposure to these chemicals in large prospective mother-child cohorts are required, with data on prenatal exposure and long-term follow-up of the children. We aimed to investigate the relationship between prenatal and childhood exposure to PBDEs and neurodevelopment at the age of six years. We determined the levels of PBDEs and other neurotoxicants in cord blood and dust collected from the homes of children for 246 families included in the PELAGIE mother-child cohort in France. We assessed two cognitive domains of the six-year-old children using the Wechsler Intelligence Scale for Children-IV. Verbal comprehension scores were lower in children from homes with higher concentrations of BDE99 (βDetects<median_vs_NonDetects=-1.6; 95% CI: -6.1, 2.9; βDetects≥median_vs_NonDetects=-5.4; -9.9, -1.0; p trend=0.02) and of BDE209 (β2nd_vs_1st_tertile=-1.8; 95% CI: -6.1, 2.5; β3rd_vs_1st_tertile=-3.2; -7.5, 1.2; p trend=0.15) in dust, particularly for boys (p trend=0.02 and 0.04, respectively). Working memory scores seemed to be lower in children with higher BDE99 concentrations in dust (p trend=0.10). No association was observed with cord blood levels of BDE209. Our findings are in agreement with those of four previous studies suggesting adverse cognitive outcomes among children associated with early-life exposure to penta-BDE mixtures, and provide new evidence for the potential neurotoxicity of BDE209. Several countries are in the process of banning the use of PBDE mixtures as flame-retardants. However, these compounds are likely to remain present in the environment for a long time to come.

Perinatal exposure to chlordecone, thyroid hormone status and neurodevelopment in infants: The Timoun cohort study in Guadeloupe (French West Indies).

BACKGROUND Perinatal exposure to endocrine-disrupting chemicals may affect thyroid hormones homeostasis and impair brain development. Chlordecone, an organochlorine insecticide widely used in the French West Indies has known estrogenic and progestin properties, but no data is available, human or animal, on its action on thyroid hormone system. OBJECTIVES Our aim was to evaluate the impact of perinatal exposure to chlordecone on the thyroid hormone system of a sample of infants from the Timoun mother-child cohort in Guadeloupe and their further neurodevelopment. METHODS Chlordecone was measured in cord blood and breast milk samples. Thyroid stimulating hormone (TSH), free tri-iodothyronine (FT3), free thyroxine (FT4) were determined in child blood at 3 months (n=111). Toddlers were further assessed at 18 months using an adapted version of the Ages and Stages Questionnaire (ASQ). RESULTS Cord chlordecone was associated with an increase in TSH in boys, whereas postnatal exposure was associated with a decrease in FT3 overall, and in FT4 among girls. Higher TSH level at 3 months was positively associated with the ASQ score of fine motor development at 18 months among boys, but TSH did not modify the association between prenatal chlordecone exposure and poorer ASQ fine motor score. CONCLUSIONS Perinatal exposure to chlordecone may affect TSH and thyroid hormone levels at 3 months, differently according to the sex of the infant. This disruption however did not appear to intervene in the pathway between prenatal chlordecone exposure and fine motor child development.

Prenatal Exposure to Glycol Ethers and Neurocognitive Abilities in 6-Year-Old Children: The PELAGIE Cohort Study

Background: Glycol ethers (GE) are widely used organic solvents. Despite the potential neurotoxicity of several families of organic solvents, little is known about the impact of GE on the neurodevelopment of infants and children. Objectives: We investigated the relation between urinary concentrations of GE metabolites in pregnant women and neurocognitive abilities in their 6-year-old children in the PELAGIE mother–child cohort. Methods: Five GE metabolites were measured in first morning void urine samples of 204 French pregnant women in early pregnancy (< 19 weeks of gestation). Psychologists assessed the neurocognitive abilities of their 6-year-old children with the Wechsler Intelligence Scale for Children IV (WISC) and the Developmental Neuropsychological Assessment (NEPSY). We analyzed the results with linear (WISC) and Poisson regression models (NEPSY), adjusted for potential confounders, including child’s stimulation at home. Results: GE metabolites were detected in 90–100% of maternal urine samples. The WISC Verbal Comprehension score was significantly lower for children with the highest tertile of urinary phenoxyacetic acid (PhAA) [β (third vs. first tertile) = –6.53; 95% CI: –11.44, –1.62]. Similarly, the NEPSY Design Copying subtest score was lower in those with the highest tertile of urinary ethoxyacetic acid (EAA) [β (third vs. first tertile) = –0.11; 95% CI: –0.21, 0.00]. The other GE metabolites we studied were not significantly associated with WISC or NEPSY scores. Conclusions: Prenatal urine concentrations of two GE metabolites were associated with lower WISC Verbal Comprehension Index scores and NEPSY Design Copying subscale scores, respectively, at age 6 years. PhAA is the primary metabolite of 2-phenoxyethanol (EGPhE), which is commonly found in cosmetics, and precursors of EAA are frequently used in cleaning agents. Additional research is needed to confirm our findings and further explore potential effects of prenatal GE exposures on neurocognitive performance in children. Citation: Béranger R, Garlantézec R, Le Maner-Idrissi G, Lacroix A, Rouget F, Trowbridge J, Warembourg C, Monfort C, Le Gléau F, Jourdin M, Multigner L, Cordier S, Chevrier C. 2017. Prenatal exposure to glycol ethers and neurocognitive abilities in 6-year-old children: the PELAGIE cohort study. Environ Health Perspect 125:684–690; http://dx.doi.org/10.1289/EHP39

