Trends in Exposure to Chemicals in Personal Care and Consumer Products

Trends in NHANES Biomonitored Exposures in California and the United States following Enactment of California's Proposition 65

BACKGROUND

The prevalence of toxic chemicals in US commerce has prompted some states to adopt laws to reduce exposure. One with broad reach is California's Proposition 65 (Prop 65), which established a list of chemicals that cause cancer, developmental harm, or reproductive toxicity. The law is intended to discourage businesses from using these chemicals and to minimize consumer exposure. However, a key question remains unanswered: Has Prop 65 reduced population-level exposure to the listed chemicals?

OBJECTIVE

We used national biomonitoring data from the Centers for Disease Control and Prevention (CDC) to evaluate the impact of Prop 65 on population-level exposures.

METHODS

We evaluated changes in blood and urine concentrations of 37 chemicals (including phthalates, phenols, VOCs, metals, PAHs, and PFAS), among US National Health and Nutrition Examination Survey (NHANES) participants in relation to the time of chemicals' Prop 65 listing. Of these, 11 were listed prior to, 11 during, and 4 after the biomonitoring period. The remaining 11 were not listed but were closely related to a Prop 65-listed chemical. Where biomonitoring data were available from before and after the date of Prop 65 listing, we estimated the change in concentrations over time for Californians compared with non-Californians, using a difference-in-differences model. We used quantile regression to estimate changes in exposure over time, as well as differences between Californians and non-Californians at the 25th, 75th, and 95th percentiles.

RESULTS

We found that concentrations of biomonitored chemicals generally declined nationwide over time irrespective of their inclusion on the Prop 65 list. Median bisphenol A (BPA) concentrations decreased 15% after BPA's listing on Prop 65, whereas concentrations of the nonlisted but closely related bisphenol S (BPS) increased 20% over this same period, suggesting chemical substitution. Californians generally had lower levels of biomonitored chemicals than the rest of the US population.

DISCUSSION

Our findings suggest that increased scientific and regulatory attention, as well as public awareness of the harms of Prop 65-listed chemicals, prompted changes in product formulations that reduced exposure to those chemicals nationwide. Trends in bisphenols and several phthalates suggest that manufacturers replaced some listed chemicals with closely related but unlisted chemicals, increasing exposure to the substitutes. Our findings have implications for the design of policies to reduce toxic exposures, biomonitoring programs to inform policy interventions, and future research into the regulatory and market forces that affect chemical exposure. https://doi.org/10.1289/EHP13956.

Silicone wristbands reveal ubiquitous human exposure to ortho-phthalates and non-ortho-phthalate plasticizers in Southern California

In the United States and abroad, ortho-phthalates and non-ortho-phthalate plasticizers continue to be used within a diverse array of consumer products. Prior California-specific biomonitoring programs for ortho-phthalates have focused on rural, agricultural communities and, to our knowledge, these programs have not measured the potential for exposure to non-ortho-phthalate plasticizers. Therefore, the potential for human exposure to ortho-phthalates and non-ortho-phthalate plasticizers have not been adequately addressed in regions of California that have higher population density. Since there are numerous sources of ortho-phthalates and non-ortho-phthalate plasticizers in population-dense, urban regions, the objective of this study was to leverage silicone wristbands to quantify aggregate ortho-phthalate and non-ortho-phthalate plasticizer exposure over a 5-day period across two different cohorts (2019 and 2020) of undergraduate students at the University of California, Riverside (UCR) that commute from all over Southern California. Based on 5 d of aggregate exposure across two different cohorts, total ortho-phthalate plus non-ortho-phthalate plasticizer concentrations ranged, on average, from ∼100,000-1,000,000 ng/g. Based on the distribution of individual ortho-phthalate and non-ortho-phthalate plasticizer concentrations, the concentrations of di-isononyl phthalate (DiNP, a high molecular weight ortho-phthalate), di (2-ethylhexyl) phthalate (DEHP, a high molecular weight ortho-phthalate), and di-2-ethylhexyl terephthalate (DEHT, a non-ortho-phthalate plasticizer) detected within wristbands were higher than the remaining seven ortho-phthalates and non-ortho-phthalate plasticizers measured, accounting for approximately 94-97% of the total mass depending on the cohort. Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California.

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.

Ketoconazole blocks progesterone production without affecting other parameters of cumulus-oocyte complex maturation

Ketoconazole (KTZ) is widely used as a fungicide, but it is also known to target steroid hormone formation which may affect female reproductive health. Our study aims to investigate the effects of KTZ on in vitro matured bovine cumulus-oocyte complexes (COCs), as a model for female reproductive toxicity. Cumulus cells of in vitro maturing COCs produce progesterone and pregnenolone, but exposure to 10-6 M KTZ effectively blocked the synthesis of these hormones. Exposure to lower concentrations of KTZ (i.e. 10-7 M and 10-8 M) had no such effect on steroidogenesis compared to the 0.1 % v/v DMSO vehicle control. Classical parameters of in vitro COC maturation, such as oocyte nuclear maturation to the metaphase II stage and expansion of the cumulus investment, were not affected by any KTZ concentration tested. Apoptosis and necrosis levels were also not altered in cumulus cells or oocytes exposed to KTZ. Moreover, oocytes exposed to KTZ during maturation showed normal cleavage and early embryo development up to day 8 post fertilization; albeit a statistically significant decrease was observed in day 8 blastocysts produced from oocytes exposed to the lowest concentration of 10-8 M KTZ. When unexposed mature oocytes were fertilized, followed by embryo culture for 8 days under KTZ exposure, no adverse effects in embryo cleavage and blastocyst formation were observed. In conclusion, KTZ has no major impact on in vitro bovine oocyte maturation and blastocyst formation in our study, even at concentrations blocking steroidogenesis.

Environmental phenol exposures in 6- to 12-week-old infants: The Infant Feeding and Early Development (IFED) study

BACKGROUND

Exposure to phenols, endocrine-disrupting chemicals used in personal care and consumer products, is widespread. Data on infant exposures are limited despite heightened sensitivity to endocrine disruption during this developmental period. We aimed to describe distributions and predictors of urinary phenol concentrations among U.S. infants ages 6-12 weeks.

METHODS

The Infant Feeding and Early Development (IFED) study is a prospective cohort study of healthy term infants enrolled during 2010-2013 in the Philadelphia region. We measured concentrations of seven phenols in 352 urine samples collected during the 6- or 8- and/or 12-week study visits from 199 infants. We used linear mixed models to estimate associations of maternal, sociodemographic, infant, and sample characteristics with natural-log transformed, creatinine-standardized phenol concentrations and present results as mean percent change from the reference level.

RESULTS

Median concentrations (μg/L) were 311 for methylparaben, 10.3 for propylparaben, 3.6 for benzophenone-3, 2.1 for triclosan, 1.0 for 2,5-dichlorophenol, 0.7 for BPA, and 0.3 for 2,4-dichlorophenol. Geometric mean methylparaben concentrations were approximately 10 times higher than published estimates for U.S. children ages 3-5 and 6-11 years, while propylparaben concentrations were 3-4 times higher. Infants of Black mothers had higher concentrations of BPA (83%), methylparaben (121%), propylparaben (218%), and 2,5-dichorophenol (287%) and lower concentrations of benzophenone-3 (-77%) and triclosan (-53%) than infants of White mothers. Triclosan concentrations were higher in breastfed infants (176%) and lower in infants whose mothers had a high school education or less (-62%). Phenol concentrations were generally higher in summer samples.

CONCLUSIONS

Widespread exposure to select environmental phenols among this cohort of healthy U.S. infants, including much higher paraben concentrations compared to those reported for U.S. children, supports the importance of expanding population-based biomonitoring programs to infants and toddlers. Future investigation of exposure sources is warranted to identify opportunities to minimize exposures during these sensitive periods of development.

Urinary phenol and paraben concentrations in association with markers of inflammation during pregnancy in Puerto Rico

Exposure to phenols and parabens may contribute to increased maternal inflammation and adverse birth outcomes, but these effects are not well-studied in humans. This study aimed to investigate relationships between concentrations of 8 phenols and 4 parabens with 6 inflammatory biomarkers (C-reactive protein (CRP); matrix metalloproteinases (MMP) 1, 2, and 9; intercellular adhesion molecule-1 (ICAM-1); and vascular cell adhesion molecule-1 (VCAM-1)) measured at two time points in pregnancy in the PROTECT birth cohort in Puerto Rico. Linear mixed models were used, adjusting for covariates of interest. Results are expressed as the percent change in outcome per interquartile range (IQR) increase in exposure. Particularly among phenols, numerous significant negative associations were found, for example, between benzophenone-3 and CRP (-11.21 %, 95 % CI: -17.82, -4.07) and triclocarban and MMP2 (-9.87 %, 95 % CI: -14.05, -5.5). However, significant positive associations were also detected, for instance, between bisphenol-A (BPA) and CRP (9.77 %, 95 % CI: 0.67, 19.68) and methyl-paraben and MMP1 (10.78 %, 95 % CI: 2.17, 20.11). Significant interactions with female fetal sex and the later study visit (at 24-28 weeks gestation) showed more positive associations compared to male fetal sex and the earlier study visit (16-20 weeks gestation). Our results suggest that phenols and parabens may disrupt inflammatory processes pertaining to uterine remodeling and endothelial function, with important implications for pregnancy outcomes. More research is needed to further understand maternal inflammatory status in an effort to improve reproductive and developmental outcomes.

