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72 result(s) for "Whyatt, Robin M."
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Neurotoxicity of Ortho-Phthalates: Recommendations for Critical Policy Reforms to Protect Brain Development in Children
Robust data from longitudinal birth cohort studies and experimental studies of perinatally exposed animals indicate that exposure to ortho-phthalates can impair brain development and increase risks for learning, attention, and behavioral disorders in childhood. This growing body of evidence, along with known adverse effects on male reproductive tract development, calls for immediate action. Exposures are ubiquitous; the majority of people are exposed to multiple ortho-phthalates simultaneously. We thus recommend that a class approach be used in assessing health impacts as has been done with other chemical classes. We propose critically needed policy reforms to eliminate ortho-phthalates from products that lead to exposure of pregnant women, women of reproductive age, infants, and children. Specific attention should be focused on reducing exposures among socially vulnerable populations such as communities of color, who frequently experience higher exposures. Ortho-phthalates are used in a vast array of products and elimination will thus necessitate a multipronged regulatory approach at federal and state levels. The fact that manufacturers and retailers have already voluntarily removed ortho-phthalates from a wide range of products indicates that this goal is feasible.
Persistent Associations between Maternal Prenatal Exposure to Phthalates on Child IQ at Age 7 Years
Prior research reports inverse associations between maternal prenatal urinary phthalate metabolite concentrations and mental and motor development in preschoolers. No study evaluated whether these associations persist into school age. In a follow up of 328 inner-city mothers and their children, we measured prenatal urinary metabolites of di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP), di-isobutyl phthalate (DiBP), di-2-ethylhexyl phthalate and diethyl phthalate in late pregnancy. The Wechsler Intelligence Scale for Children, 4th edition was administered at child age 7 years and evaluates four areas of cognitive function associated with overall intelligence quotient (IQ). Child full-scale IQ was inversely associated with prenatal urinary metabolite concentrations of DnBP and DiBP: b = -2.69 (95% confidence interval [CI] = -4.33, -1.05) and b = -2.69 (95% CI = -4.22, -1.16) per log unit increase. Among children of mothers with the highest versus lowest quartile DnBP and DiBP metabolite concentrations, IQ was 6.7 (95% CI = 1.9, 11.4) and 7.6 (95% CI = 3.2, 12.1) points lower, respectively. Associations were unchanged after control for cognition at age 3 years. Significant inverse associations were also seen between maternal prenatal metabolite concentrations of DnBP and DiBP and child processing speed, perceptual reasoning and working memory; DiBP and child verbal comprehension; and BBzP and child perceptual reasoning. Maternal prenatal urinary metabolite concentrations measured in late pregnancy of DnBP and DiBP are associated with deficits in children's intellectual development at age 7 years. Because phthalate exposures are ubiquitous and concentrations seen here within the range previously observed among general populations, results are of public health significance.
Brain anomalies in children exposed prenatally to a common organophosphate pesticide
Prenatal exposure to chlorpyrifos (CPF), an organophosphate insecticide, is associated with neurobehavioral deficits in humans and animal models. We investigated associations between CPF exposure and brain morphology using magnetic resonance imaging in 40 children, 5.9–11.2 y, selected from a nonclinical, representative community-based cohort. Twenty high-exposure children (upper tertile of CPF concentrations in umbilical cord blood) were compared with 20 low-exposure children on cortical surface features; all participants had minimal prenatal exposure to environmental tobacco smoke and polycyclic aromatic hydrocarbons. High CPF exposure was associated with enlargement of superior temporal, posterior middle temporal, and inferior postcentral gyri bilaterally, and enlarged superior frontal gyrus, gyrus rectus, cuneus, and precuneus along the mesial wall of the right hemisphere. Group differences were derived from exposure effects on underlying white matter. A significant exposure x IQ interaction was derived from CPF disruption of normal IQ associations with surface measures in low-exposure children. In preliminary analyses, high-exposure children did not show expected sex differences in the right inferior parietal lobule and superior marginal gyrus, and displayed reversal of sex differences in the right mesial superior frontal gyrus, consistent with disruption by CPF of normal behavioral sexual dimorphisms reported in animal models. High-exposure children also showed frontal and parietal cortical thinning, and an inverse dose–response relationship between CPF and cortical thickness. This study reports significant associations of prenatal exposure to a widely used environmental neurotoxicant, at standard use levels, with structural changes in the developing human brain.
