Socioeconomic factors and phthalate metabolite concentrations among United States women of reproductive age

Moderating effects of insomnia on the association between urinary phthalate metabolites and depressive symptoms in Chinese college students: focus on gender differences

OBJECTIVES

To investigate the rates of depressive symptoms in college students, explore the relationship between urinary phthalate metabolites and depressive symptoms and their gender differences, and further explore the moderating role of insomnia in this association.

METHODS

A total of 1 179 college students were recruited from 2 universities in Hefei and Shangrao cities from April to May 2019. The depressive symptoms and insomnia of college students were investigated by the Patient Health Questionnaire 9 and Insomnia Severity Index. The high-performance liquid chromatography-tandem mass spectrometry was adapted to determine the concentration of urinary phthalate metabolites. The generalized linear model was used to analyze the relationship of phthalate metabolites with depressive symptoms. Moderating analysis was used to examine whether insomnia moderated the relationship of phthalate metabolites with depressive symptoms.

RESULTS

The rates of mild depression, and moderate depression and above in college students were 31.9% and 9.2%, respectively. The phthalate metabolites exhibited a median and mean concentration spanning from 2.98 ∼ 156.55 ng/mL and 6.12 ∼ 205.53 ng/mL. The generalized linear model results showed that monobutyl phthalate (MBP) (β = 1.160, 95%CI: 0.423 ∼ 1.896) and low molecular weight phthalate (LMWP) (β = 1.230, 95%CI: 0.348 ∼ 2.113) were positively correlated with depressive symptoms, and MBP (β = 1.320, 95%CI: 0.453 ∼ 2.187) and LMWP (β = 1.396, 95%CI: 0.351 ∼ 2.440) were positively correlated with depressive symptoms only in female college students after stratified by gender. Furthermore, insomnia has a positive moderating role between MBP, LMWP, and depressive symptoms and has a sex-based difference.

CONCLUSIONS

This study suggests that there is a positive association of phthalate metabolites with depressive symptoms among Chinese college students, as well as insomnia plays a positive moderating role in this association.

Evaluating personal care product use by Environmental Working Group hazard scores in relation to consumers' sociodemographic characteristics, purchasing behaviors, and product safety perceptions

BACKGROUND

Personal care products (PCPs) are a source of environmental chemical exposures. Little research has examined the specific PCPs people use, the environmental hazards posed by those PCPs, and factors informing PCP selection.

OBJECTIVE

To examine chemical hazards of the specific products used in relation to sociodemographic factors, purchasing behaviors, and perceptions about PCP safety.

METHODS

In a cross-sectional, university-based sample (NJ, USA, N = 593), participants reported on sociodemographics, PCP purchasing behaviors and perceptions, and PCP use in the last 24-48 h (including brand and product name). Those PCPs were linked to product hazard scores (1=least hazardous, 10=most hazardous) in the Environmental Working Group's Skin Deep® database. For each participant, we calculated average hazard scores across all PCPs used and by category (e.g., haircare, skincare) and evaluated use of PCPs with high hazard scores (7-10). We fitted adjusted regression models examining associations of sociodemographic factors and participants' perceptions and purchasing behaviors with product hazard scores.

RESULTS

Of 9349 unique PCPs used by participants, 68% matched to Skin Deep®. Average hazard scores varied by participant characteristics (e.g., age) for perfumes/colognes, beauty, and skin care products. The relative risk (RR) of recent use of a hair product with a high hazard score was twice as high in non-Hispanic Black women compared to non-Hispanic White women (RR:1.99; 95%CI:1.37, 2.89). Frequent use of healthy product apps (β = -0.49, 95%CI:-0.77, -0.21), reading product ingredient labels (β = -0.26; 95%CI:-0.82, -0.30), and seeking eco-friendly products (β = -0.17; 95%CI:-0.36, -0.01) were associated with use of skin care products with lower hazard scores. Results for hair and beauty products were similar. Concerns about PCP health impacts and regulation were associated with using products with lower hazard scores.

IMPACT STATEMENT

Personal care products (PCPs) can contain numerous endocrine disrupting and carcinogenic chemicals. In a U.S. university-based sample, we linked the PCPs used by participants in the last 24-48 h to hazard scores in the Skin Deep® database. Average hazard scores of the PCPs used by participants varied by sociodemographic factors. Participant behaviors (e.g., use of healthy product apps) and perceptions of PCP safety and regulation were associated with the average hazard scores of the PCPs they used. Our findings suggest that education and tools to inform PCP choice may help consumers choose safer products and potentially, reduce chemical exposures.

Phthalates are detected in the follicular fluid of adolescents and oocyte donors with associated changes in the cumulus cell transcriptome

OBJECTIVE

To investigate the follicular fluid (FF) phthalate levels in adolescents undergoing fertility preservation compared with oocyte donors and explore its association with ovarian reserve and cumulus cell (CC) gene expression.

DESIGN

Retrospective study and molecular analysis of CCs and FF.

SUBJECTS

Adolescents (n = 20, 16.7 ± 0.6 years) undergoing fertility preservation and oocyte donors (n = 24, 26.2 ± 0.4 years).

EXPOSURE

Not applicable.

MAIN OUTCOME MEASURES

Patient demographics, ovarian stimulation, and oocyte retrieval outcomes were analyzed for each group. The FF levels of 9 phthalate metabolites were assessed individually and as molar sums representative of common compounds (all phthalates, ƩPhthalates; di(2-ethylhexyl) phthalate (DEHP)-associated phthalate metabolites, ƩDEHP), exposure sources (plastics, ƩPlastic; personal care products, ƩPCP), and modes of action (antiandrogenic, ƩAA) and compared between the 2 groups. The transcriptome of CC associated with mature oocytes was compared between adolescents and oocyte donors using bulk ribonucleic acid sequencing.

RESULTS

The FF ƩPlastic and ƩPCP levels were significantly higher in adolescents than in oocyte donors. The FF ƩDEHP, ƩPlastic, ƩPCP, ƩAA, and ƩPhthalates levels were positively associated with antral follicle count in oocyte donors when adjusted for age, body mass index, and race/ethnicity. Ribonucleic acid sequencing analysis revealed 248 differentially expressed genes in CCs of adolescents within the top quartile (n = 4) of the FF ƩPhthalates levels compared with those of the adolescents within the bottom half (n = 9). Genes enriched in pathways involved in cell motility and development were significantly down-regulated.

CONCLUSIONS

Adolescents undergoing fertility preservation cycles demonstrate higher levels of phthalate metabolites in their FF than oocyte donors. Higher phthalate levels are associated with alterations in cumulus cells transcriptome in adolescents. The phthalate metabolite levels in FF are associated with higher antral follicle count levels in oocyte donors.

Improving the Health and Environmental Health Literacy of Professionals: Evaluating the Effect of a Virtual Intervention on Phthalate Environmental Health Literacy

The American College of Obstetricians and Gynecologists provided updated guidance in 2021, recommending that reproductive health professionals should include discussion of environmental exposures with their patients. However, environmental health is seldom included in medical training, with endocrine-disrupting chemicals, such as phthalates-linked to adverse pregnancy outcomes-being among the least discussed. We developed a one-hour virtual educational intervention to train reproductive health professionals on the routes of phthalate exposure, potential associated health impacts, and suggestions on how to discuss exposure reduction with patients. The intervention was designed to include perspectives from patients, scientists, and clinicians. Using a pre/post/post design, we evaluated the impact of the intervention on reproductive health professionals' phthalate-related reproductive health literacy via a validated environmental health literacy (EHL) scale, their confidence in discussing phthalates, and the frequency of discussions about phthalates with patients. All materials, including the study questionnaires and intervention materials, were administered virtually to reproductive health professionals (n = 203) currently seeing patients working in the United States. After completing the intervention, reproductive health professionals' average EHL increased (pre-course: 22.3, post-course: 23.7, 2 months post-course: 24.0), as did their confidence in discussing phthalates with their patients (pre-course: 1% (2/203) reported being quite confident, post-course: 64% (131/203) reported being quite confident, and 2 months post course: 86% (174/203) reported being quite confident). Additionally, the reported frequency of discussions about phthalates with patients rose substantially (pre-course: 0% (0/203) reported usually discussing phthalates with patients, and 2 months post-course: 86% (175/203) reported usually discussing phthalates with patients): In line with the recommendations of the American College of Obstetricians and Gynecologists, this online phthalate educational intervention tool increased EHL among reproductive health professionals and shifted clinical care to include discussion about phthalates, a reproductive toxicant.

Management of phthalates in Canada and beyond: can we do better to protect human health?

Ortho-phthalates (herein referred to as phthalates) are synthetic chemicals used in thousands of different everyday products and materials. Nearly ubiquitous environmental exposure is reflected by phthalate metabolites in the urine of almost all Canadians. However, phthalate exposure tends to be higher amongst people of low socioeconomic status and ethnic minorities. Substantial evidence shows that certain phthalates cause harm to human health, particularly developing fetuses and children. Governments vary in their approach to assessing and managing risks associated with phthalates. Canada continues to take a more permissive stance on phthalate regulations compared to the EU and some US states. We argue that the recent Canadian national risk assessment on phthalates does not appropriately reflect the growing evidence demonstrating harm to human health from phthalate exposure and does not adequately consider the evidence showing higher exposures faced by vulnerable populations. Canadians would benefit from adopting a more stringent regulatory approach to phthalates. Specifically, Canada should expand phthalate restrictions to apply to all consumer products, implement sunset dates toward eliminating the use of existing phthalates, and mandate publicly available evidence of no harm for phthalate alternatives. Canadian alignment on phthalate regulations with the EU and a growing number of US states could encourage other countries to follow suit.

Temporal trends in phthalate metabolite exposure of girls in the United States across sociodemographic factors and intersectional social identities: National Health and Nutrition Examination Survey (NHANES) 2001-2018

BACKGROUND

Exposure to phthalates during the pubertal window is linked to an increased risk of chronic diseases. Understanding temporal trends in exposure can inform public health initiatives.

OBJECTIVE

Characterize temporal trends in phthalate metabolite levels in adolescent girls overall and by sociodemographic characteristics.

