Urinary phthalate metabolite concentrations among pregnant women in Northern Puerto Rico: distribution, temporal variability, and predictors

Prenatal exposure to phthalates and childhood wheeze and asthma in the PROGRESS cohort

INTRODUCTION

Prenatal phthalate exposure may influence lung development and lead to wheezing and asthma in childhood, and these associations may vary by sex. Despite ubiquity of exposure, there is limited epidemiologic data on these associations in Latin America.

METHODS

We assessed 593 mother-child dyads enrolled in the Programming Research in Obesity, Growth, Environment, and Social Stressors birth cohort in Mexico City. We quantified 15 phthalate metabolites in 2nd and 3rd trimester maternal urine. Report of ever wheeze, wheeze in the past 12 months (current wheeze) and ever asthma were obtained using a validated survey when children were 4 and 6 years of age. We examined individual associations with modified Poisson models. Mixture effects were assessed using Bayesian Weighted Quantile Sum (BWQS) regression. All models were adjusted for child's sex, maternal age and education at enrollment, and parity.

RESULTS

In Poisson models, a doubling of mono (carboxy-isononyl) phthalate (MCNP) during the 2nd trimester was associated with higher risk of wheeze (RR: 1.14, 95 % CI: 1.01, 1.29), and asthma (RR: 1.44, 95 % CI: 1.05, 1.97) at 4 years of age. Higher concentrations of the sum of di-isononyl phthalate metabolites (∑DiNP) during the 2nd trimester were also associated with asthma at 4 years of age (RR: 1.30, 95 % CI: 1.04, 1.61). Mixture associations of phthalate metabolite concentrations during the 2nd trimester and asthma at 4 years of age were stronger in males (BWQS, OR: 1.94, 95 % CI: 0.90, 4.60; 90 % CrI: 1.04, 3.73) compared to females (BWQS, OR: 1.23, 95 % CI: 0.56, 2.88; 90 % CrI: 0.61, 2.55). Additionally, we observed stronger inverse associations between prenatal phthalate mixtures during the 3rd trimester and current wheeze at 4 and 6 years of age in females (BWQS, OR: 0.54, 90 % CrI: 0.35, 0.82; OR: 0.45, 90 % CrI: 0.22, 0.84) compared to males (BWQS, OR: 0.95, 90 % Cri: 0.68, 1.35; OR: 0.97, 90 % CrI: 0.59, 1.54).

CONCLUSIONS

Prenatal phthalate metabolite concentrations were associated with respiratory outcomes in childhood, with some evidence of sex specific effects. Future work investigating phthalate exposure and wheeze trajectories/lung function will be important for understanding how these may predict later disease.

Asking Why Is Necessary to Address Health Disparities: A Critical Approach for Solution-Oriented Environmental Epidemiological Research

BACKGROUND

In environmental epidemiology, we use an array of tools from various, related disciplines to answer key questions about environmental exposures in relation to health outcomes. Typically, we ask questions related to what, who, where, when, and how. We value these questions because they contribute to novel scientific discovery and our understanding of disease etiology linked to environmental exposures. In addition, these questions help us better understand who might be at highest risk of exposure and subsequent risk of disease. Although necessary for the goals of environmental epidemiology, these questions are insufficient for addressing environmental health disparities. Specifically, these questions may be able to help us describe exposure-health outcome associations but are limited in their ability to move beyond identification to intervening on observed disparities to achieve environmental health equity.

OBJECTIVES

We sought to emphasize the need to value and routinely add the key question of "Why?" in environmental epidemiological studies. In asking this additional critical question, we can identify and incorporate the structural determinants and drivers of environmental exposure disparities and determine whether these factors are linked to existing and historically recalcitrant health disparities. Further, we can design effective studies that build on existing frameworks to address the fundamental causes of environmental health disparities.

DISCUSSION

This commentary underscores the need to routinely incorporate "why" questions in the practice of environmental epidemiology. By asking and addressing "Why?" we can employ better, more solution-oriented study designs, improve data collection, and enhance our ability to collaborate with diverse study populations through trust-building and community-engaged research. Incorporating these approaches will move environmental epidemiology forward from mostly documenting to actively addressing environmental health disparities. https://doi.org/10.1289/EHP14513.

Associations of prenatal exposure to phthalates and their mixture with lung function in Mexican children

Early life phthalates exposure has been associated with adverse respiratory outcomes. However, evidence linking prenatal phthalates exposure and childhood lung function has been inconclusive. Additionally, few studies have examined phthalates exposure as a mixture and explored sexually dimorphic associations. We aimed to investigate sex-specific associations of prenatal phthalates mixtures with childhood lung function using the PROGRESS cohort in Mexico (N = 476). Prenatal phthalate concentrations were measured in maternal urine collected during the 2nd and 3rd trimesters. Children's lung function was evaluated at ages 8-13 years. Individual associations were assessed using multivariable linear regression, and mixture associations were modeled using repeated holdout WQS regression and hierarchical BKMR; data was stratified by sex to explore sex-specific associations. We identified significant interactions between 2nd trimester phthalates mixture and sex on FEV1 and FVC z-scores. Higher 2nd trimester phthalate concentrations were associated with higher FEV1 (β = 0.054, 95 %CI: 0.005, 0.104) and FVC z-scores (β = 0.074, 95 % CI: 0.024, 0.124) in females and with lower measures in males (FEV1, β = -0.017, 95 %CI: -0.066, 0.026; FVC, β = -0.014, 95 %CI: -0.065, 0.030). This study indicates that prenatal exposure to phthalates is related to childhood lung function in a sex-specific manner.

Phthalate exposure during pregnancy and its association with thyroid hormones: A prospective cohort study

Phthalate esters (PAEs) possess endocrine-disrupting properties. Studies in humans have indicated that in utero phthalate exposure affects maternal thyroid hormones, which are essential for fetal growth and development. However, these studies also reported inconsistent results on the relationship between phthalates and thyroid hormones. This prospective cohort study aimed to assess phthalate exposure across the three trimesters of pregnancy and its association with thyroid hormone levels. From 2019 to 2022, we recruited 672 pregnant women, and two urine samples and one blood sample were collected from each participant during the pregnancy. We examined the urine samples from 663, 335, and 294 women in the first, second, and third trimester, respectively, for the following seven phthalate metabolites: monoethyl phthalate (MEP) from diethyl phthalate (DEP); mono-n-butyl phthalate (MnBP) and mono-iso-butyl phthalate (MiBP) from dibutyl phthalate (DBP); monobenzyl phthalate (MBzP) from butyl benzyl phthalate; and three di(2-ethylhexyl) phthalate (DEHP) metabolites, mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP). Additionally, we examined the levels of free thyroxine (FT4), thyroid-stimulating hormone (TSH), and total triiodothyronine (TT3) in the serum samples of the following participants: 596, 627, and 576 in the first trimester; 292, 293, and 282 in the second trimester; and 250, 250, and 248 in the third trimester, respectively. Other than MBzP, which was detected in 25%-33% of the samples, other metabolites were detectable in >86% of urine samples, indicating widespread exposure to DEP, DBP, and DEHP. The detected phthalate exposure levels in our cohort were significantly higher than those reported in other countries. Metabolite levels varied across the trimesters, implying changes in exposure and metabolism throughout pregnancy. The observed variability in urinary concentrations of phthalate metabolites, which ranged from poor to moderate, underscores the importance of taking multiple measurements during pregnancy for precise exposure assessment. Using a linear mixed model, we analyzed the effects of repeated phthalate exposure on thyroid hormone levels while adjusting for potential confounders. We observed significant linear trends in FT4, TSH, and, to a lesser extent, TT3 across quartiles of specific phthalate metabolites. Comparing the highest to the lowest quartiles, we found a significant increase in FT4 levels, ranging from 2 to 3.7%, associated with MEP; MECPP; MEHHP; and the sum of seven metabolites (∑7PAE), three DEHP metabolites (∑3DEHP), two DBP metabolites (∑DBP), and both low molecular weight (∑LMW) and high molecular weight metabolites. Increased TSH levels (5%-16%) were observed for all phthalate metabolites (except MEHHP) and their molar sums, including ∑7PAE. For TT3, a significant increase was observed with MEP (2.2%) and a decrease was observed with ∑DBP (-2.7%). A higher TSH/FT4 ratio was observed with the highest quartiles (third or fourth) of several phthalate metabolites: MEP (8.8%), MiBP (8.7%), MnBP (22.2%), ∑7PAE (15.3%), ∑DBP (16.4%), and ∑LMW (18.6%). These hormonal alterations, most notably in the second and third trimesters, suggest that phthalate exposure may impact fetal growth and development by affecting maternal thyroid function.

Personal care product use patterns in association with phthalate and replacement biomarkers across pregnancy

BACKGROUND

Humans are exposed to phthalates, a class of non-persistent chemicals, through multiple products, including personal care and cosmetics. Associations between specific phthalates and product use have been inconsistent. However, determining these connections could provide avenues for exposure reduction.

OBJECTIVE

Examine the association between patterns of personal care product use and associations with phthalate and replacement biomarkers.

METHODS

In the Human Placenta and Phthalates Study, 303 women were enrolled in early pregnancy and followed for up to 8 visits across gestation. At each visit, women completed a questionnaire about product use in the prior 24 hours and contributed urine samples, subsequently analyzed for 18 phthalate and replacement metabolites. At early, mid-, and late pregnancy, questionnaire responses were condensed and repeated metabolite concentrations were averaged. Latent class analysis (LCA) was used to determine groups of women with similar use patterns, and weighted associations between group membership and biomarker concentrations were assessed.

RESULTS

LCA sorted women into groups which largely corresponded to: (1) low fragranced product use (16-23% of women); (2) fragranced product and low body wash use (22-26%); 3) fragranced product and low bar soap use (26-51%); and (4) low product use (7-34%). Monoethyl phthalate (MEP) urinary concentrations were 7-10% lower and concentrations of summed di(2-ethylhexyl) terephthalate metabolites were 15-21% lower among women in the "low fragranced product use" group compared to the population mean. Few other consistent associations between group and biomarker concentrations were noted.

IMPACT STATEMENT

Personal care products and cosmetics are a known exposure source for phthalates and potentially represent one of the most accessible intervention targets for exposure reduction. However, in this analysis accounting for concurrent use and fragranced status of products, we did not find any use patterns that corresponded to universally lower levels.

Gestational glyphosate exposure and early childhood neurodevelopment in a Puerto Rico birth cohort

INTRODUCTION

N-(phosphonomethyl)glycine, or glyphosate, is a non-selective systemic herbicide widely used in agricultural, industrial, and residential settings since 1974. Glyphosate exposure has been inconsistently linked to neurotoxicity in animals, and studies of effects of gestational exposure among humans are scarce. In this study we investigated relationships between prenatal urinary glyphosate analytes and early childhood neurodevelopment.

METHODS

Mother-child pairs from the PROTECT-CRECE birth cohort in Puerto Rico with measures for both maternal urinary glyphosate analytes and child neurodevelopment were included for analysis (n = 143). Spot urine samples were collected 1-3 times throughout pregnancy and analyzed for glyphosate and aminomethylphosphonic acid (AMPA), an environmental degradant of glyphosate. Child neurodevelopment was assessed at 6, 12, and 24 months using the Battelle Developmental Inventory, 2nd edition Spanish (BDI-2), which provides scores for adaptive, personal-social, communication, motor, and cognitive domains. We used multivariable linear regression to examine associations between the geometric mean of maternal urinary glyphosate analytes across pregnancy and BDI-2 scores at each follow-up. Results were expressed as percent change in BDI-2 score per interquartile range increase in exposure.