Effects of Behavioral, Clinical, and Policy Interventions in Reducing Human Exposure to Bisphenols and Phthalates: A Scoping Review

BACKGROUND

There is growing interest in evidence-based interventions, programs, and policies to mitigate exposures to bisphenols and phthalates and in using implementation science frameworks to evaluate hypotheses regarding the importance of specific approaches to individual or household behavior change or institutions adopting interventions.

OBJECTIVES

This scoping review aimed to identify, categorize, and summarize the effects of behavioral, clinical, and policy interventions focused on exposure to the most widely used and studied bisphenols [bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF)] and phthalates with an implementation science lens.

METHODS

A comprehensive search of all individual behavior, clinical, and policy interventions to reduce exposure to bisphenols and phthalates was conducted using PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Google Scholar. We included studies published between January 2000 and November 2022. Two reviewers screened references in CADIMA, then extracted data (population characteristics, intervention design, chemicals assessed, and outcomes) for studies meeting inclusion criteria for the present review.

RESULTS

A total of 58 interventions met the inclusion criteria. We classified interventions as dietary (n = 27 ), clinical (n = 13 ), policy (n = 14 ), and those falling outside of these three categories as "other" (n = 4 ). Most interventions (81%, 47/58) demonstrated a decrease in exposure to bisphenols and/or phthalates, with policy level interventions having the largest magnitude of effect.

DISCUSSION

Studies evaluating policy interventions that targeted the reduction of phthalates and BPA in goods and packaging showed widespread, long-term impact on decreasing exposure to bisphenols and phthalates. Clinical interventions removing bisphenol and phthalate materials from medical devices and equipment showed overall reductions in exposure biomarkers. Dietary interventions tended to lower exposure with the greatest magnitude of effect in trials where fresh foods were provided to participants. The lower exposure reductions observed in pragmatic nutrition education trials and the lack of diversity (sociodemographic backgrounds) present limitations for generalizability to all populations. https://doi.org/10.1289/EHP11760.

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.

Suspect Screening Analysis of Pooled Human Serum Samples Using GC × GC/TOF-MS

Humans interact with thousands of chemicals. This study aims to identify substances of emerging concern and in need of human health risk evaluations. Sixteen pooled human serum samples were constructed from 25 individual samples each from the National Institute of Environmental Health Sciences' Clinical Research Unit. Samples were analyzed using gas chromatography (GC) × GC/time-of-flight (TOF)-mass spectrometry (MS) in a suspect screening analysis, with follow-up confirmation analysis of 19 substances. A standard reference material blood sample was also analyzed through the confirmation process for comparison. The pools were stratified by sex (female and male) and by age (≤45 and >45). Publicly available information on potential exposure sources was aggregated to annotate presence in serum as either endogenous, food/nutrient, drug, commerce, or contaminant. Of the 544 unique substances tentatively identified by spectral matching, 472 were identified in females, while only 271 were identified in males. Surprisingly, 273 of the identified substances were found only in females. It is known that behavior and near-field environments can drive exposures, and this work demonstrates the existence of exposure sources uniquely relevant to females.

A genome-wide association study of 24-hour urinary excretion of endocrine disrupting chemicals

Ubiquitous exposure to environmental endocrine disrupting chemicals (EDCs) instigates a major public health problem, but much remains unknown on the inter-individual differences in metabolism and excretion of EDCs. To examine this we performed a two-stage genome-wide association study (GWAS) for 24-hour urinary excretions of four parabens, two bisphenols, and nine phthalate metabolites. Results showed five genome-wide significant (p-value < 5x10-8) and replicated single nucleotide polymorphisms (SNPs) representing four independent signals that associated with mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). Three of the four signals were located on chromosome 10 in a locus harboring the cytochrome P450 (CYP) genes CYP2C9, CYP2C58P, and CYP2C19 (rs117529685, pMECPP = 5.38x10-25; rs117033379, pMECPP = 1.96x10-19; rs4918798, pMECPP = 4.01x10-71; rs7895726, pMEHHP = 1.37x10-15, r2 with rs4918798 = 0.93). The other signal was on chromosome 6 close to the solute carrier (SLC) genes SLC17A1, SLC17A3, SLC17A4, and SCGN (rs1359232, pMECPP = 7.6x10-16). These four SNPs explained a substantial part (8.3 % - 9.2 %) of the variance in MECPP in the replication cohort. Bioinformatics analyses supported a likely causal role of CYP2C9 and SLC17A1 in metabolism and excretion of MECPP and MEHHP. Our results provide biological insights into mechanisms of phthalate metabolism and excretion with a likely causal role for CYP2C9 and SLC17A1.

Reducing Transdermal Uptake of Semivolatile Plasticizers from Indoor Environments: A Clothing Intervention

Models and laboratory studies suggest that everyday clothing influences the transdermal uptake of semivolatile organic compounds, including phthalate plasticizers, from indoor environments. However, this effect has not been documented in environmental exposure settings. In this pilot study, we quantified daily excretion of 17 urinary metabolites (μg/day) for phthalates and phthalate alternatives in nine participants during 5 days. On Day 0, baseline daily excretion was determined in participants' urine. Starting on Day 1, participants refrained from eating phthalate-heavy foods and using personal care products. On Days 3 and 4, participants wore precleaned clothing as an exposure intervention. We observed a reduction in the daily excretion of phthalates during the intervention; mono-n-butyl phthalate, monoisobutyl phthalate (MiBP), and monobenzyl phthalate were significantly reduced by 35, 38, and 56%, respectively. Summed metabolites of di(2-ethylhexyl)phthalate (DEHP) were also reduced (27%; not statistically significant). A similar reduction among phthalate alternatives was not observed. The daily excretion of MiBP during the nonintervention period strongly correlated with indoor air concentrations of diisobutyl phthalate (DiBP), suggesting that inhalation and transdermal uptake of DiBP from the air in homes are dominant exposure pathways. The results indicate that precleaned clothing can significantly reduce environmental exposure to phthalates and phthalate alternatives.

Midpregnancy Phthalate and Phenol Biomarkers in Relation to Infant Body Composition: The Healthy Start Prospective Cohort

BACKGROUND

Gestational phthalate and phenol exposure disrupts adipogenesis, contributing to obesity in mice. Whether gestational phthalate or phenol exposure is associated with infant body composition has not been investigated in humans.

OBJECTIVE

We examined associations between biomarkers of phthalate and phenol exposure in midpregnancy and infant size and body composition at birth and at 5 months of age.

METHODS

Analyses were conducted among 438 infants from the Healthy Start prospective pregnancy cohort. Sixteen phthalate and phenol biomarkers were quantified in spot urine samples collected at 24-28 wk of gestation. Infant outcomes measured at birth and at 5 months of age included size [weight (in grams)] and body composition [fat and lean masses (in grams); percentage fat mass]. Single- (linear) and multipollutant (quantile g-computation) models were used to estimate associations of phthalate and phenol biomarkers with infant outcomes at birth and at 5 months of age. Models were adjusted for sociodemographics, sample collection timing, and lifestyle factors and used to examine for effect modification by infant sex.

RESULTS

In single-pollutant models, mono-benzyl phthalate and di-n -butyl phthalate were inversely associated with percentage fat mass [β : - 0.49 (95% CI: - 0.91 , - 0.08 ) and - 0.51 (95% CI: - 1.02 , 0.01), respectively] in male but not female infants at birth. Similar, but less precise, associations were observed at 5 months of age. In multipollutant models, a 1-quartile increase in the phthalate and phenol biomarker mixture was inversely associated with percentage fat mass at birth [- 1.06 (95% CI: - 2.21 , 0.1)] and at 5 months of age [- 2.14 (95% CI: - 3.88 , - 0.39 )] among males, but associations were null among females [0.48 (95% CI: - 0.78 , 1.75) and - 0.64 (95% CI: - 2.68 , 1.41), respectively]. Similar associations were observed with infant weight.

CONCLUSION

In this U.S.-based prospective cohort, gestational phthalate and phenol biomarkers were inversely associated with infant weight and fat mass, particularly in males. https://doi.org/10.1289/EHP12500.

Endocrine disruptors in plastics alter β-cell physiology and increase the risk of diabetes mellitus

Plastic pollution breaks a planetary boundary threatening wildlife and humans through its physical and chemical effects. Of the latter, the release of endocrine disrupting chemicals (EDCs) has consequences on the prevalence of human diseases related to the endocrine system. Bisphenols (BPs) and phthalates are two groups of EDCs commonly found in plastics that migrate into the environment and make low-dose human exposure ubiquitous. Here we review epidemiological, animal, and cellular studies linking exposure to BPs and phthalates to altered glucose regulation, with emphasis on the role of pancreatic β-cells. Epidemiological studies indicate that exposure to BPs and phthalates is associated with diabetes mellitus. Studies in animal models indicate that treatment with doses within the range of human exposure decreases insulin sensitivity and glucose tolerance, induces dyslipidemia, and modifies functional β-cell mass and serum levels of insulin, leptin, and adiponectin. These studies reveal that disruption of β-cell physiology by EDCs plays a key role in impairing glucose homeostasis by altering the mechanisms used by β-cells to adapt to metabolic stress such as chronic nutrient excess. Studies at the cellular level demonstrate that BPs and phthalates modify the same biochemical pathways involved in adaptation to chronic excess fuel. These include changes in insulin biosynthesis and secretion, electrical activity, expression of key genes, and mitochondrial function. The data summarized here indicate that BPs and phthalates are important risk factors for diabetes mellitus and support a global effort to decrease plastic pollution and human exposure to EDCs.