METHODS

We used the cross-sectional data from each cycle of NHANES from years 2001-2018. We included participants aged 8-14 years who had at least one urinary measurement of the selected 12 phthalate metabolites within the study period (n = 2063). We used multivariable linear regression to assess temporal trends for selected individual phthalate metabolite concentrations (ng/ml) and source groupings of parent metabolites (sum low and high molecular weight phthalates; ∑LMW and ∑HMW), overall and by sociodemographic characteristics (race/ethnicity), nativity, socioeconomic status (SES), intersection of race/ethnicity-SES) to assess for modification.

RESULTS

Overall, levels of ∑HMW and ∑LMW declined between 2001 and 2018; however, only ∑LMW consistently differed by all sociodemographic characteristics. Trends in ∑LMW concentration were significantly higher across all racial/ethnic groups, ranging from an average of 35% (Other Hispanic) to 65% (Mexican American and non-Hispanic Black) higher than non-Hispanic White (all p-values <0.0001). Compared to non-Hispanic White, a significant decrease in MiBP concentrations was observed for non-Hispanic Black (15% decrease βSpline = -0.16, p < 0.0001) and Other Hispanic (28% decrease, βSpline = -0.33, p = 0.01) in 2011-2018 versus 2001-2010. Summary and individual LMW metabolite phthalate concentrations were 11%-49% higher among girls with low vs. high SES. LMW metabolites MBP and MiBP were on average 22% and 35% higher, respectively, among foreign-born vs. U.S.-born girls. Compared to non-Hispanic Whites, all racial/ethnic groups had statistically significant higher trends in ∑LMW concentrations irrespective of SES.

SIGNIFICANCE

Girls identifying with a historically disadvantaged racial/ethnic groups exhibited elevated ∑LMW concentrations irrespective of SES; suggesting the need for targeted interventions to mitigate exposure among the most historically disadvantaged strata.

Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells

Phthalates are a class of known endocrine-disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian function, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 h in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1 to 100 μg/ml). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways was confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary, but both interfere with PPAR signaling in granulosa cells.

Maternal pre-pregnancy BMI influences the associations between bisphenol and phthalate exposures and maternal weight changes and fat accumulation

BACKGROUND

Bisphenols and phthalates are two classes of endocrine-disrupting chemicals (EDCs) thought to influence weight and adiposity. Limited research has investigated their influence on maternal weight changes, and no prior work has examined maternal fat mass. We examined the associations between exposure to these chemicals during pregnancy and multiple maternal weight and fat mass outcomes.

METHODS

This study included a sample of 318 women enrolled in a Canadian prospective pregnancy cohort. Second trimester urinary concentrations of 2 bisphenols and 12 phthalate metabolites were quantified. Self-reported and measured maternal weights and measured skinfold thicknesses were used to calculate gestational weight gain, 3-months and 3- to 5-years postpartum weight retention, late pregnancy fat mass gain, total postpartum fat mass loss, and late postpartum fat mass retention. Adjusted robust regressions examined associations between chemicals and outcomes in the entire study population and sub-groups stratified by pre-pregnancy body mass index (BMI). Bayesian kernel machine regression examined chemical mixture effects.

RESULTS

Among women with underweight or normal pre-pregnancy BMIs, MBzP was negatively associated with weight retention at 3- to 5-years postpartum (B = -0.04, 95%CI: -0.07, -0.01). Among women with overweight or obese pre-pregnancy BMIs, MEHP and MMP were positively associated with weight retention at 3-months and 3- to 5-years postpartum, respectively (B's = 0.12 to 0.63, 95%CIs: 0.02, 1.07). DEHP metabolites and MCNP were positively associated with late pregnancy fat mass gain and late postpartum fat mass retention (B's = 0.04 to 0.18, 95%CIs: 0.001, 0.32). Further, the mixture of EDCs was positively associated with late pregnancy fat mass gain.

CONCLUSION

In this cohort, pre-pregnancy BMI was a key determinant of the associations between second trimester exposure to bisphenols and phthalates and maternal weight changes and fat accumulation. Investigations of underlying physiological mechanisms, windows of susceptibility, and impacts on maternal and infant health are needed.

Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells

Phthalates are a class of known endocrine disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian functions, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 hours in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1-100 μg/mL). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways were confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary and interfere with PPAR signaling in granulosa cells.

Development of a Phthalate Environmental Reproductive Health Literacy (PERHL) Scale

BACKGROUND

Substantial evidence exists linking phthalate exposure to adverse reproductive health outcomes. Current US federal regulations of consumer product chemicals place the onus on individuals to mitigate their exposure to phthalates, with assumptions of sufficient environmental health literacy (EHL). Few validated scales for people of reproductive age exist to evaluate phthalate-specific EHL.

OBJECTIVES

Our objective is to develop a multidimensional scale characterizing latent factors of phthalate knowledge, risk perception, and self-efficacy to inform individual-level interventions for reducing phthalate exposure.

METHODS

We distributed a survey with 31 items to 117 participants in the Environmental Reproductive and Glucose Outcomes (ERGO) cohort who gave birth within the last 5 years. Exploratory factor analysis (EFA) was used to identify underlying latent factors. Internal reliability was assessed via omega hierarchical coefficient. Average sum scores for each latent factor and the overall Phthalate Environmental Reproductive Health Literacy (PERHL) score were calculated. Associations between latent factors, overall PERHL score, and sociodemographic characteristics were explored using linear models.

RESULTS

Six latent factors were identified as follows: "Awareness of Phthalate Reproductive Health Impacts," "Uncertainty," "Protective Behavior/Risk Control," "Regulatory Interest," "Awareness of Phthalate Exposure Pathways," and "General Phthalate Knowledge." Each factor demonstrated acceptable to strong internal reliability, with coefficients ranging between 0.63 and 0.93. Non-white participants had lower scores for the "Awareness of Phthalate Reproductive Health Impacts" [β : - 0.35 , 95% confidence interval (CI): - 0.63 , - 0.07 ], "Awareness of Phthalate Exposure Pathways" (β : - 0.32 , 95% CI: - 0.57 , - 0.07 ), and "General Phthalate Knowledge" (β : - 0.36 , 95% CI: - 0.66 , - 0.06 ), but no significant difference in scores on "Uncertainty" (β : 0.17, 95% CI: - 0.16 , 0.50), "Protective Behavior/Risk Control" (β : - 0.04 , 95% CI: - 0.36 , 0.28), or "Regulatory Interest" (β : - 0.21 , 95% CI: - 0.51 , 0.09). No associations were seen for age or educational attainment and latent or sum factors.

DISCUSSION

Six latent factors were identified for the PERHL scale. Non-white race and ethnicity was associated with lower scores for knowledge-related scale factors. https://doi.org/10.1289/EHP13128.

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.

Racial and Ethnic Disparities in Phthalate Exposure and Preterm Birth: A Pooled Study of Sixteen U.S. Cohorts

BACKGROUND

Phthalate exposures are ubiquitous during pregnancy and may contribute to racial and ethnic disparities in preterm birth.

OBJECTIVES

We investigated race and ethnicity in the relationship between biomarkers of phthalate exposure and preterm birth by examining: a) how hypothetical reductions in racial and ethnic disparities in phthalate metabolites might reduce the probability of preterm birth; and b) exposure-response models stratified by race and ethnicity.

METHODS

We pooled individual-level data on 6,045 pregnancies from 16 U.S. cohorts. We investigated covariate-adjusted differences in nine urinary phthalate metabolite concentrations by race and ethnicity [non-Hispanic White (White, 43%), non-Hispanic Black (Black, 13%), Hispanic/Latina (38%), and Asian/Pacific Islander (3%)]. Using g-computation, we estimated changes in the probability of preterm birth under hypothetical interventions to eliminate disparities in levels of urinary phthalate metabolites by proportionally lowering average concentrations in Black and Hispanic/Latina participants to be approximately equal to the averages in White participants. We also used race and ethnicity-stratified logistic regression to characterize associations between phthalate metabolites and preterm birth.

RESULTS

In comparison with concentrations among White participants, adjusted mean phthalate metabolite concentrations were consistently higher among Black and Hispanic/Latina participants by 23%-148% and 4%-94%, respectively. Asian/Pacific Islander participants had metabolite levels that were similar to those of White participants. Hypothetical interventions to reduce disparities in metabolite mixtures were associated with lower probabilities of preterm birth for Black [13% relative reduction; 95% confidence interval (CI): - 34 % , 8.6%] and Hispanic/Latina (9% relative reduction; 95% CI: - 19 % , 0.8%) participants. Odds ratios for preterm birth in association with phthalate metabolites demonstrated heterogeneity by race and ethnicity for two individual metabolites (mono-n-butyl and monoisobutyl phthalate), with positive associations that were larger in magnitude observed among Black or Hispanic/Latina participants.

CONCLUSIONS

Phthalate metabolite concentrations differed substantially by race and ethnicity. Our results show hypothetical interventions to reduce population-level racial and ethnic disparities in biomarkers of phthalate exposure could potentially reduce the probability of preterm birth. https://doi.org/10.1289/EHP12831.

Predictors of Phthalate Metabolites Exposure among Healthy Pregnant Women in the United States, 2010-2015

Phthalate use and the concentrations of their metabolites in humans vary by geographic region, race, ethnicity, sex, product use and other factors. Exposure during pregnancy may be associated with detrimental reproductive and developmental outcomes. No studies have evaluated the predictors of exposure to a wide range of phthalate metabolites in a large, diverse population. We examined the determinants of phthalate metabolites in a cohort of racially/ethnically diverse nulliparous pregnant women. We report on urinary metabolites of nine parent phthalates or replacement compounds-Butyl benzyl phthalate (BBzP), Diisobutyl phthalate (DiBP), Diethyl phthalate (DEP), Diisononyl phthalate (DiNP), D-n-octyl phthalate (DnOP), Di-2-ethylhexyl terephthalate (DEHTP), Di-n/i-butyl phthalate (DnBP), Di-isononyl phthalate (DiNP) and Di-(2-ethylhexyl) phthalate (DEHP) from urine collected up to three times from 953 women enrolled in the Nulliparous Mothers To Be Study. Phthalate metabolites were adjusted for specific gravity. Generalized estimating equations (GEEs) were used to identify the predictors of each metabolite. Overall predictors include age, race and ethnicity, education, BMI and clinical site of care. Women who were Non-Hispanic Black, Hispanic or Asian, obese or had lower levels of education had higher concentrations of selected metabolites. These findings indicate exposure patterns that require policies to reduce exposure in specific subgroups.