RESULTS

Prenatal AMPA concentrations were negatively associated with communication domain at 12 months (%change = -5.32; 95%CI: 9.04, -1.61; p = 0.007), and communication subdomain scores at 12 and 24 months. At 24 months, four BDI-2 domains were associated with AMPA: adaptive (%change = -3.15; 95%CI: 6.05, -0.25; p = 0.038), personal-social (%change = -4.37; 95%CI: 7.48, -1.26; p = 0.008), communication (%change = -7.00; 95%CI: 11.75, -2.26; p = 0.005), and cognitive (%change = -4.02; 95%CI: 6.72, -1.32; p = 0.005). Similar trends were observed with GLY concentrations, but most confidence intervals include zero. We found no significant associations at 6 months.

CONCLUSIONS

Our results suggest that gestational exposure to glyphosate is associated with adverse early neurodevelopment, with more pronounced delays at 24 months. Given glyphosate's wide usage, further investigation into the impact of gestational glyphosate exposure on neurodevelopment is warranted.

Phthalate exposure and blood pressure in U.S. children aged 8-17 years (NHANES 2013-2018)

BACKGROUND

Current evidence from epidemiologic studies suggested that phthalate metabolites might be associated with blood pressure (BP) changes. However, the special relationship between phthalate metabolites and BP changes in children has not been clearly elucidated in existing researches.

OBJECTIVES

We investigated the links between phthalate metabolites and various BP parameters, including systolic/diastolic BP, mean arterial pressure (MAP), and the presence of hypertension.

METHODS

The population sample consisted of 1036 children aged 8 to 17 years from the 2013-2018 NHANES in the United States. High performance liquid chromatography-electrospray ionization-tandem mass spectrometry was used to measure urinary concentrations of 19 phthalate metabolites. Systolic/diastolic BP were derived from the average of three valid measurements, and MAP was calculated as (systolic BP + 2 × diastolic BP)/3. Hypertension was defined as mean systolic BP and/or diastolic BP that was ≥ 95th percentile for gender, age, and height reference. Linear regression, logistic regression, and weighted quantile sum (WQS) regression models were employed to assess the associations between phthalate exposure and systolic/diastolic BP, MAP, and hypertension.

RESULTS

Ten of 19 phthalate metabolites including MCNP, MCOP, MECPP, MBP, MCPP, MEP, MEHHP, MiBP, MEOHP, and MBzP had detection frequencies > 85% with samples more than 1000. MCNP, MCOP, MECPP, MBP, MCPP, MEHHP, MiBP, MEOHP, and MBzP were generally negatively associated with systolic/diastolic BP and MAP, but not protective factors for hypertension. These associations were not modified by age (8-12 and 13-17 years) or sex (boys and girls). The above-mentioned associations were further confirmed by the application of the WQS analysis, and MCOP was identified as the chemical with the highest weight.

CONCLUSION

Phthalate metabolites were associated with modest reductions in systolic/diastolic BP, and MAP in children, while appeared not protective factors for hypertension. Given the inconsistent results among existing studies, our findings should be confirmed by other cohort studies.

Statistical methods for chemical mixtures: a roadmap for practitioners

Quantitative characterization of the health impacts associated with exposure to chemical mixtures has received considerable attention in current environmental and epidemiological studies. With many existing statistical methods and emerging approaches, it is important for practitioners to understand when each method is best suited for their inferential goals. In this study, we conduct a review and comparison of 11 analytical methods available for use in mixtures research, through extensive simulation studies for continuous and binary outcomes. These methods fall in three different classes: identifying important components of a mixture, identifying interactions and creating a summary score for risk stratification and prediction. We carry out an illustrative data analysis in the PROTECT birth cohort from Puerto Rico. Most importantly we develop an integrated package "CompMix" that provides a platform for mixtures analysis where the practitioner can implement a pipeline for several types of mixtures analysis. Our simulation results suggest that the choice of methods depends on the goal of analysis and there is no clear winner across the board. For selection of important toxicants in the mixture and for identifying interactions, Elastic net by Zou et al. (Enet), Lasso for Hierarchical Interactions by Bien et al (HierNet), Selection of nonlinear interactions by a forward stepwise algorithm by Narisetty et al. (SNIF) have the most stable performance across simulation settings. Additionally, the predictive performance of the Super Learner ensembling method by Van de Laan et al. and HierNet are found to be superior to the rest of the methods. For overall summary or a cumulative measure, we find that using the Super Learner to combine multiple Environmental Risk Scores can lead to improved risk stratification properties. We have developed an R package "CompMix: A comprehensive toolkit for environmental mixtures analysis", allowing users to implement a variety of tasks under different settings and compare the findings. In summary, our study offers guidelines for selecting appropriate statistical methods for addressing specific scientific questions related to mixtures research. We identify critical gaps where new and better methods are needed.

Associations of concentrations of eight urinary phthalate metabolites with the frequency of use of common adult consumer and personal-care products

This study analyzed the relationship between urine concentrations of phthalate metabolites (UCOM) and personal care products (PCPs) used in adults and examined the change in UCOM according to the usage frequency of PCPs based on raw data from the 3rd Korean National Environmental Health Survey conducted between 2015 and 2017. The relationship between PCP use frequency and UCOM was analyzed using multiple regression analysis, adjusting for baseline factors. The regression model consisted of a Crude Model with log-transformed UCOM before and after adjustment for urine creatinine concentrations. Model 1 was additionally adjusted for age, sex, and obesity, while Model 2 was additionally adjusted for smoking, alcohol consumption, pregnancy history, average monthly income of the household, and PCP exposure within the past 2 days. PCP usage frequency was significantly associated with the UCOM without adjustment for urine creatinine and correlated with demographic characteristics, urine creatinine concentration, and PCP exposure within the past 2 days. This study on exposure to urinary phthalates will play a crucial role in Korean public health by aligning with the fundamentals of research priorities and providing representative data on phthalate exposure for conducting population-level studies.

Long-term impacts of endocrine-disrupting chemicals exposure on kidney function: A community-based cohort study

This study explores the extended renal effects of endocrine-disrupting chemicals (EDCs) exposure, a linkage already established with adverse health outcomes, notably chronic kidney disease. To delve deeper, the Chang Gung Community Research Center conducted a longitudinal study with 887 participants. Among them, 120 individuals were scrutinized based on EDC scores, analyzing 17 urinary EDCs and renal function. Findings revealed elevated mono-(2-ethylhexyl) phthalate (MEHP) and bisphenol A levels in higher EDC exposure cases. MEHP notably correlated with increased urinary albumin-to-creatinine ratio (UACR), predicting a > 15% decline in estimated glomerular filtration rate. Higher MEHP levels also hinted at declining renal function. UACR escalation linked significantly with specific EDCs: MEHP, methylparaben, nonylphenol, and 4-tert-octylphenol. This research underscores enduring renal hazards tied to environmental EDC exposure, particularly MEHP, emphasizing the urgent call for robust preventive public health strategies.

Personal Care Products, Socioeconomic Status, and Endocrine-Disrupting Chemical Mixtures in Black Women

Personal care products (PCPs) are sources of exposure to endocrine-disrupting chemicals (EDCs) among women, and socioeconomic status (SES) may influence these exposures. Black women have inequitable exposure to EDCs from PCP use, but no study has investigated how exposure to EDCs through PCPs may vary by SES, independent of race. Using data from the Study of Environment, Lifestyle, and Fibroids, a cohort of reproductive-aged Black women (n = 751), we quantified associations between PCPs and urinary biomarker concentrations of EDC mixtures (i.e., phthalates, phenols, parabens) within SES groups, defined using k-modes clustering based on education, income, marital status, and employment. Information about PCP use and SES was collected through questionnaires and interviews. We used principal component analysis to characterize the EDC mixture profiles. Stratified linear regression models were fit to assess associations between PCP use and EDC mixture profiles, quantified as mean differences in PC scores, by SES group. Associations between PCP use and EDC mixture profiles varied by SES group; e.g., vaginal powder use was associated with a mixture of phenols among lower SES women, whereas this association was null for higher SES women. Findings suggest that SES influences PCP EDC exposure in Black women, which has implications for public health interventions.

Ultra-processed and fast food consumption, exposure to phthalates during pregnancy, and socioeconomic disparities in phthalate exposures

BACKGROUND

Consuming ultra-processed foods may increase exposure to phthalates, a group of endocrine disruptors prevalent in food contact materials.

OBJECTIVES

Investigate associations between ultra-processed food intake and urinary phthalates during pregnancy, and evaluate whether ultra-processed foods mediate socioeconomic disparities in phthalate exposures.

METHODS

In a socioeconomically diverse sample of 1031 pregnant women from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) Study in the urban South, the Block Food Frequency Questionnaire was administered and urinary phthalate metabolites were measured in the second trimester. Linear regressions modeled associations between phthalates and overall ultra-processed food consumption, individual ultra-processed foods, and exploratory factor analysis dietary patterns. Causal mediation analyses examined whether ultra-processed food intake mediates relationships between socioeconomic disparities and phthalate exposures.

RESULTS

Ultra-processed foods constituted 9.8-59.0 % (mean = 38.6 %) of participants' diets. 10 % higher dietary proportion of ultra-processed foods was associated with 13.1 % (95 %CI: 3.4 %-22.9 %) higher molar sum concentrations of di(2-ethylhexyl) phthalate metabolites (ΣDEHP). 10 % higher consumption of minimally-processed foods was associated with lower ΣDEHP (10.8 %: 3.4 %-22.9 %). Ultra- and minimally-processed food consumption were not associated with non-DEHP metabolites. Standard deviation higher consumptions of hamburger/cheeseburger, French fries, soda, and cake were associated with 10.5 % (4.2 %-17.1 %), 9.2 % (2.6 %-16.2 %), 7.4 % (1.4 %-13.6 %), and 6.0 % (0.0 %-12.4 %), respectively, higher ΣDEHP. Exploratory factor analysis corroborated positive associations of processed food with ΣDEHP, and uncovered a healthy dietary pattern associated with lower urinary ΣDEHP, mono(2-ethyl-5-hydroxyhexyl) (MEHHP), mono(2-ethyl-5-carboxypentyl) (MECPP), mono(2-carboxymethylhexyl) (MCMHP), and mono-isononyl (MINP) phthalates. Significant indirect effects indicated that lower income and education levels were associated with 1.9 % (0.2 %-4.2 %) and 1.4 % (0.1 %-3.3 %) higher ΣDEHP, respectively, mediated via increased ultra-processed food consumption.

CONCLUSIONS

Consumption of ultra-processed foods may increase exposure to phthalates. Policies to reduce dietary phthalate exposures from food packaging and processing are needed, as socioeconomic barriers can preclude dietary recommendations as a sole means to reduce phthalate exposures.

Variability and Longitudinal Trajectories of Phthalate and Replacement Biomarkers across Pregnancy in the Human Placenta and Phthalates Study

Human exposure to phthalates is widespread, but assessment of variability across pregnancy has been hampered by short half-lives of phthalate biomarkers and a few repeated measures in prior studies. We aimed to characterize the variability and longitudinal profiles of phthalate and replacement biomarkers across pregnancy. Within the Human Placenta and Phthalates Study, 303 pregnant women provided urine samples at up to 8 visits across gestation. Concentrations of 14 metabolites of phthalates and 4 metabolites of replacements were quantified in each sample, and subject-specific averages within each trimester were calculated. We examined variability in individual biomarker concentrations across the 8 visits, within trimesters, and across trimester-specific averages using intraclass correlation coefficients (ICCs). To explore longitudinal exposure biomarker profiles, we applied group-based trajectory modeling to trimester-specific averages over pregnancy. Pooling multiple visits into trimester-specific averages improved the ICCs for all biomarkers. Most biomarkers generally showed stable concentrations across gestation, i.e., high-, medium-, and low-concentration profiles, with small proportions of participants falling into the "high"-exposure groups. Variability over pregnancy is likely attributable to random fluctuations around a baseline exposure rather than true changes in concentrations over time.

