Parabens in 24h urine samples of the German Environmental Specimen Bank from 1995 to 2012

Repeated-dose toxicity and toxicokinetic study of isobutylparaben in rats subcutaneously treated for 13 weeks

Parabens have historically served as antimicrobial preservatives in a range of consumables such as food, beverages, medications, and personal care products due to their broad-spectrum antibacterial and antifungal properties. Traditionally, these compounds were believed to exhibit low toxicity, causing minimal irritation, and possessing limited sensitization potential. However, recent evidence suggests that parabens might function as endocrine-disrupting chemicals (EDCs). Consequently, extensive research is underway to elucidate potential human health implications arising from exposure to these substances. Among these parabens, particular concerns have been raised regarding the potential adverse effects of iso-butylparaben (IBP). Studies have specifically highlighted its potential for inducing hormonal disruption, significant ocular damage, and allergic skin reactions. This study aimed to evaluate the prolonged systemic toxicity, semen quality, and estrus cycle in relation to endocrine disruption endpoints, alongside assessing the toxicokinetic behavior of IBP in Sprague-Dawley rats following a 13-week repeated subcutaneous administration. The rats were administered either the vehicle (4% Tween 80) or IBP at dosage levels of 2, 10, and 50 mg/kg/day for 13 weeks. Blood collection for toxicokinetic study was conducted on three specified days: day 1 (1st), day 30 (2nd), and day 91 (3rd). Systemic toxicity assessment and potential endocrine effects were based on various parameters including mortality rates, clinical signs, body weights, food and water consumption, ophthalmological findings, urinalysis, hematological and clinical biochemistry tests, organ weights, necropsy and histopathological findings, estrus cycle regularity, semen quality, and toxicokinetic behavior. The findings revealed that IBP induced local irritation at the injection site in males at doses ≥ 10 mg/kg/day and in females at 50 mg/kg/day; however, systemic toxicity was not observed. Consequently, the no-observed-adverse-effect level (NOAEL) for IBP was determined to be 50 mg/kg/day in rats of both sexes, indicating no impact on the endocrine system. The toxicokinetics of IBP exhibited dose-dependent systemic exposure, reaching a maximum dose of 50 mg/kg/day, and repeated administration over 13 weeks showed no signs of accumulation.

Temporal trends in exposure to parabens, benzophenones, triclosan, and triclocarban in adult females in Kyoto, Japan, from 1993 to 2016

Products used in daily life can contain chemicals such as parabens, benzophenones, triclosan, and triclocarban that have potential endocrine-disrupting effects. Little is known about the temporal trends of exposure levels to some of these chemicals in Japan. Our study assessed the intake and risk associated with exposure to commonly used chemicals. We measured the concentrations of five parabens, four benzophenones, and triclosan and triclocarban in 133 single spot urine samples. The urine samples were collected in 1993, 2000, 2003, 2009, 2011, and 2016 from healthy female residents in Kyoto, Japan. With the exception of methylparaben, ethylparaben, and butylparaben, there were no significant fluctuations in the concentrations of target chemicals over the study period; however, methylparaben, ethylparaben, and butylparaben showed temporal changes in concentrations. Methylparaben concentrations peaked in 2003 with a median value of 309 μg/g creatinine, ethylparaben concentrations peaked in 1993 with a median value of 17.3 μg/g creatinine, and butylparaben showed a decline, with the median values becoming non-detectable in 2009 and 2016. We calculated estimated daily intakes and hazard quotients for each chemical. In the analysis of total samples, 2.3% (3 samples) for butylparaben and 0.8% (1 sample) for propylparaben were found to surpass a hazard quotient of 1. Overall, 3% (n = 4) of the study participants exceeded a hazard index of 1. The potential health risks associated with exposure to butylparaben and propylparaben emphasize the need for further monitoring and research.