Exposure to phthalate metabolites, bisphenol A, and psychosocial stress mixtures and pregnancy outcomes in the Atlanta African American maternal-child cohort

BACKGROUND

Consumer products are common sources of exposure for phthalates and bisphenol A (BPA), which disrupt the endocrine system. Psychosocial stressors have been shown to amplify the toxic effects of endocrine disruptors but, information is limited among African Americans (AAs), who experience the highest rates of adverse pregnancy outcomes and are often exposed to the highest levels of chemical and non-chemical stressors. We examined the association between an exposure mixture of phthalate metabolites, BPA, and psychosocial stressors with gestational age at delivery and birthweight for gestational age z-scores in pregnant AA women.

STUDY DESIGN

Participants were enrolled in the Atlanta African American Maternal-Child Cohort (N = 247). Concentrations of eight phthalate metabolites and BPA were measured in urine samples collected at up to two timepoints during pregnancy (8-14 weeks gestation and 20-32 weeks gestation) and were averaged. Psychosocial stressors were measured using self-reported, validated questionnaires that assessed experiences of discrimination, gendered racial stress, depression, and anxiety. Linear regression was used to estimate individual associations between stress exposures (chemical and psychosocial) and birth outcomes. We leveraged quantile g-computation was used to examine joint effects of chemical and stress exposures on gestational age at delivery (in weeks) and birthweight for gestational age z-scores.

RESULTS

A simultaneous increase in all phthalate metabolites and BPA was associated with a moderate reduction in birthweight z-scores (mean change per quartile increase = -0.22, 95% CI = -0.45, 0.0). The association between our exposure mixture and birthweight z-scores became stronger when including psychosocial stressors as additional exposures (mean change per quantile increase = -0.35, 95% CI = -0.61, -0.08). Overall, we found null associations between exposure to chemical and non-chemical stressors with gestational age at delivery.

CONCLUSIONS

In a prospective cohort of AA mother-newborn dyads, we observed that increased prenatal exposure to phthalates, BPA, and psychosocial stressors were associated with adverse pregnancy outcomes.

Evaluating Neighborhood-Level Differences in Hair Product Safety by Environmental Working Group Ratings among Retailers in Boston, Massachusetts

BACKGROUND

Personal care products are a notable source of exposure to endocrine-disrupting chemicals (EDCs). Racial/ethnic differences in the use of hair products containing EDCs are reported, with women and children of color more commonly using hair products that are hormonally active and contain EDCs than other racial/ethnic groups. There is limited research examining the neighborhood-level social and economic factors that may contribute to these reported disparities.

OBJECTIVES

We aimed to examine the safety of hair products across sociodemographically diverse neighborhoods in Boston, Massachusetts.

METHODS

Eight neighborhoods were identified based on indicators of race/ethnicity and socioeconomic status (SES). We randomly selected 50 stores and collected data on the hair products for sale and their corresponding Environmental Working Group (EWG) Skin Deep hazard score. The association between neighborhood and EWG hazard category (low, moderate, high) was examined using a multinomial logistic regression.

RESULTS

A total of 14,019 hair products were identified in the eight neighborhoods. When considering products with EWG hazard scores, Roxbury, a lower income community of color, and Mission Hill, a lower income community, were reported to have a higher percentage of high-hazard hair products in comparison with Beacon Hill [12.2% (163/1,332), 11.4% (65/571) vs. 7.9% (30/382), respectively]. Differences between the safety of hair products were observed, with Roxbury and Mission Hill reporting more than a 2-fold higher risk ratio (RR) of finding hair products with high vs. low EWG scores in comparison with that of Beacon Hill [RR for Roxbury: 2.3, 95% confidence interval (CI): 1.1, 4.6; RR for Mission Hill: 2.3, 95% CI: 1.0, 5.4]. Other neighborhoods were also observed to have an increased RR in comparison with Beacon Hill, however, with 95% CIs that extended beyond the null.

DISCUSSION

Retail stores in neighborhoods with a higher percentage of residents of color and lower SES were found to be more likely to sell products with high hazard scores than stores in a higher SES and predominately non-Hispanic White neighborhood. https://doi.org/10.1289/EHP10653.

A Scoping Review of Nutritional Biomarkers Associated with Food Security

Food insecurity affects more than 40 million individuals in the United States and is linked to negative health outcomes due, in part, to poor dietary quality. Despite the emergence of metabolomics as a modality to objectively characterize nutritional biomarkers, it is unclear whether food security is associated with any biomarkers of dietary quality. This scoping review aims to summarize studies that examined associations between nutritional biomarkers and food security, as well as studies that investigated metabolomic differences between people with and without food insecurity. PubMed, Embase, Scopus, and AGRICOLA were searched through August 2022 for studies describing food insecurity and metabolic markers in blood, urine, plasma, hair, or nails. The 78 studies included consisted of targeted assays quantifying lipids, dietary nutrients, heavy metals, and environmental xenobiotics as biochemical features associated with food insecurity. Among those biomarkers which were quantified in at least five studies, none showed a consistent association with food insecurity. Although three biomarkers of dietary quality have been assessed between food-insecure versus food-secure populations, no studies have utilized untargeted metabolomics to characterize patterns of small molecules that distinguish between these two populations. Further studies are needed to characterize the dietary quality profiles of individuals with and without food insecurity.

Cumulative Risk Evaluation of Phthalates Under TSCA

The U.S. Environmental Protection Agency (EPA) is currently conducting separate Toxic Substances Control Act (TSCA) risk evaluations for seven phthalates: dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DIBP), dicyclohexyl phthalate (DCHP), di-isodecyl phthalate (DIDP), and diisononyl phthalate (DINP). Phthalates are highly abundant plastic additives used primarily to soften materials and make them flexible, and biomonitoring shows widespread human exposure to a mixture of phthalates. Evidence supports biological additivity of phthalate mixture exposures, including the enhancement of toxicity affecting common biological targets. Risk estimates based on individual phthalate exposure may not be protective of public health. Thus, a cumulative risk approach is warranted. While EPA initially did not signal that it would incorporate cumulative risk assessment (CRA) as part of its current risk evaluation for the seven phthalates, the agency recently announced that it is reconsidering if CRA for phthalates would be appropriate. Based on our review of existing chemical mixtures risk assessment guidance, current TSCA scoping documents for the seven phthalates, and pertinent peer-reviewed literature, we delineate a CRA approach that EPA can easily implement for phthalates. The strategy for using CRA to inform TSCA risk evaluation for existing chemicals is based upon integrative physiology and a common adverse health outcome algorithm for identifying and grouping relevant nonchemical and chemical stressors. We recommend adjustments for how hazard indices (HIs) or margins of exposure (MOEs) based on CRA are interpreted for determining "unreasonable risk" under TSCA.

Phthalates and bone mineral density: a systematic review

BACKGROUND

Exposure to endocrine disruptors, such as phthalates, may impact bone mineral density (BMD) through a variety of mechanisms. Studies of phthalate exposure and BMD in humans are scarce.

OBJECTIVES

To synthesize published data on the association between phthalate metabolites and BMD in humans and to provide methodological suggestions for future research.

METHODS

A single investigator searched PubMed for relevant studies, including observational studies of phthalate exposure and BMD in children and postmenopausal women. Twelve studies were screened with 5 meeting the eligibility criteria and included for review. A quality assessment form was used as a quality measure and key information was extracted from the included studies.

RESULTS

In one prospective study among postmenopausal women, higher levels of monocarboxyoctyl phthalate (MCOP) and monocarboxynonyl phthalate (MCNP) were significantly associated with lower BMD among nonusers of hormone therapy (HT). In cross-sectional studies of postmenopausal women, monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono (3-carboxypropyl) phthalate (MCPP), and mono-benzyl phthalate (MBzP) were negatively associated with BMD, and MCNP was positively associated with BMD, but these results were not replicated across studies. In studies of fetal exposure to phthalates and childhood BMD, significant positive associations between MCPP and BMD in children at age 12 years were found in 1 study, while associations were null in the other study.

CONCLUSIONS

Studies among postmenopausal women provide suggestive evidence of an association between urinary phthalate metabolite concentration and decreased BMD. Results from studies of childhood BMD are inconclusive given the limited data and their limitations. More research is needed to address limitations and further investigate the association between phthalate exposure and human BMD.

Determinants of urinary phthalate biomarker concentrations in pre- and perimenopausal women with consideration of race

BACKGROUND/OBJECTIVES

Phthalates are endocrine disruptors in consumer plastics and personal care products. Our objectives were to identify determinants of phthalate biomarkers in women during the hormonally-sensitive midlife period, and to consider differences between non-Hispanic White and Black women.

METHODS

We used information from the Midlife Women's Health Study of pre- and peri-menopausal women from Baltimore, Maryland (enrolled 2006-2015). We collected sociodemographic/health information via baseline questionnaires or during clinic visits and measured nine phthalate metabolites in pools of 2-4 urines collected across one menstrual cycle. We calculated molar sums of metabolites to estimate exposure to di(2-ethylhexyl) phthalate (ΣDEHP), personal care product phthalates (ΣPCPs), and phthalates in plastics (ΣPlastics). Accounting for meaningful predictors from bivariable analyses, our multivariable linear regression models evaluated determinants of phthalate biomarkers in all women (n = 689), non-Hispanic White women only (n = 467), or non-Hispanic Black women only (n = 195).

RESULTS

In multivariable analyses of all women, those who were perimenopausal, widowed/divorced, non-Hispanic Black, with higher family income, with lower BMI, or who reported more frequent nausea had higher monoethyl phthalate (MEP) and ΣPCP. Non-Hispanic White women who were perimenopausal had lower mono-(3-carboxypropyl) phthalate (MCPP) and monobutyl phthalate (MBP), those who consume alcohol had higher mono-isobutyl phthalate (MiBP), and those with higher BMI had lower MEP and higher MCPP. Alternatively, widowed/divorced Black women had higher ΣDEHP, monobenzyl phthalate (MBzP), and ΣPlastics, whereas Black women with higher income had higher MEP and ΣPCP. Black women who described themselves as having "as much" physical activity as others or who reported a skin condition had lower MBzP and MCPP, respectively.