Reproductive toxicity of emerging plasticizers, flame retardants, and bisphenols, using culture of the rat fetal testis†

The use of bis (2-ethylhexyl) phthalate (DEHP), 2,2'4,4'-tetrabromodiphenyl ether (BDE47), and bisphenol A (BPA), as plasticizers, flame retardants, and epoxy resins, respectively, has been regulated due to their endocrine disrupting activities. Replacements for these chemicals are found in human matrices, yet the endocrine disrupting potential of these emerging contaminants is poorly characterized. We compared the effects of legacy chemicals with those of their replacements using fetal rat testis organ culture. Fetal testes sampled at gestation day 15 were grown ex vivo, and the impact was evaluated after a 3-day exposure to 10 μM of each legacy chemical; two BPA analogs (bisphenol M and bisphenol TMC); three replacements for DEHP/MEHP (2,2,4-trimethyl-1,3-pentanediol diisobutyrate, diisononyl-phthalate, and diisodecyl adipate); or two replacements for BDE47 (tributoxyethyl phosphate and isopropylated triphenyl phosphate). We showed that only BPA and MEHP significantly decrease testosterone secretions after 24 h, while BPM and BPTMC have the opposite effect. Luteinizing hormone-stimulated testosterone was reduced by BPA and MEHP but was increased by BPTMC. After exposure, testes were used for immunofluorescent staining of germ cells, Sertoli cells, and Leydig cells. Interestingly, exposures to BPM or BPTMC induced a significant increase in the Leydig cell density and surface area. A decrease in germ cell density was observed only after treatment with MEHP or BDE47. MEHP also significantly decreased Sertoli cell proliferation. These studies show that some replacement chemicals can affect testicular function, while others appear to show little toxicity in this model. These findings provide essential information regarding the need for their regulation.

A rapid micro chamber method to measure SVOC emission and transport model parameters

Assessing exposure to semivolatile organic compounds (SVOCs) that are emitted from consumer products and building materials in indoor environments is critical for reducing the associated health risks. Many modeling approaches have been developed for SVOC exposure assessment indoors, including the DustEx webtool. However, the applicability of these tools depends on the availability of model parameters such as the gas-phase concentration at equilibrium with the source material surface, y₀, and the surface-air partition coefficient, K_s, both of which are typically determined in chamber experiments. In this study, we compared two types of chamber design, a macro chamber, which downscaled the dimensions of a room to a smaller size with roughly the same surface-to-volume ratio, and a micro chamber, which minimized the sink-to-source surface area ratio to shorten the time required to reach steady state. The results show that the two chambers with different sink-to-source surface area ratios yield comparable steady-state gas- and surface-phase concentrations for a range of plasticizers, while the micro chamber required significantly shorter times to reach steady state. Using y₀ and K_s measured with the micro chamber, we conducted indoor exposure assessments for di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP) and di(2-ethylhexyl) terephthalate (DEHT) with the updated DustEx webtool. The predicted concentration profiles correspond well with existing measurements and demonstrate the direct applicability of chamber data in exposure assessments.

Association between urinary phthalate biomarker concentrations and adiposity among postmenopausal women

BACKGROUND

Obesity is a leading risk factor for chronic diseases, potentially related to excess abdominal adiposity. Phthalates are environmental chemicals that have been suggested to act as obesogens, driving obesity risk. For the associations between phthalates and adiposity, prior studies have focused primarily on body mass index. We hypothesize that more refined measures of adiposity and fat distribution may provide greater insights into these associations given the role of central adiposity in chronic disease risk.

OBJECTIVES

To evaluate associations between urinary phthalate biomarkers and both visceral and subcutaneous adipose tissue (VAT and SAT) among postmenopausal women enrolled in the Women's Health Initiative (WHI).

METHODS

We included 1125 WHI participants with available, coincident measurements of urinary phthalate biomarkers (baseline, year 3) and VAT and SAT (baseline, year 3, year 6). VAT and SAT measurements were estimated from DXA scans. Multilevel mixed-effects models estimated the prospective associations between urinary phthalate biomarkers at baseline and VAT and SAT three years later.

RESULTS

In multivariable adjusted models, we observed positive associations between some phthalate biomarkers, including the sum of di-isobutyl phthalate (ΣDiBP) biomarkers, MCNP, and ΣDEHP, with VAT three years later. For example, we observed positive associations between concentrations of ΣDiBP and VAT (Q4 vs Q1 β = 7.15, 95% CI -1.76-16.06; Q3 vs Q1 β = 10.94, 95% CI 3.55-18.33). Associations were generally attenuated but remained significant after additional adjustment for SAT. MBzP was positively associated with SAT. Other phthalate biomarkers investigated (MEP, MCOP, MCPP, ΣDBP) were not significantly associated with VAT or SAT.

DISCUSSION

Based on robust measures of adiposity, this study provides supportive evidence that higher urinary concentrations of select phthalate compounds were associated with higher VAT levels over time in postmenopausal women. Efforts to replicate these findings are needed.

Harmonized human biomonitoring in European children, teenagers and adults: EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014-2021)

As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants of three age groups: (i) 3,576 children aged 6-12 years, (ii) 3,117 teenagers aged 12-18 years and (iii) 4,102 young adults aged 20-39 years. The participants were recruited between 2014 and 2021 in 11-12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability and will give leverage to national policy makers for the implementation of targeted measures.

Low-dose phthalates promote breast cancer stem cell properties via the oncogene ΔNp63α and the Sonic hedgehog pathway

BACKGROUND

The omnipresence of human phthalate (PAE) exposure is linked to various adverse health issues, including breast cancer. However, the effects of low-dose PAE exposure on breast cancer stem cells (BCSCs) and the underlying mechanism remain unexplored.

METHODS

BCSCs from breast cancer cell lines (MDA-MB-231 and MCF-7) were enriched using a tumorsphere formation assay. Gene and protein expression was detected by measurement of quantitative real-time reverse transcription PCR, western blot, and immunofluorescence assays. Transient transfection assays were used to evaluate the involvement of Gli1, a signaling pathway molecule and ΔNp63α, an oncogene in influencing the PAE-induced characteristics of BCSCs.

RESULTS

PAE (butylbenzyl phthalate, BBP; di-butyl phthalate, DBP; di-2-ethylhexyl phthalate, DEHP) exposure of 10^-9 M significantly promoted the tumorsphere formation ability in BCSCs. Breast cancer spheroids with a 10^-9 M PAE exposure had higher levels of BCSC marker mRNA and protein expression, activated sonic hedgehog (SHH) pathway, and increased mRNA and protein levels of an oncogene, ΔNp63α. Furthermore, suppression of the SHH pathway attenuated the effects of PAEs on BCSCs. And the overexpression of ΔNp63α enhanced PAE-induced characteristics of BCSCs, while low expression of ΔNp63α inhibited the promotion effects of PAEs on BCSCs and the SHH pathway.

CONCLUSION

Low-dose PAE exposure promoted the stem cell properties of BCSCs in a ΔNp63α- and SHH-dependent manner. The influence of low-dose exposure of PAEs and its relevance for the lowest observed effect concentrations requires further investigation, and the precise underlying mechanism needs to be further explored.

Occurrence and seasonal variation of plasticizers in sediments and biota from the coast of Mahdia, Tunisia

Plasticizers are compounds often involved in the manufacturing of plastic products. Nevertheless, the ageing of the latter generates plasticizers that generally end up in the marine environment. In fact, marine pollution by phthalate acid esters (PAEs) and their alternatives has become an environmental and health issue of serious concern, as they are largely and ubiquitously present in the environment and aquatic organisms. In the present study, four PAEs, such as diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and one non-phthalate plasticizer (NPP), namely di-2-ethylhexyl terephthalate (DEHT), are wanted in different marine compartments from the coast of Mahdia in Tunisia such as sediment, seagrass, and mussel. The most abundant and frequently detected congener was DEHT at the concentrations reached 1.181 mg/kg in the sediment, 1.121 mg/kg in the seagrass, and 1.86 mg/kg in the mussel. This result indicates that the DEHT could emerge through the food chain and therefore bioaccumulate in marine compartments. In addition, we noticed that the seasonal variations of plasticizers were seriously affected by environmental factors including industrial and urban discharges.