Urinary concentrations of bisphenol A, parabens and benzophenone-type ultra violet light filters in relation to sperm DNA fragmentation in young men: A chemical mixtures approach

People are daily exposed to multiple endocrine disruptor compounds (EDCs) that may interfere with different molecular and cellular processes, promoting a potential estrogenic, androgenic, or anti-androgenic state. However, most epidemiological studies attempting to establish relationships between EDCs exposure and health effects are still considering individual compounds. A few studies have shown associations between exposure to individual non-persistent EDCs and sperm DNA fragmentation (SDF) in different male populations. Thus, the aim of this study was to investigate associations between combined exposure to non-persistent EDCs and SDF index in young men. A cross-sectional study was conducted with 158 healthy university students from Southeaster Spain. The participants provided spot urine and semen samples on the same day. The concentrations of urinary bisphenol A (BPA), benzophenones [2,4-dihydroxybenzophenone (BP-1); 2,2',4,4'-tetrahydroxybenzophenone (BP-2), 2-hydroxy-4-methoxybenzophenone (BP-3), 2,2'-dihydroxy-4-methoxybenzophenone (BP-8), 4-hydroxybenzophenone (4OHBP)], and parabens (methylparaben, ethylparaben, propylparaben, butylparaben) were measured by dispersive liquid-liquid microextraction and ultrahigh-performance liquid chromatography with tandem mass spectrometry detection. SDF was analysed using a Sperm Chromatin Dispersion test. Statistical analyses were carried out using Bayesian Kernel Machine Regression models to evaluate associations between combined exposure to these compounds and SDF index while adjusting by relevant covariates. The increase in urinary concentration of 4OHBP was found to be the most important contributor to the negative association between urinary EDCs concentrations and SDF index, being of -5.5 % [95 % CI: -10.7, -0.3] for those in percentile 50, and - 5.4 % [95 % CI: -10.8, -0.1] for those in percentile 75. No significant associations were observed between other EDCs and SDF index. Our findings show that urinary 4OHBP levels may be associated with a decrease in the SDF index. Nonetheless, the effects we observed were likely to be small and of uncertain clinical significance. Further research is needed to replicate our findings in other male populations.

Exposure Profile and Characteristics of Parabens and Alkylphenols in Plasma among Rural Adults in Central China

Parabens and alkylphenols pose serious hazards to human health, yet there are few studies on their exposure profiles and health risks in rural Chinese populations. In this study, 804 participants were selected from the Henan Rural Cohort in mid-eastern China. The plasma levels of parabens (methylparaben, ethylparaben, propylparaben, butylparaben (BuP)) and alkylphenols (4-tert-butylphenol (4-t-BP), 4-tert-octylphenol (4-t-OP)) were analyzed via liquid chromatography-tandem mass spectrometry. Linear regression models were used to investigate factors that may influence pollutant exposure levels. The correlation between contaminants was assessed using Spearman's correlation. The human contaminant intake was estimated using the estimated daily intake (EDI). The health risk was assessed using the hazard quotient (HQ). The detection frequency of four parabens and two alkylphenols exceeded 75%, with median concentrations of 0.444, 0.067, 0.078, 0.053, 8.810, and 6.401 ng/mL, respectively. Significant correlations were observed between parabens, as well as between 4-t-BP and 4-t-OP. Regarding gender, paraben concentrations were higher in women than in men, except for BuP. The EDI for pollutants except 4-t-OP was lower than their respective tolerable/acceptable daily intake. In total, 85.70% of participants had 4-t-OP HQ > 1. A widespread exposure to parabens and alkylphenols among the rural population was found. The high health risks of alkylphenol exposure indicate that alkylphenols should be used with caution.

Urinary Paraben Concentrations and Associations with the Periconceptional Urinary Metabolome: Untargeted and Targeted Metabolomics Analyses of Participants from the Early Pregnancy Study

BACKGROUND

Parabens, found in everyday items from personal care products to foods, are chemicals with endocrine-disrupting activity, which has been shown to influence reproductive function.

OBJECTIVES

This study investigated whether urinary concentrations of methylparaben, propylparaben, or butylparaben were associated with the urinary metabolome during the periconceptional period, a critical window for female reproductive function. Changes to the periconceptional urinary metabolome could provide insights into the mechanisms by which parabens could impact fertility.