Associations of phthalates, phthalate replacements, and their mixtures with eicosanoid biomarkers during pregnancy

Humans are exposed to complex mixtures of phthalates. Gestational exposure to phthalates has been linked to preeclampsia and preterm birth through potential pathways such as endocrine disruption, oxidative stress, and inflammation. Eicosanoids are bioactive signaling lipids that are related to a variety of homeostatic and inflammatory processes. We investigated associations between urinary phthalates and their mixtures with plasma eicosanoid levels during pregnancy using the PROTECT cohort in Puerto Rico (N = 655). After adjusting for covariates, we estimated pair-wise associations between the geometric mean of individual phthalate metabolite concentrations across pregnancy and eicosanoid biomarkers using multivariable linear regression. We used bootstrapping of adaptive elastic net regression (adENET) to evaluate phthalate mixtures associated with eicosanoids and subsequently create environmental risk scores (ERS) to represent weighted sums of phthalate exposure for each individual. After adjusting for false-discovery, in single-pollutant analysis, 14 of 20 phthalate metabolites or parent compound indices showed significant and primarily negative associations with multiple eicosanoids. In our mixture analysis, associations with several metabolites of low molecular weight phthalates - DEP, DBP, and DIBP - became prominent. Additionally, MEHHTP and MECPTP, metabolites of a new phthalate replacement, DEHTP, were selected as important predictors for determining the concentrations of multiple eicosanoids from different pathway groups. A unit increase in phthalate ERS derived from bootstrapping of adENET was positively associated with several eicosanoids mainly from Cytochrome P450 pathway. For example, an increase in ERS was associated with 11(S)-HETE (β = 1.6, 95% CI: 0.020, 3.180), (±)11,12-DHET (β = 2.045, 95% CI: 0.250, 3.840), 20(S)-HETE (β = 0.813, 95% CI: 0.147, 1.479), and 9 s-HODE (β = 2.381, 95% CI: 0.657, 4.104). Gestational exposure to phthalates and phthalate mixtures were associated with eicosanoid levels during pregnancy. Results from the mixture analyses underscore the complexity of physiological impacts of phthalate exposure and call for further in-depth studies to examine these relationships.

Maternal phthalate exposure during pregnancy and testis function of young adult sons

BACKGROUND

Phthalate exposure during fetal life may disrupt testicular development. Congruent with this, studies have found shorter anogenital distance, reduced penile size and altered hormone levels in infant boys whose mothers were exposed to higher levels of some phthalates during pregnancy. Few studies have explored if such adverse effects persist in adulthood. Thus, we aimed to explore if there is an association between fetal phthalate exposure and markers of testicular function in young adult men.

METHODS

In a longitudinal mother-child cohort from Copenhagen, Denmark, we examined 100 young men whose mothers during pregnancy had serum drawn and analyzed for 34 phthalate metabolites. Examinations of the young men took place at 18-20 years of age and included measurements of adult markers of testicular function (reproductive hormones, penile size, anogenital distance (AGD), testis volume, semen quality) and growth factors. Associations between maternal serum concentrations of phthalate metabolites and reproductive measures in the young men were tested using multiple linear regression.

RESULTS

Most consistently, higher maternal phthalate exposure was associated with higher luteinizing hormone (LH) but unchanged testosterone in adult sons. Congruently, higher maternal exposure was associated with lower total and free testosterone/LH ratios in adult sons. For example, twice as high maternal MiNP was associated with a 7.9 % (95 % CI 1.6-13.8) lower free testosterone/LH ratio. There was no consistent pattern of associations between the different phthalate metabolites and other reproductive hormones, clinical outcomes, or semen quality. None of the tested associations was significant after multiplicity adjustment.

CONCLUSIONS

In this exploratory study, higher maternal exposure to some phthalates was associated with impaired testicular Leydig cell function evidenced by a lower total and free testosterone/LH ratio in adult sons. This unique 18-20-year follow-up study raises concern and suggests that exposure of pregnant women to phthalates may have long-term effects on adult reproductive health in male offspring.

The effect of phthalates exposure during pregnancy on asthma in infants aged 0 to 36 months: a birth cohort study

This cohort study sought to investigate the effects of phthalates exposure during pregnancy on offspring asthma and its association with placental stress and inflammatory factor mRNA expression levels. A total of 3474 pregnant women from the China Ma'anshan birth cohort participated in this study. Seven phthalate metabolites were detected in urine samples during pregnancy by solid phase extraction-high-performance liquid chromatography tandem mass spectrometry. Placenta stress and inflammation mRNA expression were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). Early pregnancy may be the critical period when phthalates exposure increases the risk of asthma in infants and young children, and there is a certain gender difference in the risk of asthma in infants and young children. Moreover, through the placenta stress and inflammatory factor associated with infant asthma found anti-inflammatory factor of interleukin-10 (IL-10) mRNA expression will reduce the risk of 36-month-old male infant asthma. The expression of interleukin-4(IL-4) and macrophage (M2) biomarker cluster of differentiation 206(CD206) mRNA reduced the risk of asthma in 18-month-old female infants. Placental stress and inflammatory response were analyzed using mediating effects. Tumor necrosis factor-α (TNFα) showed a complete mediating effect between mono-benzyl phthalate (MBzP) exposure in early pregnancy and asthma in 12-month-old males, and IL-10 also showed a complete mediating effect between mono-n-butyl phthalate (MBP) exposure in early and late pregnancy and asthma in 36-month-old males. In summary, exposure to phthalates during pregnancy may contribute to the development of asthma in infants, which may be associated with placental stress and inflammation.

Examining the association between prenatal maternal stress and infant non-nutritive suck

BACKGROUND

This study examined the relationship between prenatal maternal stress (PREMS) and non-nutritive suck (NNS) and tested its robustness across 2 demographically diverse populations.

METHODS

The study involved 2 prospective birth cohorts participating in the national Environmental influences on Child Health Outcomes (ECHO) Program: Illinois Kids Development Study (IKIDS) and ECHO Puerto Rico (ECHO-PROTECT). PREMS was measured during late pregnancy via the 10-item Perceived Stress Scale (PSS-10). NNS was sampled from 1- to 8-week-olds using a custom pacifier for ~5 min.

RESULTS

Overall, 237 mother-infant dyads completed this study. Despite several significant differences, including race/ethnicity, income, education, and PREMS levels, significant PREMS-NNS associations were found in the 2 cohorts. In adjusted linear regression models, higher PREMS, measured through PSS-10 total scores, related to fewer but longer NNS bursts per minute.

CONCLUSIONS

A significant association was observed between PREMS and NNS across two diverse cohorts. This finding is important as it may enable the earlier detection of exposure-related deficits and, as a result, earlier intervention, which potentially can optimize outcomes. More research is needed to understand how NNS affects children's neurofunction and development.

IMPACT

In this double-cohort study, we found that higher maternal perceived stress assessed in late pregnancy was significantly associated with fewer but longer sucking bursts in 1- to 8-week-old infants. This is the first study investigating the association between prenatal maternal stress (PREMS) and infant non-nutritive suck (NNS), an early indicator of central nervous system integrity. Non-nutritive suck is a potential marker of increased prenatal stress in diverse populations. Non-nutritive suck can potentially serve as an early indicator of exposure-related neuropsychological deficits allowing for earlier interventions and thus better prognoses.

The cumulative risk assessment of phthalates exposure in preterm neonates

Phthalates are widely used plasticizers in various consumer products and medical devices, with some reporting as having estrogenic and anti-androgenic endocrine-disrupting effects. Premature neonates may be exposed to high levels of specific phthalates during hospitalization in the neonatal intensive care unit (NICU) because of reliance on multiple medical procedures that pose a possible health risk. The present study utilized seven urinary phthalate metabolites of dibutyl phthalate isomers [(di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP)], butylbenzyl phthalate (BBzP), and di(2-ethylhexyl) phthalate (DEHP) that had been previously measured in 33 preterm neonates sampled at hospital admission (N = 23) and daily during their NICU stay (N = 260). We aimed to perform: (1) cumulative risk assessment (CRA) using the volume and creatinine-adjusted models; (2) examine the temporal variability of CRA from repeated measures and (3) estimate the risk of cumulative exposure to phthalates based on their anti-androgenic and/or estrogenic properties. We multiplied the relative activity of individual phthalates exhibiting estrogenic or anti-androgenic effects by daily intake. For each preterm neonate, CRA was assessed based on the hazard index (HI) metric [the sum of hazard quotients] based on three reference doses for anti-androgenicity: the tolerable daily intake (TDI) from the European Food Safety Authority, the reference dose (RfD-AA) published in 2010 and newly revised published in 2020 (NRfD-AA). The metabolites of BBzP and DEHP were 2-23 fold higher in preterm neonates during their NICU stay. Median HIs increased in the order of HI_NRfDAA > HI_RfDAA > HI_TDI. In the creatinine-based model, 87% (92%), 87% (96%), and 100% (100%) of preterm neonates at admission (during NICU stay) showed HI_TDI, HI_RfD-AA, and HI_NRfD-AA exceeding 1, respectively with DEHP the most prevalent. The temporal reproducibility of HI (based on three reference doses) during preterm neonate stay in the NICU was high, with intra-class correlation coefficients ranging between 0.77 and 0.97, suggesting persistent exposure to phthalates. The four phthalates that preterm neonates were exposed to in the NICU exhibited estrogenic binding and anti-androgenic effects with median values (creatinine-based) of 98.7 and 56.9 μg/kg body weight/day, respectively. This was especially true for DEHP. The results indicate that preterm neonates in this NICU setting are probably at high risk of cumulative phthalate exposure with anti-androgenic properties that may have long-term adverse reproductive and developmental effects.

Screening for phthalates biomarkers and its potential role in infertility outcomes in Jordan

BACKGROUND

Phthalates are endocrine disrupting chemicals that are used in plastic and personal care products. Phthalate exposure has been linked to reproductive and fertility outcomes.

OBJECTIVES

This study aimed to assess the phthalate exposures using both urinary level of two DEHP metabolites in females and questionnaires. It also aimed to investigate the association between phthalate levels and reproductive and fertility outcomes.

METHODS

325 females with and without fertility problems at gynaecology clinics filled out a questionnaire and provided a urine sample. Urine samples were analyzed for two DEHP metabolites: MEHHP, mono (2-ethyl-5-hydroxyhexyl) phthalate; MEOHP, mono (2-ethyl-5-oxohexyl) phthalate, using an HPLC/MS/MS analytical method.

RESULTS

We observed a significant difference between cases and controls in terms of heating plastic in the microwave and use of skin and eye make-up, sunscreen, and nail polish. Our findings showed that MEOHP exposure is significantly associated with infertility among Jordanian women (Adjusted OR = 1.66, 95% CI: 1.14, 2.40, p-value = 0.002).

SIGNIFICANCE

To the best of our knowledge, our study is the first of its kind done in Jordan to screen for phthalate exposure and investigate its association with infertility. Our study demonstrated high exposure of the Jordanian population to DEHP. It confirms the association between DEHP exposure and infertility.

IMPACT STATEMENT

We measured phthalates in infertile and fertile women, in a community unaware of phthalate sources or its impacts, and with no regulation limits set. We aimed to increase awareness to environmental exposure to phthalates, emphasize the importance of implementation of public health interventions to control and minimize the effects of phthalate exposure and provide a base for further studies and future research to aid in the formation of policies and guidelines for the manufacturing and use of phthalates.