Urinary phenols and parabens metabolites associated with cardiovascular disease among adults in the United States

The field of environmental health has begun to examine the effects of higher-order chemical combinations. The current literature lacks studies exploring associations between multiple organic chemical mixtures and cardiometabolic diseases (CVDs). This study aimed to evaluate associations between urinary phenols, parabens metabolites, and total and individual CVDs among a nationally representative sample of adults in the US. This cross-sectional study analyzed 7 urinary chemicals detected among the general population from the 2005-2016 National Health and Nutrition Examination Survey (NHANES, n=10,428). Multivariate logistic regression and weighted quantile sum (WQS) regression were applied to examine relationships between phenols and parabens metabolites, alone and in combination, and total and individual CVDs prevalence. Compared with the lowest quartile, URBPA (OR: 1.52; 95% CI: 1.20-1.91; P=0.001) levels in the highest quartile were independently associated with increased total CVD. The WQS index of phenols and parabens mixtures were independently correlated with total CVD (adjusted odds ratios [OR]: 1.16; 95% confidence interval [CI]:1.06-1.28; P=0.002), angina (adjusted OR: 1.30; 95% CI: 1.07-1.59; P=0.009), and heart attack (adjusted OR: 1.30; 95% CI: 1.12-1.51, P<0.001). Urinary bisphenol A (URBPA, weight=0.636) was the most heavily weighted component in the total CVD model. Restricted cubic spline regression demonstrated positive correlations and nonlinear associations between URBPA and both total CVD (P for nonlinearity=0.032) and individual CVD (heart attack; P for nonlinearity=0.031). Our findings suggested that high combined levels of phenols, and parabens are associated with an increased CVD risk, with URBPA contributing the highest risk.

Exposure to phthalates, phenols, and parabens mixture and alterations in sex steroid hormones among adolescents

Exposure to phthalates (PAEs), phenols, and parabens has been linked with sex hormone imbalance; however, previous studies were predominantly limited to adults and failed to examine the combined effects of these chemicals mixture among adolescents. Thus, we used the data from the National Health and Nutrition Examination Survey (2013-2016) to explore the associations of urinary PAEs, phenols, and parabens biomarkers with sex hormones among participants aged 12-19 years old (n = 613). Latent class analysis (LCA) and quantile-based g-computation (QGC) were applied to assess the associations of the latent exposure profiles and chemicals mixture with sex hormone indicators, including steroid hormones and sex hormone binding globulin (SHBG), in adolescents and by sex. Using LCA, four latent classes were identified among all participants. Compared with the class characterized by "Low exposure", the class represented by "High PAEs" [mono (2-ethyl-5-carboxypentyl) phthalate (MECPP), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and monobenzyl phthalate (MBZP)] had lower level of estradiol (E₂) [β = -0.249, 95% confidence interval (CI): -0.419, -0.08], free androgen index (FAI) (β = -0.258, 95%CI: -0.512, -0.005) and free testosterone (FT) (β = -0.248, 95%CI: -0.496, -0.001) among male adolescents. These results were echoed by the results in QGC analyses, where PAEs mixture was negatively associated with E₂ (β = -0.137, 95% CI: -0.263, -0.011), FAI (β = -0.198, 95%CI: -0.387, -0.008) and FT (β = -0.189, 95%CI: -0.375, -0.002) among male adolescents. By contrast, the associations of the identified latent classes or chemicals mixture with sex hormone indicators were generally nonsignificant among female counterparts, except for a positive association between PAEs mixture and SHBG (β = 0.121, 95%CI: 0.012, 0.23). Our study demonstrated that exposure to PAEs, particularly MECPP, MEHHP, and MBZP, would be a threat to the sex hormone homeostasis of male adolescents.

Exposure to phthalate esters in Japanese females in Kyoto, Japan from 1993 to 2016: Temporal trends and associated health risks

Phthalates are used as plasticizers in many products used in daily life worldwide. Due to industrial and economic developments, exposure among general population to phthalates may vary geographically and temporally. However, studies are lacking for investigating temporal changes in phthalate exposure in the Japanese population. In the present study, the temporal trends in exposure to various phthalates were assessed among a group of Japanese adult female population over 1993-2016 and derived associated risks. For this purpose, urine samples of healthy Japanese females in Kyoto, Japan (N = 132) collected in 1993, 2000, 2003, 2009, 2011, and 2016, were employed and measured for the concentrations of 18 phthalate metabolites. Over this period, the detection rates of mono(3-carboxypropyl) phthalate (MCPP) and monoisobutyl phthalate (MiBP) decreased, and the geometric means of the urinary concentrations of mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) showed a significant decreasing trend. Cumulative risk due to exposure to dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), butyl benzyl phthalate (BBP), and di-2-ethylhexyl phthalate (DEHP) showed a dramatic decrease only between 1993 and 2000. The maximum hazard quotient (HQ_M) was attributed to DEHP in most subjects regardless of sampling year. This study showed the temporal trend of the exposure of Japanese females to several phthalate esters over two decades. As of the late 2010's, DEHP was still the predominant component of phthalate ester exposure in the population. The HI value, however, indicates that direct risk due to phthalate exposure was unlikely among the studied population.

Variability of Urinary Concentrations of Phenols, Parabens, and Triclocarban during Pregnancy in First Morning Voids and Pooled Samples

Urinary concentrations of phenols, parabens, and triclocarban have been extensively used as biomarkers of exposure. However, because these compounds are quickly metabolized and excreted in urine, characterizing participants' long-term average exposure from a few spot samples is challenging. To examine the variability of urinary concentrations of these compounds during pregnancy, we quantified four phenols, four parabens, and triclocarban in 357 first morning voids (FMVs) and 203 pooled samples collected during the second and third trimesters of 173 pregnancies. We computed intraclass correlation coefficients (ICCs) by the sample type (FMV and pool) across two trimesters and by the number of composite samples in pools, ranging from 2 to 4, within the same trimester. Among the three compounds detected in more than 50% of the samples, the ICCs across two trimesters were higher in pools (0.29-0.68) than in FMVs (0.17-0.52) and the highest ICC within the same trimester was observed when pooling either two or three composites. Methyl paraben and propyl paraben primarily exposed via cosmetic use had approximately 2-3 times higher ICCs than bisphenol A primarily exposed via diet. Our findings support that within-subject pooling of biospecimens can increase the reproducibility of pregnant women's exposure to these compounds and thus could potentially minimize exposure misclassification.

Longitudinal exposure to consumer product chemicals and changes in plasma oxylipins in pregnant women

BACKGROUND

Exposure to consumer product chemicals during pregnancy may increase susceptibility to pregnancy disorders by influencing maternal inflammation. However, effects on specific inflammatory pathways have not been well characterized. Oxylipins are a diverse class of lipids that act as important mediators and biomarkers of several biological pathways that regulate inflammation. Adverse pregnancy outcomes have been associated with circulating oxylipin levels in pregnancy. In this study, we aimed to determine the longitudinal associations between plasma oxylipins and urinary biomarkers of three classes of consumer product chemicals among pregnant women.

METHODS

Data come from a study of 90 pregnant women nested within the LIFECODES cohort. Maternal plasma and urine were collected at three prenatal visits. Plasma was analyzed for 61 oxylipins, which were grouped according to biosynthetic pathways that we defined by upstream: 1) fatty acid precursor, including linoleic, arachidonic, docosahexaenoic, or eicosapentaenoic acid; and 2) enzyme pathway, including cyclooxygenase (COX), lipoxygenase (LOX), or cytochrome P450 (CYP). Urine was analyzed for 12 phenol, 12 phthalate, and 9 organophosphate ester (OPE) biomarkers. Linear mixed effect models were used for single-pollutant analyses. We implemented a novel extension of quantile g-computation for longitudinal data to examine the joint effect of class-specific chemical mixtures on individual plasma oxylipin concentrations.

RESULTS

We found that urinary biomarkers of consumer product chemicals were positively associated with pro-inflammatory oxylipins from several biosynthetic pathways. Importantly, these associations depended upon the chemical class of exposure biomarker. We estimated positive associations between urinary phenol biomarkers and oxylipins produced from arachidonic acid by LOX enzymes, including several important pro-inflammatory hydroxyeicosatetraenoic acids (HETEs). On average, mean concentrations of oxylipin produced from the arachidonic acid/LOX pathway were 48%-71% higher per quartile increase in the phenol biomarker mixture. For example, a simultaneous quartile increase in all urinary phenols was associated with 53% higher (95% confidence interval [CI]: 11%, 111%) concentrations of 12-HETE. The positive associations among phenols were primarily driven by methyl paraben, 2,5-dichlorophenol, and triclosan. Additionally, we observed that phthalate and OPE metabolites were associated with higher concentrations of oxylipins produced from linoleic acid by CYP enzymes, including the pro-inflammatory dihydroxy-octadecenoic acids (DiHOMEs). Associations among DiHOME oxylipins were driven by metabolites of benzylbutyl and di-isodecyl phthalate, and by the metabolite of tris(1,3-dichloro-2-propyl) phosphate among OPEs. We also observed inverse associations between phthalate and OPE metabolites and oxylipins produced from other pathways; however, adjusting for a plasma indicator of dietary fatty acid intake attenuated those results.

CONCLUSIONS

Our findings support the hypothesis that consumer product chemicals may have diverse impacts on inflammation processes in pregnancy. Certain pro-inflammatory oxylipins were generally higher among participants with higher urinary chemical biomarker concentrations. Associations varied by class of chemical and by the biosynthetic pathway of oxylipin production, indicating potential specificity in the inflammatory effects of these environmental chemicals during pregnancy that warrant investigation in larger studies.