Maternal Prenatal Urinary Phthalate Metabolite Concentrations and Child Mental, Psychomotor, and Behavioral Development at 3 Years of Age
Background: Research suggests that prenatal phthalate exposures affect child executive function and behavior. Objective: We evaluated associations between phthalate metabolite concentrations in maternal prenatal urine and mental, motor, and behavioral development in children at 3 years of age. Methods: Mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), monoisobutyl phthalate (MiBP), and four di-2-ethylhexyl phthalate metabolites were measured in a spot urine sample collected from 319 women during the third trimester. When children were 3 years of age, the Mental Development Index (MDI) and Psychomotor Development Index (PDI) were measured using the Bayiey Scales of Infant Development II, and behavior problems were assessed by maternal report on the Child Behavior Checklist. Results: Child PDI scores decreased with increasing log, MnBP [estimated adjusted ß-coefficient = -2.81; 95% confidence interval (CI): -4.63, -1.0] and log, MiBP (ß = -2.28; 95% CI: -3.90, -0.67); odds of motor delay increased significantly [per log, MnBP: estimated adjusted odds ratio (OR) = 1.64; 95% CI: 1.10, 2.44; per log, MiBP: adjusted OR = 1.82; 95% CI: 1.24, 2.66]. In girls, MDI scores decreased with increasing log, MnBP (ß = -2.67; 95% CI: -4.70, -0.65); the child sex difference in odds of mental delay was significant (p = 0.037). The ORs for clinically withdrawn behavior were 2.23 (95% CI: 1.27, 3.92) and 1.57 (95% CI: 1.07, 2.31) per log, unit increase in MnBP and MBzP, respectively, for clinically internalizing behaviors, the OR was 1.43 (95% CI: 1.01, 1.90) per log, unit increase in MBzP. Significant child sex differences were seen in associations between MnBP and MBzP and behaviors in internalizing domains (p < 0.05). Conclusion: Certain prenatal phthalate exposures may decrease child mental and motor development and increase internalizing behaviors.
Asthma in Inner-City Children at 5–11 Years of Age and Prenatal Exposure to Phthalates: The Columbia Center for Children’s Environmental Health Cohort
Studies suggest that phthalate exposures may adversely affect child respiratory health. We evaluated associations between asthma diagnosed in children between 5 and 11 years of age and prenatal exposures to butylbenzyl phthalate (BBzP), di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), and diethyl phthalate (DEP). Phthalate metabolites were measured in spot urine collected from 300 pregnant inner-city women. Children were examined by an allergist or pulmonologist based on the first parental report of wheeze, other respiratory symptoms, and/or use of asthma rescue/controller medication in the preceding 12 months on repeat follow-up questionnaires. Standardized diagnostic criteria were used to classify these children as either having or not having current asthma at the time of the physician examination. Children without any report of wheeze or the other asthma-like symptoms were classified as nonasthmatics at the time of the last negative questionnaire. Modified Poisson regression analyses were used to estimate relative risks (RR) controlling for specific gravity and potential confounders. Of 300 children, 154 (51%) were examined by a physician because of reports of wheeze, other asthma-like symptoms, and/or medication use; 94 were diagnosed with current asthma and 60 without current asthma. The remaining 146 children were classified as nonasthmatic. Compared with levels in nonasthmatics, prenatal metabolites of BBzP and DnBP were associated with a history of asthma-like symptoms (p < 0.05) and with the diagnosis of current asthma: RR = 1.17 (95% CI: 1.01, 1.35) and RR = 1.25 (95% CI: 1.04, 1.51) per natural log-unit increase, respectively. Risk of current asthma was > 70% higher among children with maternal prenatal BBzP and DnBP metabolite concentrations in the third versus the first tertile. Prenatal exposure to BBzP and DnBP may increase the risk of asthma among inner-city children. However, because this is the first such finding, results require replication.
