Personal care product use predicts urinary concentrations of some phthalate monoesters

Phthalate exposure in Thai children and adolescents

Background

Phthalates are found in products made of plastic. Because of concerns regarding the hazards of phthalate exposure, including endocrine disruption, many countries have regulations to restrict their use in products used by children. However, in Thailand, no such restrictions exist, and data relating to phthalate exposure are scarce.

Objectives

To determine the level of exposure of Thai children and adolescents to phthalates, and study its associations with sociodemographic data and the exposure to potential sources of phthalates.

Methods

Healthy children aged 2–18 y were enrolled into the present cross-sectional study between January 2016 and December 2016 inclusive. Their anthropometric indices and Tanner staging were determined. Urinary concentrations of the phthalate metabolites, monomethyl phthalate (MMP) and mono-n-butyl phthalate (MBP), were determined in spot samples by high-performance liquid chromatography to estimate the level of phthalate exposure. Associations between sociodemographic data, exposure to potential sources of phthalates, and phthalate metabolite concentrations were analyzed.

Results

We included 103 boys and 118 girls with a mean age of 9.4 ± 3.64 (range 2.8–17.1) y and detected MMP in 28.5% and MBP in 88.6%. The geometric means (interquartile range) of urinary MMP and MBP were 3400 (2489, 4642) and 214.4 (164, 279) μg/g creatinine (Cr), respectively. Significant associations were found between exposure to floor cleaning products and Cr-adjusted urinary MMP level (P < 0.05), and paint and Cr-adjusted urinary MMP and MBP levels (P < 0.05). Prepuberty was significantly associated with urinary Cr-adjusted MMP level.

Conclusion

Urinary phthalate metabolite levels were high in a proportion of Thai children and adolescents. Exposure to floor cleaning products and paint is associated with phthalate exposure, and advanced Tanner stage is negatively associated with urinary Cr-adjusted MBP.

Characterization of phthalates exposure and risk for cosmetics and perfume sales clerks

High levels of phthalates in name-brand cosmetics products have raised concerns about phthalate exposure and the associated risk for cosmetics sales clerks. We assessed the exposure and risk of phthalates in 23 cosmetics, 4 perfume, and 9 clothing department store sales clerks. We collected 108 urine samples pre- and post-shift and analyzed for phthalate monoesters through liquid chromatography-electrospray ionization-tandem mass spectrometry. Phthalates in 32 air samples were collected and analyzed through gas chromatography-mass spectrometry. Demographic characteristics and information on the exposure scenarios were obtained through questionnaires. Principal component analysis, cluster and risk analysis were applied to identify the exposure profile and risk of phthalate. Median post-shift levels of urinary mono-2-ethylhexyl phthalate (MEHP) and monomethyl phthalate (MMP) were significantly higher than the corresponding pre-shift levels in cosmetics group (53.3 vs. 30.9 μg/g-c for MEHP; 34.4 vs. 22.5 μg/g-c for MMP; both P < 0.05) and the post-shift levels of urinary MMP was significantly higher than the corresponding pre-shift levels in perfume group (26.6 vs. 14.9 μg/g-c, P < 0.05). Median levels of air diethyl phthalate (DEP) in cosmetics (1.77 μg/m³) and perfume (1.75 μg/m³) groups and di-(2-ethylhexyl) phthalate (DEHP) in perfume group (6.98 μg/m³) were higher than those in clothing group (DEP: 0.89; DEHP: 2.16 μg/m³). Over half of cosmetic (70%) and perfume sale clerks had exceeded cumulative risk of phthalate exposure for anti-androgenic effect. We concluded that cosmetic and perfume workers had increased risks of reproductive or hepatic effects for DBP and DEHP exposure. We suggest that not only inhalation but dermal exposure is important route of phthalate exposure for cosmetics and perfume workers.

Predictors and correlations of phthalate metabolite concentrations in urine and seminal plasma among reproductive-aged men

BACKGROUND

Certain phthalates are suspected to be endocrine disruptors that are adversely associated with male reproductive health. However, the predictors and correlations of phthalate metabolite concentrations in urine and seminal plasma among reproductive-aged men have not been thoroughly studied.

OBJECTIVE

To investigate the predictors and correlations of phthalate metabolite concentrations in urine and seminal plasma among adult Chinese males.

METHOD

We measured mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-n-octyl phthalate (MOP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) concentrations in seminal plasma and repeated spot-urine samples from 687 men who visited a reproductive center. Mixed-effect models were used to examine the associations of sociodemographic, lifestyle and medical factors with urinary metabolite concentrations. Linear regression models were used to identify predictors of metabolite concentrations in seminal plasma and correlations between metabolite concentrations in spot urine samples and seminal plasma.

RESULTS

Measurements taken from spot urine samples poorly predicted same-day seminal plasma concentrations (all R²<0.10). Inverse associations were observed between education level and urinary MBP and MEOHP and between household income and urinary MMP; receiving intravenous infusion therapy was associated with increased urinary MBP, MEHHP and MEOHP, use of facial cleanser/cream was associated with increased MEP, and smoking was associated with increased MEHP. The predictors of metabolite concentrations in seminal plasma differed from those in urine, except for the association of intravenous infusion therapy with MBP. BMI was associated with increased seminal plasma MBP, MEHP and MEOHP, smoking was associated with increased MEP, and contact with plastics was associated with increased MEOHP.

CONCLUSIONS

Phthalate metabolite concentrations in adult men varied in accordance with sociodemographic variables, lifestyle factors and intravenous therapy. Measures of metabolite levels in urine may not directly reflect the exposure status of the male reproductive system.

Prevalence and predictors of phthalate exposure in pregnant women in Charleston, SC

Phthalates are plasticizers commonly detected in human urine due to widespread exposure from PVC plastics, food packaging, and personal care products. Several phthalates are known antiandrogenic endocrine disruptors, which raises concern for prenatal exposure during critical windows of fetal development. While phthalate exposure is ubiquitous, certain demographics are subject to greater or lesser exposure. We sampled urine from 378 pregnant women during the second trimester of gestation living in Charleston, SC, and measured eight urinary phthalate metabolites as biomarkers of phthalate exposure: monobutyl phthalate (MBP), 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), monoisobutyl phthalate (MiBP), and monomethyl phthalate (MMP). Demographic data was collected from questionnaires administered at the time of specimen collection. All phthalate metabolites were detected in over 93% of urine samples. On average, concentrations were highest for MEP (median = 47.0 ng/mL) and lowest for MMP (median = 1.92 ng/mL). Sociodemographic characteristics associated with elevated phthalate concentrations included being unmarried, less educated, having a low income, high body mass index (BMI), and/or being African American. After racial stratification, age, BMI, education, and income were significantly associated with phthalate concentrations in African American women. Marital status was associated with phthalate concentrations in Caucasian women only, with greater concentrations of MBP, MEHHP, MiBP, and MMP in unmarried versus married women. Results of this cross-sectional study provide evidence for significant racial and demographic variations in phthalate exposure.

Neighborhood Factors and Urinary Metabolites of Nicotine, Phthalates, and Dichlorobenzene

BACKGROUND AND OBJECTIVES

Exposures to environmental chemicals are ubiquitous in the US. Little is known about how neighborhood factors contribute to exposures.

METHODS

Growing Up Healthy is a prospective cohort study of environmental exposures and growth and development among Hispanic and African American children (n = 506) in New York City. We sought to determine associations between neighborhood-level factors (eg, housing type, school, time spent indoors versus outdoors) and urinary biomarkers of chemical exposures suspected to be associated with these characteristics (cotinine, 2,5-dichlorophenol, and phthalate metabolites) adjusted by age, sex, race, and caregiver education and language.

RESULTS

Urinary cotinine concentrations revealed a prevalent exposure to secondhand smoke; children living in public housing had higher concentrations than those in private housing. In homes with 1 smoker versus none, we found significant differences in urinary cotinine concentrations by housing, although not in homes with 2 or more smokers. Children in charter or public schools had higher urinary cotinine concentrations than those in private schools. School type was associated with exposures to both low- and high-molecular-weight phthalates, and concentrations of both exposure biomarkers were higher for children attending public versus private school. 2,5-Dichlorophenol concentrations declined from 2004 to 2007 (P = .038) and were higher among charter school children.

CONCLUSIONS

Housing and school type are associated with chemical exposures in this minority, inner city population. Understanding the role of neighborhood on environmental exposures can lead to targeted community-level interventions, with the goal of reducing environmental chemical exposures disproportionately seen in urban minority communities.

Influence of race on prenatal phthalate exposure and anogenital measurements among boys and girls

BACKGROUND

Select phthalates have antiandrogenic activity, which raises concern for adverse developmental outcomes given widespread exposure of pregnant women. Investigators have reported associations between maternal urinary phthalates and altered anogenital distance (AGD), a marker of in utero androgen activity, among offspring. However, data assessing the impact of race on these associations is sparse.