CONCLUSION

We identified important determinants of phthalate biomarkers in midlife women and observed some differences by race. Future studies could consider reasons for these differences when developing interventions to reduce phthalate disparities and related health effects.

Microbiome alterations associated with phthalate exposures in a US-based sample of Latino workers

Low-wage service sector jobs are largely occupied by racial/ethnic minority workers who often experience an increased risk of elevated chemical exposures, including chemicals like phthalates, compared to the general public. Phthalates have been linked with adverse health effects, including increased risk of atopy and asthma. An important etiological component in respiratory disease, including asthma, is the role of the upper respiratory microbiota in atopic disease development. However, it is unclear how the upper respiratory microbiome is affected by chemical exposures, and how this may impact respiratory outcomes. As Latino workers are often disproportionately exposed to increased concentrations of chemicals and Hispanics have higher rates of adverse respiratory health conditions such as asthma, the aim of this pilot study was to evaluate the effects of 10 unique phthalate urinary biomarkers on the 16S rRNA nasal microbiome. Nasal and urinary samples were collected from 20 facility workers (plumbers, landscapers, electricians) and 20 custodial workers. Our analysis revealed altered microbial composition and diversity according to phthalate urinary biomarker concentration within the two worker groups. Higher urinary biomarker concentrations of select phthalates (MBP, MBIP, and ∑DEHP) were associated with increased Moraxella relative abundance, which has been positively associated with asthma. Within-sample alpha diversity levels were decreased in facility workers and were generally inversely associated with most phthalate urinary biomarker concentrations. Our research suggests that exposure to chemicals in this vulnerable worker group may impact the respiratory microbiome, which may increase risk of development of adverse health conditions. Further research is warranted to refine the mechanistic pathways that underpin the relationships between phthalate exposures and respiratory microbial communities to provide key insights on respiratory pathologies and, most importantly, to identify modifiable risk factors that can be used to direct mitigation efforts aimed at ameliorating the harmful effects of chemical exposures in this understudied occupational population.

Concurrent Assessment of Phthalates/HEXAMOLL® DINCH Exposure and Wechsler Intelligence Scale for Children Performance in Three European Cohorts of the HBM4EU Aligned Studies

Information about the effects of phthalates and non-phthalate substitute cyclohexane-1,2-dicarboxylic acid diisononyl ester (HEXAMOLL^® DINCH) on children's neurodevelopment is limited. The aim of the present research is to evaluate the association between phthalate/HEXAMOLL^® DINCH exposure and child neurodevelopment in three European cohorts involved in HBM4EU Aligned Studies. Participating subjects were school-aged children belonging to the Northern Adriatic cohort II (NAC-II), Italy, Odense Child Cohort (OCC), Denmark, and PCB cohort, Slovakia. In each cohort, children's neurodevelopment was assessed through the Full-Scale Intelligence Quotient score (FSIQ) of the Wechsler Intelligence Scale of Children test using three different editions. The children's urine samples, collected for one point in time concurrently with the neurodevelopmental evaluation, were analyzed for several phthalates/HEXAMOLL^® DINCH biomarkers. The relation between phthalates/HEXAMOLL^® DINCH and FSIQ was explored by applying separate multiple linear regressions in each cohort. The means and standard deviations of FSIQ were 109 ± 11 (NAC-II), 98 ± 12 (OCC), and 81 ± 15 (PCB cohort). In NAC-II, direct associations between FSIQ and DEHP's biomarkers were found: 5OH-MEHP+5oxo-MEHP (β = 2.56; 95% CI 0.58-4.55; N = 270), 5OH-MEHP+5cx-MEPP (β = 2.48; 95% CI 0.47-4.49; N = 270) and 5OH-MEHP (β = 2.58; 95% CI 0.65-4.51; N = 270). On the contrary, in the OCC the relation between DEHP's biomarkers and FSIQ tended to be inverse but imprecise (p-value ≥ 0.10). No associations were found in the PCB cohort. FSIQ was not associated with HEXAMOLL^® DINCH in any cohort. In conclusion, these results do not provide evidence of an association between concurrent phthalate/DINCHHEXAMOLLR DINCH exposure and IQ in children.

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.

Association of prenatal exposure to ambient air pollution with adverse birth outcomes and effect modification by socioeconomic factors

BACKGROUND

Maternal exposure to air pollution has been associated with birth outcomes; however, few studies examined biologically critical exposure windows shorter than trimesters or potential effect modifiers.

OBJECTIVES

To examine associations of prenatal fine particulate matter (PM_2.5), by trimester and in biologically critical windows, with birth outcomes and assess potential effect modifiers.

METHODS

This study used two pregnancy cohorts (CANDLE and TIDES; N = 2099) in the ECHO PATHWAYS Consortium. PM_2.5 was estimated at the maternal residence using a fine-scale spatiotemporal model, averaged over pregnancy, trimesters, and critical windows (0-2 weeks, 10-12 weeks, and last month of pregnancy). Outcomes were preterm birth (PTB, <37 completed weeks of gestation), small-for-gestational-age (SGA), and continuous birthweight. We fit multivariable adjusted linear regression models for birthweight and Poisson regression models (relative risk, RR) for PTB and SGA. Effect modification by socioeconomic factors (maternal education, household income, neighborhood deprivation) and infant sex were examined using interaction terms.

RESULTS

Overall, 9% of births were PTB, 10.4% were SGA, and mean term birthweight was 3268 g (SD = 558.6). There was no association of PM_2.5 concentration with PTB or SGA. Lower birthweight was associated with higher PM_2.5 averaged over pregnancy (β -114.2, 95%CI -183.2, -45.3), during second (β -52.9, 95%CI -94.7, -11.2) and third (β -45.5, 95%CI -85.9, -5.0) trimesters, and the month prior to delivery (β -30.5, 95%CI -57.6, -3.3). Associations of PM_2.5 with likelihood of SGA and lower birthweight were stronger among male infants (p-interaction ≤0.05) and in those with lower household income (p-interaction = 0.09).

CONCLUSIONS

Findings from this multi city U.S. birth cohort study support previous reports of inverse associations of birthweight with higher PM_2.5 exposure during pregnancy. Findings also suggest possible modification of this association by infant sex and household income.

Levels and health risks of urinary phthalate metabolites and the association between phthalate exposure and unexplained recurrent spontaneous abortion: a large case-control study from China

Phthalate acid esters (PAEs) are environmental endocrine disruptors that can interfere with endocrine processes and cause adverse reproductive outcomes. The link between PAE exposure and unexplained recurrent spontaneous abortion (URSA) remains unknown. In this study, nine urinary metabolites of PAEs (mPAEs) were measured in 594 URSA cases and 569 healthy controls. The measured mPAEs were ubiquitously detected and present at higher levels (median: 203 ng/mL) in the URSA cases than in the controls (median: 161 ng/mL). Multiple logistic regression analysis showed that URSA was associated with higher concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), mono (2-ethylhexyl) phthalate (mEHP), and mono-ethyl phthalate (mEP) and lower concentrations of mono-isobutyl phthalate (miBP). Moreover, a quantile-based g-computation (QGC) model revealed a positive association between mPAEs mixture and URSA. The URSA cases showed significantly higher concentrations of di-(2-ethylhexyl) phthalate (DEHP) than the controls. This was consistent with the health risk assessment, which suggested that DEHP is the main contributors to potential non-carcinogenic risk. DEHP accounted for over 80% of total risk. The large case-control study results suggest that PAE exposure may increase the risk of URSA, and that policy-makers and public health experts should pay more attention to DEHP exposure.

Phthalate exposure among U.S. college-aged women: Biomonitoring in an undergraduate student cohort (2016-2017) and trends from the National Health and Examination Survey (NHANES, 2005-2016)

Importance

Phthalates are ubiquitous and many are known or suspected human reproductive and endocrine-disrupting toxicants. A data gap exists in reporting on biomonitoring of phthalate biomarkers in college-aged adults.

Objective

To analyze phthalate exposure in a cross-sectional sample of female college students using urinary phthalate metabolite concentrations and compare to reference populations including college-aged women sampled in the National Health and Nutrition Examination Survey (NHANES).

Methods

Nine monoester phthalate metabolites were analyzed in spot urine collected from 215 female undergraduates (age 18–22, 2016–2017) at a public university in Charleston, SC USA and a subset of participants completed a questionnaire detailing demographics and behaviors including personal care and cosmetic product use (e.g. in the past 6 or 24 hrs). Urine specific gravity was used to assess effect of urine dilution. Phthalate metabolite concentrations were compared to reference populations and the temporal trends of the same age-group in the National Health and Nutrition Examination Survey (NHANES) were analyzed.

Results

Total urinary phthalate metabolite concentrations in individuals ranged three orders of magnitude (geometric mean 56.6 ng/mL, IQR 26.6–114 ng/mL). A third of urine samples had relatively high urine specific gravity levels indicating potential dehydration status. All geometric mean concentrations were similar to the U.S. female population in the most recent NHANES cycle (2015–2016) except for MEP and mono-isobutyl phthalate (MiBP). Relatively low MEP and MiBP may be explained by a time trend of declining MEP in the general U.S. population, the sociocultural character of this cohort, and the time of day of spot sampling in evening. NHANES data indicate a significant effect of sample timing on phthalate metabolite concentrations and decline in most, but not all, phthalate metabolites sampled in women aged 18–22 years over the decade (2005–2016).

Significance

This study reports phthalate metabolites in college-aged women, an understudied group, emphasizes the benefit of survey information for interpreting biomonitoring data, and is a useful case study for communicating phthalate chemical exposure risks to college students.