Maternal urine phthalate metabolite exposure and miscarriage risk: a nested case-control study of the Zunyi Birth Cohort

Phthalates (PAEs) are widespread persistent organic pollutants and endocrine disruptors. However, the associations between PAE exposure and the risk of miscarriage in humans are unclear, and an insufficient number of studies have evaluated the possible threshold or dose-dependent effects of first trimester PAE exposure on miscarriage risk. Our research measured the levels of mono-methyl phthalate (MMP), mono-ethyl phthalate, mono-isobutyl phthalate, MiBP mono-butyl phthalate (MBP), mono-octyl phthalate, mono-benzyl phthalate, mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) in maternal urine collected in early gestation between 150 pregnancies ending in miscarriage and 150 pregnancies with live birth. We also estimated the odds ratios (ORs) and 95% confidence intervals (CIs) for miscarriage and each PAE as a continuous variable or quartile. A restrictive cubic splines was used to assess dose-dependent effects after controlling for maternal characteristics (e.g., age, educational level). we identified monotonically increasing dose-dependent effects of MEHHP and MMP on the risk of miscarriage. The largest effect estimates were approximately threefold higher for the highest MBP (OR = 2.57; 95% CI = 1.32-5.01) or MMP quartile (OR = 3.57; 95% CI = 1.82-7.00) and two-fold higher for the highest MEHHP quartile (OR = 2.12; 95% CI = 1.10-4.11). Our research preliminarily obtained possible thresholds of MBP, MEHHP, and MMP which were 18.07, 2.38, and 0.80 µg/g Cr for the risk of miscarriage, respectively. First-trimester exposure to MBP, MEHHP, and MMP exceeding certain thresholds increases the risk of miscarriage.

Gestational Exposure to Phthalates and Phthalate Replacements in Relation to Neurodevelopmental Delays in Early Childhood

Phthalates have been linked to changes in child neurodevelopment. However, sex-specificity has been reported inconsistently, and little is known about the impact of recent phthalate replacement chemicals. Our analysis included mother−child pairs (N = 274) from the PROTECT birth cohort in Puerto Rico. Phthalate metabolites were measured in multiple maternal urine collected during pregnancy. Neurodevelopment was measured at 6, 12, and 24 months of age using the Battelle Developmental Inventory-2nd edition (BDI), which provides scores for adaptive, personal-social, communication, motor, and cognitive domains. Multivariable linear regression was used to examine associations between phthalate metabolite concentrations and BDI scores, adjusting for maternal age, maternal education, child age, and specific gravity. Sex-specificity was assessed with sex X exposure interaction terms and stratified models. Results show that all five domains were significantly associated with mono-3-carboxypropyl phthalate (MCPP) at age 24 months, suggesting a holistic developmental delay related to this metabolite. Sex-specificity existed for all timepoints (p-interaction < 0.2), in general, showing stronger associations among boys. For example, metabolites of a recent phthalate replacement, di-2-ethylhexyl terephthalate (DEHTP), were differentially associated with the adaptive domain (boys −7.53%/IQR, 95% CI: −14.58, −0.48 vs. girls −0.85%/IQR, 95% CI: −5.08, 3.37), and the cognitive domain (boys −6.05%/IQR, 95% CI: −10.88, −1.22 vs. girls −1.93%/IQR, 95%CI: −4.14, 0.28) at 6 months. To conclude, gestational exposure to phthalates and phthalate replacements was associated with neurodevelopmental delay across multiple domains, with differences by sex and child age.

Reviewing the variability in urinary concentrations of non-persistent organic chemicals: evaluation across classes, sampling strategies and dilution corrections

Various biomonitoring studies have been carried out to investigate the exposure of populations by measuring non-persistent organic chemicals in urine. To accurately assess the exposure, study designs should be carefully developed to maximise reproducibility and achieve good characterization of the temporal variability. To test these parameters, the intraclass correlation coefficients (ICCs) are calculated from repeated measurements and range from poor (<0.4) to excellent (≥0.75). Several studies have reported ICCs based on diverse study designs, but an overview, including recommendations for future studies, was lacking. Therefore, this review aimed to collect studies describing ICCs of non-persistent organic chemicals, discuss variations due to study design and formulate recommendations for future studies. More than 60 studies were selected, considering various chemical classes: bisphenols, pyrethroids, parabens, phthalates, alternative plasticizers and phosphate flame retardants. The variation in ICCs for an individual chemical was high (e.g. ICC of propyl paraben = 0.28-0.91), showing the large impact of the study design and of the specific exposure sources. The highest ICCs were reported for parabens (median = 0.52), while lowest ICCs were for 3-phenoxybenzoic acid (median = 0.08) and bisphenol A (median = 0.20). Overall, chemicals that had an exposure source with high variation, such as the diet, showed lower ICCs than those with more stable exposure sources, such as indoor materials. Urine correction by specific gravity had an overall positive effect on reducing the variability of ICCs. However, this effect was mostly seen in the adult population, while specific compounds showed less variation with creatinine correction. Single samples might not accurately capture the exposure to most non-persistent organic chemicals, especially when small populations are sampled. Future studies that examine compounds with low ICCs should take adequate measures to improve accuracy, such as correcting dilution with specific gravity or collecting multiple samples for one participant.

Variability in urinary phthalates, phenols, and parabens across childhood and relation to adolescent breast composition in Chilean girls

BACKGROUND

Epidemiologic evidence suggests that environmental factors acting as endocrine disrupting chemicals (EDCs) are associated with mammographic breast density and the risk of breast cancer. Exposure to EDCs during puberty, a period of rapid breast development, may affect susceptibility to breast carcinogenesis.

METHODS

In a cohort of 366 Chilean adolescents from the Growth and Obesity Cohort Study, we evaluated the relation between urinary concentrations of 15 suspected EDC biomarkers across three pubertal time points (Tanner breast stage 1 (B1), 4 (B4), and 1-year post-menarche) and breast fibroglandular volume (FGV; percent FGV [%FGV] and absolute FGV [aFGV]) and total breast volume (tBV) at 2-years post-menarche. We used linear mixed models to test differences in creatinine-corrected EDC biomarker concentrations at B4 and 1-year post-menarche compared to B1 and calculated intraclass correlation coefficients (ICC) of EDC concentrations across time points to appraise the consistency of measurements. We fit multivariable generalized estimating equations (GEEs) to evaluate windows of susceptibility for the association between log10-transformed EDCs and log10-transformed breast outcomes. GEEs were adjusted for age, body fat percentage, total caloric intake, and maternal education.

RESULTS

Urinary EDC biomarker concentrations highly varied across pubertal time points (ICC range 0.01-0.30). For 12 EDCs, biomarker concentrations decreased over time. Triclosan measured at 1-year post-menarche was inversely associated with %FGV at 2-years post-menarche (β = -0.025, 95 % confidence interval = -0.041, -0.008). Mono(2-ethyl-5-carboxypentyl) phthalate and the sum of di(2-ethylhexyl) phthalate metabolite concentrations at B4 were positively associated with aFGV and tBV at 2-years post-menarche. No measured phenols were associated with aFGV and tBV, while no measured parabens were associated with %FGV and aFGV.

CONCLUSIONS

Our study suggests relatively high variability in EDC biomarker concentrations across the peripubertal time period. We also found evidence to suggest that there may be pubertal windows of susceptibility to select EDCs for the association with adolescent breast density.

Urinary levels of parabens, phthalate metabolites, bisphenol A and plasticizer alternatives in a Belgian population: Time trend or impact of an awareness campaign?

A human biomonitoring study was carried out in 2015 within an adult population living in Liege (Belgium). Some phthalate metabolites and parabens were measured in the urine of 252 participants, and information were collected about their food habits, life styles and home environment to identify some predictors of exposure. Concomitantly, an awareness campaign was initiated by the Provincial Authorities of Liege and spread over 2 years. Three years later (2018), 92 of the initial participants provided again urine samples, and the levels of phthalate metabolites, phthalate substitute (DINCH), parabens, bisphenol-A and bisphenol alternatives (bisphenol-S, -F, -Z, -P) were determined and compared to those obtained in 2015 to assess time trends. In 2015, methyl- and ethylparaben were the most abundant parabens (P50 = 9.12 μg/L and 1.1 μg/L respectively), while propyl- and butylparaben were sparsely detected. Except for mono-2-ethylhexyl phthalate and 6-OH-mono-propyl-heptyl phthalate, all other targeted phthalate metabolites were positively quantified in most of the urine samples (between 89 and 98%) with median concentrations ranging between 2.7 μg/L and 21.3 μg/L depending on the metabolite. The multivariate regression models highlighted some significant associations between urinary phthalate metabolite or paraben levels and age, rural or urban character of the residence place, and the use of some personal care products. However, all determination coefficients were weak meaning that the usual covariates included in the models only explained a small part of the variance. Between 2015 and 2018, levels of parabens and phthalate metabolites significantly decreased (from 1.3 to 2.5 fold) except for monoethyl phthalate which seemed to remain quite constant. Contrariwise, all bisphenol alternatives and DINCH metabolites were measured in higher concentrations in 2018 vs 2015 while BPA levels did not differ significantly. However, it was not feasible to unequivocally highlight an impact of the awareness campaign on the exposure levels of the population.

Variability and correlations of synthetic chemicals in urine from a New York City-based cohort of pregnant women

Fetal exposure to environmental chemicals has been associated with adverse health outcomes in children and later into adulthood. While several studies have examined correlations and variability of non-persistent chemical exposures throughout pregnancy, many do not capture more recent exposures, particularly in New York City. Our goal was to characterize exposure to phthalates, bisphenols, polycyclic aromatic hydrocarbons, and organophosphate pesticides among pregnant women residing in New York City who enrolled in the New York University Children's Health and Environment Study (NYU CHES) between 2016 and 2018. We measured urinary chemical metabolite concentrations in 671 women at early, mid, and late pregnancy (median 10.8, 20.8, and 29.3 weeks, respectively). We calculated Spearman correlation coefficients among chemical concentrations at each measurement time point. We compared changes in population-level urinary metabolites at each stage using paired Wilcoxon signed-rank tests and calculated intraclass correlation coefficients (ICCs) to quantify intra-individual variability of metabolites across pregnancy. Geometric means and ICCs were compared to nine other pregnancy cohorts that recruited women in 2011 or later as well as nationally reported levels from women of child-bearing age. Compared with existing cohorts, women in NYU CHES had higher geometric means of organophosphate pesticides (Σdiethylphosphates = 28.7 nmol/g cr, Σdimethylphosphates = 57.3 nmol/g cr, Σdialkyl phosphates = 95.9 nmol/g cr), bisphenol S (0.56 μg/g cr), and 2-naphthalene (8.98 μg/g cr). Five PAH metabolites and two phthalate metabolites increased between early to mid and early to late pregnancy at the population level. Spearman correlation coefficients for chemical metabolites were generally below 0.50. Intra-individual exposures varied over time, as indicated by low ICCs (0.22-0.88, median = 0.38). However, these ICCs were often higher than those observed in other pregnancy cohorts. These results provide a general overview of the chemical metabolites measured in NYU CHES in comparison to other contemporary pregnancy cohorts and highlight directions for future studies.

