Racial/Ethnic Differences in Hormonally-Active Hair Product Use: A Plausible Risk Factor for Health Disparities

Associations of personal care product use during pregnancy and the postpartum period with markers of postpartum glycemic control - Results from the ERGO Study

BACKGROUND

Personal care products frequently contain endocrine disrupting chemicals (EDCs) including parabens and phthalates, which can alter glucose metabolism. The postpartum period is a time of rapid metabolic change, but whether EDC-associated product use impacts postpartum glucose metabolism is unknown.

METHODS

We included 270 participants from the Boston, MA-based Environmental Reproductive and Glucose Outcomes (ERGO) pregnancy cohort with data on self-reported personal care product use at ≤4 pregnancy visits (median: 11, 19, 26, 36 weeks of gestation) and 1 postpartum visit (median: 9 weeks). We quantified postpartum hemoglobin A1c (HbA1c), fasting insulin, fasting- and 2-h glucose post-75-g oral glucose tolerance test, and calculated homeostatic model assessment for insulin sensitivity (HOMA2-S) and beta-cell function (HOMA2-B). Using covariate-adjusted linear regression, we estimated visit-specific associations of product use with postpartum glycemic outcomes.

RESULTS

Associations of product use with postpartum glycemic measures were mixed. Users of certain hair products had lower postpartum insulin sensitivity compared to non-users (e.g., Visit1 hair gel/spray: 22.8% difference [95% CI: 39.2, -1.9] in mean HOMA2-S). Conversely, users of products like deodorant, liquid- and bar soap, had higher insulin sensitivity and lower glucose levels (e.g., postpartum deodorant: 32.1% difference [95% CI: 7.0, 63.1] in mean HOMA2-S; -3.1 mg/dL [95% CI: 6.3, -0.04] mean fasting glucose). Associations with other products were inconsistent across timepoints or null.

CONCLUSION

Use of certain personal care products during the perinatal period was associated with altered postpartum glucose metabolism. Larger studies are needed to understand the impacts of product use patterns on glycemic outcomes.

Chemicals of concern in select packaged hair relaxers available on the Kenyan market: an examination of ingredient labels and measurement of pH

Background

There is an emerging interest in the investigation of hair relaxers as important sources of exposure to chemicals of concern (CoCs) and their associated adverse health effects. We focused on documentation of CoCs by examining labels of selected relaxers currently available on the market in Nakuru and Embu Counties, Kenya and measured the pH profiles to ensure compliance with Kenya Bureau of Standards.

Methods

We enrolled 746 women aged 15-50 years in a cross-sectional study, which ascertained participants' sociodemographic characteristics, personal care products use in the last 7-14 days and ever use of hair dyes and chemical relaxers including the brand names of products used. Based on participants' questionnaire responses and product availability at beauty shops and supermarkets, we purchased 22 different relaxer products. The label of each product was reviewed and we recorded relaxer strength, manufacturer and location, listed ingredients, and other claims. To identify CoCs, we cross-checked the list of ingredients against the Campaign for Safe Cosmetics' (CSC) Red List and European Union's prohibited and restricted substances (Annex II and III respectively), Regulation 1223/2009 on cosmetics. The pH profiles of each product were determined using a benchtop pH meter.

Results

Twenty-seven CoCs were documented upon examination with each relaxer listing more than one CoC. Thirteen out of 27 (48.2%) were fragrance chemicals with d-limonene/limonene and linalool, each being listed as an ingredient in 9 products. Fourteen (63.6%) relaxers had undisclosed ingredients listed as 'fragrance' and/or 'parfum'. Six of the identified CoCs are classified as Tier 1 (Do not use for everyone) per CSC Red List while 14.8% (4) are prohibited and 55.6% (15) are restricted substances per EU regulations. The pH values of the relaxers were within Kenya Bureau of Standards required range of 11-13.

Conclusion

These findings create awareness of CoCs listed on labels of selected hair relaxers. This justifies the need for consumer education on potentially harmful chemicals and their associated risks. Further, our findings justify the need for laboratory study to evaluate and quantify CoCs that are listed as well as those that are not listed on the label.

Racial/ethnic disparities in the association of environmental exposure to phthalates and bisphenols mixtures with diabetes mellitus: NHANES 2013-2016

We evaluated the association between urinary concentrations of phthalates/bisphenols mixtures and diabetes mellitus (DM) and poorly controlled DM, stratified by sex, and race/ethnicity in 2718 adults from the 2013 to 2016 National Health and Nutrition Examination Survey. DM was self-reported or defined by glucose tests/hypoglycemic use. Poorly controlled DM was defined by HbA1c ≥ 8%. Principal component analyses allowed to identify three mixtures: (1) DEHP (di(2-ethylhexyl) phthalate metabolites), (2) LMW/BPs (bisphenol A, F, S, and low molecular weight phthalates), and (3) high molecular weight phthalates. Group weighted quantile sum regression showed that the DEHP mixture was associated with lower DM prevalence in women and "other races" participants. Conversely, the LMW/BPs mixture was associated with higher DM odds, mainly among Mexican Americans. Race/ethnicity seems to determine the association between the different exposure mixtures and DM prevalence and poorly controlled DM.

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.

Young infants' exposure to parabens: lotion use as a potential source of exposure

BACKGROUND

Parabens are widely used as antimicrobials in personal care products and pharmaceuticals. While previous studies demonstrate paraben exposure is ubiquitous, data investigating infants' exposure is limited.

OBJECTIVE

We sought to characterize infants' exposure to parabens and identify factors associated with higher levels of exposure.

METHODS

Families enrolled in the CHildren's Immune ResPonse Study between 2016-2018. Parents completed questionnaires, providing information on demographics and lifestyle factors. Urine samples were collected when infants were 1 to 3 months old (n = 71) and 12 months old (n = 29), with 18 infants evaluated at both ages. Parabens were measured in urine samples using liquid chromatography tandem mass spectrometry and served as an indicator of exposure.

RESULTS

Methylparaben (MP), ethylparaben (EP), and propylparaben (PP) were detected in >70% of urine samples, and concentrations ranged several orders of magnitude (specific-gravity-corrected medians: MP = 25.4 PP = 3.55; EP = 0.90 ng/mL). Butylparaben was detected less frequently (<50%). Paraben concentrations were lower than those reported for older children and adults; however, we did not find statistically significant differences in paraben concentrations by infant age. Correlations between measurements taken over time were poor, suggesting paraben exposure is variable, and multiple measurements are needed to capture cumulative exposure information. We observed differences in exposure by race/ethnicity and socioeconomic status; non-White infants and infants whose parents completed less education had higher paraben exposure. Recent lotion usage strongly predicted paraben exposure in 1-3-month-olds. For example, infants using lotion in the past seven days had urinary MP concentrations 355% higher than infants without lotion usage (eß = 4.55, 95% Confidence Interval = 1.68, 12.55, p < 0.001). Together, our results suggest infants are ubiquitously exposed to parabens and personal care product use may be an important source of exposure.

IMPACT

To the best of our knowledge, this is the first paper to report paraben levels and evaluate predictors of exposure in infants. This study supports the hypothesis that universal exposure to parabens extends to infants, as indicated by urinary biomarker concentrations. Of the predictors evaluated, lotion use in the last seven days was the strongest predictor of exposure in 1-3-month-olds. Given infant paraben levels are strongly correlated to lotion use, there may be an opportunity for parents to reduce paraben exposure by limiting its application or consulting ingredient labels to ensure no parabens are present.