Prenatal Exposure to Phthalates and Childhood Body Size in an Urban Cohort
Phthalate exposures are hypothesized to increase obesity; however, prior research has been largely cross-sectional. We evaluated associations between prenatal phthalate exposures and body mass index (BMI) at child ages 5 and 7 years. Nine metabolites of six phthalates-di(2-ethylhexyl) phthalate (DEHP), di-n-octyl-, di-iso-butyl-, di-n-butyl-, butylbenzyl-, and diethyl phthalates-were measured in spot urine samples collected from pregnant African-American and Dominican women during their third trimester, and from their children at ages 3 and 5 years. To reduce multiple comparison issues, we initially used principal component analysis (PCA) to identify major patterns of natural log (ln)-transformed metabolite concentrations. Height and weight were assessed at ages 5 and 7 years, and fat mass and waist circumference at age 7. Linearized generalized estimating equation analyses related maternal component scores to child anthropometric outcomes at ages 5 (n = 326) and 7 (n = 330) years. PCA identified a DEHP component and a non-DEHP component. In boys, higher maternal non-DEHP, but not DEHP, component scores were associated with lower BMI z-score (β = -0.30; 95% CI: -0.50, -0.10, n = 156), lower fat percentage (β = -1.62; 95% CI: -2.91, -0.34, n = 142), and smaller waist circumference (β = -2.02; 95% CI: -3.71, -0.32, n = 124). No significant associations with anthropometric outcomes were seen in girls (for BMI z-score, β = 0.07; 95% CI: -0.18, 0.31, n = 181). Interactions between sex and non-DEHP component association with outcomes were statistically significant (p < 0.01). Contrary to hypotheses, prenatal non-DEHP phthalate exposures were associated with lower BMI z-score, waist circumference, and fat mass in boys during early childhood. Maresca MM, Hoepner LA, Hassoun A, Oberfield SE, Mooney SJ, Calafat AM, Ramirez J, Freyer G, Perera FP, Whyatt RM, Rundle AG. 2016. Prenatal exposure to phthalates and childhood body size in an urban cohort. Environ Health Perspect 124:514-520; http://dx.doi.org/10.1289/ehp.1408750.
Characterization of Phthalate Exposure among Pregnant Women Assessed by Repeat Air and Urine Samples
Background: Although urinary concentrations of phthalate metabolites are frequently used as biomarkers in epidemiologic studies, variability during pregnancy has not been characterized. Methods: We measured phthalate metabolite concentrations in spot urine samples collected from 246 pregnant Dominican and African-American women. Twenty-eight women had repeat urine samples collected over a 6-week period. We also analyzed 48-hr personal air samples (n = 96 women) and repeated indoor air samples (n = 32 homes) for five phthalate diesters. Mixed-effects models were fit to evaluate reproducibility via intraclass correlation coefficients (ICC). We evaluated the sensitivity and specificity of using a single specimen versus repeat samples to classify a woman's exposure in the low or high category. Results: Phthalates were detected in 85-100% of air and urine samples. ICCs for the unadjusted urinary metabolite concentrations ranged from 0.30 for mono-ethyl phthalate to 0.66 for monobenzyl phthalate. For indoor air, ICCs ranged from 0.48 [di-2-ethylhexyl phthalate (DEHP)] to 0.83 [butylbenzyl phthalate (BBzP)]. Air levels of phthalate diesters correlated with their respective urinary metabolite concentrations for BBzP (r = 0.71), di-isobutyl phthalate (r = 0.44), and diethyl phthalate (DEP; r = 0.39). In women sampled late in pregnancy, specific gravity appeared to be more effective than creatinine in adjusting for urine dilution. Conclusions: Urinary concentrations of DEP and DEHP metabolites in pregnant women showed lower reproducibility than metabolites for di-n-butyl phthalate and BBzP. A single indoor air sample may be sufficient to characterize phthalate exposure in the home, whereas urinary phthalate biomarkers should be sampled longitudinally during pregnancy to minimize exposure misclassification.
International Studies of Prenatal Exposure to Polycyclic Aromatic Hydrocarbons and Fetal Growth
Objectives: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitously distributed human mutagens and carcinogens. However, lack of adequate air monitoring data has limited understanding of the effects of airborne PAHs on fetal growth. To address this gap in knowledge, we examined the association between prenatal exposure to airborne PAHs and birth weight, birth length, and birth head circumference, respectively, in Krakow, Poland, and New York City (NYC). Methods: The parallel prospective cohort studies enrolled nonsmoking, healthy, and nonoccupationally exposed women and their newborns. Personal air monitoring of pregnant women was conducted over 48 hr. To control for maternal environmental tobacco smoke (ETS) exposure, we excluded those with umbilical cord plasma cotinine concentrations > 25 ng/mL. Mean cord plasma cotinine concentrations in both ethnic groups were$\\leq 0.5 ng/mL$. Results: Prenatal PAH exposure was 10-fold higher in Krakow than in NYC. Prenatal PAH exposure was associated with significantly reduced birth weight in both Krakow Caucasians (p < 0.01) and in NYC African Americans (p < 0.01), controlling for known and potential confounders, but not in NYC Dominicans. Within the lower exposure range common to the two cities$(1.80-36.47 ng/m^3)$, the effect per unit PAH exposure on birth weight was 6-fold greater for NYC African Americans than for Krakow Caucasians (p = 0.01). Conclusions: These results confirm the adverse reproductive effect of relatively low PAH concentrations in two populations and suggest increased susceptibility of NYC African Americans. Fetal growth impairment has been linked to child developmental and health problems. Thus, substantial health benefits would result from global reduction of PAH emissions.