OBJECTIVES

To evaluate associations between prenatal phthalate exposure and AGD in a racially diverse newborn population.

METHODS

We prospectively collected second trimester urine from 187 African American and 193 white mothers, and used liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to measure eight phthalate metabolites and calculate molar sums. We measured anopenile (APD) and anoscrotal (ASD) distances of 171 boys and anoclitoral (ACD) and anofourchette (AFD) distances of 128 girls at delivery. We collected sociodemographic and clinical data from questionnaires and delivery records.

RESULTS

We identified a statistically significant inverse association for mono-2-ethylhexyl phthalate (MEHP) and APD in boys (B=-1.57mm, p=0.02), which was stronger for African Americans (B=-2.07mm, p=0.04) than for whites (B=-1.23mm, p=0.22), although the racial interaction was not statistically significant (p=0.56). We found a longer ASD for higher molar sums of dibutyl phthalate (∑DBP; B=0.99mm, p=0.04), with stronger associations for whites (B=1.30mm, p=0.04) than for African Americans (B=0.39mm, p=0.59), again without a statistically significant racial interaction (p=0.34). Among girls, we found inverse associations for tertiles of MEHP with AFD and ACD, and statistically significant race-based interactions, in which ACD was longer for whites and shorter for African Americans, following exposure to monoethyl phthalate (MEP; p=0.01) and ∑DBP (p=0.08).

CONCLUSIONS

Our findings suggest race and sex play important roles in phthalate-associated reproductive developmental toxicity, with important implications for designing future investigations and health interventions.

Urine Arsenic and Arsenic Metabolites in U.S. Adults and Biomarkers of Inflammation, Oxidative Stress, and Endothelial Dysfunction: A Cross-Sectional Study

BACKGROUND

Arsenic (As) exposure has been associated with increased risk for cardiovascular disease (CVD) and with biomarkers of potential CVD risk and inflammatory processes. However, few studies have evaluated the effects of As on such biomarkers in U.S. populations, which are typically exposed to low to moderate As concentrations.

OBJECTIVES

We investigated associations between As exposures and biomarkers relevant to inflammation, oxidative stress, and CVD risk in a subset of participants from the New Hampshire Health Study, a population with low to moderate As exposure (n=418).

METHODS

Associations between toenail As, total urine As (uAs), and %uAs metabolites [monomethyl (%uMMA^V), dimethyl (%uDMA^V), and inorganic (%iAs) species] and plasma biomarkers, including soluble plasma vascular and cellular adhesion molecules (VCAM-1 and ICAM-1, respectively), matrix metalloproteinase-9 (MMP-9), tumor necrosis factor-α, plasminogen activator inhibitor-1 (PAI-1), and urinary oxidative stress marker 15-F_2t-isoprostane (15-F_2t-IsoP), were evaluated using linear regression models.

RESULTS

Covariate-adjusted estimates of associations with a doubling of urinary As suggested an 8.8% increase in 15-F_2t-IsoP (95% CI: 3.2, 14.7), and a doubling of toenail As was associated with a 1.7% increase in VCAM-1 (95% CI: 0.2, 3.2). Additionally, a 5% increase in %uMMA was associated with a 7.9% increase in 15-F_2t-IsoP (95% CI: 2.1, 14.1), and a 5% increase in %uDMA was associated with a 2.98% decrease in 15-F_2t-IsoP [(95% CI: -6.1, 0.21); p=0.07]. However, in contrast with expectations, a doubling of toenail As was associated with a 2.3% decrease (95% CI: -4.3, -0.3) in MMP-9, and a 5% increase in %uMMA was associated with a 7.7% decrease (95% CI: -12.6, -2.5) in PAI-1.

CONCLUSION

In a cross-sectional study of U.S. adults, we observed some positive associations of uAs and toenail As concentrations with biomarkers potentially relevant to CVD pathogenesis and inflammation, and evidence of a higher capacity to metabolize inorganic As was negatively associated with a marker of oxidative stress. https://doi.org/10.1289/EHP2062.

Dietary B Vitamin Intake Is Associated with Lower Urinary Monomethyl Arsenic and Oxidative Stress Marker 15-F2t-Isoprostane among New Hampshire Adults

Background: Arsenic exposure has been associated with an increased risk of cardiovascular disease (CVD). Growing evidence suggests that B vitamins facilitate arsenic metabolism and may protect against arsenic toxicity. However, to our knowledge, few studies have evaluated this in US populations.Objective: Our objective was to examine whether higher B vitamin intake is associated with enhanced arsenic metabolism and lower concentrations of preclinical markers of CVD among New Hampshire adults.Methods: We used weighted quantile sum (WQS) regression to evaluate the collective impact of 6 dietary B vitamins (thiamin, riboflavin, folate, niacin, and vitamins B-6 and B-12) on 1) the proportion of arsenic metabolites in urine and 2) 6 CVD-related markers [including urinary 15-F_2t-isoprostane (15-F_2t-IsoP)] among 418 participants (26-75 y of age) from the New Hampshire Health Study. Contributions of arsenic metabolites to B vitamin-CVD marker associations were also explored in structural equation models.Results: In WQS models, the weighted sum of B vitamin intakes from food sources was inversely associated with the proportion of monomethyl arsenic species in urine (uMMA) (β: -1.03; 95% CI: -1.91, -0.15; P = 0.02). Thiamin and vitamins B-6 and B-12 contributed the most to this association, whereas riboflavin had a negligible effect. Higher overall B vitamin intake was also inversely associated with 15-F_2t-IsoP (β: -0.21; 95% CI: -0.32, -0.11; P < 0.01), with equal contributions from the 6 B vitamins, which was partially explained by differences in the proportion of uMMA (indirect effect β: -0.01; 95% CI: -0.04, -0.00).Conclusions: Among New Hampshire adults, higher intakes of certain B vitamins (particularly thiamin and vitamins B-6 and B-12 from food sources) may reduce the proportion of uMMA, an intermediate of arsenic metabolism that has been associated with an increased risk of CVD. Higher overall B vitamin intake may also reduce urinary 15-F_2t-IsoP, a marker of oxidative stress and potential risk factor for CVD, in part by reducing the proportion of uMMA.

Phthalate metabolites in Norwegian mothers and children: Levels, diurnal variation and use of personal care products

Exposure to phthalates has been associated with reproductive and developmental toxicity. Data on levels of these compounds in the Norwegian population is limited. In this study, urine samples were collected from 48 mothers and their children in two counties in Norway. Eleven different phthalate metabolites originating from six commonly used phthalates in consumer products were determined. Concentrations of phthalate metabolites were significantly higher in children compared to mothers except for mono-ethyl phthalate (MEP). The mothers provided several urine samples during 24hours (h) and diurnal variation showed that the concentrations in the morning urine samples (24-8h) were significantly higher than at other time-periods for most of the phthalate metabolites. Intraclass correlation coefficients (ICCs) for 24-hour time-period were in the range of 0.49-0.81. These moderate to high ICCs indicate that one spot urine sample can be used to estimate the exposure to phthalates. Since a significant effect of time of day was observed, it is still advisable to standardize the collection time point to reduce the variation. For the mothers, the use of personal care products (PCPs) were less associated with morning urine samples than early day (8-12h) and evening (16-24h) urine samples. The use of perfume and hair products were positively associated with the urinary concentrations of low molecular weight phthalates. Use of shower soap and shampoo were positively associated with urinary concentration of di(2-ethylhexyl) phthalate (DEHP) metabolites. For children, face cream use was positively associated with phthalate metabolites in the morning samples, and hand soap use was negatively associated with concentration of urinary DEHP metabolites in afternoon/evening samples. Since different PCPs were associated with the urinary phthalate metabolites in different time-periods during a day, more than one spot urine sample might be required to study associations between urinary phthalate metabolites and the use of PCPs.

Personal Care Product Use in Men and Urinary Concentrations of Select Phthalate Metabolites and Parabens: Results from the Environment And Reproductive Health (EARTH) Study

BACKGROUND

Personal care products (PCPs) are exposure sources to phthalates and parabens; however, their contribution to men's exposure is understudied.

OBJECTIVES

We examined the association between PCP use and urinary concentrations of phthalate metabolites and parabens in men.

METHODS

In a prospective cohort, at multiple study visits, men self-reported their use of 14 PCPs and provided a urine sample (2004-2015, Boston, MA). We measured urinary concentrations of 9 phthalate metabolites and methylparaben, propylparaben, and butylparaben. We estimated the covariate-adjusted percent change in urinary concentrations associated with PCP use using linear mixed and Tobit mixed regressions. We also estimated weights for each PCP in a weighted binary score regression and modeled the resulting composite weighted PCP use.