Advancing environmental epidemiologic methods to confront the cancer burden

Even though many environmental carcinogens have been identified, studying their effects on specific cancers has been challenging in nonoccupational settings, where exposures may be chronic but at lower levels. Although exposure measurement methods have improved considerably, along with key opportunities to integrate multi-omic platforms, there remain challenges that need to be considered, particularly around the design of studies. Cancer studies typically exclude individuals with prior cancers and start recruitment in midlife. This translates into a failure to capture individuals who may have been most susceptible because of both germline susceptibility and higher early-life exposures that lead to premature mortality from cancer and/or other environmentally caused diseases like lung diseases. Using the example of breast cancer, we demonstrate how integration of susceptibility, both for cancer risk and for exposure windows, may provide a more complete picture regarding the harm of many different environmental exposures. Choice of study design is critical to examining the effects of environmental exposures, and it will not be enough to just rely on the availability of existing cohorts and samples within these cohorts. In contrast, new, diverse, early-onset case-control studies may provide many benefits to understanding the impact of environmental exposures on cancer risk and mortality. This article is part of a Special Collection on Environmental Epidemiology.

Hair Straightener Use in Relation to Prevalent and Incident Fibroids in the Sister Study with a Focus on Black Women

BACKGROUND

Uterine fibroids disproportionately affect Black women, and exposure to chemicals from hair relaxers or straighteners ("straighteners") may contribute to fibroid development.

OBJECTIVES

We examined the association between straightener use and prevalent young-onset uterine fibroids (diagnosed before age 36 y), as well as incident fibroids (diagnosed age 36-60 y), with a focus on Black women. We also examined differences in associations across birth cohorts as proxies for formulation changes.

METHODS

Data from 4,162 Black women in the Sister Study, a prospective cohort of women 35-74 y of age (enrolled 2003-2009), were analyzed. We used logistic regression to estimate odds ratios (ORs) for the association of straightener use at 10-13 y of age and self-reported young-onset fibroids. We used Cox regression to assess hazard ratios (HRs) for straightener use (age 10-13 y and in 12 months before enrollment) and incident fibroids among 779 premenopausal Black women. Similar analyses were conducted in 40,782 non-Hispanic White women.

RESULTS

Over 70% of Black women used straighteners. In comparison with no use, any [OR = 1.15 ; 95% confidence interval (CI): 0.96, 1.36] and frequent use (OR = 1.18 ; 95% CI: 0.99, 1.42) of straighteners at 10-13 y of age were associated with young-onset fibroids. This association was most apparent among those born between 1928 and 1945 (OR = 1.78 ; 95% CI: 1.15, 2.74) and 1965-1974 (OR = 1.64 ; 95% CI: 0.82, 3.29). Fibroid incidence from 36 to 60 y of age was modestly associated with use of straighteners at 10-13 y of age [hazard ratio ( HR ) = 1.14 ; 95% CI: 0.81, 1.63] and in the 12 months prior to enrollment (HR = 1.32 ; 95% CI: 0.88, 2.00). Among non-Hispanic White women, straightener use at 10-13 y of age was similarly associated with young-onset fibroids (OR = 1.23 ; 95% CI: 1.03, 1.47) despite lower use (≤ 5 % ) of straighteners. Sensitivity analyses indicated a potential for bias due to fibroid misclassification, with an overestimation of the effect likely if nulliparous women or women from households with lower education reported their fibroid status less accurately.

DISCUSSION

Hair straightener use may be positively associated with fibroid risk. https://doi.org/10.1289/EHP14493.

Impact of Structural Racism and Social Determinants of Health on Disparities in Breast Cancer Mortality

The striking ethnic and racial disparities in breast cancer mortality are not explained fully by pathologic or clinical features. Structural racism contributes to adverse conditions that promote cancer inequities, but the pathways by which this occurs are not fully understood. Social determinants of health, such as economic status and access to care, account for a portion of this variability, yet interventions designed to mitigate these barriers have not consistently led to improved outcomes. Based on the current evidence from multiple disciplines, we describe a conceptual model in which structural racism and racial discrimination contribute to increased mortality risk in diverse groups of patients by promoting adverse social determinants of health that elevate exposure to environmental hazards and stress; these exposures in turn contribute to epigenetic and immune dysregulation, thereby altering breast cancer outcomes. Based on this model, opportunities and challenges arise for interventions to reduce racial and ethnic disparities in breast cancer mortality.

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.

Exposure to Environmental Chemicals and Infertility Among US Reproductive-Aged Women

Environmental chemical exposure has been rising over the past few decades but its impact on fertility remains uncertain. We assessed exposures to 23 common chemicals across a range of sociodemographic characteristics and their relationship with self-reported infertility. The analytic sample was non-pregnant women aged 18-49 years without a history of hysterectomy or oophorectomy (n = 2579) from the National Health and Nutrition Examination Survey (2013-2016). Environmental chemical exposure was assessed with biospecimens and dichotomized as high and low levels of exposure based on the median. Logistic regression models estimated the adjusted odds ratio (aOR) and 95% confidence intervals (CIs) for the association between high levels of exposure and infertility, adjusted for age, race, education level, family income, and smoking status. We observed associations between infertility and cadmium [aOR: 1.88; 95% CI: 1.02-3.47] and arsenic [aOR: 1.88 (1.05-3.36)]. Two pesticides hexachlorobenzene [OR: 2.04 (1.05-3.98)] and oxychlordane [OR: 2.04 (1.12-3.69)] were also associated with infertility in unadjusted analyses. There were negative associations with two Per- and polyfluoroalkyl substances with n-perfluorooctanoic acid [aOR: 0.51: (0.30-0.86)] and n-perfluorooctane sulfonic acid [aOR: 0.51: (0.26-0.97). Specific chemicals may contribute to infertility risk, highlighting the need for targeted public health strategies to mitigate exposure.

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

BACKGROUND

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

OBJECTIVES

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

DISCUSSION

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

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.

Evaluation of dermal exposure to phthalates and parabens resulting from the use of hair relaxers

Hair relaxers have been suggested as a source of exposure to parabens and phthalates. However, dermally absorbed doses of these chemicals resulting from consumer use of hair relaxers have yet to be quantified, and results from epidemiological studies have consistently demonstrated that there is no increased risk for hormone-sensitive, reproductive cancers associated with use of hair relaxers among Black women. Therefore, dermal absorption of parabens and phthalates associated with hair relaxer use for several commercially available hair relaxer kits was modeled using IH SkinPerm™. The chemicals detected in the hair relaxer kits included methylparaben (MP), ethylparaben (EP), butylparaben (BP), diethyl phthalate (DEP), bis(2-ethylhexyl) phthalate (DEHP), and the phthalate substitute bis(2-ethylhexyl) adipate (DEHA). The daily absorbed dose ranges (mg/kg/day), standardized over a year of product use, were as follows: 8.64 × 10-5-0.00116 MP, 2.30 × 10-8-3.07 × 10-6 EP, 3.24 × 10-8-4.33 × 10-6 BP, 8.65 × 10-9-1.15 × 10-6 DEP, and 8.94 × 10-7-0.000119 DEHP for Kit #1; 8.44 × 10-5-0.00113 MP and 7.91 × 10-5-0.00106 DEP for Kit #2; and 2.49 × 10-6-3.33 × 10-5 MP, 1.52 × 10-8-2.03 × 10-6 EP, 3.29 × 10-9-4.39 × 10-7 DEP, and 3.11 × 10-6-4.14 × 10-5 DEHA for Kit #3. These absorbed doses were well below applicable health-based guidance values, indicating consumer exposure from product use is not expected to pose a health risk. These results provide valuable information for health risk evaluations for hair relaxer use.