Maternal urinary phthalates and sex-specific placental mRNA levels in an urban birth cohort
Background Prenatal urinary concentrations of phthalates in women participants in an urban birth cohort were associated with outcomes in their children related to neurodevelopment, autoimmune disease risk, and fat mass at 3,5,7, and 8 years of life. Placental biomarkers and outcomes at birth may offer biologic insight into these associations. This is the first study to address these associations with candidate genes from the phthalate and placenta literature, accounting for sex differences, and using absolute quantitation methods for mRNA levels. Methods We measured candidate mRNAs in 180 placentas sampled at birth ( HSD17B1, AHR, CGA, CYP19A1, SLC27A4, PTGS2, PPARG, CYP11A1 ) by quantitative PCR and an absolute standard curve. We estimated associations of log e mRNA with quartiles of urinary phthalate monoesters using linear mixed models. Phthalate metabolites ( N  = 358) and mRNAs ( N  = 180) were transformed to a z-score and modeled as independent, correlated vectors in relation to large for gestational age (LGA) and gestational diabetes mellitus (GDM). Results CGA was associated with 4 out of 6 urinary phthalates. CGA was 2.0 log e units lower at the 3 rd vs. 1 st quartile of mono-n-butyl phthalate (MnBP) (95% confidence interval (CI): −3.5, −0.5) in male placentas, but 0.6 log e units higher (95% CI: −0.8, 1.9) in female placentas (sex interaction p  = 0.01). There was an inverse association of MnBP with PPARG in male placentas (−1.1 log e units at highest vs. lowest quartile, 95% CI: −2.0, −0.1). CY19A1 , CYP11A1, CGA were associated with one or more of the following in a sex-specific manner: monobenzyl phthalate (MBzP), MnBP, mono-iso-butyl phthalate (MiBP). These 3 mRNAs were lower by 1.4-fold (95% CI: −2.4, -1.0) in male GDM placentas vs. female and non-GDM placentas ( p -value for interaction = 0.04). The metabolites MnBP/MiBP were 16% higher (95% CI: 0, 22) in GDM pregnancies. Conclusions Prenatal concentrations of certain phthalates and outcomes at birth were modestly associated with molecular changes in fetal placental tissue during pregnancy. Associations were stronger in male vs. female placentas, and associations with MnBP and MiBP were stronger than other metabolites. Placental mRNAs are being pursued further as potential mediators of exposure-induced risks to the health of the child.
Children’s Urinary Phthalate Metabolites and Fractional Exhaled Nitric Oxide in an Urban Cohort
Abstract Rationale Phthalates are used widely in consumer products. Exposure to several phthalates has been associated with respiratory symptoms and decreased lung function. Associations between children’s phthalate exposures and fractional exhaled nitric oxide (FeNO), a biomarker of airway inflammation, have not been examined. Objectives We hypothesized that urinary concentrations of four phthalate metabolites would be positively associated with FeNO and that these associations would be stronger among children with seroatopy or wheeze. Methods In an urban ongoing birth cohort, 244 children had phthalate metabolites determined in urine collected on the same day as FeNO measurement. Repeated sampling gathered 313 observations between ages 4.9 and 9.1 years. Seroatopy was assessed by specific IgE. Wheeze in the past year was assessed by validated questionnaire. Regression models used generalized estimating equations. Measurements and Main Results Log-unit increases in urinary concentrations of metabolites of diethyl phthalate (DEP) and butylbenzyl phthalate (BBzP) were associated with a 6.6% (95% confidence interval [CI] 0.5–13.1%) and 8.7% (95% CI, 1.9–16.0%) increase in FeNO, respectively, adjusting for other phthalate metabolites and potential covariates/confounders. There was no association between concentrations of metabolites of di(2-ethylhexyl) phthalate or di-n-butyl phthalate and FeNO. There was no significant interaction by seroatopy. The BBzP metabolite association was significantly stronger among children who wheeze (P = 0.016). Conclusions Independent associations between exposures to DEP and BBzP and FeNO in a cohort of inner-city children were observed. These results suggest that these two ubiquitous phthalates, previously shown to have substantial contributions from inhalation, are positively associated with airway inflammation in children.