Determinants of phthalate exposures in pregnant women in New York City

Previous studies have provided data on determinants of phthalates in pregnant women, but results were disparate across regions. We aimed to identify the food groups and demographic factors that predict phthalate exposure in an urban contemporary pregnancy cohort in the US. The study included 450 pregnant women from the New York University Children's Health and Environment Study in New York City. Urinary concentrations of 22 phthalate metabolites, including metabolites of di-2-ethylhexylphthalate (DEHP), were determined at three time points across pregnancy by liquid chromatography coupled with tandem mass spectrometry. The Diet History Questionnaire II was completed by pregnant women at mid-pregnancy to assess dietary information. Linear mixed models were fitted to examine determinants of urinary phthalate metabolite concentrations. Using partial-linear single-index (PLSI) models, we assessed the major contributors, among ten food groups, to phthalate exposure. Metabolites of DEHP and its ortho-phthalate replacement, diisononyl phthalate (DiNP), were found in >90% of the samples. The sum of creatinine-adjusted DiNP metabolite concentrations was higher in older and single women and in samples collected in summer. Hispanic and non-Hispanic Black women had lower urinary concentrations of summed metabolites of di-n-octyl phthalate (DnOP), but higher concentrations of low molecular weight phthalates compared with non-Hispanic White women. Each doubling of grain products consumed was associated with a 20.9% increase in ∑DiNP concentrations (95%CI: 4.5, 39.9). PLSI models revealed that intake of dried beans and peas was the main dietary factor contributing to urinary ∑DEHP, ∑DiNP, and ∑DnOP levels, with contribution proportions of 76.3%, 35.8%, and 27.4%, respectively. Urinary metabolite levels of phthalates in pregnant women in NYC varied by age, marital status, seasonality, race/ethnicity, and diet. These results lend insight into the major determinants of phthalates levels, and may be used to identify exposure sources and guide interventions to reduce exposures in susceptible populations.

Sex-specific associations between maternal exposure to parabens, phenols and phthalates during pregnancy and birth size outcomes in offspring

Current evidence on the effects of prenatal exposure to endocrine disrupting chemicals on birth size remains largely inconclusive. We aimed to investigate sex-specific associations between maternal exposure to parabens, phenols and phthalates during pregnancy and birth weight, length and head/abdominal circumferences. We performed a prospective study of 88 pregnant women who underwent amniocentesis in the period 2012 to 2014. Maternal urine samples were collected during pregnancy in weeks 12 to 36 (median: 18 weeks). The concentrations of parabens, phenols and individual phthalate diester metabolites were analyzed by isotope-diluted liquid chromatography-tandem mass spectrometry and osmolality adjusted. Linear regression models estimated the associations between urinary levels of selected compounds (tertile(T2-T3)_medium/high versus T1_low exposure) and birth size, stratified by offspring sex. A total of three parabens, two phenols, four individual phthalate metabolites and four sums of diester metabolites were detectable above limits of detection in at least 60% of urine samples. Overall, we observed few statistically significant associations, but medium/high exposure to bisphenol A (BPA) in male offspring was associated with statistically significant lower birth size across most outcomes [birth weight: -428 g (95% CI -756 to -99.4); birth length: -1.76 cm (95% CI -3.28 to -0.25); abdominal circumference: -1.97 cm (95% CI -3.55 to -0.39)]. Similarly, medium/high exposure to methyl paraben (MeP) in male offspring was associated with lower birth weight (-661 g, 95% CI -1251 to -70.7) and length (-3.11 cm, 95% CI -5.76 to -0.46) compared to low exposure. None of these associations were statistically significant in female offspring. Across all compounds, individual exposures were associated with more negative estimates of birth weight for male than for female offspring. Our study indicates that prenatal exposure to BPA and MeP may negatively affect birth size outcomes, with a possible sex effect. Given the small sample size, these findings need to be replicated in future larger studies.

Urinary phthalate metabolite concentrations and personal care product use during pregnancy - Results of a pilot study

INTRODUCTION

Phthalates are reproductive toxicants commonly found in personal care products (PCPs). These endocrine disrupting chemicals are associated with pregnancy complications, including gestational diabetes. Yet, little is known about PCP use as a contributor to urinary phthalate metabolite concentrations in pregnancy.

METHODS

We conducted a pilot study among 108 pregnant participants to examine the associations of self-reported PCP use with 14 phthalate and 2 DINCH (di(isononyl) cyclohexane-1,2-dicarboxylate) metabolite concentrations measured in single spot urine samples during pregnancy (median: 36 weeks of gestation). At the time of urine collection, participants self-reported use of hair products (within the last month) and other PCPs (within the last 48 h). We used linear regression to estimate associations for natural log-transformed, specific gravity-corrected concentrations of common PCP-associated phthalate metabolites (monoethyl phthalate [MEP], mono-n-butyl phthalate [MBP], and mono-isobutyl phthalate [MIBP]) in our primary analyses, and additional phthalate metabolites in secondary analyses.

RESULTS

Most urinary metabolites were detected for >90% of participants. Participants who reported using hair oil within the past month had MEP concentrations 125% higher (95% confidence interval [CI]: -0.1, 408) than non-users. For other personal care products, we observed the greatest percent difference in PCP-associated metabolites for MIBP among hair gel users (39.3%, 95% CI: -6.3, 107) and for MEP among conditioner/crème rinse users (-55.4%, 95% CI: -76.4, -15.6) compared to non-users.

CONCLUSION

Findings suggest that self-reported use of hair oils during late pregnancy may be associated with higher urinary concentrations of MEP. Hair gel use in late pregnancy may also be associated with higher urinary phthalate metabolite concentrations, while conditioner/crème rinse use may be associated with lower levels if MEP.

Exposure characteristics of phthalate metabolites among the Zunyi cohort of pregnant women in Southwest China

Reported evidence has increasingly indicated that exposure to phthalates can cause adverse pregnancy outcomes. However, phthalate exposure levels among pregnant women remains unclear. We aimed to evaluate the concentrations and predictors of phthalate metabolites in urine samples of the ongoing Zunyi cohort of pregnant women from Southwest China. The urine samples were collected from 1003 pregnant women during their third trimester of pregnancy. The concentrations of nine phthalate metabolites in urine samples were then determined. Data on socio-demographic profiles of the participants, lifestyle during pregnancy, parity, and sampling season were collected using questionnaires. The detectable rate of phthalate metabolites ranged from 76 to 100%. On average, mono-butyl phthalate exhibited the highest median concentration (62.45 μg/L), while mono-benzyl phthalate exhibited the lowest median concentration (0.04 μg/L). Urine concentrations of phthalate metabolites were significantly higher in older, multiparous, higher body mass index, higher income, and passive smoking during pregnancy participants. The levels of low-molecular-weight phthalate metabolites were highest during the summer. The findings indicate the health of pregnant women and fetuses in Zunyi may be generally harmed by the high exposure of phthalate metabolites, especially by mono-n-butyl phthalate. In addition, phthalate metabolites present a demographic and seasonal differential distribution among the study population. Targeted measures to reduce phthalate exposure for high-risk pregnant women and during high-exposure seasons may have potential benefits for maternal and fetal health protection.

Correlates of non-persistent endocrine disrupting chemical mixtures among reproductive-aged Black women in Detroit, Michigan

Some studies indicate that Black women have higher exposure to multiple non-persistent endocrine disrupting chemicals (EDCs) than white women, but little is known about correlates of exposure to EDC mixtures. Using baseline data from a prospective cohort study of reproductive-aged Black women (N = 751), we characterized profiles of EDC mixtures and identified correlates of exposure. At baseline, we quantified biomarkers of 16 phthalates, 7 phenols, 4 parabens, and triclocarban in urine and collected covariate data through self-administered questionnaires and interviews. We used principal component (PC) analysis and k-means clustering to describe EDC mixture profiles. Associations between correlates and PCs were estimated as the mean difference (β) in PC scores, while associations between correlates and cluster membership were estimated as the odds ratio (OR) of cluster membership. Personal care product use was consistently associated with profiles of higher biomarker concentrations of non-persistent EDCs. Use of nail polish, menstrual and vaginal products (e.g., vaginal powder, vaginal deodorant), and sunscreen was associated with a mixture of phthalate and some phenol biomarkers using both methods. Current vaginal ring use, a form of hormonal contraception placed inside the vagina, was strongly associated with higher concentrations of high molecular weight phthalate biomarkers (k-means clustering: OR = 2.42, 95% CI = 1.28, 4.59; PCA: β = -0.32, 95% CI = -0.71, 0.07). Several dietary, reproductive, and demographic correlates were also associated with mixtures of EDC biomarkers. These findings suggest that personal care product use, diet, and contraceptive use may be sources of exposure to multiple non-persistent EDCs among reproductive-aged Black women. Targeted interventions to reduce exposure to multiple EDCs among Black women are warranted.

Environmental endocrine disruptor concentrations in urine samples from Mexican Indigenous women

The Indigenous communities in Mexico show significant degrees of vulnerability to pollution due to the lack of knowledge of health risks, traditions, low levels of support, and restricted access to healthcare. As a result, exposure to environmental endocrine disruptors increases in these populations through plastic components or indoor air pollution. Therefore, the aim of the study was to evaluate the exposure to phthalate metabolites, 1-hydroxypyrene, and bisphenol A through biomonitoring data from indigenous Mexican women. A total of 45 women from the Tocoy community in San Luis Potosí, Mexico, were included. Urine samples were analyzed for Bisphenol A and 4 phthalate metabolites by ultra-performance liquid chromatography couples to tandem mass spectrometry; additionally, the 1-hydroxypyrene concentrations were evaluated by high-performance liquid chromatography coupled to a fluorescence detector. Among the main pollution sources were the use of plastic containers and burning garbage (98-100%). Indigenous women presented an exposure of 100% to mono-2-ethyl phthalate, mono-n-butyl phthalate, and 1-hydroxypyrene, with a median (25th-75th percentiles) of 17,478 (11,362-37,355), 113.8 (61.7-203.5), and 1.2 (0.9-1.7) µg/g creatinine, respectively. The major findings show urinary mono-2-ethyl phthalate concentrations higher than those measured from other studies. Therefore, these results show an impressive exposure to di(2-ethylhexyl) phthalate in Indigenous women. The current study reflects the absence of regulatory policies in marginalized populations. It highlights the need to design strategies that mitigate exposure and the importance of biological monitoring to evaluate and prevent health risk associated with exposure to environmental endocrine disruptors.

Urinary phthalate metabolites in pregnant women: occurrences, related factors, and association with maternal hormones

In this study, we aimed to evaluate phthalate metabolite levels in pregnant women, to explore the factors influencing exposure, and to assess phthalate metabolite levels in relation to thyroid hormone synthesis. We recruited 463 pregnant women and collected urine, blood, and questionnaire data at participant's first prenatal examination. Ten phthalate metabolites were analyzed: mono-isobutyl phthalate (MiBP); mono-methyl phthalate (MMP); mono-ethyl phthalate (MEP); mono-n-butyl phthalate (MnBP); mono-n-octyl phthalate (MOP); mono-benzyl phthalate (MBzP); and the metabolite of di-2-ethylhexyl phthalate (DEHP), which were mono (2-ethylhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-carboxypentyl) phthalate. Multivariable generalized estimating equation models and linear mixed models were used to predict urinary biomarker concentrations and to assess the associations between phthalate exposure and thyroid hormones. Positive associations were found between phthalate metabolites and lower education (MEP and MOP), living near the road (MEP, MnBP, and ∑DEHP), and consuming more puffed food (MEP and MBzP). In addition, MnBP (percent change [%△] = 4.25; 95% confidence interval [CI] = 0.32, 8.18) and ∑DEHP (%△ = 5.12; 95% CI = 1.25, 8.99) were positively associated with thyroid-stimulating hormones, although MEP and MnBP were inversely associated with free thyroxine and total triiodothyronine. Our findings suggest that certain habits and behaviors were predictive of the positive presence of phthalate metabolites and that certain phthalate esters are associated with altered thyroid hormone levels.