RESULTS

Four hundred men contributed 1,037 urine samples (mean of 3/man). The largest percent increase in monoethyl phthalate (MEP) was associated with use of cologne/perfume (83%, p-value<0.01) and deodorant (74%, p-value<0.01). In contrast, the largest percent increase for parabens was associated with the use of suntan/sunblock lotion (66-156%) and hand/body lotion (79-147%). Increases in MEP and parabens were generally greater with PCP use within 6 h of urine collection. A subset of 10 PCPs that were used within 6 h of urine collection contributed to at least 70% of the weighted score and predicted a 254-1,333% increase in MEP and parabens concentrations. Associations between PCP use and concentrations of the other phthalate metabolites were not statistically significant.

CONCLUSIONS

We identified 10 PCPs of relevance and demonstrated that their use within 6 h of urine collection strongly predicted MEP and paraben urinary concentrations. https://doi.org/10.1289/EHP1374.

Ultrasound gel as an unrecognized source of exposure to phthalates and phenols among pregnant women undergoing routine scan

BACKGROUND

Systemic absorption of phthalates and parabens has been demonstrated after dermal application of body lotion, and medical devices such as intravenous bags and tubing have been identified as a source of exposure to di(2-ethylhexyl) phthalate (DEHP). However, use of products during medical procedures such as aqueous gel applied during obstetrical ultrasound in pregnancy has not been investigated as a potential source of endocrine disrupting chemical (EDC) exposure. Human studies have associated EDCs with various adverse pregnancy outcomes. There is a need to identify sources of inadvertent exposure to EDCs especially during vulnerable developmental periods such as pregnancy.

OBJECTIVES

We conducted a pilot study to determine whether use of gel during routine obstetrical ultrasound increased urinary concentrations of phthalate and phenol biomarkers.

METHODS

We recruited 13 women from the Massachusetts General Hospital who provided spot urine samples at the time of their second trimester anatomic survey. The first sample was collected prior to the procedure (pre-exposure, time 1), and two additional samples were obtained at approximately 1-2h (time 2) and 7-12h (time 3) post-exposure following the scan.

RESULTS

Urinary concentrations of several DEHP metabolites and metabolite of diisononyl cyclohexane-1,2-dicarboxylate (DINCH) increased across time. For example, the geometric mean concentrations of mono(2-ethyl-5-hydroxyhexyl) phthalate increased from 3.1ng/ml to 7.1ng/ml (p-value=0.03) between time 1 and time 3. We also observed significant differences in concentrations of metabolites of butylbenzyl phthalate (BBzP), di-n-butyl phthalate (DnBP), and di-isobutyl phthalate (DiBP). For example, mono-n-butyl phthalate (metabolite of DnBP) decreased from 3.5ng/ml to 1.8ng/ml (p-value=0.04) between time 1 and time 2, but then increased to 6.6ng/ml (p-value=0.002) at time 3. Propylparaben concentrations increased from 8.9ng/ml to 33.6ng/ml between time 1 and time 2 (p-value=0.005), followed by a decrease to 12.9ng/ml at time 3 (p-value=0.01). However, we cannot rule out the possibility that some of the observed differences are due to other sources of exposure to these compounds.

CONCLUSIONS

While additional research is needed, this pilot study potentially identifies a previously unknown source of phthalate and paraben exposure among pregnant women undergoing routine ultrasound examination.

Transplacental Transfer of Monomethyl Phthalate and Mono(2-ethylhexyl) Phthalate in a Human Placenta Perfusion System

The transplacental passage of monomethylphtalate (mMP) and mono (2-ethylhexyl) phthalate (mEHP) was studied using an ex vivo placental perfusion model with simultaneous perfusion of fetal and maternal circulation in a single cotyledon. Umbilical cord blood and placental tissue collected both before and after perfusion were also analyzed. Placentas were obtained immediately after elective cesarean section and dually perfused in a recirculation system. mMP or mEHP was added to maternal perfusion medium to obtain concentrations at 10 and 25 μg/L, respectively. The placental transfer was followed analyzing samples from fetal and maternal perfusion media by liquid chromatography–mass spectrometry–mass spectrometry (LC-MS-MS). Four perfusions with mMP indicated a slow transplacental transfer, with a fetomaternal ratio (FM ratio) of 0.30 ± 0.03 after 150 min of perfusion. Four perfusions with mEHP indicated a very slow or nonexisting placental transfer. mEHP was only detected in fetal perfusion media from two perfusions, giving rise to FM ratios of 0.088 and 0.20 after 150 min of perfusion. Detectable levels of mMP, mEHP, monoethylphthalate (mEP), and monobutylphthalate were found in tissue. Higher tissue levels of mMP after perfusions with mMP compared to perfusions with mEHP suggest an accumulation of mMP during perfusion. No tendency for accumulation of mEHP was observed during perfusions with mEHP compared to perfusions with mMP. Detectable levels of mEHP and mEP were found in umbilical cord plasma samples. mMP and possibly other short-chained phthalate monoesters in maternal blood can cross the placenta by slow transfer, whereas the results indicate no placental transfer of mEHP. Further studies are recommended.

Protective effects of sulforaphane on di-n-butylphthalate-induced testicular oxidative stress injury in male mice offsprings via activating Nrf2/ARE pathway

Di-N-butylphthalate (DBP) is one of the most common endocrine-disrupting chemicals which can disrupt human endocrine system, especially in the male reproductive system. Here, this study was aimed to determine whether sulforaphane (SFN) could protect against testicular oxidative stress injury induced by DBP in male mice offsprings. Wild-type (Nrf2^+/+) and Nrf2-deficient (Nrf2^-/-) timed-pregnant mice were given DBP orally from embryonic day (E)14.5 to E19.5. Subsequently, the oxidative stress markers were evaluated. Besides, Nrf2, NF-κB, I-kB, HO-1 and NQO-1 expression levels in the testis were measured by immunohistochemical staining or western blot analysis. DBP significantly reduced anogenital distance (AGD) and influenced testes growth in male mice offsprings, while SFN ameliorated these phenotypes. After DBP stimulation, the testicular morphology, testicular cell apoptosis index and the oxidative stress markers exhibited statistical differences compared with Control group, while SFN supplementation showed obvious improvements. In addition, administration of SFN could obviously increase the expression level of Nrf2 and its downstream ARE gene battery, such as HO-1, NQO-1 in the testis. Meanwhile, SFN pretreatment did not confer protection against DBP-induced testicular oxidative stress injury in Nrf2 knockout mice. Therefore, the present findings suggested that SFN could effectively protect against DBP-induced testicular oxidative stress injury through Nrf2/ARE signaling pathways in male mice offsprings.

Associations of Prenatal Urinary Bisphenol A Concentrations with Child Behaviors and Cognitive Abilities

BACKGROUND

Prenatal bisphenol A (BPA) exposure has been associated with adverse neurodevelopment in epidemiological studies. However, prior studies had limited statistical power to examine sex-specific effects, and few examined child cognition.

OBJECTIVES

We estimated the association between prenatal BPA exposure and child neurobehavior at 3 y of age in a prospective cohort of 812 mothers and their children.

METHODS

We measured BPA concentration in urine samples collected at ∼12 wk gestation among women enrolled in a 10-city Canadian cohort study. At approximately 3 y of age, we assessed children’s cognitive abilities with the Wechsler Primary and Preschool Scale of Intelligence^TM–III (WPPSI-III) and two scales of the Behavior Rating Inventory of Executive Function–Preschool (BRIEF-P). Parents reported children’s behavior using the Behavior Assessment System for Children–2 (BASC-2) and the Social Responsiveness Scale^TM–2 (SRS-2). We estimated covariate-adjusted differences in neurobehavioral outcomes with a doubling in BPA concentration and sex-specific associations.

RESULTS

BPA was not associated with WPPSI-III scores; child sex did not modify these associations. The association between BPA and BRIEF-P scores was modified by child sex (BPA×sex p-values≤0.03). For example, a doubling of BPA concentration was associated with 1-point (95% CI: 0.3, 1.7) poorer working memory in boys and 0.5-point (95% CI: −1.1, 0.1) better scores in girls. BPA was not associated with most BASC-2 scales; however, it was associated with more internalizing and somatizing behaviors in boys, but not in girls (BPA×sex p&-values≤0.08). A doubling of BPA concentration was associated with poorer SRS-2 scores [β=0.3 ( 95% CI: 0, 0.7)]; this association was not modified by sex.

CONCLUSION

Prenatal urinary BPA concentration was associated with some aspects of child behavior in this cohort, and some associations were stronger among boys. https://doi.org/10.1289/EHP984.

Personal care product use among adults in NHANES: associations between urinary phthalate metabolites and phenols and use of mouthwash and sunscreen

Personal care product use is a well-established pathway of exposure for notable endocrine disrupting compounds (EDCs), including phthalates, parabens, triclosan, benzophenone-3 (BP3), and bisphenol-A. We utilized questionnaire data from the National Health and Nutrition Examination Survey 2009-2012 cycles to examine the associations between use of sunscreen and mouthwash and urinary concentrations of phthalate metabolites and phenols in a nationally representative population of US adults (n=3529). Compared with individuals who reported "Never" using mouthwash, individuals who reported daily use had significantly elevated urinary concentrations of mono-ethyl phthalate, methyl and propyl parabens, and BP3 (28%, 30%, 39%, and 42% higher, respectively). Individuals who reported "Always" using sunscreen had significantly higher urinary concentrations of triclosan, methyl, ethyl, and propyl parabens, and BP3 (59%, 92%, 102%, 151%, and 510% higher, respectively) compared with "Never" users of sunscreen. Associations between exposure biomarkers and sunscreen use were stronger in women compared with men, and associations with mouthwash use were generally stronger in men compared with women. These results suggest that sunscreen and mouthwash may be important exposure sources for EDCs.