Wristband Personal Passive Samplers and Suspect Screening Methods Highlight Gender Disparities in Chemical Exposures

Wristband personal samplers enable human exposure assessments for a diverse range of chemical contaminants and exposure settings with a previously unattainable scale and cost-effectiveness. Paired with nontargeted analyses, wristbands can provide important exposure monitoring data to expand our understanding of the environmental exposome. Here, a custom scripted suspect screening workflow was developed in the R programming language for feature selection and chemical annotations using gas chromatography-high-resolution mass spectrometry data acquired from the analysis of wristband samples collected from five different cohorts. The workflow includes blank subtraction, internal standard normalization, prediction of chemical uses in products, and feature annotation using multiple library search metrics and metadata from PubChem, among other functionalities. The workflow was developed and validated against 104 analytes identified by targeted analytical results in previously published reports of wristbands. A true positive rate of 62 and 48% in a quality control matrix and wristband samples, respectively, was observed for our optimum set of parameters. Feature analysis identified 458 features that were significantly higher on female-worn wristbands and only 21 features that were significantly higher on male-worn wristbands across all cohorts. Tentative identifications suggest that personal care products are a primary driver of the differences observed.

Impact of Skin Care Products on Phthalates and Phthalate Replacements in Children: the ECHO-FGS

BACKGROUND

Phthalates and their replacements have been implicated as developmental toxicants. Young children may be exposed to phthalates/replacements when using skin care products (SCPs).

OBJECTIVES

Our objective is to assess the associations between use of SCPs and children's urinary phthalate/replacement metabolite concentrations.

METHODS

Children (4-8 years old) from the Environmental Influences on Child Health Outcomes-Fetal Growth Study (ECHO-FGS) cohort provided spot urine samples from 2017 to 2019, and mothers were queried about children's SCP use in the past 24 h (n = 906 ). Concentrations of 16 urinary phthalate/replacement metabolites were determined by liquid chromatography-tandem mass spectrometry (n = 630 ). We used linear regression to estimate the child's use of different SCPs as individual predictors of urinary phthalate/replacement metabolites, adjusted for urinary specific gravity, age, sex assigned at birth, body mass index, and self-reported race/ethnic identity, as well as maternal education, and season of specimen collection. We created self-organizing maps (SOM) to group children into "exposure profiles" that reflect discovered patterns of use for multiple SCPs.

RESULTS

Children had lotions applied (43.0%) frequently, but "2-in-1" hair-care products (7.5%), sunscreens (5.9%), and oils (4.3%) infrequently. Use of lotions was associated with 1.17-fold [95% confidence interval (CI): 1.00, 1.34] greater mono-benzyl phthalate and oils with 2.86-fold (95% CI: 1.89, 4.31) greater monoethyl phthalate (MEP), 1.43-fold (95% CI: 1.09, 1.90) greater monobutyl phthalate (MBP), and 1.40-fold (95% CI: 1.22, 1.61) greater low-molecular-weight phthalates (LMW). Use of 2-in-1 haircare products was associated with 0.84-fold (95% CI: 0.72, 0.97) and 0.78-fold (95% CI: 0.62, 0.98) lesser mono(3-carboxypropyl) phthalate (MCPP) and MBP, respectively. Child's race/ethnic identity modified the associations of lotions with LMW, oils with MEP and LMW, sunscreen with MCPP, ointments with MEP, and hair conditioner with MCPP. SOM identified four distinct SCP-use exposure scenarios (i.e., profiles) within our population that predicted 1.09-fold (95% CI: 1.03, 1.15) greater mono-carboxy isononyl phthalate, 1.31-fold (95% CI: 0.98, 1.77) greater mono-2-ethyl-5-hydroxyhexyl terephthalate, 1.13-fold (95% CI: 0.99, 1.29) greater monoethylhexyl phthalate, and 1.04-fold (95% CI: 1.00, 1.09) greater diethylhexyl phthalate.

DISCUSSION

We found that reported SCP use was associated with urinary phthalate/replacement metabolites in young children. These results may inform policymakers, clinicians, and parents to help limit children's exposure to developmental toxicants. https://doi.org/10.1289/EHP13937.

Hair product use and urinary biomarker concentrations of non-persistent endocrine disrupting chemicals among reproductive-aged Black women

BACKGROUND

Studies have shown an association between hair product use and adverse health outcomes. Scientists have hypothesized that exposure to endocrine-disrupting chemicals (EDCs) drives these associations, but few studies have directly evaluated associations between hair product use and biomarkers of EDCs. Even more limited are studies of Black women, who frequently use EDC-containing products (e.g., hair relaxers).

OBJECTIVE

We estimated associations between hair product use and EDC biomarker concentrations.

METHODS

We leveraged cross-sectional data from the Study of Environment, Lifestyle, and Fibroids, a cohort of females aged 23-34 years who self-identified as Black/African American from the Detroit-metropolitan area (USA; n = 425). On structured questionnaires, participants reported their past 24-h and past 12-month use of hair products, including relaxers/straighteners/perms, styling products, moisturizers, oils, and hair food. We quantified urinary concentrations of 19 phthalate/phthalate alternative metabolites, 7 phenols, and 4 parabens using high performance liquid chromatography isotope dilution tandem mass spectrometry. EDC biomarker concentrations were creatinine-adjusted and natural log-transformed. We used multivariable linear regression to estimate mean percent differences in EDC biomarker concentrations and 95% confidence intervals (CIs) associated with hair product use, adjusting for sociodemographic confounders.

RESULTS

Hair product use was associated with greater concentrations of multiple EDC biomarkers. Notably, use of hair products in the previous 24 h (compared with non-use) was associated with 16.2% (95% CI = 0.7%, 35.9%), 35.0% (95% CI = 2.6%, 77.6%), and 32.3% (95% CI = 8.8%, 92.0%) higher concentrations of mono-isobutyl phthalate, methyl paraben, and ethyl paraben, respectively. Use of hair relaxers/straighteners/perms, styling products, moisturizers, oils, and hair food in the past 12 months was also associated with higher concentrations of multiple phthalate, phenol, and paraben biomarkers.

CONCLUSION

Hair product use was associated with higher biomarker concentrations of multiple phthalates, phenols, and parabens. These findings suggest that hair products are potentially important exposure sources for hormonally-active chemicals among Black women.

Frequency of personal care product use among reproductive-aged Black individuals and associations with socio-demographic characteristics

BACKGROUND

Compared to White women, Black women in the United States are more likely to use personal care products (PCPs) with higher concentrations of endocrine-disrupting chemicals (EDCs) and harsher chemical formulations. This may contribute to differential health outcomes in Black women such as increased risk of breast cancer, cardiometabolic outcomes, adverse birth outcomes, and uterine fibroids.

OBJECTIVE

Classify distinct PCP use patterns across multiple types of products and examine how patterns vary by socio-demographic characteristics.

METHODS

The Study of Environment, Lifestyle and Fibroids is a cohort study of reproductive-aged Black individuals living around Detroit, Michigan. Using self-reported data on frequency of PCP collected between 2013-2018, we employed latent class analysis to identify distinct groups of participants with similar PCP use. Socio-demographic characteristics were compared across latent classes.

RESULTS

Among 1562 participants, we identified 6 latent classes: Lower Overall; Higher Nailcare; Higher Skincare; Moderate Overall; Higher Makeup/Haircare/Skincare; Higher Overall. Makeup and nailcare usage were the most predictive for classifying participants into groups. Participants in classes with less frequent use of all PCPs and those with only high use of nailcare products, were more likely to report lower socio-economic status (SES), be current smokers, have a body mass index of ≥35 kg/m2, and have ≥3 births. In comparison, participants in classes with average and more frequent use of PCPs were more likely to report higher SES, be non-smokers, be nulliparous, and have ever used oral contraceptives.

IMPACT STATEMENT

This study is one of the first detailed assessments of PCP usage among a large cohort of young adult Black women that considers multiple product categories including makeup, hair, skin, nail, and vaginal products. Latent class analysis was used to capture complex patterns of PCP use and identify distinct groups of individuals with similar product use. Although the latent classes are specific to this study population, the identified socio-demographic characteristics or behaviors associated with latent classes may inform targeted and impactful exposure reduction strategies in similar populations.