Personal care products: Demographic characteristics and maternal hormones in pregnant women from Puerto Rico

Personal care products (PCPs) refer to a wide variety of items commonly characterized as health or beauty products. PCPs contain a number of ingredients, often including a wide range of endocrine disrupting chemicals such as phthalates and parabens. The present study examines the association between self-reported PCP use and prenatal sex-steroids and thyroid hormones levels in women from Puerto Rico. We recruited pregnant women (n = 1070) through the Puerto Rico PROTECT Cohort and collected blood, demographic and pregnancy-related data at recruitment and subsequent visits. PCP use in the 48-h preceding the blood sample was collected through self-reported questionnaires. Nine hormones (corticotropin-releasing hormone [CRH], sex-hormone binding globulin [SHBG], estriol [E3], progesterone, testosterone, thyroid-stimulating hormone [TSH], total triiodothyronine [T3], total thyroxine [T4], and free thyroxine [fT4]) were measured in maternal serum samples at two points during pregnancy. Linear mixed models with random intercepts were used to examine associations between PCP use and serum hormone levels. Use of cosmetics significantly increased with age, household income and education level (p < 0.01). Use of hair products, such as hair dyes and bleach, relaxers, and mousse, was associated with lower levels of all sex steroid hormones compared to non-use: SHBG (%Δ = -7.1, 95%CI: -12.4,-1.8), E3 (%Δ = -23.2, 95%CI: -32.2,-13.0), progesterone (%Δ = -21.5, 95%CI: -29.4,-12.9) and testosterone (%Δ = -21.5, 95%CI: -33.1,-7.8) adjusted for maternal age, education and pre-pregnancy body mass index. Our findings suggest that household income and education level influence PCP use among pregnant women in this study. Use of certain hair products was associated with lower concentrations of sex steroid hormones. Although there are limitations to questionnaire data, characterizing PCP use is inexpensive and may represent exposure from multiple classes of chemicals, including chemicals that may not specifically appear on product labels and/or have not been tested for endocrine disrupting potential, making it a useful complement to chemical biomarker data.

Identification of profiles and determinants of maternal pregnancy urinary biomarkers of phthalates and replacements in the Illinois Kids Development Study

BACKGROUND/OBJECTIVES

Pregnant women are exposed to multiple phthalates and their replacements, which are endocrine disrupting chemicals associated with adverse maternal and child health outcomes. Identifying maternal characteristics associated with phthalate/replacement exposure during pregnancy is important.

METHODS

We evaluated 13 maternal sociodemographic and lifestyle factors, enrollment year, and conception season as determinants of exposure biomarkers of phthalates and their replacements in 482 pregnant women from the Illinois Kids Development Study (I-KIDS, enrolled 2013-2018). We quantified 19 phthalate/replacement metabolites in pools of five first-morning urines collected across pregnancy. K-means clustering identified women with distinct patterns of biomarker concentrations and principal component analysis (PCA) identified principal component (PC) profiles of biomarkers that exist together. We used multivariable regression models to evaluate associations of predictors with identified k-means clusters and PCs.

RESULTS

K-means clustering identified two clusters of women: 1) low phthalate/di(2-ethylhexyl) terephthalate (∑DEHTP) and 2) high phthalate/∑DEHTP biomarker concentrations. PCA identified four PCs with loadings heaviest for biomarkers of plasticizer phthalates [di-isononyl, di-isodecyl, di-n-octyl phthalates] (PC1), of other phthalates [dibenzyl, di-n-butyl, di-iso-butyl phthalates] (PC2), of phthalate replacements [∑DEHTP, di(isononyl) cyclohexane-1,2-dicarboxylate (∑DiNCH)] (PC3), and of monoethyl phthalate [MEP] (PC4). Overall, age, marital status, income, parity, pre-pregnancy BMI, caffeine intake, enrollment year, and conception season were independently associated with k-means cluster membership and at least one PC. Additionally, race/ethnicity, education, employment, pregnancy intention, smoking status, alcohol intake, and diet were associated with at least one PC. For instance, women who conceived in the spring, summer, and/or fall months had lower odds of high phthalate/∑DEHTP cluster membership and had lower plasticizer phthalate, phthalate replacement, and MEP PC scores.

CONCLUSIONS

Conception season, enrollment year, and several sociodemographic/lifestyle factors were predictive of phthalate/replacement biomarker profiles. Future studies should corroborate these findings, with a special focus on replacements to which pregnant women are becoming increasingly exposed.

The association between urinary glyphosate and aminomethyl phosphonic acid with biomarkers of oxidative stress among pregnant women in the PROTECT birth cohort study

BACKGROUND

Glyphosate is a widely used herbicide in global agriculture. Glyphosate and its primary environmental degradate, aminomethyl phosphonic acid (AMPA), have been shown to disrupt endocrine function and induce oxidative stress in in vitro and animal studies. To our knowledge, these relationships have not been previously characterized in epidemiological settings. Elevated urinary levels of glyphosate and AMPA may be indicative of health effects caused by previous exposure via multiple mechanisms including oxidative stress.

METHODS

Glyphosate and AMPA were measured in 347 urine samples collected between 16 and 20 weeks gestation and 24-28 weeks gestation from pregnant women in the PROTECT birth cohort. Urinary biomarkers of oxidative stress, comprising 8-isoprostane-prostaglandin-F2α (8-iso-PGF2α), its metabolite 2,3-dinor-5,6-dihydro-15-F2 t-isoprostane (8-isoprostane metabolite) and prostaglandin-F2α (PGF2α), were also measured. Linear mixed effect models assessed the association between exposures and oxidative stress adjusting for maternal age, smoking status, alcohol consumption, household income and specific gravity. Potential nonlinear trends were also assessed using tertiles of glyphosate and AMPA exposure levels.

RESULTS

No significant differences in exposure or oxidative stress biomarker concentrations were observed between study visits. An interquartile range (IQR) increase in AMPA was associated with 9.5% (95% CI: 0.5-19.3%) higher 8-iso-PGF2α metabolite concentrations. Significant linear trends were also identified when examining tertiles of exposure variables. Compared to the lowest exposure group, the second and third tertiles of AMPA were significantly associated with 12.8% (0.6-26.5%) and 15.2% (1.8-30.3%) higher 8-isoprostane metabolite, respectively. An IQR increase in glyphosate was suggestively associated with 4.7% (-0.9 to 10.7%) higher 8-iso-PGF2α.

CONCLUSIONS

Urinary concentrations of the main environmental degradate of glyphosate, AMPA, were associated with higher levels of certain oxidative stress biomarkers. Associations with glyphosate reflected similar trends, although findings were not as strong. Additional research is required to better characterize the association between glyphosate exposure and biomarkers of oxidative stress, as well as potential downstream health consequences.

Biomarkers of Exposure to Phthalate Mixtures and Adverse Birth Outcomes in a Puerto Rico Birth Cohort

BACKGROUND

Humans are exposed to complex mixtures of phthalate chemicals from a range of consumer products. Previous studies have reported significant associations between individual phthalate metabolites and pregnancy outcomes, but mixtures research is limited.

OBJECTIVES

We used the Puerto Rico Testsite for Exploring Contamination Threats longitudinal pregnancy cohort to investigate associations between phthalate metabolite mixtures and pregnancy outcomes.

METHODS

Women (n=462 carrying females, n=540 carrying males) provided up to three urine samples throughout gestation (median 18, 22, and 26 wk), which were analyzed for 13 phthalate metabolites. Pregnancy outcomes including preterm birth (PTB), spontaneous PTB, small and large for gestational age (SGA, LGA), birth weight z-score, and gestational age at delivery were abstracted from medical records. Environmental risk scores (ERS) were calculated as a weighted linear combination of the phthalates from ridge regression and adaptive elastic net, which are variable selection methods to handle correlated predictors. Birth outcomes were regressed on continuous ERS. We assessed gestational average and visit-specific ERS and stratified all analyses by fetal sex. Finally, we used Bayesian kernel machine regression (BKMR) to explore nonlinear associations and interactions between metabolites.

RESULTS

Differences in metabolite weights from ridge and elastic net were apparent between birth outcomes and between fetal sexes. An interquartile range increase in gestational average phthalate ERS was associated with increased odds of PTB [male odds ratio (OR)=1.56; 95% confidence interval (CI): 1.08, 2.27; female OR=1.91; 95% CI: 1.23, 2.98], spontaneous PTB (male OR=2.32; 95% CI: 1.46, 3.68; female OR=2.00; 95% CI: 1.04, 3.82), and reduced gestational age at birth (male β=-0.39 wk, 95% CI: -0.62, -0.15; female β=-0.29 wk, 95% CI: -0.52, -0.05). Analyses by study visit suggested that exposure at ∼22 wk (range 20-24 wk) was driving those associations. Bivariate plots from BKMR analysis revealed some nonlinear associations and metabolite interactions that were different between fetal sexes.

DISCUSSION

These results suggest that exposure to phthalate mixtures was associated with increased risk of early delivery and highlight the need to study mixtures by fetal sex. We also identified various metabolites displaying nonlinear relationships with measures of birth weight. https://doi.org/10.1289/EHP8990.

Association Between Phthalate Exposure in Pregnancy and Gestational Diabetes: A Chinese Cross-Sectional Study

Objective

The present study aims to explore the association between phthalate exposure and the risk of gestational diabetes mellitus (GDM).

Materials and Methods

A total of 11 plasticizer metabolites were measured in patient morning urine using high-performance liquid chromatography. Furthermore, fasting blood glucose and fasting insulin were detected in first-trimester blood samples. The chemical concentration was described using the median, the metabolite concentration difference between the GDM and control groups was compared using the bootstrap method, and the correlations of the fasting blood glucose, fasting insulin, insulin resistance index, and phthalic acid ester (PAE) metabolites were analyzed using Spearman correlation analysis. The multivariate logistic regression model and predictive probability map were performed to help assess the linearity and nature of any dose–response relationship.

Results

Of the 224 women recruited for the present study, 200 met the inclusion criteria. Their measured outcomes and biomonitoring data were examined for the presence of chemicals. The results showed that the patients in the GDM group had higher mono-(2-ethylhexyl) phthalate (MEHP) and methylerythritol cyclophosphane concentrations in their bodies than the patients in the control group. Statistically significant MEHP–GDM associations were also observed (P < 0.001). The GDM and MEHP dose–response relationships were different among pregnant women aged <35 years and those aged >35 years (P < 0.001). Furthermore, gestational age >28 weeks exhibited similar changes to those aged ≤28 weeks (P = 0.059).

Conclusion

The findings of the present study add to the growing body of evidence supporting phthalate exposure as a GDM risk factor.