Variability and predictors of urinary concentrations of organophosphate flame retardant metabolites among pregnant women in Rhode Island

BACKGROUND

Organophospate flame retardants (PFRs) are chemicals of emerging concern due to restrictions on polybrominated diphenyl ether flame retardant formulations. We describe the occurrence, variability, and predictors of urinary metabolites of PFRs among pregnant women.

METHODS

In 2014-2015, 59 women from Providence, RI provided up to 3 spot urine samples during pregnancy (~12, 28, and 35 weeks' gestation). We created a pooled urine sample per woman and measured nine relevant metabolites in individual and pooled samples. We used linear mixed models to calculate intraclass correlation coefficients (ICCs) across the 3 measurements and to assess sociodemographic and dietary predictors of PFRs.

RESULTS

The median (IQR) of bis-2-chloroethyl phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), and diphenyl phosphate (DPhP), the metabolites most frequently detected, from pooled samples were: 0.31 μg/L (0.17-0.54), 1.18 μg/L (0.64-2.19), 0.93 μg/L (0.72-1.97), respectively. We observed fair to good reproducibility for BCEP (ICC = 0.50), BDCPP (ICC = 0.60), and DPhP (ICC = 0.43), and excellent agreement between the urinary flame retardant metabolite concentrations averaged across pregnancy versus pooled urine sample concentrations for BCEP (ICC = 0.95), BDCPP (ICC = 0.89), and DPhP (ICC = 0.93). Adjusting for pertinent sociodemographic factors and gestational week of urine collection, each 1 kg increase in pre-pregnancy weight was associated with greater BCEP (1.1%; 95% CI: 0.1, 2.1), BDCPP (1.5%; 95% CI: 0.3, 2.7), and DPhP (0.5%; 95% CI: 0.0, 1.1). Dietary factors were generally not associated with urinary flame retardant metabolites.

CONCLUSIONS

Urinary concentrations of BCEP, BDCPP, and DPhP were frequently detected among women in this pilot study and had fair reproducibility across pregnancy. Body size may be an important predictor of urinary flame retardant metabolite concentrations.

Food consumption survey of Shanghai adults in 2012 and its associations with phthalate metabolites in urine

BACKGROUND

Diet is considered to be a significant exposure pathway for phthalates. In this study, we assessed the associations between food consumption and urinary concentrations of phthalate metabolites among Shanghai adults.

METHODS

A cross-sectional study involving 2418 participants was conducted in the fall of 2012. Recent food consumption was assessed by a 24-h dietary recall survey, and a Food Frequency Questionnaire (FFQ) characterized long-term dietary patterns. Urinary metabolites of six phthalates were measured.

RESULTS

Both the 24-h recall survey and FFQ identified wheat, dairy, and fruits as being positively associated with the excretion of phthalate metabolites. The 24-h recall data also showed positive associations with processed meats and alcohol. We evaluated the impact of reported consumption of multiple food categories simultaneously (wheat, fruits, meats, etc.) on metabolite excretion and found that, as more food types were consumed, the number of metabolites excreted, as well as their concentrations, increased with high significance (p values<0.0001). We also evaluated the two survey instruments together. When both surveys reported consumption of fruits and dairy, the numbers of metabolites and their concentrations were significantly higher compared to when both surveys reported non-consumption, (p values<0.000001). Rice consumption was found to be negatively associated with phthalate excretion; frequent and high levels of rice consumption were found to be associated with lower excretion of metabolites.

CONCLUSION

Food consumption was associated with phthalate exposure in Shanghai adults. Both 24-h recall and FFQ identified significant associations between consumption of food types and phthalate exposure.

Early-life exposure to EDCs: role in childhood obesity and neurodevelopment

Endocrine-disrupting chemicals (EDCs) might increase the risk of childhood diseases by disrupting hormone-mediated processes that are critical for growth and development during gestation, infancy and childhood. The fetus, infant and child might have enhanced sensitivity to environmental stressors such as EDCs due to their rapid development and increased exposure to some EDCs as a consequence of development-specific behaviour, anatomy and physiology. In this Review, I discuss epidemiological studies examining the relationship between early-life exposure to bisphenol A (BPA), phthalates, triclosan and perfluoroalkyl substances (PFAS) with childhood neurobehavioural disorders and obesity. The available epidemiological evidence suggest that prenatal exposure to several of these ubiquitous EDCs is associated with adverse neurobehaviour (BPA and phthalates) and excess adiposity or increased risk of obesity and/or overweight (PFAS). Quantifying the effects of EDC mixtures, improving EDC exposure assessment, reducing bias from confounding, identifying periods of heightened vulnerability and elucidating the presence and nature of sexually dimorphic EDC effects would enable stronger inferences to be made from epidemiological studies than currently possible. Ultimately, improved estimates of the causal effects of EDC exposures on child health could help identify susceptible subpopulations and lead to public health interventions to reduce these exposures.

Molecular Characteristics of the Endometrium in Uterine Adenomyosis and Its Biochemical Microenvironment

Adenomyosis, which manifests with focally or diffusely scattered endometrial tissue within the uterine myometrium, is an endometriosis-like disease with controversial pathogenesis and compromised reproductive outcomes. This review, including the in vitro and in vivo studies performed on human or mouse models, is aimed to summarize the specific molecular characteristics of endometrium in the biochemical microenvironments of uterine adenomyosis. Many studies attributed the endometrium as the main cause of pathogenesis, with evidence of differential genetic expression and/or epigenetic modulation as well as estrogen-induced epithelial-mesenchymal transition. However, some studies indicated that the myometrium could play a role in the development of disease, based on findings of smooth muscle metaplasia and/or fibroblast-to-myofibroblast transdifferentiation by the influence of local biochemical factors. To date, it remains unclear whether adenomyosis is a genetically determined or a microenvironmentally induced disorder or whether the dysregulation of local factors may elicit the alteration of genetic expression in the endometrium. Similarly, it is uncertain whether the endometrial characteristics would remain consistent or could change along with a woman's reproductive life. Further longitudinal studies of the epigenetic controls or system biology are needed to elucidate the pathogenesis. Discovery of effective conservative treatments to improve the reproductive outcomes of patients with adenomyosis is still warranted.

Phthalate-induced oxidative stress and association with asthma-related airway inflammation in adolescents

BACKGROUND

In Belgium, around 8.5% of the children have asthmatic symptoms. Increased asthma risk in children has been reported in relation to exposure to phthalate plasticizers but the underlying mechanisms are largely unknown.

AIM

The aim of this study was to identify if oxidative stress, assessed by excision of 8-hydroxydeoxyguanosine (8-OHdG) from damaged DNA, is an intermediate marker for the association between phthalate exposure and doctor-diagnosed asthma.

MATERIAL AND METHODS

In 418 14-15-year-old youngsters, recruited as a representative sample of residents of Flanders (Belgium), personal exposure to phthalates was assessed by measuring phthalate metabolites in urine: mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP), mono-isobutyl phthalate (MiBP) and mono-ethyl phthalate (MEP). Analysis of 8-OHdG in urine was used as a sensitive biomarker of oxidative stress at the level of DNA. The presence of doctor-diagnosed asthma was elicited by a self-administered questionnaire. Associations were assessed using multiple linear and logistic regression models. Mediation was tested using Baron and Kenny's regression approach.

RESULTS

A significant increased risk of a youngster being diagnosed with asthma was found for both urinary MnBP (metabolite of dibutyl phthalate (DBP)) and the sum of the three di(2-ethylhexyl) phthalate metabolites (ΣDEHP=MEHP+MEHHP+MEOHP), with respective odds ratio of 1.84 [95% CI: 1.02, 3.32] for MnBP and 1.94 [95% CI: 1.07, 3.51] for ΣDEHP. In addition, we observed significant associations between all urinary phthalate metabolites and increased urinary levels of 8-OHdG. The associations were stronger in girls than in boys. We did not found evidence that 8-OHdG was associated with doctor-diagnosed asthma.

CONCLUSION

The results of our study are in line with other findings from epidemiological surveys and raise further concern about DEHP and DBP as risk factors for asthma, however, the underlying mechanisms are not yet well understood.