Legacy and alternative plasticizers in surface sediment of black-odorous urban rivers across China: Occurrence, spatial distribution, and ecological risk assessment

In this study, surface sediment samples from 173 black-odorous urban rivers in 74 cities of China were investigated regarding the occurrence, spatial distribution, and ecological risk of legacy phthalates (LPs) and alternative plasticizers (APs). The total concentrations of Σ₇LPs and Σ₆APs ranged from 0.0035 to 522 μg/g dw (median: 33 μg/g dw; mean: 60 μg/g dw) and from 0.0015 to 16 μg/g dw (median: 16 μg/g dw; mean: 2.2 μg/g dw), respectively. Di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and di-iso-butyl phthalate (DiBP) were the dominant LPs, and di-iso-decyl phthalate and di-iso-nonylcyclohexane-1,2-dicarboxylate were the dominant APs. The concentrations and compositions of the LPs and APs varied among different sites and regions, implying location-specific use or production of LPs and APs. The pollutant concentrations in southern and central China were higher than those in northern China. Among the seven regions, Northwest China had the lowest concentrations of LPs and APs. This could be related to industry development level, municipal facilities, and population density. Total organic carbon (TOC) was significantly and positively correlated with the pollutant concentrations, implying that TOC could be an important influencing factor for the distribution of LPs and APs in sediments. The risk quotients of DiBP and DnBP in almost all sediment samples were above 1, indicating the high ecological risks to aquatic organisms. Nevertheless, DEHP, di-methyl phthalate, di-ethyl phthalate, and di-n-octyl phthalate showed low or moderate ecological risks for most sampling sites.

Trends in environmental chemical concentrations in the Canadian population: Biomonitoring data from the Canadian Health Measures Survey 2007-2017

Ten years of nationally representative biomonitoring data collected between 2007 and 2017 are available from the Canadian Health Measures Survey (CHMS). These data establish baseline environmental chemical concentrations in the general population. Here we sought to evaluate temporal trends in environmental chemical exposures in the Canadian population by quantifying changes in biomarker concentrations measured in the first five two-year cycles of the CHMS. We identified 39 chemicals that were measured in blood or urine in at least three cycles and had detection rates over 50% in the Canadian population. We calculated geometric mean concentrations for each cycle using the survey weights provided. We then conducted analyses of variance to test for linear trends over all cycles. We also calculated the percent difference in geometric means between the first and most recent cycle measured. Of the 39 chemicals examined, we found statistically significant trends across cycles for 21 chemicals. Trends were decreasing for 19 chemicals from diverse chemical groups, including metals and trace elements, phenols and parabens, organophosphate pesticides, per- and polyfluoroalkyl substances, and plasticizers. Significant reductions in chemical concentrations included di-2-ethylhexyl phthalate (DEHP; 75% decrease), perfluorooctane sulfate (PFOS; 61% decrease), perfluorooctanoic acid (PFOA; 58% decrease), dimethylphosphate (DMP; 40% decrease), lead (33% decrease), and bisphenol A (BPA; 32% decrease). Trends were increasing for two pyrethroid pesticide metabolites, including a 110% increase between 2007 and 2017 for 3-phenoxybenzoic acid (3-PBA). No significant trends were observed for the remaining 18 chemicals that included arsenic, mercury, fluoride, acrylamide, volatile organic compounds, and polycyclic aromatic hydrocarbons. National biomonitoring data indicate that concentrations, and therefore exposures, have decreased for many priority chemicals in the Canadian population. Concentrations for other chemical groups have not changed or have increased, although average concentrations remain below thresholds of concern derived from human exposure guidance values. Continued collection of national biomonitoring data is necessary to monitor trends in exposures over time.

Gestational Phthalate Exposure and Preschool Attention Deficit Hyperactivity Disorder in Norway

Supplemental Digital Content is available in the text.

Prenatal phthalate exposure has been linked to altered neurobehavioral development in both animal models and epidemiologic studies, but whether or not these associations translate to increased risk of neurodevelopmental disorders is unclear. We used a nested case-cohort study design to assess whether maternal urinary concentrations of 12 phthalate metabolites at 17 weeks gestation were associated with criteria for Attention Deficit Hyperactivity Disorder (ADHD) classified among 3-year-old children in the Norwegian Mother, Father and Child Cohort Study (MoBa). Between 2007 and 2011, 260 children in this substudy were classified with ADHD using a standardized, on-site clinical assessment; they were compared with 549 population-based controls. We modeled phthalate levels both linearly and by quintiles in logistic regression models adjusted for relevant covariates and tested for interaction by child sex. Children of mothers in the highest quintile of di-iso-nonyl phthalate (∑DiNP) metabolite levels had 1.70 times the odds of being classified with ADHD compared with those in the lowest quintile (95% confidence interval [CI] = 1.03 to 2.82). In linear models, there was a trend with the sum of di-2-ethylhexyl phthalate metabolites (∑DEHP); each natural log-unit increase in concentration was associated with 1.22 times the odds of ADHD (95% CI = 0.99 to 1.52). In boys, but not girls, mono-n-butyl phthalate exposure was associated with increased odds of ADHD (odds ratio [OR] 1.42; 95% CI = 1.07 to 1.88). Additional adjustment for correlated phthalate metabolites attenuated estimates. These results suggest gestational phthalate exposure may impact the behavior of children as young as 3 years.

Temporal Trends of Phenol, Paraben, and Triclocarban Exposure in California Pregnant Women during 2007-2014

Little is known about temporal trends of pregnant women's exposures to environmental phenols and parabens. We quantified four phenols [bisphenol A (BPA), bisphenol F, bisphenol S, and triclosan), four parabens [butyl paraben, ethyl paraben (ETPB), methyl paraben (MEPB), and propyl paraben (PRPB)], and triclocarban in 760 urine samples collected during 2007-2014 from 218 California pregnant women participating in a high-familial risk autism spectrum disorder cohort. We applied multiple regression to compute least square geometric means of urinary concentrations and computed average annual percent changes. We compared our urinary concentrations with those of other study populations to examine geographic variations in pregnant women's exposure to these target compounds. Urinary concentrations of BPA, MEPB, ETPB, and PRPB in this study population decreased over the study period [percent change per year (95% confidence interval): -5.7% (-8.2%, -3.2%); -13.0% (-18.1%, -7.7%); -5.5% (-11.0%, 0.3%); and -13.3% (-18.3%, -8.1%), respectively] and were consistently lower than those in pregnant women in other U.S. regions during the same study period. In recent years, certain phenols and parabens with known adverse health effects are being regulated or replaced with alternatives, which explains decreased body burdens observed in this study population. Either the national regulations or the advocacy campaigns in California may have influenced exposures or consumer product choices.

A comprehensive study of the effects of phthalates on marine mussels: Bioconcentration, enzymatic activities and metabolomics

In this study, marine mussels (Mytilus coruscus) were exposed to three typical PAEs (dimethyl phthalate [DMP], dibutyl phthalate [DBP] and di(2-ethylhexyl) phthalate [DEHP]) at a range of doses for different times to investigate the ecotoxicological effects. The accumulation of the three PAE congeners in M. coruscus exhibited the following trend: DEHP > DBP > DMP. The antioxidant response of mussel gonadal tissue was enhanced with increasing concentrations of PAEs. For the DBP and DEHP treatment groups, glutathione (GSH) worked in concert with antioxidant enzymes to protect cells against reactive oxygen species (ROS), while GSH played a prominent antioxidant role in the DMP-treated group. The metabolomics results revealed that PAE exposure disrupted the metabolic balance of mussels. Overall, PAEs affect the amino acid metabolism, lipid metabolism, energy metabolism, osmoregulation and nerve activities of mussels. Our results provide further insight into the toxicological effects of PAEs on marine organisms.

Effect of prenatal phthalate exposure on childhood atopic dermatitis: A systematic review and meta-analysis

Background: The association between prenatal exposure to phthalate and childhood atopic dermatitis (AD) has previously been investigated; however, the results are inconsistent. Objective: We aimed to perform a systematic review and meta-analysis of birth cohort studies to investigate whether prenatal exposure to phthalate increases the risk of developing AD in children. Methods: We performed an electronic search of medical literature data bases. Studies were critically appraised, and a meta-analysis was performed. Results: Among 129 articles identified, 11 studies met the eligibility criteria. Included studies originated from Europe (n = 5), the United States (n = 4), and Asia (n = 2). The study sample size ranged from 147 to 1024 mother-child pairs. Quality assessment by using the Newcastle-Ottawa scale of all the studies had scores of ≥6. A meta-analysis of data from eight selected studies suggested that monobenzyl phthalate (MBzP) exposure was significantly associated with the risk of AD development (odds ratio 1.16 [95% confidence interval, 1.04-1.31]; I² = 17.36%). However, AD development was not associated with other phthalate metabolites, such as mono-(2-ethylhexyl) phthalate, monoethyl phthalate, mono-isobutyl phthalate, mono-n-butyl phthalate, and the sum of di-[2-ethylhexyl] phthalate on the development of AD (all p values were > 0.05). Conclusion: Our meta-analysis suggested that prenatal exposure to phthalates may be associated with the development of childhood AD. However, further research is needed because only MBzP showed statistical significance and the number of articles in the literature is still insufficient.