Prenatal exposure to persistent and non-persistent chemical mixtures and associations with adverse birth outcomes in the Atlanta African American Maternal-Child Cohort

BACKGROUND

African Americans (AAs) experience higher rates of preterm birth and fetal growth restriction relative to other pregnant populations. Differential in utero exposure to environmental chemicals may partially explain these health disparities, as AAs are disproportionately exposed to environmental hazards.

OBJECTIVE

We examined the individual and mixture effects of non-persistent chemicals and persistent organic pollutants (POPs) on gestational age at birth and birthweight for gestational age z-scores within a prospective cohort of pregnant AAs.

METHODS

First-trimester serum and urine samples obtained from participants within the Atlanta African American Maternal-Child cohort were analyzed for 43 environmental chemicals, including per-and polyfluoroalkyl substances (PFAS), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides, pyrethroid insecticides, phthalates, bisphenol A, nicotine, and the primary metabolite of delta-9-tetrahydrocannabinol. Linear regression was used to estimate individual associations between chemicals and gestational age and birthweight z-scores (N ranging from 107 to 523). Mixture associations were estimated using quantile g-computation, principal component (PC) analyses, and hierarchical Bayesian kernel machine regression among complete cases (N = 86).

RESULTS

Using quantile g-computation, increasing all chemical exposures by one quantile was modestly associated with a reduction in gestational age (mean change per quartile increase = -0.47, 95% CI = -1.56, 0.61) and birthweight z-scores (mean change per quartile increase = -0.49, 95% CI = -1.14, 0.15). All PCs were associated with a reduction in birthweight z-scores; associations were greatest in magnitude for the two PCs reflecting exposure to combined tobacco, insecticides, PBDEs, and phthalates. In single pollutant models, we observed inconsistent and largely non-significant associations.

SIGNIFANCE

We conducted multiple targeted exposure assessment methods to quantify levels of environmental chemicals and leveraged mixture methods to quantify their joint effects on gestational age and birthweight z-scores. Our findings suggest that prenatal exposure to multiple classes of persistent and non-persistent chemicals is associated with reduced gestational age and birthweight z-scores in AAs.

IMPACT

African Americans (AAs) experience higher rates of preterm birth and fetal growth restriction relative to other pregnant populations. Differential in utero exposure to environmental chemicals may partially explain these health disparities, as AAs are disproportionately exposed to environmental hazards. In the present study, we analyzed serum and urine samples for levels of 43 environmental chemicals. We used quantile g-computation, principal component analysis, and BKMR to assess associations between chemical exposure mixtures and adverse birth outcomes. Our findings suggest that prenatal exposure to multiple classes of chemicals is associated with reduced birthweight z-scores, a proxy for fetal growth, in AAs.

Reproductive and Social Policies, Sociopolitical Stress, and Implications for Maternal and Child Health Equity

PURPOSE OF REVIEW

Although many environmental exposures (e.g., air pollution) are geographically patterned and persist as a result of historic economic policies (e.g., redlining), the impact of reproductive and social policies on maternal and child health remains incompletely understood. Reproductive and social policies are increasingly important for maternal and child health equity, particularly following the 2022 US Supreme Court decision in Dobbs v Jackson Women's Health Organization ("Dobbs decision"), which restricted access to abortion. Here, we summarize the literature from original research studies examining influences of reproductive and social policy on maternal and child health, focusing on impacts on adverse birth outcomes and policies as sources of stress.

RECENT FINDINGS

Several studies suggest that those most impacted by the Dobbs decision are younger, non-white, socioeconomically disadvantaged, and living in states with less access to government safety net programs, all of which are compounded by environmental injustices. Further, studies conducted in the wake of the Dobbs decision find elevated stress levels among women of reproductive age. This may represent one pathway leading to adverse birth outcomes, as epidemiologic studies demonstrate that preterm birth rates increased following the 2016 election, a period of heightened stress. Reproductive and social policies are understudied contributors to adverse outcomes for reproductive-aged women and their children. This has important implications for maternal and child health equity, as those who will be the most impacted by reproductive and social policies already experience the highest rates of adverse birth outcomes and environmental toxicant exposure.

Associations between use of chemical hair products and epigenetic age: Findings from the Sister Study

Background

Hair products may be a source of harmful chemicals and have been linked to age-related health outcomes. We investigated whether the use of hair products is related to epigenetic age in a sample of Black (both Hispanic and non-Hispanic) and non-Hispanic White women.

Methods

In a subset of 4358 participants aged 35-74 years from the Sister Study, we estimated cross-sectional associations between self-reported use of four chemical hair products (permanent dye, semipermanent dye, straighteners/relaxers, and hair permanents/body waves) in the year before enrollment (2003-2009) and three DNA methylation-based measures of epigenetic age (DunedinPACE, GrimAge age acceleration [GrimAgeAccel], and PhenoAge age acceleration [PhenoAgeAccel]) using survey-weighted multivariable linear regressions. Associations were estimated both overall and by self-identified race and ethnicity, adjusting for chronological age, socioeconomic and lifestyle factors, body mass index, menopausal status, and DNA methylation platform.

Results

Associations between the use of hair products and the three epigenetic age measures were largely null. Use of hair permanents/body waves was modestly associated with higher DunedinPACE among all participants (βever-never = 0.010; 95% confidence interval [CI] = 0.001, 0.019) and with lower PhenoAgeAccel among Black women (βever-never = -1.53; 95% CI = -2.84, -0.21).

Conclusion

In this US-based study, we found little evidence of associations between chemical hair product use and epigenetic age in Black and non-Hispanic White women. Observed associations were modest and largely not supported by dose-response relationships or were inconsistent across epigenetic age measures. Previously observed associations between chemical hair product use and aging-related health outcomes may not be explained by the biological aging pathways captured by DunedinPACE, GrimAgeAccel, or PhenoAgeAccel. Alternative biological pathways are worth investigating in racially diverse samples.

Untangling Associations of Microbiomes of Pregnancy and Preterm Birth

This review illuminates the complex interplay between various maternal microbiomes and their influence on preterm birth (PTB), a driving and persistent contributor to neonatal morbidity and mortality. Here, we examine the dynamics of oral, gastrointestinal (gut), placental, and vaginal microbiomes, dissecting their roles in the pathogenesis of PTB. Importantly, focusing on the vaginal microbiome and PTB, the review highlights (1) a protective role of Lactobacillus species; (2) an increased risk with select anaerobes; and (3) the influence of social health determinants on the composition of vaginal microbial communities.

Risk perception and use of personal care products by race and ethnicity among a diverse population

Personal care products can contain phthalates, parabens and other endocrine-disrupting chemicals. However, information on perception of risks from personal care product use and how use varies by race and ethnicity is limited. We evaluated differences in personal care product use and risk perception in a diverse sample of participants recruited from a US college campus and online. A self-administered questionnaire captured information on sociodemographic factors, personal care product use trends and perception of risk associated with them. Pearson's chi-square and Fisher's exact tests were used to determine differences in personal care product use and risk perception by race and ethnicity. Ordered logistic regressions were performed to measure associations between personal care product use frequency across racial/ethnic categories. Participant (n = 770) mean age was 22.8 years [standard deviation ± 6.0]. Daily use of make-up (eye = 29.3%; other = 38.0%; all = 33.7%) and skincare products (55%) was most frequently reported among Middle Eastern and North African participants. Non-Hispanic Black participants reported the highest daily use of hairstyling products (52%) and lotion (78%). Daily make-up use was more frequently reported among females (41%) than males (24.6%). Levels of agreement were similar across racial and ethnic groups, that personal care product manufacturers should be required to list all ingredients (≥87%). There were significant associations between the frequency of use of some personal care products and racial/ethnic categories when the use frequencies of participants from other racial/ethnic categories were compared to the use frequency of non-Hispanic White participants. There were significant differences in daily use frequency, levels of trust, perception of safety and health risks associated with personal care products by race and ethnicity, underscoring that there may be different sources of exposure to chemicals in personal care products by race and ethnicity.