METHODS

Urinary paraben concentrations were measured in paired pre- and postconception urine samples from 42 participants in the Early Pregnancy Study, a prospective cohort of 221 women attempting to conceive. We performed untargeted and targeted metabolomics analyses using ultrahigh-performance liquid chromatography quadrupole time-of-flight mass spectrometry. We used principal component analysis, orthogonal partial least-squares discriminant analysis, and permutation testing, coupled with univariate statistical analyses, to find metabolites associated with paraben concentration at the two time points. Potential confounders were identified with a directed acyclic graph and used to adjust results with multivariable linear regression. Metabolites were identified using fragmentation data.

RESULTS

Seven metabolites were associated with paraben concentration (variable importance to projection score > 1 , false discovery rate-corrected q -value < 0.1 ). We identified four diet-related metabolites to the Metabolomics Standards Initiative (MSI) certainty of identification level 2, including metabolites from smoke flavoring, grapes, and olive oil. One metabolite was identified to the class level only (MSI level 3). Two metabolites were unidentified (MSI level 4). After adjustment, three metabolites remained associated with methylparaben and propylparaben, two of which were diet-related. No metabolomic markers of endocrine disruption were associated with paraben concentrations.

DISCUSSION

This study identified novel relationships between urinary paraben concentrations and diet-related metabolites but not with metabolites on endocrine-disrupting pathways, as hypothesized. It demonstrates the feasibility of integrating untargeted metabolomics data with environmental exposure information and epidemiological adjustment for confounders. The findings underscore a potentially important connection between diet and paraben exposure, with applications to nutritional epidemiology and dietary exposure assessment. https://doi.org/10.1289/EHP12125.

Cell cycle, apoptosis, cell differentiation, and lipid metabolism gene expression in endometriotic tissue and exposure to parabens and benzophenones

AIM

To describe the expression profile in endometriotic tissue of genes involved in four signaling pathways related to the development and progression of endometriosis (cell cycle, apoptosis, cell differentiation and lipid metabolism) and to explore its relationship with the women exposure to chemicals with hormonal activity released from cosmetics and personal care products (PCPs).

METHODS

This cross-sectional study, encompassed within the EndEA study, comprised a subsample of 33 women with endometriosis. Expression levels of 13 genes (BMI1, CCNB1, CDK1, BAX, BCL2L1, FOXO3, SPP1, HOXA10, PDGFRA, SOX2, APOE, PLCG1 and PLCG2) in endometriotic tissue and urinary concentrations of 4 paraben (PB) and 3 benzophenone (BP) congeners were quantified. Bivariate linear and logistic regression analyses were performed to explore the associations between exposure and gene expression levels.

RESULTS

A total of 8 out 13 genes (61.5 %) were expressed in >75 % of the samples. Exposure to congeners of PBs and/or BPs was associated with the overexpression of CDK1 gene (whose protein drives cells through G2 phase and mitosis), HOXA10 and PDGFRA genes (whose proteins favor pluripotent cell differentiation to endometrial cells), and APOE (whose protein regulates the transport and metabolism of cholesterol, triglycerides and phospholipids in multiple tissues) and PLCG2 genes (whose protein creates 1D-myo-inositol 1,4,5-trisphosphate and diacylglycerol, two important second messengers).

CONCLUSIONS

Our findings suggest that women exposure to cosmetic and PCP-released chemicals might be associated with the promotion of cell cycle and cell differentiation as well as with lipid metabolism disruption in endometriotic tissue, three crucial signaling pathways in the development and progression of endometriosis. However, further studies should be accomplished to confirm these preliminary data.