Association between gestational phthalate exposure and newborn head circumference; impacts by race and sex

Observational and experimental studies report associations between gestational phthalate exposure and fetal development, yet few data exist to characterize phthalate effects on head circumference (HC) or to estimate the impact of race or sex. To address this data gap, we enrolled 152 African American and 158 white mothers with uncomplicated singleton pregnancies from the Charleston, South Carolina (USA) metropolitan area in a prospective birth cohort. Study participants provided up to two urine specimens during mid and late gestation, completed a study questionnaire, and allowed access to hospital birth records. We measured eight phthalate monoester metabolites using liquid chromatography with tandem mass spectrometry, and calculated molar sums of phthalate parent diesters. After specific gravity correction, we tested for associations between phthalates and neonatal HC (cm) and cephalization index (cm/g) using multiple informant linear regression with inverse probability weighting to account for selection bias between repeated urine sampling, adjusted for maternal race, age, body mass index, education, and smoking. We explored interactions by maternal race and infant sex. A doubling of urinary monoethyl phthalate (MEP) concentration was associated with a -0.49% (95%CI: -0.95%, -0.02%) smaller head circumference, although seven other phthalate metabolites were null. There were no statistically significant associations with cephalization index. HC was larger for whites than African American newborns (p < 0.0001) but similar for males and females (p = 0.16). We detected interactions for maternal race with urinary monobutyl phthalate (MBP; p = 0.03), monobenzyl phthalate (MBzP; p = 0.01), monoethylhexyl phthalate (MEHP; p = 0.05), monomethyl phthalate (MMP; p = 0.02), and the sum of dibutyl phthalate metabolites (∑DBP; p = 0.05), in which reduced HC circumference associations were stronger among whites than African Americans, and interactions for sex with MBP (p = 0.08) and MiBP (p = 0.03), in which associations were stronger for females than males. Our results suggest that gestational phthalate exposure is associated with smaller neonatal HC and that white mothers and female newborns have greater susceptibility.

A pilot investigation of couple-level phthalates exposure and in vitro fertilization (IVF) outcomes

Phthalates are reproductive toxicants in experimental animal studies and exposure has been associated with infertility in human populations, although the results have been inconsistent. To help to address the data gap, we conducted a hypothesis-generating investigation of associations between urinary phthalate metabolites and reproductive outcomes among women (n = 56) and their male partners (n = 43) undergoing in vitro fertilization (IVF). Urine was collected from participants on the day of oocyte retrieval. Samples were analyzed for a series of phthalates, MEP, MBP, MPP, MHxP, MEHP, MEHHP, MECPP, MiNP, MiDP, MCHP, and MBzP, using liquid chromatography-tandem mass spectrometry. We employed Poisson regression with robust variance estimation to estimate associations between urinary phthalate levels and biochemical pregnancy and live birth, adjusted for partner's concentration and confounding factors. Doublings in women's MBP (relative risk (RR) = 0.32, 95 % CI: 0.13, 0.78), and men's MEHP (RR = 0.28, 95 % CI: 0.09, 0.83), were associated with a lower likelihood for pregnancy. Doublings in women's (RR = 0.08, 95 % CI: 0.01, 0.67) and men's (RR = 0.13, 95 % CI: 0.02, 0.92) MHxP were associated with a lower likelihood of live birth. Our results suggest that phthalate exposure may impact IVF outcomes, and underscore the importance of including male partners when investigating the impact of phthalate exposure on IVF. These results also suggest that clinical recommendations should include male partners for limiting phthalate exposure. Still, a larger and more comprehensive investigation is necessary to more definitively assess the risks.

Cohort profile: Center for Research on Early Childhood Exposure and Development in Puerto Rico

PURPOSE

Puerto Rican children experience high rates of asthma and obesity. Further, infants born in Puerto Rico are more at risk for being born prematurely compared with infants on the mainland USA. Environmental exposures from multiple sources during critical periods of child development, potentially modified by psychosocial factors, may contribute to these adverse health outcomes. To date, most studies investigating the health effects of environmental factors on infant and child health have focused on single or individual exposures.

PARTICIPANTS

Infants currently in gestation whose mother is enrolled in Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) cohort, and infants and children already born to mothers who participated in the PROTECT study.

FINDINGS TO DATE

Data collection and processing remains ongoing. Demographic data have been collected on 437 mother-child pairs. Birth outcomes are available for 420 infants, neurodevelopmental outcomes have been collected on 319 children. Concentrations of parabens and phenols in maternal spot urine samples have been measured from 386 mothers. Center for Research on Early Childhood Exposure and Development mothers have significantly higher urinary concentrations of dichlorophenols, triclosan and triclocarban, but lower levels of several parabens compared with reference values from a similar population drawn from the National Health and Nutrition Examination Survey.

FUTURE PLANS

Data will continue to be collected through recruitment of new births with a target of 600 children. Seven scheduled follow-up visits with existing and new participants are planned. Further, our research team continues to work with healthcare providers, paediatricians and early intervention providers to support parent's ability to access early intervention services for participants.

The Bisphenol A Induced Oxidative Stress in Non-Alcoholic Fatty Liver Disease Male Patients: A Clinical Strategy to Antagonize the Progression of the Disease

Introduction: Bisphenol A (BPA) exposure has been correlated to non-alcoholic fatty liver disease (NAFLD) development and progression. We investigated, in a clinical model, the effects of the administration of 303 mg of silybin phospholipids complex, 10 μg of vitamin D, and 15 mg of vitamin E (RealSIL, 100D, IBI-Lorenzini, Aprilia, Italy) in male NAFLD patients exposed to BPA on metabolic, hormonal, and oxidative stress-related parameters. Methods: We enrolled 32 male patients with histologic diagnosis of NAFLD and treated them with Realsil 100D twice a day for six months. We performed at baseline clinical, biochemical, and food consumption assessments as well as the evaluation of physical exercise, thiobarbituric acid reactive substances (TBARS), plasmatic and urinary BPA and estrogen levels. The results obtained were compared with those of healthy control subjects and, in the NAFLD group, between baseline and the end of treatment. Results: A direct proportionality between TBARS levels and BPA exposure was shown (p < 0.0001). The therapy determined a reduction of TBARS levels (p = 0.011), an improvement of alanine aminotransferase, aspartate aminotransferase, insulinemia, homeostatic model assessment insulin resistance, C reactive protein, tumor necrosis factor alpha (p < 0.05), an increase of conjugated BPA urine amount, and a reduction of its free form (p < 0.0001; p = 0.0002). Moreover, the therapy caused an increase of plasmatic levels of the native form of estrogens (p = 0.03). Conclusions: We highlighted the potential role of BPA in estrogen oxidation and oxidative stress in NAFLD patients. The use of Realsil 100D could contribute to fast BPA detoxification and to improve cellular antioxidant power, defending the integrity of biological estrogen-dependent pathways.

Sonoelectrochemical Degradation of Propyl Paraben: An Examination of the Synergy in Different Water Matrices

The synergistic action of anodic oxidation using boron-doped diamond and low-frequency ultrasound in different water matrices and operating conditions for the decomposition of the emerging contaminant propyl paraben was investigated. The degree of synergy was found to decrease with an increase in current in the range 1.25–6.25 mA/cm² or the ultrasound power until 36 W/L, where a further decrease was observed. Despite the fact that the increased propyl paraben concentration decreased the observed kinetic constant for both the separated and the hybrid process, the degree of synergy was increased from 37.3 to 43.4% for 0.5 and 2 mg/L propyl paraben, respectively. Bicarbonates (100–250 mg/L) or humic acid (10–20 mg/L) enhanced the synergy significantly by up to 55.8%, due to the higher demand for reactive oxygen species. The presence of chloride ions decreased the observed synergistic action in comparison with ultrapure water, possibly due to the electro-generation of active chlorine that diffuses to the bulk solution. The same behavior was observed with the secondary effluent that contained almost 68 mg/L of chlorides. The efficiency was favored in a neutral medium, while the hybrid process was delayed in alkaline conditions.

Onset and tempo of sexual maturation is differentially associated with gestational phthalate exposure between boys and girls in a Mexico City birth cohort

Phthalates are endocrine disrupting compounds commonly found in consumer products, exposure to which may influence reproductive maturation. Effects from exposure in utero on the onset and progression of sexual development are understudied. We examined longitudinal associations between gestational phthalate exposure and sexual maturation at two points in adolescence (8-14, 9-18 years). Gestational exposure was quantified using the geometric mean of 3 trimester-specific urinary phthalate metabolite measurements. Sexual maturation was assessed using Tanner stages and menarche onset for girls and Tanner stages and testicular volume for boys. Generalized estimating equations for correlated ordinal multinomial responses were used to model relationships between phthalates and odds of transitioning to the next Tanner stage, while generalized additive (GA) mixed models were used to assess the odds of menarche. All models were adjusted for child age (centered around the mean), BMI z-score, change in BMI between visits, time (years) between visits (ΔT), and interactions between ΔT and mean-centered child age and the natural log of exposure metabolite concentration. Among girls, a doubling of gestational MBzP concentrations was associated with increased odds of being at a higher Tanner stage for breast development at 8-14 years (OR = 4.62; 95% CI: 1.38, 15.5), but with slower progression of breast development over the follow-up period (OR = 0.65 per year; 95% CI: 0.46, 0.92) after adjustment for child age and BMI z-score. Similar results were found for ∑DEHP levels and breast development. In boys, a doubling of gestational MBP concentrations was associated with lower odds of being at a higher Tanner stage for pubic hair growth at 8-14 years (OR = 0.37; 95% CI: 0.14, 0.95) but with faster progression (OR: 1.28; 95% CI: 0.97, 1.69). These results indicate that gestational phthalate exposures may impact the onset and progression of sexual development, and that these relationships differ between boys and girls.