Socioeconomic and racial/ethnic differences in use of endocrine-disrupting chemical-associated personal care product categories among pregnant women

Personal care products (PCPs) are important and modifiable sources of exposure to endocrine disrupting chemicals (EDCs). Research is limited on how EDC-associated PCP use differs by race/ethnicity and socioeconomic status (SES), particularly during the sensitive period of pregnancy. We investigated differences in PCP use by race/ethnicity and SES among 497 participants in the LIFECODES pregnancy cohort (Boston, Massachusetts). Participants self-reported race/ethnicity, SES indicators (maternal education; insurance status), and recent PCP use via questionnaire at ≤4 prenatal visits. We evaluated trimester-specific differences in use of individual PCP categories by race/ethnicity and SES indicators. We used Poisson regression to estimate trimester-specific mean total product categories used by race/ethnicity and SES indicators. In the first trimester, compared to non-Hispanic White women, Hispanic women reported higher use of hair gel (45% vs. 28%), perfume (75% vs. 39%), and "other" hair products (37% vs. 19%). Compared to women with a college degree, women without a college degree reported higher use of perfume (79% vs. 41%) and bar soap (74% vs. 56%); patterns were similar for insurance status. The estimated mean total product categories used was significantly lower in Asian compared to non-Hispanic White women in all trimesters (e.g., Trimester 1: 4.8 vs. 6.7 categories; p<0.001). Patterns of PCP use differed by race/ethnicity and SES, with implications for potentially modifiable differential EDC exposure and associated pregnancy outcomes.

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.

Personal care product use among diverse women in California: Taking Stock Study

BACKGROUND

Personal care product use may contribute to elevated body burdens of consumer product chemicals among women of color; however, racial/ethnic differences in product use has been understudied. Community-engaged research can support the recruitment of diverse participants.

OBJECTIVE

To document personal care product use among a diverse group of women (aged 18-34 years) living in California.

METHODS

Through a community-academic partnership, we surveyed 357 women in California about product use information for 54 cosmetic, hair, menstrual/intimate care, and leave-on and rinse-off personal care products. We compared type and frequency of product use among Black, Hispanic/Latinx, Asian, and White women. We also summarized use of scented products and reasons women select products.

RESULTS

Women reported using a median of 8 products daily, with some women reporting up to 30 products daily. Hispanic/Latinx and Asian women used more cosmetics, and Black women used more hair and menstrual/intimate products than other women. Of the 54 products compared, there were significant differences in use by race/ethnicity for 28 products, with the largest number of significant differences between Black and White women.

SIGNIFICANCE

There is growing information on chemical exposures from personal care products and consequent adverse health effects, with implications for health disparities. Yet, there remains limited information on the range and types of products used by diverse racial/ethnic communities. This study helps close an important gap on product use inventories that can enable more informed public health interventions to limit exposures from personal care products.

Determinants of phthalate exposure among a U.S.-based group of Latino workers

BACKGROUND

Phthalates are endocrine disrupting compounds linked to various adverse health effects. U.S. national biomonitoring data indicate that select minority subgroups may suffer disparate exposures to phthalates. Still, exposures and their respective determinants among these subgroups are not well characterized.

OBJECTIVE

We sought to examine determinants of phthalate exposure in a subsample of US-based Latino adults.

METHODS

We conducted a cross-sectional study on 94 Latino immigrant adults in Maryland. Participants were >18 years of age and working in a service-based industry. We administered an interviewer-administered questionnaire to capture information on potential exposure determinants (e.g., demographic characteristics, consumer product use, and workplace exposures and behaviors) and using HPLC/MS-MS we quantified concentrations of 9 urinary phthalate metabolites: monoethyl phthalate (MEP, diethyl phthalate metabolite); mono-n-butyl phthalate (MBP, di-n-butyl phthalate metabolite); mono-isobutyl phthalate (MiBP, di-isobutyl phthalate metabolite; monobenzyl phthalate (MBzP, benzylbutyl phthalate metabolite); molar sum of di-2-ethylhexyl phthalate or DEHP metabolites [mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECCP)]; and mono(3-carboxypropyl) phthalate (MCPP, a non-specific metabolite of several phthalates including di-n-butyl phthalate and di-n-octyl phthalate). DEHP was analyzed as the molar sum of four metabolites (ΣDEHP = MEHP + MEHHP + MECPP + MEOHP). Spearman correlations, Wilcoxon-Mann-Whitney, and Kruskal-Wallis tests were conducted to assess bivariate associations between metabolite concentrations and potential exposure determinants. Covariates associated with metabolites at p < 0.10 in bivariate analyses were included in multivariable linear regression models to assess the independent effects of predictors on metabolite concentrations.

RESULTS

Uncorrected median phthalate metabolite concentrations were lower in our study population (50% of samples ranged between 1.4 and 23.6 μg/L. While we observed some significant associations with select predictors in our bivariate analysis, select associations were attenuated in multivariable regression models. In our final multivariable linear regression models, we found that use of bleach (β = 1.15, 95%CI:0.30, 2.00) and consumption pasta/rice/noodles (β = 0.87, 95%CI: 0.27, 1.46) was positively associated with MBzP concentrations. MEP concentrations were inversely associated with use of furniture polish (β = -1.17, 95%CI: 2.21, -0.12) and use of scented dryer sheets (β = -1.08, 95%CI: 2.01, -0.14). Lastly, ΣDEHP concentrations were inversely associated with use of degreaser (ßDEHP = -0.65, 95%CI: 1.25, -0.05).

CONCLUSIONS

In this predominantly U.S.-based Central American subsample of adults, we observed lower metabolite concentrations than those previously reported in other U.S. studies and other countries. Our findings could be due, in part, to temporal trends in phthalate exposures and cultural differences related to exposure-related behaviors. While some exposure determinants were identified in our bivariate analyses, results from multivariable regression models did not provide clear results as many associations were attenuated. Environmental exposures may vary within minority subgroups and should be explored further in future studies to further inform exposure mitigation strategies.

Maternal Food and Beverage Consumption Behaviors and Discrepant Phthalate Exposure by Race

Background: Differential exposure to endocrine-disrupting chemicals, including phthalate diesters, may contribute to persistent racial/ethnic disparities in women’s reproductive health outcomes. We sought to characterize sources of gestational exposure to these agents that may differ according to maternal race. Methods: We enrolled pregnant Black (n = 198), including African American, and White (n = 197) women during the second trimester, and measured eight phthalate monoester metabolites in urine. We assessed confounder-adjusted associations between multiple food and beverage consumption habits, summarized using a principal component analysis, as predictors of maternal urinary phthalate metabolite levels, stratified by race. Results: Whites reported significantly greater unprocessed food consumption (42.5% vs. 32.0%; p < 0.001) and storage of food in clear unbreakable plastic containers (66.5% vs. 49.3%; p < 0.001) than Blacks, while Blacks consumed more canned fruits and vegetables (23.5% vs. 12.2%; p < 0.001) than Whites. Using plastics for food storage, microwaving in plastic containers, and using hard plastic water bottles was associated with urinary phthalate concentrations, especially DEHP metabolites (e.g., mean difference = 5.13%; 95% CI: 3.05, 7.25). These associations were driven primarily by Black pregnant women. Conclusions: Targeted interventions to reduce maternal exposure to phthalates need to be designed with specific attention to differences in food and beverage consumption behaviors among Black and White women.

Exposure to organophosphate esters, phthalates, and alternative plasticizers in association with uterine fibroids

Exposure to endocrine disrupting chemicals is suggested to be responsible for the development or progression of uterine fibroids. However, little is known about risks related to emerging chemicals, such as organophosphate esters (OPEs) and alternative plasticizers (APs). A case-control study was conducted to investigate whether exposures to OPEs, APs, and phthalates, were associated with uterine fibroids in women of reproductive age. For this purpose, the cases (n = 32) and the matching controls (n = 79) were chosen based on the results of gynecologic ultrasonography among premenopausal adult women in Korea and measured for metabolites of several OPEs, APs, and major phthalates. Logistic regression models were employed to assess the associations between chemical exposure and disease status. Factor analysis was conducted for multiple chemical exposure assessments as a secondary analysis. Among OPE metabolites, diphenyl phosphate (DPHP), 2-ethylhexyl phenyl phosphate (EHPHP), and 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP) were detected in >80% of the subjects. Among APs, metabolites of di-isononyl phthalate (DINP) and di(2-propylheptyl) phthalate (DPrHpP) were detected in >75% of the urine samples. The odds ratios (ORs) of uterine fibroids were significantly higher among the women with higher exposures to tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-butoxyethyl) phosphate (TBOEP), di(2-ethylhexyl) terephthalate (DEHTP), DPrHpP, and di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH). In addition, urinary concentrations of mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), a sum of five di(2-ethylhexyl) phthalate metabolites (∑5DEHP), and mono(4-methyl-7-hydroxyoctyl) phthalate (OH-MINP) were significantly higher in the cases. In factor analysis, a factor heavily loaded with DPrHpP and DEHP was significantly associated with uterine fibroids, supporting the observation from the single chemical regression model. We found for the first time that several metabolites of OPEs and APs are associated with increased risks of uterine fibroids among pre-menopausal women. Further epidemiological and mechanistic studies are warranted to validate the associations observed in the present study.

Relationship between urinary phthalate metabolites and diabetes: Korean National Environmental Health Survey (KoNEHS) cycle 3 (2015-2017)

BACKGROUND

We aimed to determine relationship diabetes according to urinary phthalate metabolites using adult data from Korean National Environmental Health Survey cycle 3 (2015-2017).

METHOD

This study was conducted on 3,781 adults aged 19 years and older (1,648 men and 2,133 women) based on KoNEHS cycle 3. Participants' data were analyzed by gender; Relationship between phthalate metabolites in the urine and diabetes was analyzed by dividing the sociodemographic variables, health behavior-related variables, and urinary phthalate metabolite concentrations into quartiles. To determine the relationship between urinary phthalate metabolites and the prevalence of diabetes, the odds ratio (OR) was calculated using logistic regression analysis.

RESULTS

Based on the 1st quartile of each metabolite, the ORs for di-2-ethylhexyl phthalate (DEHP) (4th quartile), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) (2nd quartile, 3rd quartile and 4th quartile), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) (4th quartile), mono-(2-ethyl-5-carboxypentyl) phthalate (MECCP) (4th quartile), mono-n-butyl phthalate (MnBP) (3rd quartile and 4th quartile), mono-benzyl phthalate (MBzP) (2nd quartile) and 4th quartile), and mono (3-carboxypropyl) phthalate (MCPP) (3rd quartile and 4th quartile) were significantly higher after the adjustment in men. The ORs for DEHP (2nd quartile, 3rd quartile and 4th quartile), MEHHP (2nd quartile, 3rd quartile and 4th quartile), MEOHP (4th quartile), MECCP (4th quartile), MBzP (4th quartile), and MCPP (4th quartile) were significantly higher after the adjustment in women.