Comparative study of hydrolytic metabolism of dimethyl phthalate, dibutyl phthalate and di(2-ethylhexyl) phthalate by microsomes of various rat tissues

Phthalates are used in food packaging, and are transferred to foods as contaminants. In this study, we examined the hydrolytic metabolism of dimethyl phthalate (DMP), dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) by rat tissue microsomes. We found that carboxylesterase and lipase contribute differently to these activities. When DMP, DBP and DEHP were incubated with rat liver microsomes, DBP was most effectively hydrolyzed to the phthalate monoester, followed by DMP, and the activity toward DEHP was marginal. In contrast, small-intestinal microsomes exhibited relatively higher activity toward long-side-chain phthalates. Pancreatic microsomes showed high activity toward DEHP and DBP. Liver microsomal hydrolase activity toward DMP was markedly inhibited by bis(4-nitrophenyl)phosphate, and could be extracted with Triton X-100. The activity toward DBP and DEHP was partly inhibited by carboxylesterase inhibitor, and was partly solubilized with Triton X-100. Ces1e, Ces1d and Ces1f expressed in COS cells exhibited the highest hydrolase activity toward DBP, showing a similar pattern to that of liver microsomes. Ces1e showed activity towards DMP and DEHP. Pancreatic lipase also hydrolyzed DBP and DEHP. Thus, carboxylesterase and lipase contribute differently to phthalate hydrolysis: short-side-chain phthalates are mainly hydrolyzed by carboxylesterase and long-side-chain phthalates are mainly hydrolyzed by lipase.

Evaluation of exposure to phthalate esters and DINCH in urine and nails from a Norwegian study population

Phthalate esters (PEs) and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) used as additives in numerous consumer products are continuously released into the environment, leading to subsequent human exposure which might cause adverse health effects. The human biomonitoring approach allows the detection of PEs and DINCH in specific populations, by taking into account all possible routes of exposure (e.g. inhalation, transdermal and oral) and all relevant sources (e.g. air, dust, personal care products, diet). We have investigated the presence of nine PE and two DINCH metabolites and their exposure determinants in 61 adult residents of the Oslo area (Norway). Three urine spots and fingernails were collected from each participant according to established sampling protocols. Metabolite analysis was performed by LC-MS/MS. Metabolite levels in urine were used to back-calculate the total exposure to their corresponding parent compound. The primary monoesters, such as monomethyl phthalate (MMP, geometric mean 89.7ng/g), monoethyl phthalate (MEP, 104.8ng/g) and mono-n-butyl phthalate (MnBP, 89.3ng/g) were observed in higher levels in nails, whereas the secondary bis(2-ethylhexyl) phthalate (DEHP) and DINCH oxidative metabolites were more abundant in urine (detection frequency 84-100%). The estimated daily intakes of PEs and DINCH for this Norwegian population did not exceed the established tolerable daily intake and reference doses, and the cumulative risk assessment for combined exposure to plasticizers with similar toxic endpoints indicated no health concerns for the selected population. We found a moderate positive correlation between MEP levels in 3 urine spots and nails (range: 0.56-0.68). Higher frequency of personal care products use was associated with greater MEP concentrations in both urine and nail samples. Increased age, smoking, wearing plastic gloves during house cleaning, consuming food with plastic packaging and eating with hands were associated with higher levels in urine and nails for some of the metabolites. In contrast, frequent hair and hand washing was associated with lower urinary levels of monoisobutyl phthalate (MiBP) and mono(2-ethyl-5-hydroxyhexyl) phthalate (5-OH-MEHP), respectively.

A Novel Method for Calculating Potency-Weighted Cumulative Phthalates Exposure with Implications for Identifying Racial/Ethnic Disparities among U.S. Reproductive-Aged Women in NHANES 2001-2012

Phthalates are ubiquitous chemicals linked to hormonal disruptions that affect reproduction and development. Multiple antiandrogenic phthalates exposure during fetal development can have greater impacts than individual exposure; thus, the National Academy of Sciences (NAS) recommends them for cumulative assessment. Using National Health and Nutrition Examination Survey data (NHANES, 2001-2012), we developed a potency-weighted sum of daily intake (∑androgen-disruptor; μg/kg/day) of di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), butyl benzyl phthalate (BBzP), and di(2-ethylhexyl) phthalate (DEHP) based on NAS recommendations, and included diethyl phthalate (DEP) and diisononyl phthalate (DiNP) in additional metrics (2005-2012). We compared racial/ethnic differences in ∑androgen-disruptor among 2842 reproductive-aged women. In sensitivity analyses, we assessed the influence of potency assumptions, alternate urine dilution adjustment methods, and weighting phthalate metabolites directly rather than daily intake estimates of parent compounds. We found that DEHP contributed most to ∑androgen-disruptor (48-64%), and that ∑androgen-disruptor decreased over time. Black women generally had higher cumulative exposures than white women, although the magnitude and precision of the difference varied by model specification. Our approach provides a blueprint for combining chemical exposures linked to common adverse outcomes, and should be considered in future exposure, risk, and epidemiological studies.

Urinary Concentrations of Bisphenol A and Phthalate Metabolites Measured during Pregnancy and Risk of Preeclampsia

BACKGROUND

Preeclampsia represents a major cause of maternal mortality and morbidity worldwide. Although it is known that the placenta plays a central role in development of preeclampsia, investigation into the contribution of environmental toxicants to the risk of preeclampsia has been sparse.

OBJECTIVES

In the present study we examined the relationship between longitudinally measured urinary BPA and phthalate metabolite concentrations during gestation and preeclampsia.

METHODS

A nested case-control study of preterm birth was performed in 2011 from women enrolled in a prospective birth cohort study at Brigham and Women's Hospital in Boston. There were 50 cases of preeclampsia as part of this study. Urine samples were analyzed for concentrations of BPA and nine phthalate metabolites several times during pregnancy. Adjusted Cox proportional hazard models were used to calculate hazard ratios of preeclampsia in association with an interquartile range increase in BPA and phthalate concentrations and were weighted to reflect results generalizable to the base population.

RESULTS

Adjusted hazard ratios indicated that an interquartile range increase of urinary concentrations of BPA (1.53; 95% CI: 1.04, 2.25) and MEP (monoethyl phthalate) (1.72; 95% CI: 1.28, 2.30) at 10 weeks gestation was associated with onset of preeclampsia, whereas significantly elevated hazard ratios were found across gestation for all DEHP [di(2-ethylhexyl) phthalate] metabolites. These relationships differed based on infant sex.

CONCLUSIONS

Urinary concentrations of BPA and several phthalate metabolites were significantly associated with increased risk of preeclampsia. If validated, these results indicate an environmental contribution of endocrine-disrupting chemicals to preeclampsia and suggest a modifiable means to reduce the mortality and morbidity associated with this condition.

CITATION

Cantonwine DE, Meeker JD, Ferguson KK, Mukherjee B, Hauser R, McElrath TF. 2016. Urinary concentrations of bisphenol A and phthalate metabolites measured during pregnancy and risk of preeclampsia. Environ Health Perspect 124:1651-1655; http://dx.doi.org/10.1289/EHP188.

Dibutyl Phthalate (DBP)-Induced Apoptosis and Neurotoxicity are Mediated via the Aryl Hydrocarbon Receptor (AhR) but not by Estrogen Receptor Alpha (ERα), Estrogen Receptor Beta (ERβ), or Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) in Mouse Cortical Neurons

Dibutyl phthalate (di-n-butyl phthalate, DBP) is one of the most commonly used phthalate esters. DBP is widely used as a plasticizer in a variety of household industries and consumer products. Because phthalates are not chemically bound to products, they can easily leak out to enter the environment. DBP can pass through the placental and blood–brain barriers due to its chemical structure, but little is known about its mechanism of action in neuronal cells. This study demonstrated the toxic and apoptotic effects of DBP in mouse neocortical neurons in primary cultures. DBP stimulated caspase-3 and LDH activities as well as ROS formation in a concentration (10 nM–100 µM) and time-dependent (3–48 h) manner. DBP induced ROS formation at nanomolar concentrations, while it activated caspase-3 and LDH activities at micromolar concentrations. The biochemical effects of DBP were accompanied by decreased cell viability and induction of apoptotic bodies. Exposure to DBP reduced Erα and Pparγ mRNA expression levels, which were inversely correlated with protein expression of the receptors. Treatment with DBP enhanced Ahr mRNA expression, which was reflected by the increased AhR protein level observed at 3 h after exposure. ERα, ERβ, and PPARγ antagonists stimulated DBP-induced caspase-3 and LDH activities. AhR silencing demonstrated that DBP-induced apoptosis and neurotoxicity are mediated by AhR, which is consistent with the results from DBP-induced enhancement of AhR mRNA and protein expression. Our study showed that AhR is involved in DBP-induced apoptosis and neurotoxicity, while the ERs and PPARγ signaling pathways are impaired by the phthalate.