Cohort profile: the Environmental Reproductive and Glucose Outcomes (ERGO) Study (Boston, Massachusetts, USA) - a prospective pregnancy cohort study of the impacts of environmental exposures on parental cardiometabolic health

PURPOSE

Pregnancy and the postpartum period are increasingly recognised as sensitive windows for cardiometabolic disease risk. Growing evidence suggests environmental exposures, including endocrine-disrupting chemicals (EDCs), are associated with an increased risk of pregnancy complications that are associated with long-term cardiometabolic risk. However, the impact of perinatal EDC exposure on subsequent cardiometabolic risk post-pregnancy is less understood. The Environmental Reproductive and Glucose Outcomes (ERGO) Study was established to investigate the associations of environmental exposures during the perinatal period with post-pregnancy parental cardiometabolic health.

PARTICIPANTS

Pregnant individuals aged ≥18 years without pre-existing diabetes were recruited at <15 weeks of gestation from Boston, Massachusetts area hospitals. Participants completed ≤4 prenatal study visits (median: 12, 19, 26, 36 weeks of gestation) and 1 postpartum visit (median: 9 weeks), during which we collected biospecimens, health histories, demographic and behavioural data, and vitals and anthropometric measurements. Participants completed a postpartum fasting 2-hour 75 g oral glucose tolerance test. Clinical data were abstracted from electronic medical records. Ongoing (as of 2024) extended post-pregnancy follow-up visits occur annually following similar data collection protocols.

FINDINGS TO DATE

We enrolled 653 unique pregnancies and retained 633 through delivery. Participants had a mean age of 33 years, 10% (n=61) developed gestational diabetes and 8% (n=50) developed pre-eclampsia. Participant pregnancy and postpartum urinary phthalate metabolite concentrations and postpartum glycaemic biomarkers were quantified. To date, studies within ERGO found higher exposure to phthalates and phthalate mixtures, and separately, higher exposure to radioactive ambient particulate matter, were associated with adverse gestational glycaemic outcomes. Additionally, certain personal care products used in pregnancy, notably hair oils, were associated with higher urinary phthalate metabolite concentrations, earlier gestational age at delivery and lower birth weight.

FUTURE PLANS

Future work will leverage the longitudinal data collected on pregnancy and cardiometabolic outcomes, environmental exposures, questionnaires, banked biospecimens and paediatric data within the ERGO Study.

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.

A systematic review of association between use of hair products and benign and malignant gynecological conditions

Hair products often contain chemicals like para-phenylenediamine (PPD) and endocrine-disrupting chemicals (EDCs); giving rise to concerns about the possible adverse effects such as hormonal disturbances and carcinogenicity. The objective of this systematic review was to evaluate the association between the use of different hair products and benign and malignant gynecological conditions. Studies were identified from three databases including PubMed, Embase, and Scopus, and evaluated in accordance with PRISMA guidelines. The risk of bias was assessed using the Newcastle-Ottawa Scale. A total of 17 English-language studies met the inclusion criteria. Associations of hair relaxer or hair dye use with breast and ovarian cancer were observed in at least one well-designed study, but these findings were not consistent across studies. Further sub-analysis showed 1.08 times (95 % CI: 1.01-1.15) increased risk of breast cancer in females with permanent hair dye use. Chang et al. reported strong association between uterine cancer risk and hair relaxer use (HR 1.8, 95 % CI: 1.12-2.88), with no observed association with hair dye use. Studies conducted by Wise et al. and James-Todd et al. for benign gynecological conditions; including uterine leiomyoma (IRR 1.17, 95 % CI: 1.06-1.30), early onset of menarche (RR 1.4, 95 % CI: 1.1-1.9), and decreased fecundability (FR 0.89, 95 % CI: 0.81-0.98) revealed positive associations with hair relaxer use, but these findings were based on small sample sizes. In summary, the available evidence regarding personal use of hair products and gynecological conditions is insufficient to determine whether a positive association exists.

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.

Personal Care Product Use during Puberty and Incident Breast Cancer among Black, Hispanic/Latina, and White Women in a Prospective US-Wide Cohort

BACKGROUND

Some personal care products (PCPs) contain endocrine-disrupting chemicals that may affect breast cancer (BC) risk. Patterns of use vary by race and ethnicity. Use often starts in adolescence, when rapidly developing breast tissue may be more susceptible to environmental carcinogens. Few studies have examined associations of BC with PCP use during this susceptible window.

OBJECTIVES

We characterized race and ethnicity-specific patterns of PCP use at 10-13 years of age and estimated associations of use with incident BC.

METHODS

At enrollment (2003-2009), Sister Study participants (n = 4,049 Black, 2,104 Latina, and 39,312 White women) 35-74 years of age reported use of 37 "everyday" PCPs during the ages of 10-13 y (did not use, sometimes, or frequently used). We conducted race and ethnicity-specific latent class analyses to separately identify groups of women with similar patterns of beauty, hair, and skincare/hygiene product use. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of identified PCP classes and single products with incident BC using Cox proportional hazards regression.

RESULTS

During a mean follow-up time of 10.8 y, 280 Black, 128 Latina, and 3,137 White women were diagnosed with BC. Classes of adolescent PCP use were not clearly associated with BC diagnosis among Black, Latina, or White women. HRs were elevated but imprecise for frequent nail product and perfume use in Black women (HR = 1.34; 95% CI: 0.85, 2.12) and greater hair product use in Black (HR = 1.28; 95% CI: 0.91, 1.80) and Latina (HR = 1.42; 95% CI: 0.81, 2.48) women compared with lighter use. In single-product models, we observed higher BC incidence associated with frequent use of lipstick, nail products, pomade, perfume, makeup remover, and acne/blemish products in at least one group.

DISCUSSION

This work provides some support for the hypothesis that PCP use during puberty is associated with BC risk. More research is needed to confirm these novel findings. https://doi.org/10.1289/EHP13882.

Hair relaxer use and risk of uterine cancer in the Black Women's Health Study

BACKGROUND

Chemical hair relaxers, use of which is highly prevalent among Black women in the US, have been inconsistently linked to risk of estrogen-dependent cancers, such as breast cancer, and other reproductive health conditions. Whether hair relaxer use increases risk of uterine cancer is unknown.

METHODS

In the Black Women's Health Study, 44,798 women with an intact uterus who self-identified as Black were followed from 1997, when chemical hair relaxer use was queried, until 2019. Over follow-up, 347 incident uterine cancers were diagnosed. We used multivariable Cox proportional hazards regression models, adjusted for age and other potential confounders, to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of hair relaxer use with risk of uterine cancer.

RESULTS

Compared to women who never used hair relaxers or used them infrequently (<4 years and ≤1-2 times/year), the HR for uterine cancer associated with heavy use (≥15 years and at least 5 times/year) was 1.18 (95% CI: 0.81, 1.71). However, among postmenopausal women, compared to never/light use, the HR for moderate use was 1.60 (95% CI: 1.01, 2.53), the HR for heavy use was 1.64 (1.01, 2.64), and the HR for ≥20 years of use regardless of frequency was 1.71 (1.08, 2.72). Results among premenopausal women were null.

CONCLUSIONS

In this large cohort of Black women, long-term use of chemical hair relaxers was associated with increased risk of uterine cancer among postmenopausal women, but not among premenopausal women. These findings suggest that hair relaxer use may be a potentially modifiable risk factor for uterine cancer.

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.