CONCLUSION

This study investigated relationship between urinary phthalate metabolites and diabetes. The higher urinary phthalate metabolites, the higher the prevalence of diabetes. Further regulation of phthalate may be needed, and further studies are warranted to confirm the association between phthalate concentration and other chronic diseases (such as hypertension, hyperlipidemia, and cardiovascular disease).

Plastics derived endocrine-disrupting compounds and their effects on early development

Despite the fact that the estrogenic effects of bisphenols were first described 80 years ago, recent data about its potential negative impact on birth outcome parameters raises a strong rationale to investigate further. The adverse health effects of plastics recommend to measure the impacts of endocrine-disrupting compounds (EDCs) such as bisphenols (BPA, BPS, BPF), bis(2-ethylhexyl) phthalate, and dibutyl phthalate (DBP) in human health. Exposure to these compounds in utero may program the diseases of the testis, prostate, kidney and abnormalities in the immune system, and cause tumors, uterine hemorrhage during pregnancy and polycystic ovary. These compounds also control the processes of epigenetic transgenerational inheritance of adult-onset diseases by modulating DNA methylation and epimutations in reproductive cells. The early developmental stage is the most susceptible window for developmental and genomic programming. The critical stages of the events for a normal human birth lie between the many transitions occurring between spermatogenesis, egg fertilization and the fully formed fetus. As the cells begin to grow and differentiate, there are critical balances of hormones, and protein synthesis. Data are emerging on how these plastic-derived compounds affect embryogenesis, placentation and feto-placental development since pregnant women and unborn fetuses are often exposed to these factors during preconception and throughout gestation. Impaired early development that ultimately influences fetal outcomes is at the center of many developmental disorders and contributes an independent risk factor for adult chronic diseases. This review will summarize the current status on the impact of exposure to plastic derived EDCs on the growth, gene expression, epigenetic and angiogenic activities of the early fetal development process and their possible effects on birth outcomes.

Urinary levels of phthalates and DINCH metabolites in Korean and Thai pregnant women across three trimesters

Phthalates are anti-androgenic chemicals and may cause long-lasting adverse effects on growing fetuses. Understanding their exposure profile during pregnancy, therefore, is of public health importance. Because both behavioral and physiological changes of pregnant women are expected to be substantial, the amount of phthalate exposure is expected to vary significantly over the course of pregnancy. Temporal trend of phthalate exposure during pregnancy, however, is largely unknown, especially in Asian women. The purpose of this study is to investigate the urinary concentrations of metabolites for major phthalates and alternative plasticizers over the course of pregnancy among Korean (n = 81) and Thai women (n = 102). Twenty-four metabolites from 15 plasticizers, such as dimethyl phthalate (DMP), diethyl phthalate (DEP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzyl butyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP), dioctyl phthalate (DnOP), diisononyl phthalate (DiNP), diisodecyl phthalate (DiDP), di(2-ethylhexyl) terephthalate (DEHTP), and di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH), were measured in urine samples collected in each trimester from pregnant women. While the levels of several phthalate metabolites were significantly different by trimester among Korean women, those of Thai women were relatively consistent. Urinary metabolites of DEP and DnOP were higher in Thai pregnant women compared to Korean pregnant women. The detection frequencies of the DINCH metabolite were 67.4% and 44.9% among Korean and Thai pregnant women, respectively. However, the ratio of DINCH to DEHP metabolites was significantly higher in Thai women. According to risk assessment, 11.9% of Korean and 5.3% of Thai women were considered at risk due to phthalate exposure, and DEHP, DnBP and DiBP were identified as major risk drivers. Considering the vulnerability of growing fetuses, further studies are warranted to identify major sources of exposure to these plasticizers during pregnancy.

Associations of urinary di-(2-ethylhexyl) phthalate metabolites with the residential characteristics of pregnant women

Epidemiological evidence on the associations between urinary di-(2-ethylhexyl) phthalate (DEHP) metabolites and residential characteristics is limited. Therefore, we investigated the associations of urinary DEHP metabolites with the residential characteristics of pregnant women. We collected completed questionnaires and maternal spot urine samples from 616 random pregnant women in Shengjing Hospital of China Medical University in Shenyang. Urinary DEHP metabolites concentrations, including mono-(2-ethylhexyl) phthalate (MEHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), were measured and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). Multivariable linear regression models were performed to obtain regression estimates (β) and 95% confidence intervals (CIs) after adjustment for sociodemographic characteristics. In all participants, the geometric mean of MEHP and MEHHP concentrations were 4.25 ± 4.34 and 5.72 ± 2.65 μg/L, respectively. In multivariable analyses after adjusting for sociodemographic characteristics, distance from residence to motor vehicle traffic (≥150 m versus <20 m) was negatively associated with MEHP (β = -0.241, 95% CI: -0.448, -0.033) and MEHHP (β = -0.279, 95% CI: -0.418, -0.140) concentrations. Compared with the one that had not recently been renovated, a renovated home was associated with higher MEHP (β = 0.194, 95% CI: 0.064, 0.324) and MEHHP (β = 0.111, 95% CI: 0.024, 0.197) concentrations. Air freshener use was associated with higher MEHP (β = 0.322, 95% CI: 0.007, 0.636) concentrations. Moldy walls were positively associated with MEHP (β = 0.299, 95% CI: 0.115, 0.482) and MEHHP (β = 0.172, 95% CI: 0.050, 0.294) concentrations. In contrast, humidifier use was associated with a lower MEHP concentration (β = -0.167, 95% CI: -0.302, -0.032). Residential characteristics were probably associated with the DEHP exposure of pregnant women in Shenyang. Living near the motor vehicle traffic, residential renovation, air freshener use, and moldy walls are likely risk factors for increased DEHP exposure, whereas using household humidifier could be considered a protective measure to reduce DEHP exposure.

Perinatal phthalates exposure decreases fine-motor functions in 11-year-old girls: Results from weighted Quantile sum regression

INTRODUCTION

Phthalates are a group of high production chemicals, generally used as plasticizers and odor enhancers. Phthalates cross the blood-placenta barrier and are associated with deficits in cognitive functions and behavior problems in offspring. We previously reported sex-specific associations with motor function when phthalates are considered singly. Because exposure to phthalates usually occurs as mixtures, here we assess these associations between a mixture of phthalates and motor function at age 11 years.

METHODS

Data come from the prospective cohort study of mothers and offspring who participated in the Columbia Center for Children's Environmental Health birth cohort (CCCEH). Seven phthalate metabolites were measured in maternal spot urine obtained during the third trimester and motor function was evaluated using the short form of the Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition (BOT-2) at the age of 11 years. We used Weighted Quartile Sum (WQS) regression models to examine the effect of phthalate metabolites in males and females separately. The models were adjusted for child age in months, child BMI, maternal race (African-American vs. Dominican), prenatal alcohol consumption, maternal demoralization score, HOME score, and urine specific gravity. In a secondary analysis we used linear regression models to examine the association between the sum of molar concentrations of both DEHP and non-DEHP metabolites, and outcomes of gross and fine motor functions.

RESULTS

209 mother-child pairs were eligible for this analysis. A significant decrease in fine-motor functions was observed among females, but not among males, following exposure to high levels of weighted quartile sum of seven phthalate metabolites (Covariates-adjusted coefficient estimate B = -2.7, 95% Confidence Interval [CI] -4.64 to -0.75, p = 0.01 for females [n = 116] and B = -1.63, 95%CI -3.94 to 0.69, p = 0.16 for males [n = 93]). The most highly weighted phthalate metabolites, associated with fine-motor functions among females, were MBP, MBZP, and MIBP, all non-DEHP phthalates. No significant associations were found between the weighted quartile sum of seven phthalate metabolites and gross-motor functions at the age of 11 years for males (B = -0.81, 95%CI -1.17 to 1.96, p = 0.23). With the molar sum of four non-DEHP phthalates as main predictor of linear regression models, we found significant decrease in gross and fine motor functions among females prenatally exposed to non-DEHP phthalates B = -0.98, 95%CI -1.98 to 0.03, p = 0.05 and B = -0.85, 95%CI -1.49 to -0.20, p = 0.01, respectively).

CONCLUSIONS

Phthalate exposure during pregnancy was associated with decreased motor functions among 11-year-old girls.

Bisphenol A and Phthalates in Diet: An Emerging Link with Pregnancy Complications

Endocrine-disrupting chemicals (EDCs) are exogenous substances that are able to interfere with hormone action, likely contributing to the development of several endocrine and metabolic diseases. Among them, Bisphenol A (BPA) and phthalates contaminate food and water and have been largely studied as obesogenic agents. They might contribute to weight gain, insulin resistance and pancreatic β-cell dysfunction in pregnancy, potentially playing a role in the development of pregnancy complications, such as gestational diabetes mellitus (GDM), and adverse outcomes. Pregnancy and childhood are sensitive windows of susceptibility, and, although with not univocal results, preclinical and clinical studies have suggested that exposure to BPA and phthalates at these stages of life might have an impact on the development of metabolic diseases even many years later. The molecular mechanisms underlying this association are largely unknown, but adipocyte and pancreatic β-cell dysfunction are suspected to be involved. Remarkably, transgenerational damage has been observed, which might be explained by epigenetic changes. Further research is needed to address knowledge gaps and to provide preventive measure to limit health risks connected with exposure to EDCs.