Associations of individual characteristics and lifestyle factors with metabolism of di-2-ethylhexyl phthalate in NHANES 2001-2012

BACKGROUND

Previous studies suggest that a higher ratio of primary to secondary metabolites of di-2-ethylhexyl phthalate (DEHP), reflective of a slower DEHP conversion rate, is associated with a greater physiologic effect. We examined associations of several individual characteristics and lifestyle factors with the ratio of mono-2-ethylhexyl phthalate to mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHP:MEHHP) and %MEHP (the ratio of MEHP to the sum of the secondary metabolites).

METHODS

We used the data from the National Health and Nutrition Examination Survey, 2001-2012. The study included adults with BMI<30 and no diabetes. Pregnant women were excluded. We examined associations of age, race, gender, Body Mass Index, smoking, alcohol and caffeine consumption, medication use, cancer history, and menopausal status and postmenopausal hormone use (in women) with MEHP:MEHHP and %MEHP using multivariable linear regression. The values for %MEHP were log-transformed in the analysis.

RESULTS

In multivariable analysis, non-Caucasian individuals had higher %MEHP (non-Hispanic Blacks: β=0.114, 95% Confidence interval [CI]: 0.050, 0.177; Hispanic: β=0.089, 95% CI: 0.024, 0.154; other race: β=0.126, 95% CI: 0.033, 0.219). Age was inversely associated with MEHP:MEHHP (β=-0.001, 95% CI: -0.002, -0.001) and %MEHP (β=-0.006, 95% CI: -0.008, -0.004). Overweight individuals had lower MEHP: MEHHP and lower %MEHP (β=-0.035, 95% CI: 0.062, -0.008 and β=-0.104, 95% CI: -0.162, -0.046, respectively). Alcohol consumption was inversely associated with %MEHP among men (p-trend=0.03).

CONCLUSIONS

Individual and lifestyle characteristics are associated with differences in DEHP metabolism. Understanding underlying biological mechanisms could help to identify individuals at a greater risk of adverse effects from DEHP exposure.

Is the Diabetes Epidemic Primarily Due to Toxins?

The incidence of diabetes has increased 7 to 10-fold in the past 50 y. Although increased sugar consumption, obesity, and lack of exercise certainly contribute, the effect of environmental toxins may be far greater. The data are so compelling that some researchers now label these toxins as diabetogens. This editorial summarizes the research showing which toxins are the worst offenders, how they disrupt blood sugar control, where they come from, how to assess body load, and strategies for detoxification and excretion.

Maternal exposure to di-2-ethylhexylphthalate and adverse delivery outcomes: A systematic review

Adverse pregnancy outcomes, including preterm delivery, short gestational age, and abnormal birth weight, remain a public health concern. The evidence on the association of the most common phthalate, di-2-ethylhexyl phthalate (DEHP) with adverse pregnancy outcomes remains equivocal. This systematic review summarizes published studies that investigated the association of DEHP with preterm delivery, gestational age, and birthweight. A comprehensive literature search found 15 relevant studies, most of which evaluated more than one outcome (four studies for preterm delivery, nine studies for gestational age, and ten studies for birthweight). Studies varied greatly with respect to study design, exposure assessment, analytical methods, and direction of the associations. We identified important methodological concerns which could have resulted in selection bias and exposure misclassification and contributed to null findings and biased associations. Given limitations of the previous studies discussed in this review, more thorough investigation of these associations is warranted to advance our scientific knowledge.

The Impact of Bisphenol A and Phthalates on Allergy, Asthma, and Immune Function: a Review of Latest Findings

In recent years, the impact of environmental exposure to chemicals and their immunological effects, including the development of allergy, has been a topic of great interest. Epidemiologic studies indicate that exposure to endocrine-disrupting chemicals produced in high volumes, including bisphenol A (BPA) and phthalates, is ubiquitous. The links between their exposure and the development of allergy, asthma, and immune dysfunction have been studied in vitro, in vivo, and through human cohort studies. The purpose of this review is to examine the current body of research and to highlight deficits and strengths of current findings. Emerging science indicates that deleterious immunologic changes, including increased propensity to develop wheeze, allergy, and asthma after dietary and inhalation exposure to these chemicals, may be occurring.

The Association Between Urinary Benzophenone Concentrations and Personal Care Product Use in Korean Adults

Benzophenone (BP) derivatives are widely used in personal care products (PCPs) for protection from ultraviolet radiation. Because of their broad applications, BP derivatives have been found in various human bodily fluids. In the present study, we investigated the relationship between urinary concentrations of BP derivatives and PCP use in Korean adults. A urinary BP biomonitoring survey was conducted in Korea by the Ministry of Food and Drug Safety in 2014. BP derivatives (BP-1, BP-3, and 4-OH-BP) were measured in urine samples from 168 Korean adults (mean age, 43.2 ± 15.4 years) by high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry. Information about the use of PCPs in the past 7 days was obtained by direct interviews. The mean levels of BP-1, BP-3, and 4-OH-BP were 0.87, 5.87, and 0.13 ng/g creatinine, respectively. The geometric mean levels of BP-1, BP-3, and 4-OH-BP were significantly higher in female than those in male. The medians of the urinary concentration of BP derivatives were significantly higher among users of the following PCPs than those in non-users; the PCPs included sunscreen, skin care products, functional cosmetics, makeup base, makeup, lip cosmetics, eye cosmetics, color cosmetics, perfume products, and nail products. A regression analysis revealed a significant linear association between urinary BP-3 concentrations and the number of additional cosmetic products used. These findings provide evidence of a positive association between exposure to PCPs and urinary BP derivative concentrations in Korean adults.

The association between phthalates and metabolic syndrome: the National Health and Nutrition Examination Survey 2001-2010

BACKGROUND

Higher exposure to certain phthalates is associated with a diabetes and insulin resistance, with sex differences seen. Yet, little is known about the association between phthalates and metabolic syndrome (MetS), particularly with consideration for differences by sex and menopausal status.

METHODS

We analyzed data from 2719 participants in the National Health and Nutrition Examination Survey (NHANES) 2001-2010 aged 20-80 years. Five urinary phthalate metabolites (MEP, MnBP, MiBP, MBzP, and MCPP) and DEHP metabolites were analyzed by the Centers for Disease Control and Prevention and were evaluated as population-specific quartiles. MetS was defined by National Cholesterol Education Program's Adult Treatment Panel III report criteria. Prevalence odds ratios (POR) and 95 % confidence intervals (CI) were calculated using multivariable logistic regression, adjusting for potential confounders and stratifying by sex and menopausal status.

RESULTS

Participants with MetS (32 % of the study population) had higher concentrations for all urinary phthalate metabolites. After full adjustment, higher DEHP metabolite concentrations were associated with an increased odds of MetS in men, but not women (adj. POR for men Q4 versus Q1: 2.20; 95 % CI: 1.32, 3.68 and adj. POR for women Q4 versus Q1: 1.50; 95 % CI: 0.89, 2.52). When evaluating by menopausal status, pre-menopausal women with higher concentrations of MBzP had close to a 4-fold increased odds of MetS compared to pre-menopausal women with the lowest concentrations of MBzP (adj POR: Q4 versus Q1: 3.88; 95 % CI: 1.59, 9.49).

CONCLUSIONS

Higher concentrations of certain phthalate metabolites were associated with an increased odds of MetS. Higher DEHP metabolite concentrations were associated with an increased odds of MetS for men. In women, the strongest association was between higher concentrations of MBzP and MetS, but only among pre-menopausal women.

Racial/ethnic disparities in environmental endocrine disrupting chemicals and women's reproductive health outcomes: epidemiological examples across the life course

Disparities in women's reproductive health outcomes across the life course have been well-documented. Endocrine disrupting chemicals may be one factor driving disparities, as studies suggest exposure to certain environmental endocrine disrupting chemicals, such as certain phthalates, bisphenol A, parabens and polybrominated diphenyl ethers are higher in non-whites. Yet, a limited amount of research has focused on these chemical exposures as a potential mediator of racial/ethnic differences in women's reproductive health outcomes, such as pubertal development, fibroids, infertility, and pregnancy complications. Given that race/ethnicity is a social construct, the purpose of this review was to present the current state of the literature on racial/ethnic disparities in both environmental endocrine disrupting chemicals, as well as associations between these chemicals and selected women's reproductive health outcomes. Our goal was to evaluate literature from populations based in the United States to: 1) characterize racial/ethnic differences in environmental endocrine disrupting chemicals and 2) systematically review literature on environmental endocrine disrupting chemicals and selected women's health outcomes in populations containing more than one racial/ethnic group. This review highlights the need for future work in determining whether higher exposures to some environmental endocrine disrupting chemicals might partly explain differences in women's reproductive health outcomes in these higher-exposure and high-risk groups.