The relationship between urinary phthalate metabolites and polycystic ovary syndrome in women undergoing in vitro fertilization: Nested case-control study

Certain endocrine disruptor chemicals are involved in the pathogenesis of polycystic ovary syndrome (PCOS), a hormonal disease related to infertility in women. Phthalates are the most common plasticizers found in several consumer products. Experimental and epidemiologic evidence suggests that some phthalates disrupt endocrine functions in reproductive mechanisms and development. We previously measured the levels of eight phthalate metabolites in the urine of 599 Saudi women who underwent in vitro fertilization (IVF) treatment and were enrolled in a prospective study (2015-2017). The current nested case-control study aimed to determine the association between urinary levels of phthalate metabolites and PCOS. Overall, 441 women from the IVF study were identified as eligible for this study. Women in the case group included those diagnosed with PCOS (N = 82). The control group comprised those unable to conceive due to male azoospermia or who underwent preimplantation genetic diagnosis (N = 359). Most urinary phthalate metabolite levels were several-fold higher than those reported in national surveys from other countries. The ratio of luteinizing hormone to follicle-stimulating hormone, an index of PCOS, was significantly higher in the case than in the control group, with no indication of its association with phthalate metabolites. The logistic regression model was applied after adjusting for confounders to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for each metabolite modeled as a natural logarithm (ln). For each ln-unit increase in the sum of the four di (2-ethylhexyl) phthalate (∑₄DEHP) metabolites as well as two individual metabolites, mono-(2-ethyl-5-oxohexyl) phthalate and mono-(2-ethyl-5-carboxypentyl) phthalate, the odds of PCOS increased by 40.5% [OR = 1.405 (95% CI: 1.025, 1.925)], 41.1% [OR = 1.055 (95% CI: 1.055, 1.885)], and 38.6% [OR = 1.386 (95% CI: 1.033, 1.86)], respectively. In contrast, the % odds of PCOS decreased marginally significantly by 44% [OR = 0.560 (95% CI: 0.313, 1.002)] with an ln-unit increase of %MEHP₄, the ratio of mono-(2-ethylhexyl) phthalate to ∑₄DEHP. These findings suggest that DEHP may contribute to PCOS, and further investigation is required to understand the underlying mechanisms.

Presence of parabens, phenols and phthalates in paired maternal serum, urine and amniotic fluid

OBJECTIVE

To examine whether selected endocrine disrupting chemicals were present in pregnant women and passed through the placental barrier to amniotic fluid, potentially exposing the developing fetus.

METHODS

Paired samples of maternal serum, urine and amniotic fluid were concurrently collected (<1 h) from 200 pregnant women (age >18 years) with a singleton pregnancy and undergoing amniocentesis between gestational weeks 12 - 36. The concentration of six different parabens, seven phenols, 31 metabolites from 15 phthalate diesters and the polychlorinated substance triclocarban were analyzed by isotope diluted TurboFlow-liquid chromatography-tandem mass spectrometry.

RESULTS

Concentrations of all included compounds were highest in maternal urine followed by serum, and lowest in amniotic fluid. Of the six parabens measured in amniotic fluid, methylparaben (MeP) and ethylparaben (EtP) were detectable most often (87% and 33% of the samples, respectively). Of the seven phenols measured, three (2,4-dichlorphenol, 2,5-dichlorphenol, 2-propylphenol) were detectable in the range of 14-21% of the amniotic fluid samples, at low concentrations (<0.12 ng/ml). Two secondary phthalates metabolites, mono-(2-carboxymethyl-hexyl) phthalate and mono-carboxy-iso-octyl phthalate were each present in ≤15% of the amniotic fluid samples at concentrations 2-5 times lower than in maternal serum and 20-100 times lower than in maternal urine. A modest statistically significant correlation between the levels of MeP and EtP was detected in paired maternal urine-amniotic fluid samples was detected (Spearman r_MeP: 0.246; r_EtP: 0.364). Likewise, the concentration of mono-ethyl phthalate (MEP) in paired maternal urine and amniotic fluid samples indicated a modest statistically significant correlation (Spearman r_MEP: 0.264), driven by detectable levels of MEP in only 3% of the amniotic fluid samples.

CONCLUSIONS

In general, the included parabens, phenols and phthalates were effectively metabolized and excreted via the urine, which was the matrix that reflected the highest detectable levels. The detectable levels of several included parabens and phthalates in human amniotic fluid calls for further investigations of the toxicokinetic and potential endocrine disrupting properties of individual and multiple endocrine disruptors in order to better assess the risk to the developing fetus.

DNA oxidative damage in pregnant women upon exposure to conventional and alternative phthalates

Exposure to alternative phthalates and related health effects in pregnant women are rarely reported. Nineteen phthalate metabolites and a DNA oxidative damage biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG) were determined in urine samples of pregnant women recruited in South China. The detection frequencies and concentration of selected alternative phthalates, i.e., diisononyl phthalate (DiNP), diisodecyl phthalate (DiDP) and di-(2-propylheptyl) phthalate (DPHP) were lower than those of conventional phthalates. However, mono-(6-hydroxy-2-propylheptyl) phthalate, a metabolite of DPHP, was detected in 70% of urine samples (median: 0.13 ng/mL). The estimated daily intakes of conventional plasticizers, including dimethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate and di-(2-ethylhexyl) phthalate (median range: 1.0-3.0 μg/kg_bw/day) were significantly higher than those of DiNP (0.08 μg/kg_bw/day) and DPHP (0.03 μg/kg_bw/day) (p < 0.05). Approximately 24% of pregnant women were at high risk when cumulative risk from exposure to several phthalates was considered. The concentrations of phthalate metabolites and urinary 8-OHdG were significantly correlated with each other (r = 0.206-0.772, p < 0.01), which were further conformed by multiple linear regression analysis (β = 0.168-0.639, p < 0.01). In addition, conventional phthalates were more strongly correlated with 8-OHdG than alternative phthalates (i.e., DiNP, DPHP), partly suggesting the relatively smaller health effects of alternatives due to their low exposure doses and toxicities. These findings suggested that alternative phthalates have entered the human body from consumer products in the study area, and exposure-related risk of DNA oxidative stress was comparatively lower.

Xenoestrogen exposure and kidney function in the general population: Results of a community-based study by laboratory tests and questionnaire-based interviewing

BACKGROUND

Chronic kidney disease (CKD) is a growing concern worldwide. Exposure to xenoestrogens (XEs), such as phthalates, parabens, and phenols, lead to CKD. However, kidney function and its complex relationship with XEs, lifestyle, and dietary habits are not well understood.

METHODS

In the present cross-sectional community-based cohort study, we enrolled 887 subjects for a questionnaire-based interview and laboratory tests. XE exposure concerning lifestyle/dietary habits were evaluated using questionnaires. Urinary levels of 17XE metabolites were measured in 60 subjects with high exposure risk scores and 60 subjects with low exposure risk scores.

RESULTS

Univariate and multivariate linear regression showed that a high exposure score (β ± SE: 4.226 ± 1.830, P = 0.021) was independently negatively associated with eGFR in 887 subjects. Univariate and multivariate linear regression to urinary XEs and urine albumin creatinine excretion ratio (UACR) in 120 subjects indicated that ethylparaben (EP) (β: 1.934, 95% CI: 0.135-3.733, P = 0.035) was significantly associated with increased UACR. Multivariate regression analyses of the CKD subgroup (n = 38), after adjusting for age, showed that higher levels of mono-(2-ethylhexyl) phthalate (MEHP), EP, nonylphenol (NP), and benzophenone-3 (BP-3) were significantly associated with lower estimated glomerular filtration rate (eGFR). Higher urinary levels of MEHP (OR: 3.037, 95% CI: 1.274-7.241) were more likely associated with high exposure scores (>5 points), after adjusting for diabetes, gender, eGFR, age, Na, Ca, albumin, vitamin D, systolic blood pressure (SBP), white blood cell count, total bilirubin, aspartate transaminase, and heart rate. MEHP (β ± SE: 0.033 ± 0.009, P < 0.001) was also significantly positively associated with total exposure scores after applying multivariate linear regression analyses.

CONCLUSION

XE exposure scores obtained from the questionnaires were negatively associated with kidney function. Urinary metabolites of XEs, including EP, NP, BP-3, and MEHP, are potential risk factors for microalbuminuria and decline in kidney function. MEHP seemed to have the strongest correlation with high exposure scores and decline in kidney function.

Effects of single and combined gestational phthalate exposure on blood pressure, blood glucose and gestational weight gain: A longitudinal analysis

Few studies have investigated the association of gestational exposure to phthalate with metabolic risk and have reached inconsistent conclusions. Based on the Ma'anshan Birth Cohort, 3273 women were included in the present study. All participants provided up to three urine samples for 7 phthalate metabolite measurements. The hazard index (HI) was used to evaluate the cumulative risk of multiple phthalate coexposures. The outcomes of interest included hypertensive disorders of pregnancy (HDOP), gestational diabetes mellitus (GDM), and gestational weight gain (GWG). The incidences of HDOP, GDM, and excessive GWG were 5.93%, 13.09%, and 28.95%, respectively. Exposure to a single phthalate metabolite or a specific diester during the first trimester of pregnancy elevated blood pressure (BP) and fasting plasma glucose (FPG) in the third trimester and body weight gain throughout pregnancy. However, inverse relationships were revealed for some phthalate metabolites, which were inconsistent with the results of their diesters. The HI value during the first trimester was positively associated with subsequent BP, FPG, and GWG. In addition, HI during the first trimester increased the risks of GDM [odds ratio (OR) = 1.34, 95% confidence intervals (CIs) = 1.02-1.75)] and excessive GWG (OR = 1.76, 95% CIs = 1.41-2.19) in a linear manner thereafter. Notably, phthalates might directly increase maternal blood glucose and pressure, and these changes were secondary effects of the obesiogenic effects of certain phthalates. In conclusion, exposure to single and multiple phthalates during the first trimester of pregnancy increased the risks of maternal metabolic syndrome components. However, the conflicting findings between phthalates and their metabolites need to be interpreted carefully.

Prenatal phthalate exposure reduction through an integrated intervention strategy

Pregnancy represents a sensitive susceptibility window to phthalate esters (PAEs). In this study, we develop an intervention strategy for reducing the exposure of pregnant women to phthalates. Thirty-five pregnant women, who initially underwent maternity examination, were recruited from an ongoing longitudinal prospective prenatal cohort study. The intervention strategy integrates diet, lifestyle, and environmental factors. Participants were encouraged to modify their behaviors and habits according to the intervention strategy at three different periods. Urine samples were collected from the participants after antenatal examination every month, for 8 months, to measure ten PAE metabolites. Mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-n-butyl phthalate (MnBP), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) declined significantly after the 1st intervention, while mono-isobutyl phthalate (MiBP) and mono-methyl phthalate (MMP) noticeably decreased after the 2nd intervention. The sum of the molar concentrations of MEHP, MEHHP, MEOHP, and MECPP reduced by 20 to 40% during subsequent intervention. In addition, the sum of the molar concentrations of MEP, MnBP, MMP, and MiBP as well as the sum of the molar concentrations of the ten metabolites also reduced. Our findings suggest that intervention through written recommendations can effectively reduce the burden of phthalates during pregnancy.

Pilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA

A pilot-scale expanded target assessment of mixtures of inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted in Puerto Rico (PR) to continue to inform TW exposures and corresponding estimations of cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot assessment of than 524 organic and 37 inorganic chemicals was conducted in 14 locations (7 home; 7 commercial) across PR. A follow-up 3-day temporal assessment of TW variability was conducted in December 2018 at two of the synoptic locations (1 home, 1 commercial) and included daily pre- and post-flush samples. Concentrations of regulated and unregulated TW contaminants were used to calculate cumulative in vitro bioactivity ratios and Hazard Indices (HI) based on existing human-health benchmarks. Synoptic results confirmed that human exposures to inorganic and organic contaminant mixtures, which are rarely monitored together in drinking water at the point of consumption, occurred across PR and consisted of elevated concentrations of inorganic contaminants (e.g., lead, copper), disinfection byproducts (DBP), and to a lesser extent per/polyfluoroalkyl substances (PFAS) and phthalates. Exceedances of human-health benchmarks in every synoptic TW sample support further investigation of the potential cumulative risk to vulnerable populations in PR and emphasize the importance of continued broad characterization of drinking-water exposures at the tap with analytical capabilities that better represent the complexity of both inorganic and organic contaminant mixtures known to occur in ambient source waters. Such health-based monitoring data are essential to support public engagement in source water sustainability and treatment and to inform consumer point-of-use treatment decision making in PR and throughout the US.