Phthalate metabolites in urine of children and adolescents in Germany. Human biomonitoring results of the German Environmental Survey GerES V, 2014-2017

During the population representative German Environmental Survey of Children and Adolescents (GerES V, 2014-2017) 2256 first-morning void urine samples from 3 to 17 years old children and adolescents were analysed for 21 metabolites of 11 different phthalates (di-methyl phthalate (DMP), di-ethyl phthalate (DEP), butylbenzyl phthalate (BBzP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di-cyclohexyl phthalate (DCHP), di-n-pentyl phthalate (DnPeP), di-(2-ethylhexyl) phthalate (DEHP), di-iso-nonyl phthalate (DiNP), di-iso-decyl phthalate (DiDP) and di-n-octyl phthalate (DnOP)). Metabolites of DMP, DEP, BBzP, DiBP, DnBP, DEHP, DiNP and DiDP were found in 97%-100% of the participants, DCHP and DnPeP in 6%, and DnOP in none of the urine samples. Geometric means (GM) were highest for metabolites of DiBP (MiBP: 26.1 μg/L), DEP (MEP: 25.8 μg/L), DnBP (MnBP: 20.9 μg/L), and DEHP (cx-MEPP: 11.9 μg/L). For all phthalates but DEP, GMs were consistently higher in the 3-5 years old children than in the 14-17 years old adolescents. For DEHP, the age differences were most pronounced. All detectable phthalate biomarker concentrations were positively associated with the levels of the respective phthalate in house dust. In GerES V we found considerably lower phthalate biomarker levels than in the preceding GerES IV (2003-2006). GMs of biomarker levels in GerES V were only 18% (BBzP), 23% (MnBP), 23% (DEHP), 29% (MiBP) and 57% (DiNP) of those measured a decade earlier in GerES IV. However, some children and adolescents still exceeded health-based guidance values in the current GerES V. 0.38% of the participants had levels of DnBP, 0.08% levels of DEHP and 0.007% levels of DiNP which were higher than the respective health-based guidance values. Accordingly, for these persons an impact on health cannot be excluded with sufficient certainty. The ongoing and substantial exposure of vulnerable children and adolescents to many phthalates confirms the need of a continued monitoring of established phthalates, whether regulated or not, as well as of potential substitutes. With this biomonitoring approach we provide a picture of current individual and cumulative exposure developments and body burdens to phthalates, thus providing support for timely and effective chemicals policies and legislation.

Early life exposure to phthalates in the Canadian Healthy Infant Longitudinal Development (CHILD) study: a multi-city birth cohort

BACKGROUND

Few studies have examined phthalate exposure during infancy and early life, critical windows of development. The Canadian Healthy Infant Longitudinal Development (CHILD) study, a population-based birth cohort, ascertained multiple exposures during early life.

OBJECTIVE

To characterize exposure to phthalates during infancy and early childhood.

METHODS

Environmental questionnaires were administered, and urine samples collected at 3, 12, and 36 months. In the first 1578 children, urine was analyzed for eight phthalate metabolites: mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-3-carboxypropyl phthalate (MCPP). Geometric mean (GM) concentrations were calculated by age, together with factors that may influence concentrations. Trends with age were examined using mixed models and differences within factors examined using ANOVA.

RESULTS

The highest urinary concentration was for the metabolite MBP at all ages (GM: 15-32 ng/mL). Concentrations of all phthalate metabolites significantly increased with age ranging from GM: 0.5-15.1 ng/mL at 3 months and 1.9-32.1 ng/mL at 36 months. Concentrations of all metabolites were higher in the lowest income categories except for MEHP at 3 months, among children with any breastfeeding at 12 months, and in urine collected on dates with warmer outdoor temperatures (>17 °C), except for MBzP at 3 months and MEHP at 3 and 12 months. No consistent differences were found by gender, study site, or maternal age.

CONCLUSIONS

Higher phthalate metabolite concentrations were observed among children in lower income families. Examination of factors associated with income could inform interventions aimed to reduce infant phthalate exposure.

Influence of sociodemographic, lifestyle and genetic characteristics on maternal DHA and other polyunsaturated fatty acid status in pregnancy: A systematic review

INTRODUCTION

Omega-3 DHA is important for the prevention of preterm birth, however there is limited knowledge of the determinants of omega-3 status during pregnancy. The primary objective of this systematic review was to synthesise data from existing studies assessing relationships between sociodemographic, diet, lifestyle and genetic factors and maternal DHA status.

MATERIALS AND METHODS

The Medline, Embase, Amed, and CINAHL databases were searched for studies reporting measures of maternal omega-3 status and a sociodemographic/lifestyle/genetic characteristic.

RESULTS

Twenty-two studies were included in the final analyses. Higher dietary fish consumption/PUFA intake, higher education level and an older maternal age were associated with higher maternal omega-3 status. Higher alcohol intake, smoking and FADS genotype were each associated with lower maternal omega-3 status.

DISCUSSION

Differences in findings between studies make it difficult to draw clear conclusions about the relationship between these factors and maternal omega-3 DHA status, although socioeconomic status may play a role.

Associations between socioeconomic status, psychosocial stress, and urinary levels of 8-iso-prostaglandin-F2α during pregnancy in Puerto Rico

BACKGROUND

Lower socioeconomic status (SES) and psychosocial stress during pregnancy have been associated with adverse birth outcomes. While hypothalamic-pituitary-axis activation is thought to be the primary driver, oxidative stress may also be involved mechanistically. We used data from the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) cohort (N=476) to examine associations between self-reported psychosocial stress measures, SES indicators, and urinary oxidative stress biomarker concentrations, hypothesizing that women with lower SES and increased psychosocial stress would have elevated oxidative stress biomarkers.

METHODS

Maternal age, education, marital status, insurance status, alcohol use and smoking status were obtained via self-reported questionnaires and were used as indicators of SES. Perceived stress, depression, negative life experiences, neighborhood perceptions, and social support were self-reported in questionnaires administered during pregnancy. Responses were grouped into tertiles for analysis, where the highest tertile corresponded to highest level of psychosocial stress. Urinary concentrations of 8-iso-prostaglandin F2α (8-iso-PGF2α) and its primary metabolite were measured at three study visits (median 18, 24, 28 weeks gestation) and averaged to reflect oxidative stress across pregnancy. Linear models were used to examine associations between SES indicators, tertiles of psychosocial stress and oxidative stress biomarkers.

RESULTS

Average levels of 8-iso-PGF2α and the 8-iso-PGF2α metabolite were higher among pregnant women who were younger, who had public compared to private insurance, and who were unemployed compared to employed. However, no associations were observed between psychosocial stress measures and biomarker concentrations in adjusted analyses.

CONCLUSIONS

Psychosocial stress during pregnancy, as indicated by self-reported questionnaire measures, was not associated with biomarkers of oxidative stress in the PROTECT study. However, results suggest that these biomarkers are elevated among women of lower SES, which is typically associated with stress. Notably, compared to other populations, self-reported psychosocial stress measures were lower in PROTECT compared to other populations.

Couples exposure to phthalates and its influence on in vitro fertilization outcomes

This prospective study examined the associations between the levels of eight urinary phthalate metabolites in 599 couples and in vitro fertilization (IVF) outcomes. We used log-binomial multivariate regression to estimate relative risks (RR) for the association between phthalate concentration and IVF binary outcomes (fertilization rate >50%, biochemical pregnancy, clinical pregnancy and live birth) for each woman after adjusting the model for the concentration in a male partner and each relevant confounders. RR was expressed per unit increase in log-transformed urinary metabolite concentration. The percentage of bis-2-ethylhexyl phthalate (DEHP) metabolites excreted as mono-2-ethylhexyl phthalate (MEHP) was calculated as %MEHP. Urinary MEHP in women was associated with an increased risk of biochemical pregnancy (RR = 1.35; p = 0.04), failed clinical pregnancy (RR = 1.56; p = 0.006) and live birth (RR = 1.54; p = 0.011). An increase in monoethyl phthalate was associated with a high risk of failed clinical pregnancy (RR = 1.25; p = 0.03) and live birth (RR = 1.35; p = 0.006). An increase in %MEHP was associated with an increase in the risk of biochemical pregnancy (RR = 1.55; p = 0.05), failed clinical pregnancy (RR = 1.73; p = 0.02) and live birth (RR = 1.65; p = 0.046). Our results demonstrated that exposure to some phthalates may adversely affect IVF outcomes, particularly when couples' exposure was jointly modeled, emphasizing the importance of a couple-based approach in assessing fertility outcomes. The associations between IVF outcomes and DEHP metabolites were stronger in women whose %MEHP was >75th percentile which may be due to their less efficient metabolism and excretion of DEHP and/or MEHP.

The extent and predictors of phthalate exposure among couples undergoing in vitro fertilization treatment

Phthalates are chemicals used as plasticizers and solvents in many consumer products but are suspected of disrupting the endocrine system and are known for their reproductive/developmental health risks. This study examined the extent and predictors of phthalate exposure among 599 couples undergoing in vitro fertilization. A questionnaire was administered to obtain sociodemographic, health, and lifestyle data, and two spot urine samples were collected from the couples to analyze eight phthalate metabolites, cotinine (COT) as a smoking index, and creatinine to adjust for urine dilution. Seven phthalate metabolites were detected in > 94% of the urine samples, and monobenzyl phthalate (MBzP) was found in 24% of the women and 26% of their male partners. Median phthalate levels were highest for monoethyl phthalate (MEP), at 333.26 μg/l in women and 290 μg/l in male partners, and lowest for MBzP, at 1.17 μg/l in women and 1.14 μg/l in male partners. Correlation coefficients of ≥ 0.4 between the women and their male partners for the eight urinary phthalate metabolites may indicate a shared source of exposure. A multivariate regression model was used to assess the association between predictors and each urinary phthalate metabolite. Several potential predictors for the variations in specific urinary phthalate metabolites were identified, including the body mass index, age, socioeconomic status, and regional distribution for both women and their male partners but with slightly different patterns. Women with a history of breastfeeding, using bottled water for cooking and storing food in plastic bags had lower MEP (8.7%), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) (9.2%), and both mono-iso-butyl phthalate and MECPP (8.2 and 8.1%). A history of contraceptive use was associated with an increase in MECPP (8.7%), mono-(2-ethyl-5-hydroxyhexyl) phthalate (11.4%), mono-(2-ethyl-5-oxohexyl) phthalate (7.6%), and the molar sum of bis (2-ethylhexyl) phthalate metabolites (8.9%). Urinary COT levels were associated with an increase of 10-16% in all urinary metabolites in women but of only 10.5% in mono-(2-ethylhexyl) phthalate in male partners. More than 95% of the couples reported the use of cosmetics, perfumes, and personal-care products, but we were not able to find associations with urinary phthalate metabolites, perhaps due to their short half-lives. MEP levels associated with the use of household cleaning products were 11.2% higher in male partners. Our levels were generally higher than those reported elsewhere, perhaps due to different lifestyles, cultural practices, dietary habits, use of personal-care products, and governmental legislation.

Prenatal and childhood exposure to phthalates and motor skills at age 11 years

BACKGROUND

Previous reports suggest that prenatal phthalate exposure is associated with lower scores on measures of motor skills in infants and toddlers. Whether these associations persist into later childhood or preadolescence has not been studied.