Contemporary Issues in Exposure Assessment Using Biomonitoring

In environmental epidemiology, use of biomonitoring (i.e., trace-level measurement of environmental chemicals or their metabolites in biospecimens) for exposure assessment has increased considerably in past decades. Although exposure biomarkers should reflect a person's exposure to the target chemicals (or their precursors) within a specific timeframe, timing, duration, and intensity of exposures are normally unknown and likely vary within the study period. Therefore, evaluating exposure beyond a single time point may require collecting more than one biospecimen. Of note, collection and sample processing procedures will impact integrity and usefulness of biospecimens. All of the above factors are fundamental to properly interpret biomonitoring data. We will discuss the relevance of the exposure assessment study protocol design to (a) ensure that biomonitoring specimens reflect the intended exposure, (b) consider the temporal variability of concentrations of the target biomarkers, and

Safety and effectiveness evaluation of a domestic peritoneal dialysis fluid packed in non-PVC bags: study protocol for a randomized controlled trial

BACKGROUND

Peritoneal dialysis is an important type of renal replacement therapy for uremic patients. In peritoneal dialysis, fluids fill in and flow out of the abdominal cavity three to five times per day. Usually, the fluid is packed in a polyvinyl chloride (PVC) bag. Safety concerns have arisen over di-(2-ethylhexyl) phthalate, which is essential in the formation of PVC materials. In 2011, the National Development and Reform Commission of China released a catalog of industrial structural adjustments, mandating the elimination of PVC bags for intravenous infusion and food containers. Although bags for peritoneal dialysis fluid were not included in the elimination list, several manufacturers began to develop new materials for fluid bags. HUAREN peritoneal dialysis fluid consists of the same electrolytes and buffer agent as in Baxter fluid, but is packed in bags that do not contain PVC. This multicenter randomized controlled trial was designed to compare peritoneal dialysis fluid packed in non-PVC-containing and PVC-containing bags. Further, the study sought to determine the proper dose of peritoneal dialysis fluid and the actual survival rates of Chinese patients undergoing peritoneal dialysis.

METHODS/DESIGN

The study participants are adults undergoing continuous ambulatory peritoneal dialysis for 30 days to 6 months. All eligible patients are randomized (1:1) to peritoneal dialysis with Baxter and HUAREN dialysis fluids (initial dose, 6 l/day), with dosages adjusted according to a unified protocol. The primary outcomes are the 1-, 2-, 3-, 4-, and 5-year overall survival rates. Secondary outcome measures include technique survival rates, reductions in estimated glomerular filtration rate, nutritional status, quality of life, cardiovascular events, medical costs and drop-out rates. Safety outcome measures include adverse events, changes in vital signs and laboratory parameters, peritonitis, allergies, and quality of products.

DISCUSSION

This study is the first to evaluate the long-term safety and effectiveness of a non-PVC packed peritoneal dialysis fluid. The effects of plasticizer on patient long-term survival will be determined. The characteristics of Chinese patients undergoing peritoneal dialysis will be determined, including proper dose, technique survival rates, patient survival rates, and medical costs.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01779557 .

Phthalate metabolites in urine samples from Beijing children and correlations with phthalate levels in their handwipes

Little attention has been paid to dermal absorption of phthalates even though modeling suggests that this pathway may contribute meaningfully to total uptake. We have concurrently collected handwipe and urine samples from 39 Beijing children (5-9 years) for the purpose of measuring levels of five phthalates in handwipes, corresponding concentrations of eight of their metabolites in urine, and to subsequently assess the contribution of dermal absorption to total uptake. In summer sampling, DEHP was the most abundant phthalate in handwipes (median: 1130 μg/m(2) ), while MnBP was the most abundant metabolite in urine (median: 232 ng/ml). We found significant associations between the parent phthalate in handwipes and its monoester metabolite in urine for DiBP (r = 0.41, P = 0.01), DnBP (r = 0.50, P = 0.002), BBzP (r = 0.48, P = 0.003), and DEHP (r = 0.36, P = 0.03). Assuming that no dermal uptake occurred under clothing-covered skin, we estimate that dermal absorption of DiBP, DnBP, BBzP, and DEHP contributed 6.9%, 4.6%, 6.9%, and 3.3%, respectively, to total uptake. Assuming that somewhat attenuated dermal uptake occurred under clothing-covered skin, these estimates increase to 19%, 14%, 17%, and 10%. The results indicate that absorption from skin surfaces makes a meaningful contribution to total phthalate uptake for children and should be considered in future risk assessments.

PRACTICAL IMPLICATIONS

This study indicates that children’s hands acquire substantial amounts of various phthalates. The levels measured in handwipes, although higher, are somewhat representative of levels on other body locations. Via dermal absorption, as well as hand-to-mouth activity, phthalates on hands and other body locations contribute to the overall body burden of these compounds. Dermal absorption from air and contact transfer from surfaces is expected to occur for many SVOCs commonly found indoors (e.g. bisphenols, synthetic musks, organophosphates). However, the dermal pathway has often been neglected in exposure assessments of indoor pollutants. Knowledge regarding phthalates and other SVOCs in handwipes can facilitate our understanding of risks and aid in the mitigation of adverse health effects resulting from indoor exposures. To make progress toward these goals, further studies are necessary, including investigations of phthalate level variability in skinwipes collected at different locations on the body and the impact of clothing on dermal absorption from air.

A monograph on the remediation of hazardous phthalates

Phthalates or phthalic acid esters are a group of xenobiotic and hazardous compounds blended in plastics to enhance their plasticity and versatility. Enormous quantities of phthalates are produced globally for the production of plastic goods, whose disposal and leaching out into the surroundings cause serious concerns to the environment, biota and human health. Though in silico computational, in vitro mechanistic, pre-clinical animal and clinical human studies showed endocrine disruption, hepatotoxic, teratogenic and carcinogenic properties, usage of phthalates continues due to their cuteness, attractive chemical properties, low production cost and lack of suitable alternatives. Studies revealed that microbes isolated from phthalate-contaminated environmental niches efficiently bioremediate various phthalates. Based upon this background, this review addresses the enumeration of major phthalates used in industry, routes of environmental contamination, evidences for health hazards, routes for in situ and ex situ microbial degradation, bacterial pathways involved in the degradation, major enzymes involved in the degradation process, half-lives of phthalates in environments, etc. Briefly, this handy module would enable the readers, environmentalists and policy makers to understand the impact of phthalates on the environment and the biota, coupled with the concerted microbial efforts to alleviate the burden of ever increasing load posed by phthalates.

Predictors and long-term reproducibility of urinary phthalate metabolites in middle-aged men and women living in urban Shanghai

Phthalate esters are man-made chemicals commonly used as plasticizers and solvents, and humans may be exposed through ingestion, inhalation, and dermal absorption. Little is known about predictors of phthalate exposure, particularly in Asian countries. Because phthalates are rapidly metabolized and excreted from the body following exposure, it is important to evaluate whether phthalate metabolites measured at a single point in time can reliably rank exposures to phthalates over a period of time. We examined the concentrations and predictors of phthalate metabolite concentrations among 50 middle-aged women and 50 men from two Shanghai cohorts, enrolled in 1997-2000 and 2002-2006, respectively. We assessed the reproducibility of urinary concentrations of phthalate metabolites in three spot samples per participant taken several years apart (mean interval between first and third sample was 7.5 years [women] or 2.9 years [men]), using Spearman's rank correlation coefficients and intra-class correlation coefficients. We detected ten phthalate metabolites in at least 50% of individuals for two or more samples. Participant sex, age, menopausal status, education, income, body mass index, consumption of bottled water, recent intake of medication, and time of day of collection of the urine sample were associated with concentrations of certain phthalate metabolites. The reproducibility of an individual's urinary concentration of phthalate metabolites across several years was low, with all intra-class correlation coefficients and most Spearman rank correlation coefficients ≤0.3. Only mono(2-ethylhexyl) phthalate, a metabolite of di(2-ethylhexyl) phthalate, had a Spearman rank correlation coefficient ≥0.4 among men, suggesting moderate reproducibility. These findings suggest that a single spot urine sample is not sufficient to rank exposures to phthalates over several years in an adult urban Chinese population.

Endocrine disruptor activity of multiple environmental food chain contaminants

Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation. Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens( n = 3), UV filters (n = 6), phthalates (n = 4) and a metabolite, pyrethroids (n = 9) and their metabolites (n = 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17b-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.

Vaginal douching and racial/ethnic disparities in phthalates exposures among reproductive-aged women: National Health and Nutrition Examination Survey 2001-2004

BACKGROUND

Diethyl phthalate (DEP) and di-n-butyl phthalate (DnBP) are industrial chemicals found in consumer products that may increase risk of adverse health effects. Although use of personal care/beauty products is known to contribute to phthalate exposure, no prior study has examined feminine hygiene products as a potential phthalate source. In this study, we evaluate whether vaginal douching and other feminine hygiene products increase exposure to phthalates among US reproductive-aged women.

METHODS

We conducted a cross-sectional study on 739 women (aged 20-49) from the National Health and Nutrition Examination Survey 2001-2004 to examine the association between self-reported use of feminine hygiene products (tampons, sanitary napkins, vaginal douches, feminine spray, feminine powder, and feminine wipes/towelettes) with urinary concentrations of monoethyl phthalate (MEP) and mono-n-butyl phthalate (MnBP), metabolites of DEP and DnBP, respectively.