Association of parabens and bisphenols with lung function in children aged 5-12 years from Shanghai, China

Epidemiological studies have reported potential effects of individual paraben or bisphenol exposure on lung function, but few studies have estimated their joint effects. We conducted a cross sectional survey to investigate the associations of parabens and bisphenols exposure with lung function in 205 children aged 5-12 years from Shanghai, China. Urinary concentrations of six parabens [methyl-, ethyl-, propyl-, butyl-, benzyl-, and heptyl-paraben (MeP, EtP, PrP, BuP, BzP, and HeP)] and seven bisphenols [bisphenol A (BPA), bisphenol AF (BPAF), bisphenol AP (BPAP), bisphenol B (BPB), bisphenol P (BPP), bisphenol S (BPS), and bisphenol Z (BPZ)] were assessed by the high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Lung function, including forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC, peak expiratory flow (PEF), and forced expiratory flow between 25% and 75% of forced vital capacity (FEF_25-75%), was further measured. Linear regression, bayesian kernel machine regression (BKMR), and weighted quantile sum regression (WQS) evaluated the individual and joint relationships of the parabens and bisphenols with the lung function parameters. Further, the analysis was stratified by child sex. Parabens (MeP, EtP, PrP, and BuP) and bisphenols (BPA, BPAP, BPB, and BPS) with detection rates >75% were included for analyses. In linear regressions, parabens (MeP, PrP, and BuP) were generally negatively associated with FEV₁, FVC, PEF, and FEF_25-75%, but no associations for bisphenols were found. The association of parabens with lung function was more pronounced in girls. The aforementioned negative associations between parabens and lung function were confirmed by both the BKMR and WQS, with MeP being considered most heavily weighing chemical. Our findings suggested that exposure to parabens, either individuals or as a mixture, were associated with decreased lung function in children aged 5-12 years, and these associations were stronger among girls. Considering the cross-sectional study design, large longitudinal studies are warranted to confirm our findings.

Human nails as a valuable noninvasive alternative for estimating exposure to parabens

Exposure of human to parabens (commonly used preservatives) is inevitable due to their extensively applied in numerous consumer products. Thus, a reliable noninvasive matrix reflecting long-term exposure to parabens is essential for human biomonitoring study. Human nails are potentially a valuable alternative for measuring intergrated exposure to parabens. In this work, we collected 100 paired nail and urine samples from university students in Nanjing, China, and measured simultaneously for six parent parabens and four metabolites. Methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP) were three predominant paraben analogue in both matrices, with the median concentrations being 12.9, 0.753, and 3.42 ng/mL in urine, and 1540, 154, and 961 ng/g in nail, respectively, while 4-hydroxybenzoic acid (4-HB) and 3,4-dihydroxybenzoic acid (3,4-DHB) were the most abundant metabolites (median values of 143 and 35.9 ng/mL, respectively) in urine. Gender-related analysis suggested that females exposed to more higher parabens than males. Significantly positive correlations were found between levels of MeP, PrP, EtP, and OH-MeP (r = 0.54-0.62, p < 0.01) in paired urine and nail samples. Our result here suggests that human nails, as an emerging biospecimen, are a potentially valuable biological matrix to evaluate human long-term exposure to parabens.

Prenatal paraben exposures and birth size: Sex-specific associations in a healthy population - A study from the Odense Child Cohort

OBJECTIVES

To investigate the sex-specific associations between maternal paraben concentrations in second trimester urine and birth size of the offspring.

METHODS

A prospective cohort study of 529 mother-child pairs within the Odense Child Cohort. Pregnant women were recruited to the cohort from 2010 to 2012 and provided fasting spot urine samples in second trimester (median 28.7 weeks). Concentrations of methylparaben (MeP), ethylparaben (EtP), iso-propylparaben (i-PrP), n-propylparaben (n-PrP), n-butylparaben (n-BuP) and benzylparaben (BzP) were analyzed by isotope diluted liquid-chromatography tandem-mass-spectrometry and osmolality adjusted. Exposures were categorized into tertiles or above/below level of detection. Data on maternal and birth characteristics were extracted from hospital records. Sex-stratified multiple linear regression analyses were performed according to relevant birth outcomes (length, weight, head/abdominal circumference) adjusting for a priori defined confounders.