Studying full-shift inhalation exposures to volatile organic compounds (VOCs) among Latino workers in very small-sized beauty salons and auto repair shops

Background

One in every 200 US jobs is in a beauty salon or auto repair shop, where workers are regularly exposed to volatile organic compounds (VOCs) that may cause a range of short- and long-term health issues. In these shops, Latino workers are overrepresented and lack culturally and linguistically appropriate industrial hygiene resources. This leaves a gap in knowledge on inhalation exposures to VOCs in this hard-to-reach and ubiquitous worker population.

Objective

Our goal was to recruit hard-to-reach, predominantly Spanish-speaking workers in beauty salons and auto repair shops and monitor total VOC inhalation exposures for over entire work shifts, with minimal impact on workers, clients, and business.

Methods

We developed and refined measurement and exposure assessment methods for personal and area full-shift VOC inhalation exposures.

Results

With minimal participant loss, we measured over 500 h of real-time, personal VOC exposures and recorded activities and other exposure factors for 47 participants, while also documenting chemical inventories and quantifying indoor area concentrations of specific VOCs among 10 auto repair shops and 10 beauty salons.

Conclusion

Lessons learned from our study can assist future studies of inhalation exposures in other hard-to-reach occupational populations.

Hair Transplantation in the United States: A Population-based Survey of Female and Male Pattern Baldness

Background

Androgenetic alopecia, the most common type of hair loss, can impair the patient's overall mental health. Although there are pharmaceutical and surgical treatments available, little is known about the public standpoint toward hair transplantation (HT).

Methods

A sample of individuals living in the United States (n = 1000; male and female participants were equally distributed) was asked to fill out the questionnaire. The online survey was conducted in June 2022.

Results

Most participants (42%; n = 416) were between 41 and 60 years of age. Study participants frequently reported that, with their hair loss progressing, they would not feel attractive anymore (n = 400; 40%), nor as confident as before (n = 330; 33%). Although women with minimal hair loss were willing to spend a median price of $4000 [interquartile range (IQ) IQR $1000-$5000], women with extensive hair loss were willing to spend significantly more (median = $5000; IQR $3600-$6375; P = 0.011). This was reproducible in men (P = 0.033). Although significantly fewer women considered undergoing HT (430 women versus 447 men; P < 0.001), female participants were willing to pay more for their HT compared with men (P = 0.039).

Conclusions

Individuals living in the United States consider hair loss to impair their attractiveness and regard HT as a valuable therapeutic option. More affordable and gender-specific HT should be subject to future research work.

Systematic evidence mapping informs a class-based approach to assessing personal care products and pubertal timing

BACKGROUND

Personal care products (PCPs) contain many different compounds and are a source of exposure to endocrine disrupting chemicals (EDCs), including phthalates and phenols. Early-life exposure to EDCs commonly found in PCPs has been linked to earlier onset of puberty.

OBJECTIVE

To characterize the human and animal evidence on the association between puberty-related outcomes and exposure to PCPs and their chemical constituents and, if there is sufficient evidence, identify groups of chemicals and outcomes to support a systematic review for a class-based hazard or risk assessment.

METHODS

We followed the OHAT systematic review framework to characterize the human and animal evidence on the association between puberty-related health outcomes and exposure to PCPs and their chemical constituents.

RESULTS

Ninety-eight human and 299 animal studies that evaluated a total of 96 different chemicals were identified and mapped by key concepts including chemical class, data stream, and puberty-related health outcome. Among these studies, phthalates and phenols were the most well-studied chemical classes. Most of the phthalate and phenol studies examined secondary sex characteristics and changes in estradiol and testosterone levels. Studies evaluating PCP use and other chemical classes (e.g., parabens) had less data.

CONCLUSIONS

This systematic evidence map identified and mapped the published research evaluating the association between exposure to PCPs and their chemical constituents and puberty-related health outcomes. The resulting interactive visualization allows researchers to make evidence-based decisions on the available research by enabling them to search, sort, and filter the literature base of puberty-related studies by key concepts. This map can be used by researchers and regulators to prioritize and target future research and funding to reduce uncertainties and address data gaps. It also provides information to inform a class-based hazard or risk assessment on the association between phthalate and phenol exposures and puberty-related health outcomes.

Structural Racism and Adverse Pregnancy Outcomes Through the Lens of the Maternal Microbiome

Microbiome science offers a glimpse into personalized medicine by characterizing health and disease states according to an individual's microbial signatures. Without a critical examination of the use of race as a variable, microbiome studies may be susceptible to the same pitfalls as other areas of science grounded in racist biology. We will examine the use of race as a biological variable in pregnancy-related microbiome research. Emerging data from studies that investigate the intestinal microbiome in pregnancy suggest strong influence of a poor diet on adverse pregnancy outcomes. Differences in the vaginal microbiome implicated in adverse pregnancy outcomes are frequently attributed to race. We review evidence that links systemic racism to pregnancy health outcome differences with a focus on the vaginal and intestinal microbiomes as well as diet. We also review how structural racism ultimately contributes to inequitable access to healthy food and higher risk environmental exposures among pregnant people of lower socioeconomic status and exacerbates common pregnancy comorbidities.

Endocrine-Disrupting Chemicals: Science and Policy

Endocrine-disrupting chemicals (EDCs) are chemicals that disrupt the normal functioning of endocrine system hormones, leading to a range of adverse health effects in humans and wildlife. Exposure to EDCs is ubiquitous and occurs through contaminated food and water, air, consumer products, and transfer from parents to offspring. Effective regulation has been challenging due to a limited understanding of EDCs' complex and nonlinear dose-response relationships, as well as difficulty in attributing specific health effects to individual EDC exposures in real-world scenarios. Current EDC policies face limitations in terms of the diversity and complexity of EDCs, the lack of comprehensive testing requirements, and the need for more robust regulatory frameworks that consider cumulative and mixture effects of EDCs. Understanding these aspects is crucial for developing effective and evidence-based EDC policies that can safeguard public health and the environment.

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.

Epidemiology and Risk Factors for Breast Cancer: 21st Century Advances, Gaps to Address through Interdisciplinary Science

Research methods to study risk factors and prevention of breast cancer have evolved rapidly. We focus on advances from epidemiologic studies reported over the past two decades addressing scientific discoveries, as well as their clinical and public health translation for breast cancer risk reduction. In addition to reviewing methodology advances such as widespread assessment of mammographic density and Mendelian randomization, we summarize the recent evidence with a focus on the timing of exposure and windows of susceptibility. We summarize the implications of the new evidence for application in risk stratification models and clinical translation to focus prevention-maximizing benefits and minimizing harm. We conclude our review identifying research gaps. These include: pathways for the inverse association of vegetable intake and estrogen receptor (ER)-ve tumors, prepubertal and adolescent diet and risk, early life adiposity reducing lifelong risk, and gaps from changes in habits (e.g., vaping, binge drinking), and environmental exposures.

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.

Use of Chemical Hair Straighteners and Fecundability in a North American Preconception Cohort

Chemical hair straighteners ("relaxers") are used by millions of North Americans, particularly women of color. Hair relaxers may contain endocrine-disrupting compounds, which can harm fertility. We evaluated the association between hair relaxer use and fecundability among 11,274 participants from Pregnancy Study Online (PRESTO), a North American preconception cohort study. During 2014-2022, participants completed a baseline questionnaire in which they reported their history of relaxer use and completed follow-up questionnaires every 8 weeks for 12 months or until pregnancy, whichever came first. We used multivariable-adjusted proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs). Relative to never use, fecundability was lower among current (FR = 0.81, 95% CI: 0.64, 1.03) and former (FR = 0.89, 95% CI: 0.81, 0.98) users of hair relaxers. FRs for first use of hair relaxers at ages <10, 10-19, and ≥20 years were 0.73 (95% CI: 0.55, 0.96), 0.93 (95% CI: 0.83, 1.04), and 0.85 (95% CI: 0.74, 0.98), respectively. Fecundability was lowest among those with longer durations of use (≥10 years vs. never: FR = 0.71, 95% CI: 0.54, 0.91) and more frequent use (≥5 times/year vs. never: FR = 0.82, 95% CI: 0.60, 1.11), but associations were nonmonotonic. In this preconception cohort study, use of chemical hair straighteners was associated with slightly reduced fecundability.