METHODS

In a follow up study of 209 inner-city mothers and their children the concentrations of mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), monoisobutyl phthalate (MiBP), monomethyl phthalate (MEP), mono-carboxy-isooctyl phthalate (MCOP), and four di-2-ethylhexyl phthalate metabolites (ΣDEHP) were measured in spot urine sample collected from the women in late pregnancy and from their children at ages 3, 5, and 7 years. The Bruininks-Oseretsky Test of Motor Proficiency short form (BOT-2) was administered at child age 11 to assess gross and fine motor skills.

RESULTS

The total number of children included in the study was 209. Of the 209 children, 116(55.5%) were girls and 93 were (45%) boys. Among girls, prenatal MnBP(b=-2.09; 95%CI: [-3.43, -0.75]), MBzP (b=-1.14; [95%CI: -2.13, -0.14]), and MiBP(b=-1.36; 95%CI: [-2.51, -0.21] and MEP(b=-1.23 [95%CI: -2.36, -0.11]) were associated with lower total BOT-2 composite score. MnBP (b= -1.43; 95% CI: [-2.44, -0.42]) was associated with lower fine motor scores and MiBP(b = -0.56; 95% CI: [-1.12, -0.01]) and MEP (b = -0.60; 95% CI: [-1.14, -0.06])was associated with lower gross motor scores. Among boys, prenatal MBzP (b = -0.79; 95% CI: [-1.40, -0.19]) was associated with lower fine motor composite score. The associations between MEP measured at age 3 and the BOT-2 gross motor, fine motor and total motor score differed by sex. In boys, there was an inverse association between ΣDEHP metabolites measured in childhood at ages 3 (b = -1.30; 95% CI: [-2.34, -0.26]) and 7 years (b = -0.96; 95% CI: [-1.79, -0.13]), and BOT-2 fine motor composite scores.

CONCLUSIONS

Higher prenatal exposure to specific phthalates was associated with lower motor function among 11- year old girls while higher postnatal exposure to ΣDEHP metabolites was associated with lower scores among boys. As lower scores on measures of motor development have been associated with more problems in cognitive, socioemotional functioning and behavior, the findings of this study have implications related to overall child development.

BAYESIAN ANALYSIS OF INFANT'S GROWTH DYNAMICS WITH IN UTERO EXPOSURE TO ENVIRONMENTAL TOXICANTS

Early infancy from at-birth to 3 years is critical for cognitive, emotional and social development of infants. During this period, infant's developmental tempo and outcomes are potentially impacted by in utero exposure to endocrine disrupting compounds (EDCs), such as bisphenol A (BPA) and phthalates. We investigate effects of ten ubiquitous EDCs on the infant growth dynamics of body mass index (BMI) in a birth cohort study.Modeling growth acceleration is proposed to understand the "force of growth" through a class of semiparametric stochastic velocity models. The great flexibility of such a dynamic model enables us to capture subject-specific dynamics of growth trajectories and to assess effects of the EDCs on potential delay of growth. We adopted a Bayesian method with the Ornstein-Uhlenbeck process as the prior for the growth rate function, in which the World Health Organization global infant's growth curves were integrated into our analysis. We found that BPA and most of phthalates exposed during the first trimester of pregnancy were inversely associated with BMI growth acceleration, resulting in a delayed achievement of infant BMI peak. Such early growth deficiency has been reported as a profound impact on health outcomes in puberty (e.g., timing of sexual maturation) and adulthood.

In utero effects of maternal phthalate exposure on male genital development

BACKGROUND

Phthalates are used extensively in commercial and personal care products and maternal exposure is ubiquitous. Phthalates are anti-androgenic, but the potential effects of phthalates on male penile development have not been assessed in utero.

OBJECTIVE

The study aims to investigate the association between early pregnancy phthalate exposure and fetal penile development, overall and by race.

METHODS

Prospective cohort study of women with singleton pregnancies presenting for prenatal ultrasound between 18 and 22 weeks' gestation. Maternal urine samples were assayed for eight phthalate monoester metabolites. We used maternal phthalate levels at 18 to 22 weeks' gestation as predictors of fetal size using multiple linear regression models, adjusted for fetal gestational age, maternal age, race, smoking, and education. We incorporated a phthalate by race interaction into a second set of regression models.

RESULTS

We detected statistically significant race interactions for continuous phthalates with penile width. Race interactions were also suggested for penile length and volume using tertiles of phthalates with point estimates generally positive for whites and negative for African Americans.

CONCLUSION

Penile development is significantly influenced by race, and the impact of maternal phthalates on penile measurements also varies by race. Maternal phthalate exposure can adversely affect in utero penile growth and development, especially among African Americans.

Exposure to non-persistent chemicals in consumer products and fecundability: a systematic review

BACKGROUND

Exposure to non-persistent chemicals in consumer products is ubiquitous and associated with endocrine-disrupting effects. These effects have been linked to infertility and adverse pregnancy outcomes in some studies and could affect couple fecundability, i.e. the capacity to conceive a pregnancy, quantified as time to pregnancy (TTP).

OBJECTIVE AND RATIONALE

Few epidemiologic studies have examined the impact of non-persistent chemicals specifically on TTP, and the results of these studies have not been synthesized. We undertook a systematic review to summarize the strength of evidence for associations of common non-persistent chemicals with couple fecundability and to identify gaps and limitations in the literature, with the aim of informing policy decisions and future research.

SEARCH METHODS

We performed an electronic search of English language literature published between 1 January 2007 and 25 August 2017 in MEDLINE, EMBASE.com, Global Health, DART/TOXLINE, POPLINE and DESTAF. We included human retrospective and prospective cohort, cross-sectional and case-control studies that examined phthalates, bisphenol A, triclosan, triclocarban, benzophenones, parabens and glycol ethers in consumer products, and considered TTP or fecundability as an outcome among women, men and couples conceiving without medical assistance. We excluded editorials, opinion pieces, introductions to special sections, articles that described only lifestyle (e.g. caffeine, stress) or clinical factors (e.g. semen parameters, IVF success). Standardized forms for screening, data extraction and study quality were developed using DistillerSR software and completed in duplicate. We used the Newcastle-Ottawa Scale to assess risk of bias and devised additional quality metrics based on specific methodological features of fecundability studies.

OUTCOMES

The search returned 3456 articles. There were 15 papers from 12 studies which met inclusion criteria, of which eight included biomarkers of chemical exposure. Studies varied widely in terms of exposure characterization, precluding a meta-analytic approach. Among the studies that measured exposure using biospecimens, results were equivocal for associations between either male or female phthalate exposure and TTP. There was preliminary support for associations of female exposure to some parabens and glycol ethers and of male exposure to benzophenone with longer TTP, but further research and replication of these results are needed. The results provided little to no indication that bisphenol A, triclocarban or triclosan exposure was associated with TTP.

WIDER IMPLICATIONS

Despite a growing literature on couple exposure to non-persistent endocrine-disrupting chemicals and fecundability, evidence for associations between biologically measured exposures and TTP is limited. Equivocal results with different non-persistent chemical compounds and metabolites complicate the interpretation of our findings with respect to TTP, but do not preclude action, given the documented endocrine disrupting effects on other reproductive outcomes as well as fetal development. We therefore advocate for common-sense lifestyle changes in which both females and males seeking to conceive minimize their exposure to non-persistent chemicals.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42018084304.

Phthalate metabolite exposures among immigrants living in the United States: findings from NHANES, 1999-2014

Phthalates exposure has been linked to multiple health risks, and US immigrants may have different exposures to phthalates due to lifestyle differences. Urinary concentrations of eight phthalate metabolites (mono-ethyl phthalate [MEP], mono-n-butyl phthalate [MnBP], mono-isobutyl phthalate [MiBP], mono-(3-carboxypropyl) phthalate [MCPP], mono-benzyl phthalate [MBzP], mono-2-ethylhexyl phthalate [MEHP], mono-(2-ethyl-5-hydroxyhexyl) phthalate [MEHHP], mono-(2-ethyl-5-oxohexyl) phthalate [MEOHP]) were measured in 10318 US-born and 3511 foreign-born individuals from NHANES 1999-2014. Using multivariate adjusted linear regression, we assessed whether phthalate metabolite levels differed by nativity in the whole population, within racial/ethnic groups, and by years in the US. We also tested whether immigrant demographics predicted phthalate metabolite levels. In fully adjusted models, MEP, MnBP, and MiBP were significantly higher, and MBzP significantly lower, among immigrants than US-born participants. Among immigrants, MnBP and MiBP significantly declined with longer time in the US (P_trend = 0.029 and P_trend = 0.039, respectively), while MCPP and MBzP significantly rose (P_trend = 0.019 and P_trend = 0.043, respectively). Results within each racial/ethnic group were consistent with the whole population. Among immigrants, women had significantly higher metabolite levels than men (all p < 0.01), and MEP, MnBP, and MCPP differed by race/ethnicity. Due to higher phthalate exposures, immigrants may be especially vulnerable to phthalate-associated health problems.

Phthalate exposure and odds of bacterial vaginosis among U.S. reproductive-aged women, NHANES 2001-2004

Endocrine-disrupting chemicals, such as phthalates, are an unexamined potential risk factor for bacterial vaginosis (BV) and warrant investigation because hormones affect BV. We examined the association between phthalate exposure and BV in the National Health and Nutrition Examination Survey, 2001-2004. BV outcomes were defined as intermediate (Nugent score of 4-6) and positive (7-10). Phthalate metabolites, including monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), and di(2-ethylhexyl) phthalate (DEHP) metabolites, were measured in urine. Among 854 women with complete data, multinomial logistic regression revealed that concentrations of MnBP (Q4 vs. Q1 OR = 3.01, 95% CI 1.76-5.15, p-trend <0.001) and ΣDEHP metabolites (Q4 OR = 2.55, 95% CI 1.45-4.47, p-trend = 0.03) were associated with Nugent-score BV, although only MnBP was significant after adjustment for confounders. Associations were null after adjustment for urinary creatinine (MnBP Q4 OR = 1.11, 95% CI 0.63-1.96; ΣDEHP Q4 OR = 0.72, 95% CI 0.37-1.39). Future work should further examine these relationships using direct measurements of intravaginal phthalates exposures.