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

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

Synthetic Chemical Trade as a Potential Driver of Global Health Disparities and Data Gaps on Synthetic Chemicals in Vulnerable Populations

PURPOSE OF REVIEW

Most research on toxic exposures in vulnerable populations focuses on air pollution. Synthetic chemical production, however, is a multi-billion-dollar industry that lacks appropriate international regulation to protect those exposed to toxic chemicals. This paper aims to describe the country-level import and export of key groups of synthetic chemicals using data from the United Nations Comtrade Database and provide a narrative review of the evidence from January 2018 to August 2019 on exposure to, health effects of, and interventions to reduce synthetic chemicals in vulnerable populations around the world.

RECENT FINDINGS

Generally, a small number of high-income countries export the majority of synthetic chemicals, while most low-income countries import more chemicals than they export, which may contribute to higher levels of synthetic chemicals in those settings. However, few studies have quantified exposures to synthetic chemicals in low- and middle-income countries, the health effects of such exposures, or interventions to mitigate exposures. Synthetic chemicals continue to enter markets despite our limited knowledge of their effects on human health, particularly in the most vulnerable populations. We need more research to understand the health impacts of these pervasive exposures.

Occurrence, distribution, and sources of phthalates and non-phthalate plasticizers in sediment from semi-enclosed bays of Korea

Due to strong regulation of phthalates, non-phthalate plasticizers (NPPs) have been introduced to the industrial market. In this study, concentrations of 16 phthalates and five NPPs in sediment were measured to investigate the occurrence, potential source, and ecotoxicological implications of these contaminants. Phthalates and NPPs were detected in all sediment samples, indicating ubiquitous contaminants. Di(2-ethylhexyl)phthalate (DEHP) and trioctyl trimellitate (TOTM) were the dominant for phthalates and NPPs, respectively, implying emerging contamination by TOTM. Spatial distribution of these contaminants showed decreasing gradients from inner to outer bays. Clear declining trends in phthalate and NPP concentrations were found in sediment near a wastewater treatment plant outfall, suggesting a potential source of contamination. Approximately 95% of sediment samples exceeded sediment quality guidelines for DEHP suggested by previous studies, implying that benthic organisms are suffering from adverse biological effects. This is the first report on the occurrence of NPPs in the coastal environment.

Determinants and characterization of exposure to phthalates, DEHTP and DINCH among pregnant women in the PROTECT birth cohort in Puerto Rico

BACKGROUND

As a result of evidence suggesting phthalate toxicity, their use has decreased in recent years. However, new phthalates and non-phthalate replacements have emerged in their place, with unknown potential impacts on health.

METHODS

We measured 15 phthalate, two di(2-ethylhexyl)terephthalate (DEHTP), and two di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH) urinary metabolites, collected up to three times during pregnancy from 994 women in Northern Puerto Rico (2011-2017). We used tests of linear trend to assess changes in concentrations over time and linear mixed models to identify predictors of exposure (sociodemographic characteristics, drinking water sources, diet, product use).

RESULTS

Several phthalate metabolites decreased over the study period indicating decreased exposure, while the geometric mean of DEHTP metabolites (molecular sum) increased threefold between 2014 and 2017. Intraclass correlations revealed low to moderate reproducibility of these biomarkers across pregnancy. Several metabolites were associated with maternal age, income, education, pre-pregnancy BMI, drinking public water, use of cleaning and personal care products, and ice cream consumption. DINCH metabolite concentrations remained low throughout the study period.

CONCLUSION

Although exposure to some phthalates may be decreasing, exposure to replacements, such as DEHTP, is increasing. Additional studies are needed to further characterize sources of phthalate replacement chemicals and potential exposure-related health effects among vulnerable populations.

Measured concentrations of consumer product chemicals in California house dust: Implications for sources, exposure, and toxicity potential

Household dust is a reservoir of various consumer product chemicals. Thus, characterizing comprehensive chemical profiles of house dust may help improve our understanding of residential chemical exposure. We have previously developed a method for detecting a broad spectrum of chemicals in dust by applying a combination of target, suspect screening, and non-target methods with mass spectrometry preceded by liquid chromatography and gas chromatography. Building upon a previous study that detected 271 compounds in 38 dust samples, we presented concentrations of 144 compounds that were confirmed and quantified by standards in the same set of samples. Ten compounds were measured with median concentrations greater than 10 000 ng/g of dust: cis-hexadec-6-enoic acid, squalene, cholesterol, vitamin E, bis(2-ethylhexyl) phthalate, dioctyl terephthalate, linoleic acid, tricaprylin, tris(1-chloroisopropyl) phosphate, and oxybenzone. We also reviewed in vitro toxicity screening data to identify compounds that were not previously detected in indoor dust but have potential for adverse health effects. Among 119 newly detected compounds, 13 had endocrine-disrupting potential and 7 had neurotoxic potential. Toxicity screening data were not available for eight biocides, which may adversely affect health. Our results strive to provide more comprehensive chemical profiles of house dust and identified information gaps for future health studies.

Exposure assessment to parabens, bisphenol A and perfluoroalkyl compounds in children, women and men by hair analysis

Population is continuously exposed to endocrine disrupting compounds present in everyday products such as parabens, bisphenol A (BPA), and perfluoroalkyl compounds (PFCs). The aims of this study were, first, to evaluate human exposure to three parabens (methylparaben (MeP), ethylparaben (EtP) and propylparaben (PrP)), BPA and six PFCs (perfluorobutanoic acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)) through the analysis of hair samples from children, women and men and, then, to evaluate possible relationships between pollutant concentration in hair and age, gender, smoking and dyeing habits or hair colour. Hair samples were collected from 42 volunteers from Seville (Spain) (10 children, 16 women and 16 men). Six of the monitored pollutants (MeP, EtP, PrP, BPA, PFHpA and PFOS) were detected in at least 76% of the samples analysed. The highest concentrations and frequency of detection (100% of the samples) corresponded to MeP and PrP (up to 14,187 and 9009 ng/g, respectively). BPA was found in 83% of the samples at concentrations in the range from 24 to 1427 ng/g whereas PFCs were detected at concentrations in the range from 0.6 to 15.5 ng/g, being PFHpA and PFOS the ones most frequently detected (86% and 76%, respectively). Concentrations of BPA and parabens in adults were statistically higher than those in children. The results of this study reveal the suitability of hair for biomonitoring endocrine disrupting compounds of high concern (PFCs, parabens and BPA) to which population is internally or/and externally but continuously exposed.

Occurrence and Distribution of Phthalates in Sanitary Napkins from Six Countries: Implications for Women's Health

Chemicals in feminine hygiene products can exert adverse health effects as a result of strong absorptive capacity of the vagina and vulva. However, little information is available on phthalates in sanitary napkins. We measured the concentrations of 15 phthalates in sanitary napkins collected from six countries and found total concentrations in the range of 1733-11942 ng/g. Di(isobutyl)phthalate (DiBP), bis(2-ethylhexyl)phthalate (DEHP), and di-n-butyl phthalate (DnBP) were the dominant congeners, representing a median of 27.3, 26.7, and 20.4% of the total median phthalate concentrations across all countries, respectively. The phthalates likely originated mainly from the introduction in the manufacturing process, and some may have been from the use of plastic or paper materials. The estimated intake (at the 90th percentile) of DiBP, DnBP, and DEHP from sanitary napkins approximately represented 6.35-23.6, 3.35-9.90, and 1.06-9.57%, respectively, of the total exposure, indicating that sanitary napkins are a relevant source of exposure to these chemicals. The calculated health risks of phthalates in sanitary napkins were generally low, but the carcinogenic risks in some samples exceeded acceptable levels. More research is required to investigate the contaminations in sanitary napkins and those associated with risks to women.

Urinary concentrations of environmental phenols and their associations with breast cancer incidence and mortality following breast cancer

BACKGROUND

Environmental phenols, compounds used widely in personal care and consumer products, are known endocrine disruptors. Few epidemiologic studies have examined the association of phenol biomarkers with breast cancer incidence and, to our knowledge, none have considered associations with mortality following breast cancer. We examined seven urinary phenol biomarkers in association with breast cancer incidence and subsequent mortality, and examined effect measure modification by body mass index (BMI).