Parabens Promote Protumorigenic Effects in Luminal Breast Cancer Cell Lines With Diverse Genetic Ancestry

Context

One in 8 women will develop breast cancer in their lifetime. Yet, the burden of disease is greater in Black women. Black women have a 40% higher mortality rate than White women, and a higher incidence of breast cancer at age 40 and younger. While the underlying cause of this disparity is multifactorial, exposure to endocrine disrupting chemicals (EDCs) in hair and other personal care products has been associated with an increased risk of breast cancer. Parabens are known EDCs that are commonly used as preservatives in hair and other personal care products, and Black women are disproportionately exposed to products containing parabens.

Objective

Studies have shown that parabens impact breast cancer cell proliferation, death, migration/invasion, and metabolism, as well as gene expression in vitro. However, these studies were conducted using cell lines of European ancestry; to date, no studies have utilized breast cancer cell lines of West African ancestry to examine the effects of parabens on breast cancer progression. Like breast cancer cell lines with European ancestry, we hypothesize that parabens promote protumorigenic effects in breast cancer cell lines of West African ancestry.

Methods

Luminal breast cancer cell lines with West African ancestry (HCC1500) and European ancestry (MCF-7) were treated with biologically relevant doses of methylparaben, propylparaben, and butylparaben.

Results

Following treatment, estrogen receptor target gene expression and cell viability were examined. We observed altered estrogen receptor target gene expression and cell viability that was paraben and cell line specific.

Conclusion

This study provides greater insight into the tumorigenic role of parabens in the progression of breast cancer in Black women.

Implementing a suspect screening method to assess occupational chemical exposures among US-based hairdressers serving an ethnically diverse clientele: a pilot study

BACKGROUND

There are over 700,000 hairdressers in the United States, and it is estimated that >90% are female and 31% are Black or Hispanic/Latina. Racial and ethnic minorities in this workforce may be exposed to a unique mixture of potentially hazardous chemicals from products used and services provided. However, previous biomonitoring studies of hairdressers target a narrow list of compounds and few studies have investigated exposures among minority hairdressers.

OBJECTIVE

To assess occupational chemical exposures in a sample of US-based Black and Latina hairdressers serving an ethnically diverse clientele by analyzing urine specimens with a suspect screening method.

METHODS

Post-shift urine samples were collected from a sample of US female hairdressers (n = 23) and office workers (n = 17) and analyzed via reverse-phase liquid chromatography coupled to high-resolution mass spectrometry. Detected compounds were filtered based on peak area differences between groups and matching with a suspect screening list. When possible, compound identities were confirmed with reference standards. Possible exposure sources were evaluated for detected compounds.

RESULTS

The developed workflow allowed for the detection of 24 compounds with median peak areas ≥2x greater among hairdressers compared to office workers. Product use categories (PUCs) and harmonized functional uses were searched for these compounds, including confirmed compounds methylparaben, ethylparaben, propylparaben, and 2-naphthol. Most product use categories were associated with "personal use" and included 11 different "hair styling and care" product types (e.g., hair conditioner, hair relaxer). Functional uses for compounds without associated PUCs included fragrance, hair and skin conditioning, hair dyeing, and UV stabilizer.

SIGNIFICANCE

Our suspect screening approach detected several compounds not previously reported in biomonitoring studies of hairdressers. These results will help guide future studies to improve characterization of occupational chemical exposures in this workforce and inform exposure and risk mitigation strategies to reduce potential associated work-related health disparities.

Use of personal care products during pregnancy and birth outcomes - A pilot study

Prenatal exposure to endocrine disrupting chemicals (EDCs) from personal care products may be associated with birth outcomes including preterm birth and low birth weight. There is limited research examining the role of personal care product use during pregnancy on birth outcomes. Our pilot study consisted of 164 participants in the Environmental Reproductive and Glucose Outcomes (ERGO) study (Boston, MA), with data on self-reported personal care product use at four study visits throughout pregnancy (product use in the 48 h before a study visit and hair product use in the month before a study visit). We used covariate-adjusted linear regression models to estimate differences in mean gestational age at delivery, birth length, and sex-specific birth weight-for-gestational age (BW-for-GA) Z-score based on personal care product use. Hair product use in the past month prior to certain study visits was associated with decreased mean sex-specific BW-for-GA Z-scores. Notably, hair oil use in the month prior to study visit 1 was associated with a lower mean BW-for-GA Z-score (V1: -0.71, 95% confidence interval: -1.12, -0.29) compared to non-use. Across all study visits (V1-V4), increased mean birth length was observed among nail polish users vs. non-users. In comparison, decreased mean birth length was observed among shave cream users vs. non-users. Liquid soap, shampoo, and conditioner use at certain study visits were significantly associated with higher mean birth length. Suggestive associations were observed across study visits for other products including hair gel/spray with BW-for-GA Z-score and liquid/bar soap with gestational age. Overall, use of a variety of personal care products throughout pregnancy was observed to be associated with our birth outcomes of interest, notably hair oil use during early pregnancy. These findings may help inform future interventions/clinical recommendations to reduce exposures linked to adverse pregnancy outcomes.

Relation of circulating estrogens with hair relaxer and skin lightener use among postmenopausal women in Ghana

BACKGROUND

Hair relaxers and skin lighteners have been commonly used by African women, with suggestions that they may have hormonal activity.

OBJECTIVES

To investigate the relationship of hair relaxer and skin lightener use to serum estrogen/estrogen metabolite levels.

METHODS

We utilized the postmenopausal population-based controls of the Ghana Breast Health Study to estimate adjusted geometric means (GM) and 95% confidence intervals of individual circulating estrogen levels by hair relaxer/skin lightener exposure categories.

RESULTS

Of the 585 postmenopausal women included in our analysis, 80.2% reported hair relaxer use and 29.4% skin lightener use. Ever hair relaxer use was positively associated with estriol (adjusted GM 95.4 pmol/L vs. never 74.5, p value = 0.02) and 16-epiestriol (20.4 vs. 16.8, p value = 0.05) particularly among users of lye-based hair relaxers. Positive associations between scalp burns and unconjugated estrogens were observed (e.g., unconjugated estrone: 5+ scalp burns 76.9 [59.6-99.2] vs. no burns 64.0 [53.7-76.3], p-trend = 0.03). No association was observed between use of skin lighteners and circulating estrogens.

SIGNIFICANCE

This study presents evidence that circulating 16-pathway estrogens (i.e., estriol and 16-epiestriol) may be increased in users of lye-based hair relaxer products. Among hair relaxer users, unconjugated estrogen levels were elevated in women with a greater number of scalp burns.

IMPACT STATEMENT

In this population-based study of hair relaxer and skin lightener use among postmenopausal women in Ghana, altered estrogen metabolism was observed with hair relaxer use, particularly among women using lye-based products or with a greater number of scalp burns. In contrast, skin lightener use was not associated with differences in estrogen metabolism in this population. Continued investigation of the potential biological impact on breast cancer risk of hair relaxer use is warranted.

A study on the association of placental and maternal urinary phthalate metabolites

BACKGROUND

Phthalate exposure in pregnancy is typically estimated using maternal urinary phthalate metabolite levels. Our aim was to evaluate the association of urinary and placental tissue phthalates, and to explore the role of maternal and pregnancy characteristics that may bias estimates.