Prenatal exposure to glycol ethers and cryptorchidism and hypospadias: a nested case–control study

Objectives Glycol ethers (GE) are oxygenated solvents frequently found in occupational and consumer products. Some of them are well-known testicular and developmental animal toxicants. This study aims to evaluate the risk of male genital anomalies in association with prenatal exposure to GE using urinary biomarkers of exposure. Methods We conducted a case–control study nested in two joint mother–child cohorts (5303 pregnant women). Cases of cryptorchidism and hypospadias were identified at birth and confirmed during a 2-year follow-up period (n=14 cryptorchidism and n=15 hypospadias). Each case was matched to three randomly selected controls within the cohorts for region of inclusion and gestational age at urine sampling. Concentrations of five GE acidic metabolites were measured in spot maternal urine samples collected during pregnancy. ORs were estimated with multivariate conditional logistic regressions including a Firth’s penalisation. Results Detection rates of urinary GE metabolites ranged from 8% to 93% and only two were sufficiently detected (>33%) in each cohort to be studied: methoxyacetic acid (MAA) and phenoxyacetic acid (PhAA). A significantly higher risk of hypospadias was associated with the highest tertile of exposure to MAA: OR (95% CI) 4.5(1.4 to 23.4). No association were observed with urinary concentration of PhAA, nor with the risk of cryptorchidism. Conclusions In view of the toxicological plausibility of our results, this study, despite its small sample size, raises concern about the potential developmental toxicity of MAA on the male genital system and calls for thorough identification of current sources of exposure to MAA.

An update systematic review of fetal death, congenital anomalies, and fertility disorders among health care workers

BACKGROUND Health care workers (HCWs) are occupationally exposed to various hazards, some associated with adverse pregnancy outcomes in previous reviews. This systematic review aims at synthesizing the recent literature on occupational exposures among HCWs related to fetal death, congenital anomalies, and fertility disorders. METHODS We searched the Medline database from 2000 to 2015 for articles about all potential occupational exposures of women and men working in this sector. RESULTS We retained 32 studies, most of them (n = 30) among women HCWs. Studies based on job title reported excess risks of some congenital anomalies (especially nervous and musculoskeletal systems) among HCWs compared to non-HCWs but no evidence about fetal death. Excess risks associated with specific exposures includes reports of some congenital anomalies for women exposed to anesthetic gases. Exposure to some sterilizing agents and, with less evidence, to antineoplastic drugs and to ionizing radiation, is associated with increased risks of miscarriage but not stillbirth. Strenuous work schedules appear to be associated with fertility disorders, but the evidence is limited. Only a few studies have been published since 2000 about non-ionizing radiation, or about fertility disorders related to chemical or physical agents, or about male HCWs. CONCLUSIONS Despite the establishment of recommendations to limit exposures of HCWs, some excess risks of adverse pregnancy outcomes are still reported and need to be explained.

2 Chronic dietary exposure to multiple pesticides during pregnancy and risk of hypospadias: the french elfe birth cohort

Background/aim Prenatal occupational exposure to pesticides has been associated to congenital malformations, but little is known about the effect of dietary exposure in the general population. Exposure to various pesticides through dietary intake has been recently assessed in French pregnant women. We aimed to study its association with the risk of hypospadias. Methods Among 7035 boys enrolled in 2011 the French national birth cohort Elfe, 46 have been diagnosed with hypospadias. Maternal daily intakes were estimated for 317 pesticides, based on a validated self-administered food frequency questionnaire combined with data of national monitoring programs on pesticide residues in food. Among those with non-null daily intake in >10% women (n=105), we focused on substances (n=60) with suspected endocrine disrupting properties or susceptible to impair the development of male reproductive organs. We used logistic regression to assess the risk of hypospadias in association with the dietary daily intake of 1) pesticides grouped by chemical family, or 2) individual pesticides selected a priori as the best predictors using cross-validated Elastic-Net model. Results An increased risk of hypospadias was found statistically significant for the group of anilinopyrimidine pesticides (3rd vs 1 st and 2nd tertiles of exposure; OR=2.26, 95% CI: 1.25 to 4.11), for the organochlorine pesticides family (3rd vs 1 st and 2nd tertiles; OR=2.16, 1.20; 3.91) and for the group of amide pesticides (3rd vs 1 st and 2nd tertiles; OR=1.95, 1.08; 3.52). Three individual pesticides (among 60) were selected by the Elastic-Net procedure and showed increased risk of hypospadias for λ-cyhalothrin (3rd vs 1 st and 2nd tertiles, OR=2.34, 1.26; 4.42) and for cyprodinil (3rd vs 1 st and 2nd tertiles; OR=1.66, 0.90; 3.10) and DDT (3rd vs 1 st and 2nd tertiles; OR=1.72, 0.95; 3.15). Conclusion Although the number of cases is small, our results are consistent with existing literature that have suggested increased risk of hypospadias in association with organochlorine pesticides. A confirmation with biomonitoring data would be give strength to the results.