Individual and joint effects of phthalate metabolites on biomarkers of oxidative stress among pregnant women in Puerto Rico

Exposures to phthalate compounds have been linked to adverse birth outcomes, potentially through oxidative stress mechanisms. We explored associations between mixtures of biomarkers of phthalate and phthalate replacement metabolites and oxidative stress using lipid peroxidation biomarker 8-iso-prostaglandin-F2α (8-iso-PGF2α). As 8-iso-PGF2α can be generated via both chemical (nonenzymatic) and enzymatic lipid peroxidation pathways, we calculated the ratio of 8-iso-PGF2α/prostaglandin F2α in an attempt to distinguish the potential contributions of the two pathways. Urinary biomarker measurements were taken from 775 pregnant women in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) longitudinal birth cohort at up to three time points during gestation (16-20, 20-24, and 24-28 weeks gestation). Adaptive elastic net with pairwise linear interaction terms (adENET-I) was used to determine individual phthalate metabolites and phthalate interactions that were predictive of lipid oxidative stress biomarkers, and to subsequently create environmental risk scores (ERS) to represent weighted sums of phthalate exposure for each individual at each study visit. Repeated ERS were then used in linear mixed effects models to test for associations between biomarkers of phthalate mixtures and biomarkers of oxidative stress. We also used Bayesian kernel machine regression (BKMR) to explore nonlinearity and interactions between phthalate metabolites within the mixture. An increase from the first to fourth quartile of phthalate ERS derived from adENET-I was associated with a 96.7% increase (95% CI: 74.0, 122) in the hypothesized chemical fraction of 8-iso-PGF2α and a 268% increase (95% CI: 139, 465) in the hypothesized enzymatic fraction of 8-iso-PGF2α. BKMR analyses also suggested strong linear associations between the phthalate mixture and biomarkers of lipid oxidative stress. Various phthalates displayed nonlinear relationships with both chemical and enzymatic fractions of 8-iso-PGF2α, and we observed some evidence of interactions between metabolites in the mixture. In conclusion, exposure to phthalate mixtures was strongly associated with linear increases in biomarkers of lipid oxidative stress, and differences observed between hypothesized chemical and enzymatic lipid peroxidation outcomes highlight the need to critically assess pathways of 8-iso-PGF2α generation in relation to environmental exposures.

Performance of urine, blood, and integrated metal biomarkers in relation to birth outcomes in a mixture setting

BACKGROUND

Studies on the health effects of metal mixtures typically utilize biomarkers measured in a single biological medium, such as blood or urine. However, the ability to evaluate mixture effects are limited by the uncertainty whether a unified medium can fully capture exposure for each metal. Therefore, it is important to compare and assess metal mixtures measured in different media in epidemiology studies.

OBJECTIVES

The aim of this study was to examine the mixture predictive performance of urine and blood metal biomarkers and integrated multi-media biomarkers in association with birth outcomes.

METHODS

In our analysis of 847 women from the Puerto Rico PROTECT Cohort, we measured 10 essential and non-essential metals in repeated and paired samples of urine and blood during pregnancy. For each metal, we integrated exposure estimates from paired urine and blood biomarkers into multi-media biomarkers (MMBs), using intraclass-correlation coefficient (ICC) and weighted quantile sum (WQS) approaches. Using Ridge regressions, four separate Environmental risk scores (ERSs) for metals in urine, blood, MMBICC, and MMBWQS were computed as a weighted sum of the 10 metal concentrations. We then examined associations between urine, blood, and multi-media biomarker ERSs and birth outcomes using linear and logistic regressions, adjusting for maternal age, maternal education, pre-pregnancy body mass index (BMI), and second-hand smoke exposure. The performance of each ERS was evaluated with continuous and tertile estimates and 95% confidence intervals of the odds ratio of preterm birth using area under the curve (AUC).

RESULTS

Pb was the most important contributor of blood ERS as well as the two integrated multi-media biomarker ERSs. Individuals with high ERS (3rd tertile) showed increased odds of preterm birth compared to individuals with low ERS (1st tertile), with 2.8-fold (95% CI, 1.49 to 5.40) for urine (specific gravity corrected); 3.2- fold (95% CI, 1.68 to 6.25) for blood; 3.9-fold (95% CI, 1.72 to 8.66) for multi-media biomarkers composed using ICC; and 5.2-fold (95% CI, 2.34 to 11.42) for multi-media biomarkers composed using WQS. The four ERSs had comparable predictive performances (AUC ranging from 0.64 to 0.68) when urine is examined with specific gravity corrected concentrations.

CONCLUSIONS

Within a practical metal panel, measuring metals in either urine or blood may be an equally good approach to evaluate the metals as a mixture. Applications in practical study design require validation of these methods with other cohorts, larger panels of metals and within the context of other adverse health effects of interest.

Preterm birth and PM2.5 in Puerto Rico: evidence from the PROTECT birth cohort

BACKGROUND

Preterm birth (PTB, birth before 37 weeks of gestation) has been associated with adverse health outcomes across the lifespan. Evidence on the association between PTB and prenatal exposure to air pollutants is inconsistent, and is especially lacking for ethnic/racial minority populations.

METHODS

We obtained data on maternal characteristics and behaviors and PTB and other birth outcomes for women participating in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) cohort, who lived in municipalities located along the North Coast of Puerto Rico. We assessed pre-natal PM_2.5 exposures for each infant based on the nearest US Environmental Protection Agency monitor. We estimated prenatal phthalate exposures as the geometric mean of urinary measurements obtained during pregnancy. We then examined the association between PM_2.5 and PTB using modified Poisson regression and assessed modification of the association by phthalate exposure levels and sociodemographic factors such as maternal age and infant gender.

RESULTS

Among 1092 singleton births, 9.1% of infants were born preterm and 92.9% of mothers had at least a high school education. Mothers had a mean (standard deviation) age of 26.9 (5.5) years and a median (range) of 2.0 (1.0-8.0) pregnancies. Nearly all women were Hispanic white, black, or mixed race. Median (range) prenatal PM_2.5 concentrations were 6.0 (3.1-19.8) μ g/m³. Median (interquartile range) prenatal phthalate levels were 14.9 (8.9-26.0) and 14.5 (8.4-26.0), respectively, for di-n-butyl phthalate (DBP) and di-isobutyl phthalate (DiBP). An interquartile range increase in PM_2.5 was associated with a 1.2% (95% CI 0.4, 2.1%) higher risk of PTB. There was little difference in PTB risk in strata of infant sex, mother's age, family income, history of adverse birth outcome, parity, and pre-pregnancy body mass index. Pregnancy urinary phthalate metabolite levels did not modify the PM_2.5-PTB association.

CONCLUSION

Among ethnic minority women in Puerto Rico, prenatal PM_2.5 exposure is associated with a small but significant increase in risk of PTB.

Prenatal exposure to consumer product chemical mixtures and size for gestational age at delivery

BACKGROUND

While fetal growth is a tightly regulated process, it is sensitive to environmental exposures that occur during pregnancy. Many commonly used consumer products contain chemicals that can disturb processes underlying fetal growth. However, mixtures of these chemicals have been minimally examined. We investigated associations between prenatal exposure to 33 consumer product chemicals (nine organophosphate ester flame retardant [OPE] metabolites, 12 phthalate metabolites, and 12 phenols) and the odds of small- or large-for-gestational age (SGA and LGA) births.

METHODS

This case-control study was comprised of SGA (N = 31), LGA (N = 28), and appropriate for gestational age control (N = 31) births selected from the larger LIFECODES cohort. Biomarkers of exposure to consumer product chemicals were quantified in maternal urine collected from up to three study visits during pregnancy. In a single-pollutant approach, odds ratios (OR) and 95% confidence intervals (CI) of SGA and LGA associated with an interquartile range (IQR)-increase in exposure biomarkers were estimated using multinomial logistic regression. In a multi-pollutant approach, quantile g-computation was used to jointly estimate the OR (95% CI) of SGA and LGA per simultaneous one quartile-change in all biomarkers belonging to each chemical class.

RESULTS

Among the 33 biomarkers analyzed, 20 were detected in at least 50% of the participants. After adjusting for potential confounders, we observed reduced odds of LGA in association with higher urinary concentrations of several exposure biomarkers. For example, an IQR-increase in the OPE metabolite, diphenyl phosphate, was associated with lower odds of LGA (OR: 0.40 [95% CI: 0.18, 0.87]). Using quantile g-computation, we estimated lower odds of an LGA birth for higher OPE metabolite concentrations (OR: 0.49 [95% CI: 0.27, 0.89]) and phthalate metabolite concentrations (OR: 0.23 [95% CI: 0.07, 0.73]). Associations between consumer product chemicals and SGA were largely null.

CONCLUSIONS

Joint exposure to OPEs and phthalates was associated with lower odds of delivering LGA. Associations with LGA could indicate a specific impact of these exposures on the high end of the birth weight spectrum. Future work to understand this nuance in the associations between consumer product chemical mixtures and fetal growth is warranted.

Racial/Ethnic Disparities in Pregnancy and Prenatal Exposure to Endocrine-Disrupting Chemicals Commonly Used in Personal Care Products

PURPOSE OF REVIEW

Endocrine-disrupting chemical (EDC) exposure during pregnancy is linked to adverse maternal and child health outcomes that are racially/ethnically disparate. Personal care products (PCP) are one source of EDCs where differences in racial/ethnic patterns of use exist. We assessed the literature for racial/ethnic disparities in pregnancy and prenatal PCP chemical exposures.

RECENT FINDINGS

Only 3 studies explicitly examined racial/ethnic disparities in pregnancy and prenatal exposure to PCP-associated EDCs. Fifty-three articles from 12 cohorts presented EDC concentrations stratified by race/ethnicity or among homogenous US minority populations. Studies reported on phthalates and phenols. Higher phthalate metabolites and paraben concentrations were observed for pregnant non-Hispanic Black and Hispanic women. Higher concentrations of benzophenone-3 were observed in non-Hispanic White women; results were inconsistent for triclosan. This review highlights need for future research examining pregnancy and prenatal PCP-associated EDCs disparities to understand and reduce racial/ethnic disparities in maternal and child health.

Correlates of urinary concentrations of phthalate and phthalate alternative metabolites among reproductive-aged Black women from Detroit, Michigan

BACKGROUND

Phthalates are endocrine-disrupting chemicals that are widely present in consumer products. In the United States, Black women are more highly exposed to phthalates than other racial/ethnic groups, yet information on predictors of phthalate exposure among Black women is limited.

OBJECTIVE

We evaluated the association of demographics, lifestyle, reproductive history, and personal care product use with urinary concentrations of phthalate and phthalate alternative metabolites, using cross-sectional data from a study of 754 Black women from Detroit, Michigan (2010-2012).

METHODS

Women completed questionnaires and provided urine specimens which were analyzed for 16 phthalate and phthalate alternative metabolites. We used linear regression models to estimate mean percentage differences and 95% confidence intervals (CIs) in concentrations across levels of correlates.

RESULTS

Monoethyl phthalate (MEP) and MBP concentrations were positively associated with personal care product use, particularly nail products. Educational attainment was positively associated with high molecular weight phthalate concentrations but inversely associated with monobenzyl phthalate (MBzP) concentrations. Parity was positively associated with MBzP concentrations and inversely associated with concentrations of MEP and high molecular weight phthalates.

SIGNIFICANCE

We found that sociodemographics, reproductive characteristics, and use of certain personal care products were associated with urinary phthalate concentrations among Black women. Our results emphasize the importance of examining exposure determinants among multiply marginalized populations.