METHODS

Fifty pregnancies were selected from the CANDLE Study, recruited from 2006 to 2011 in Tennessee. Linear models were used to estimate associations of urinary phthalates (2nd, 3rd trimesters) and placental tissue phthalates (birth). Potential confounders and modifiers were evaluated in categories: temporality (time between urine and placenta sample), fetal sex, demographics, social advantage, reproductive history, medication use, nutrition and adiposity. Molar and quantile normalized phthalates were calculated to facilitate comparison of placental and urinary levels.

RESULTS

Metabolites detectable in >80% of both urine and placental samples were MEP, MnBP, MBzP, MECPP, MEOHP, MEHHP, and MEHP. MEP was most abundant in urine (geometric mean [GM] 7.00 ×102 nmol/l) and in placental tissue (GM 2.56 ×104 nmol/l). MEHP was the least abundant in urine (GM 5.32 ×101 nmol/l) and second most abundant in placental tissue (2.04 ×104 nmol/l). In aggregate, MEHP differed the most between urine and placenta (2.21 log units), and MEHHP differed the least (0.07 log units). MECPP was positively associated between urine and placenta (regression coefficient: 0.31 95% CI 0.09, 0.53). Other urine-placenta metabolite associations were modified by measures of social advantage, reproductive history, medication use, and adiposity.

CONCLUSION

Phthalates were ubiquitous in 50 full-term placental samples, as has already been shown in maternal urine. MEP and MEHP were the most abundant. Measurement and comparison of urinary and placental phthalates can advance knowledge on phthalate toxicity in pregnancy and provide insight into the validity and accuracy of relying on maternal urinary concentrations to estimate placental exposures.

IMPACT STATEMENT

This is the first report of correlations/associations of urinary and placental tissue phthalates in human pregnancy. Epidemiologists have relied exclusively on maternal urinary phthalate metabolite concentrations to assess exposures in pregnant women and risk to their fetuses. Even though it has not yet been confirmed empirically, it is widely assumed that urinary concentrations are strongly and positively correlated with placental and fetal levels. Our data suggest that may not be the case, and these associations may vary by phthalate metabolite and associations may be modified by measures of social advantage, reproductive history, medication use, and adiposity.

Racial disparities in uterine fibroids and endometriosis: a systematic review and application of social, structural, and political context

IMPORTANCE

Uterine fibroids and endometriosis are 2 of the leading causes of morbidity among reproductive-aged women. There are significant racial disparities in disease prevalence, incidence, age of onset, and treatment profile in fibroids. The data on endometriosis are less clear.

OBJECTIVE

To conduct a systematic review of racial disparities in prevalence of uterine fibroids and endometriosis in the United States and summarize the literature on these 2 highly prevalent benign gynecologic conditions using a framework that explicitly incorporates and acknowledges the social, structural, and political contexts as a root cause of racial disparities between Black and White women.

EVIDENCE REVIEW

A systematic review regarding racial disparities in prevalence of fibroids and endometriosis was conducted separately. Two separate searches were conducted in PubMed to identify relevant original research manuscripts and prior systematic reviews regarding racial disparities in uterine fibroids and endometriosis using standardized search terms. In addition, we conducted a structured literature search to provide social, structural, and political context of the disparities.

FINDINGS

A systematic review of the literature indicated that the prevalence of uterine fibroids was consistently higher in Black than in White women with the magnitude of the difference varying depending on population and case definition. Prevalence of endometriosis varied considerably depending on the base population and case definition, but was the same or lower among Black vs. White women. As a result of the social, structural, and political context in the United States, Black women disproportionately experience a range of exposures across the life course that may contribute to their increased uterine fibroid incidence, prevalence, and severity of uterine fibroids. However, data suggest no racial difference in the incidence of endometriosis. Nevertheless, Black women with fibroids or endometriosis experience worse clinical and surgical outcomes than their White counterparts.

CONCLUSION AND RELEVANCE

Racial disparities in uterine fibroids and endometriosis can be linked with differential exposures to suspected etiologic agents, lack of adequate access to health care, including highly skilled gynecologic surgeons, and bias and discrimination within the health care system. Eliminating these racial disparities will require solutions that address root causes of health disparities through policy, education and programs to ensure that all patients receive culturally- and structurally-competent care.

Differences in personal care product use by race/ethnicity among women in California: implications for chemical exposures

BACKGROUND

Personal care products may contain many chemicals, some of which are suspected endocrine disrupters. This is an important source of chemical exposure for women, but little is known about how chemical exposure differs among different races/ethnicities.

OBJECTIVE

This study examines differences in personal care product use among Black, Latina, Vietnamese, Mixed Race, and White women in California.

METHODS

We used a community-based participatory process to create and administer a personal care product usage survey to 321 Black, Latina, Vietnamese, Mixed Race, and White women. We used multivariate regression models with pairwise comparisons to examine the frequency of product use by race/ethnicity.

RESULTS

We found distinct trends of personal care product use by race/ethnicity: Latina women typically used makeup most frequently; Black women used certain hair products or styles most frequently; and Vietnamese women were most likely to use facial cleansing products compared to other races/ethnicities. Latina and Vietnamese women were less likely to try to avoid certain ingredients in their products.

SIGNIFICANCE

These findings can help estimate disparities in chemical exposure from personal care product use and complement future research on health inequities due to chemical exposures in the larger environmental and social context.

Preterm birth is associated with xenobiotics and predicted by the vaginal metabolome

Spontaneous preterm birth (sPTB) is a leading cause of maternal and neonatal morbidity and mortality, yet its prevention and early risk stratification are limited. Previous investigations have suggested that vaginal microbes and metabolites may be implicated in sPTB. Here we performed untargeted metabolomics on 232 second-trimester vaginal samples, 80 from pregnancies ending preterm. We find multiple associations between vaginal metabolites and subsequent preterm birth, and propose that several of these metabolites, including diethanolamine and ethyl glucoside, are exogenous. We observe associations between the metabolome and microbiome profiles previously obtained using 16S ribosomal RNA amplicon sequencing, including correlations between bacteria considered suboptimal, such as Gardnerella vaginalis, and metabolites enriched in term pregnancies, such as tyramine. We investigate these associations using metabolic models. We use machine learning models to predict sPTB risk from metabolite levels, weeks to months before birth, with good accuracy (area under receiver operating characteristic curve of 0.78). These models, which we validate using two external cohorts, are more accurate than microbiome-based and maternal covariates-based models (area under receiver operating characteristic curve of 0.55-0.59). Our results demonstrate the potential of vaginal metabolites as early biomarkers of sPTB and highlight exogenous exposures as potential risk factors for prematurity.

Determinants of exposure to endocrine disruptors following hurricane Harvey

Hurricane Harvey was a category four storm that induced catastrophic flooding in the Houston metropolitan area. Following the hurricane there was increased concern regarding chemical exposures due to damage caused by flood waters and emergency excess emissions from industrial facilities. This study utilized personal passive samplers in the form of silicone wristbands in Houston, TX to both assess chemical exposure to endocrine disrupting chemicals (EDCs) immediately after the hurricane and determine participant characteristics associated with higher concentrations of exposure. Participants from the Houston-3H cohort (n = 172) wore a wristband for seven days and completed a questionnaire to determine various flood-related and demographic variables. Bivariate and multivariate analysis indicated that living in an area with a high Area Deprivation Index (ADI) (indicative of low socioeconomic status), identifying as Black/African American or Latino, and living in the Houston neighborhoods of Baytown and East Houston were associated with increased exposure to EDCs. These results provide evidence of racial/ethnic and socioeconomic injustices in exposure to EDCs in the Houston Metropolitan Area. Since the multiple regression models conducted did not fully explain exposure (0.047 < R2 < 0.34), more research is needed on the direct sources of EDCs within this area to create effective exposure mitigation strategies.