METHODS

Participants included 711 women with breast cancer and 598 women without breast cancer who were interviewed for the population-based Long Island Breast Cancer Study Project. Among women with breast cancer, phenol biomarkers were quantified in spot urine samples collected on average within three months of a first diagnosis of primary in situ or invasive breast cancer in 1996-1997. Women with breast cancer were monitored for vital status using the National Death Index. After a median follow-up of 17.6 years, we identified 271 deaths, including 98 deaths from breast cancer. We examined creatinine-corrected phenol concentrations and the sum of parabens (Σparabens) in association with breast cancer incidence using logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs), and with mortality using Cox regression to estimate hazard ratios (HRs) and 95% CIs. We evaluated multiplicative effect measure modification using cross-product terms in nested models.

RESULTS

The highest (vs lowest) quintiles of urinary methylparaben, propylparaben, and Σparabens were associated with risk of breast cancer with ORs ranging from 1.31 to 1.50. Methylparaben, propylparaben, and Σparabens were also associated with all-cause mortality HRs ranging from 0.68 to 0.77. Associations for breast cancer incidence were more pronounced among women with BMI < 25.0 kg/m2 than among women with BMI ≥ 25.0 kg/m2; however, associations for mortality were more pronounced among women with BMI ≥ 25 kg/m2 than among women with BMI < 25 kg/m2.

CONCLUSIONS

Select parabens may have differential associations with risk of developing breast cancer and mortality following breast cancer.

Racial disparity in maternal phthalates exposure; Association with racial disparity in fetal growth and birth outcomes

Experimental and observational data implicate phthalates as developmental toxicants. However, few data are available to assess the maternal risks of gestational exposure by race and infant sex. To begin to address this data gap, we characterized associations between maternal urinary phthalate metabolites and birth outcomes among African American and white mothers from a southeastern U.S. population. We enrolled pregnant African American (n = 152) and white (n = 158) women with singleton live births between 18 and 22 weeks gestation. We measured phthalate metabolites (mono-n-butyl phthalate (MBP), monoisobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), monoethyl phthalate (MEP), monomethyl phthalate (MMP), and the sums of DEHP (ΣDEHP) and DBP (ΣDBP) metabolites) in up to two gestational urine specimens from mothers, and evaluated confounder-adjusted associations per natural log unit greater concentration with birth weight for gestational age z-score, small for gestational age (SGA; <10th %tile), preterm birth (PTB; <37 weeks gestation), and low birth weight (LBW; <2500 g). We also tested for interactions by maternal race and infant sex. We found that lower z-scores were associated with greater MiBP (β = -0.28; 95% CI: -0.54, -0.02) and MMP (β = -0.30; 95% CI: -0.52, -0.09) concentrations, while MEP interacted with race (p = 0.04), indicating an association among whites (β = -0.14; 95% CI: -0.28, 0.001) but not among African Americans (β = 0.05; 95% CI = -0.09, 0.19). Greater MiBP (OR = 2.82; 95% CI: 1.21, 6.56) and MEOHP (OR = 2.80; 95% CI: 1.05, 7.42) were associated with an overall higher SGA risk, greater MEHP was associated with higher SGA risk (p = 0.10) in whites (OR = 3.26 95% CI: 0.64, 16.56) but not in African Americans (OR = 0.71 95% CI: 0.07, 7.17), and the associations for MiBP (p = 0.02) and ΣDBP (p = 0.02) varied by infant sex. We detected interactions for PTB in which African Americans were at higher risk than whites for greater MiBP (p = 0.08) and MEP (p = 0.02) although lower risk for greater MEHP (p = 0.09). Greater MEP was associated with an overall higher LBW risk (OR = 1.33; 95% CI: 0.95, 1.86), and males were at higher risk than females with greater MBP (p = 0.002), MiBP (p = 0.02), MBzP (p = 0.01), MEP (p = 0.002), MMP (p = 0.09), and ΣDBP (p = 0.01) concentrations. Overall, our results suggest that gestational phthalate exposure is associated with adverse maternal birth outcomes, and that the effects vary by maternal race and infant sex.

Fetal growth in environmental epidemiology: mechanisms, limitations, and a review of associations with biomarkers of non-persistent chemical exposures during pregnancy

BACKGROUND

Non-persistent chemicals, such as phthalates, environmental phenols, organophosphate pesticides, and others, are challenging to study because of their ubiquity in the environment, diverse exposure routes, and high temporal variability of biomarkers. Nonetheless, there is interest in understanding how gestational exposure to these chemicals may affect fetal growth, as perturbations to normal fetal growth are related to a plethora of adverse health outcomes in childhood and adulthood.

METHODS

The purpose of this review is to describe the state of the science on this topic. We searched PubMed for studies that included both 1) biomarkers of non-persistent chemicals collected during pregnancy and 2) fetal growth outcomes measured at birth (e.g., birth weight) or by ultrasound in utero (e.g., estimated fetal weight).

RESULTS

The bulk of the literature we found uses biomarkers measured at a single time point in pregnancy and birth weight as the primary measure of fetal growth. There is a small, but growing, body of research that uses ultrasound measures to assess fetal growth during pregnancy. In addition to summarizing the findings of the publications we identified, we describe inconsistencies in methodology, areas for improvement, and gaps in existing knowledge that can be targeted for improvement in future work. This literature is characterized by variability in methodology, likely contributing to the inconsistency of results reported. We further discuss maternal, placental, and fetal pathways by which these classes of chemicals may affect fetal growth.

CONCLUSIONS

To improve understanding of how everyday chemical exposures affect fetal growth, and ultimately lifelong health outcomes, mechanisms of toxicant action should be considered alongside improved study designs for future hypothesis-driven research.

Correlation and temporal variability of urinary biomarkers of chemicals among couples: Implications for reproductive epidemiological studies

BACKGROUND

Exposure to some environmental chemicals is ubiquitous and linked to a variety of adverse outcomes, including children's health. While few studies have assessed the contribution of both male and female exposures to children's health, understanding the patterns of couple's exposure is needed to understand their joint effects.

OBJECTIVE

We assessed the correlation patterns between male and female partners' concentrations of 37 environmental chemical biomarkers. We also assessed the temporal reliability of the biomarkers within couples.

METHODS

We calculated Spearman pairwise correlations between specific gravity adjusted urinary biomarker concentrations and hair mercury concentrations among 380 couples enrolled in the Environment and Reproductive Health (EARTH) study at the Massachusetts General Hospital Fertility Center (2004-2017). We calculated intra-class correlation coefficients (ICCs) for couple's biomarkers to assess the temporal variability of these exposures within a couple using multiple paired-samples from couples.

RESULTS

All biomarkers were positively correlated within couples (range: 0.05 for tert-butylphenyl phenyl phosphate to 0.66 for triclosan). In general, the biomarkers with the highest within couple correlation were those of chemicals for which diet (e.g., di(2-ethylhexyl) phthalate), personal care products use (e.g., triclosan, benzophenone-3), and the indoor environment (e.g., 2,5-dichlorophenol) are considered primary exposure sources. Most other biomarkers were moderately correlated (0.3-<0.6). Similar patterns of temporal reliability were observed across biomarkers.

CONCLUSIONS

Urinary concentrations of several biomarkers were mostly moderately correlated within couples, suggesting similar exposure sources. Future epidemiological studies should collect samples from both partners to be able to accurately determine the contribution of maternal and paternal exposures to offspring health.

Elevated concentrations of urinary triclocarban, phenol and paraben among pregnant women in Northern Puerto Rico: Predictors and trends

BACKGROUND

Understanding important sources and pathways of exposure to common chemicals known or suspected to impact human health is critical to eliminate or reduce the exposure. This is particularly important in areas such as Puerto Rico, where residents have higher exposures to numerous chemicals, as well as higher rates of many adverse health outcomes, compared to the mainland US.

OBJECTIVE

The aim of this study was to assess distributions, time trends, and predictors of urinary triclocarban, phenol, and paraben biomarkers measured at multiple times during pregnancy among women living in Northern Puerto Rico.

METHODS

We recruited 1003 pregnant women between years 2010 and 2016 from prenatal clinics and collected urine samples and questionnaire data on personal care product use at up to three separate visits, between 16 and 28 weeks gestation. Urine samples were analyzed for triclocarban, seven phenols and four parabens: 2,4-dichlorophenol, 2,5-dichlorophenol, benzophenone-3, bisphenol A (BPA), bisphenol S (BPS), bisphenol F, triclosan, butylparaben, ethylparaben, methylparaben, and propylparaben.

RESULTS

Detectable triclocarban, phenol and paraben concentrations among pregnant women were prevalent and tended to be higher than levels measured in women of reproductive age from the general US population, especially triclocarban, which had a median concentration 37 times higher in Puerto Rico participants (2.6 vs 0.07 ng/mL). A decreasing temporal trend was statistically significant for urine concentrations of BPA during the study period, while the BPA substitute BPS showed an increasing temporal trend. Significant and positive associations were found between biomarker concentrations with the products use in the past 48-h (soap, sunscreen, lotion, cosmetics). There was an increasing trend of triclocarban/triclosan urinary concentrations with increased concentrations of triclocarban/triclosan listed as the active ingredient in the bar soap/liquid soap products reported being used.

CONCLUSION

Our results suggest several potential exposure sources to triclocarban, phenols, and parabens in this population and may help inform targeted approaches to reduce exposure.