RESULTS

A greater proportion of black women than white and Mexican American women reported use of vaginal douches, feminine spray, feminine powder, and wipes/towelettes in the past month whereas white women were more likely than other racial/ethnic groups to report use of tampons (p < 0.05). Douching in the past month was associated with higher concentrations of MEP but not MnBP. No other feminine hygiene product was significantly associated with either MEP or MnBP. We observed a dose-response relationship between douching frequency and MEP concentrations (p(trend) < 0.0001); frequent users (≥2 times/month) had 152.2% (95% confidence intervals (CI): (68.2%, 278.3%)) higher MEP concentrations than non-users. We also examined whether vaginal douching mediates the relationship between race/ethnicity and phthalates exposures. Black women had 48.4% (95% CI: 16.8%, 88.6%; p = 0.0002) higher MEP levels than white women. Adjustment for douching attenuated this difference to 26.4% (95% CI:-0.9%, 61.2%; p = 0.06). Mediation effects of douching were statistically significant for black-white differences (z = 3.71, p < 0.001) but not for differences between Mexican Americans and whites (z = 1.80, p = 0.07).

CONCLUSIONS

Vaginal douching may increase exposure to DEP and contribute to racial/ethnic disparities in DEP exposure. The presence of environmental chemicals in vaginal douches warrants further examination.

Exposure to select phthalates and phenols through use of personal care products among Californian adults and their children

INTRODUCTION

Certain phenols and phthalates are used in many consumer products including personal care products (PCPs).

AIMS

We aimed to study the associations between the use of PCPs and urinary concentrations of biomarkers of select phenols and phthalates among Californian adults and their children. As an additional aim we compared phenols and phthalate metabolites concentrations measured in adults and children urine samples collected the same day.

METHODS

Our study relied on a subsample of 90 adult-child pairs participating in the Study of Use of Products and Exposure Related Behavior (SUPERB). Each adult and child provided one to two urine samples in which we measured concentrations of selected phenols and phthalate metabolites. We computed Spearman correlation coefficients to compare concentrations measured in adults and children urine samples collected the same day. We used adjusted linear and Tobit regression models to study the associations between the use of PCPs in the past 24h and biomarker concentrations.

RESULTS

Benzophenone-3 and parabens concentrations were higher in adults compared to their children. Conversely children had higher mono-n-butyl phthalate and mono-isobutyl phthalate concentrations. No significant difference was observed for the other compounds. The total number of different PCPs used was positively associated with urinary concentrations of methyl, propyl and butyl parabens and the main metabolite of diethyl phthalate in adults. Among children, the use of a few specific products including liquid soap, hair care products and sunscreen was positively associated with urinary concentrations of some phenols or phthalate metabolites.

DISCUSSION

These results strengthen the body of evidence suggesting that use of PCPs is an important source of exposure to parabens and diethyl phthalate in adults and provide data on exposure to selected phenols and phthalates through use of PCPs in children.

Effects of mono(2-ethylhexyl)phthalate on cytoplasmic maturation of oocytes--The bovine model

Phthalates are known reproductive toxicants, but their intracellular disruptive effects on oocyte maturation competence are less known. We studied the potential risk associated with acute exposure of oocytes to mono(2-ethylhexyl)phthalate (MEHP). First, bovine oocytes were matured in vitro with or without 50 μM MEHP and examined for mitochondrial features associated with DNA fragmentation. MEHP increased reactive oxygen species levels and reduced the proportion of highly polarized mitochondria along with alterations in genes associated with mitochondrial oxidative phosphorylation (CYC1, MT-CO1 and ATP5B). In a second set of experiments, we associated the effects of MEHP on meiotic progression with those on cytoplasmic maturation. MEHP impaired reorganization of cytoplasmic organelles in matured oocytes reflected by reductions in category I mitochondria, type III cortical granules and class I endoplasmic reticulum. These alterations are associated with the previously reported reduced developmental competence of MEHP-treated bovine oocytes, and reveal the risk associated with acute exposure.

Serum phthalate levels and time to pregnancy in couples from Greenland, Poland and Ukraine

Phthalates are ubiquitous industrial chemicals that have been associated with altered reproductive function in rodents. Several human studies have reported an inverse association between male testosterone and phthalate levels. Our aim was to investigate time to pregnancy (TTP) according to serum levels of diethylhexyl phthalate (DEHP) and diisononyl phthalate (DiNP) metabolites in both partners. In 2002-2004 we enrolled 938 pregnant women and 401 male spouses from Greenland, Poland and Ukraine. Six oxidized metabolites of DEHP and DiNP were summarized for each of the two parent compounds to provide proxies of the internal exposure. We used Cox discrete-time models to estimate fecundability ratios (FR) and 95% confidence intervals (95% CIs) for men and women according to their proxy-DEHP or -DiNP serum levels adjusted for a fixed set of covariates.

The FR was slightly elevated among women with high levels of DEHP (FR=1.14, 95% CI 1.00;1.30) suggesting a shorter TTP in these women. The FR was unrelated to DiNP in women, whereas the results for men were inconsistent pointing in opposite directions. First-time pregnant women from Greenland with high serum DiNP levels had a longer TTP. This study spanning large contrast in environmental exposure does not indicate adverse effects of phthalates on couple fecundity. The shorter TTP in women with high levels of DEHP metabolites is unexplained and needs further investigation.

Concentrations of phthalate metabolites in breast milk in Korea: estimating exposure to phthalates and potential risks among breast-fed infants

Phthalates have been associated with endocrine disruption and developmental effects in many experimental and epidemiological studies. Developing infants are among the most susceptible populations to endocrine disruption. However, limited information is available on phthalate exposure and its associated risks among breast-fed newborn infants. In the present study, breast milk samples were collected from 62 lactating mothers at 1 month post-partum from four cities of Korea in 2012 and were evaluated for six phthalate metabolites (mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), mono(2-ethyl-hexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and monoethyl phthalate (MEP)). MEP was detected in all breast milk samples, with a median concentration of 0.37 μg/L, and MiBP, MnBP and MEHP were detected in 79-89% of samples, with median concentrations of 1.10, 1.70, and 2.08 μg/L, respectively. However, MEHHP and MEOHP, the oxidized forms of di-ethyl-hexyl phthalate (DEHP), were detected in only one sample. For exposure assessment, the levels of phthalate diesters were estimated based on the parent:metabolite ratios in the breast milk that are reported elsewhere. For risk assessment, the endocrine-related toxicity of the monoester was assumed to be the same as that of its diester form. Median daily intake estimates of phthalates, including both monoester and diester forms, through breast milk consumption ranged between 0.91 and 6.52 μg/kg body weight (bw) for DEHP and between 0.38 and 1.43 μg/kg bw for di-n-butyl phthalate (DnBP). Based on the estimated daily intake, up to 8% of infants exceeded the reference dose of anti-androgenicity (RfD AA) for DEHP, and 6% of infants exceeded the tolerable daily intake (TDI) for DnBP. Breast milk MiBP and MnBP concentrations showed significant positive associations with maternal consumption of whipped cream or purified water. Considering vulnerability of young infants, efforts to mitigate phthalate exposure among lactating women are warranted.

Associations of urinary phthalates with body mass index, waist circumference and serum lipids among females: National Health and Nutrition Examination Survey 1999-2004

BACKGROUND/OBJECTIVES

Exposure to environmental chemicals could be one of the contributors to the increasing obesity epidemic. Very little is known about the association of phthalates, ubiquitous chemicals widely used in consumer products, with obesity and lipid metabolism. This study investigated the association of urinary phthalate metabolites and, for the first time, the ratios of the major metabolites of the most common phthalate, di-2-ethylhexyl phthalate, with body mass index (BMI), waist circumference and serum lipid levels in the US female population.

METHODS

This cross-sectional study used the data from the National Health and Nutrition Examination Survey, 1999-2004 and was restricted to women aged ⩾18 years, who were not pregnant and had no history of diabetes. Using multivariate ordered logistic regression, we examined associations of seven urinary phthalate metabolites and their metabolic ratios with the BMI, waist circumferences, total cholesterol, triglycerides and high- and low-density lipoprotein cholesterol.

RESULTS

BMI was positively associated with monobutyl phthalate (MBP) and mono-2-ethylhexyl phthalate (MEHP) (odds ratio (OR)=1.13; 95% confidence interval (CI), 1.03-1.23 and OR=1.12; 95% CI, 1.03-1.23, respectively). Waist circumference was positively associated with MBP (OR=1.13; 95% CI, 1.03-1.24). A higher ratio of MEHP to mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was positively associated with both BMI (OR=1.21; 95% CI, 1.09-1.34) and waist circumference (OR=1.20; 95% CI, 1.10-1.31). There were no other significant associations.

CONCLUSIONS

A higher metabolic ratio of MEHP to MEHHP, reflective of slower oxidative conversion of MEHP, is associated with greater BMI and waist circumference.