RESULTS

Higher paraben levels were detected in pregnant women who were older, more obese, who smoked and were primigravidae. Generally, higher maternal paraben exposure was consistently associated with lower birth size in female but not in male offspring, but with few substantial or statistically significant. Higher maternal exposure to n-BuP during pregnancy was associated with a statistically significant lower birth size in female offspring only [birth weight: -137 g (95 % CI -256; -19), head circumference: -0.48 cm (95 % CI -0.90; -0.05), abdominal circumference: -0.65 cm (95 % CI -1.21; -0.08)]. No differences in birth size were observed for other parabens.

CONCLUSION

Higher maternal exposure to n-butylparaben was associated with lower birth size in female but not male offspring.

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

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

Urinary paraben concentrations of adult women by fasting status: Comparison between Korea and the United States

Personal care products (PCPs) are considered as a major source of paraben exposure; however, the dietary contribution is not well known. We compared the urinary levels of methyl-, ethyl-, and propyl-paraben (MeP, EtP, and PrP), and investigated their associations with fasting status and contacts with other potential exposure sources among Korea and the US adult women. A group of fasting, non-pregnant adult women (n = 469) was recruited from Seoul, Ansan/Incheon, and Jeju, Korea in 2015-2016, and their urine was measured for parabens. Non-fasting Korean women of matching age (25-45 years) were chosen from the Korean National Environmental Health Survey (KoNEHS) Cycle 3 (n = 579). For the US women, both fasting (n = 154) and non-fasting (n = 201) females were chosen from the NHANES 2015-2016 participants. In fasting Korean women, the urinary MeP, EtP, and PrP concentrations (median) were measured at 47.30, 17.90, and 2.30 ng/mL, respectively. Urinary EtP and PrP levels in fasting Korean women were significantly lower than those in non-fasting women (EtP and PrP median of 26.40 and 3.57 ng/mL). On average, the difference in urinary EtP levels by fasting status was greater among the highly exposed groups. In the US population, EtP levels were significantly lower (median ranged 1.55-1.80 ng/mL depending on fasting status), but MeP levels were higher (67.90-84.35 ng/mL) than those of the Korean population. When only fasting women were considered, the median EtP levels of Korean women were 11.5-fold greater than those of US women, suggesting that the non-dietary contributions of EtP exposure could not be ignored among Korean women. Regardless of fasting status, MeP and PrP were significantly correlated, and their urinary levels in fasting Korean women were correlated with the use of several personal care products. The major dietary and non-dietary sources that may explain EtP exposure in Korean women warrant further investigation.

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

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

Developing human biomonitoring as a 21st century toolbox within the European exposure science strategy 2020-2030

Human biomonitoring (HBM) is a crucial approach for exposure assessment, as emphasised in the European Commission's Chemicals Strategy for Sustainability (CSS). HBM can help to improve chemical policies in five major key areas: (1) assessing internal and aggregate exposure in different target populations; 2) assessing exposure to chemicals across life stages; (3) assessing combined exposure to multiple chemicals (mixtures); (4) bridging regulatory silos on aggregate exposure; and (5) enhancing the effectiveness of risk management measures. In this strategy paper we propose a vision and a strategy for the use of HBM in chemical regulations and public health policy in Europe and beyond. We outline six strategic objectives and a roadmap to further strengthen HBM approaches and increase their implementation in the regulatory risk assessment of chemicals to enhance our understanding of exposure and health impacts, enabling timely and targeted policy interventions and risk management. These strategic objectives are: 1) further development of sampling strategies and sample preparation; 2) further development of chemical-analytical HBM methods; 3) improving harmonisation throughout the HBM research life cycle; 4) further development of quality control / quality assurance throughout the HBM research life cycle; 5) obtain sustained funding and reinforcement by legislation; and 6) extend target-specific communication with scientists, policymakers, citizens and other stakeholders. HBM approaches are essential in risk assessment to address scientific, regulatory and societal challenges. HBM requires full and strong support from the scientific and regulatory domain to reach its full potential in public and occupational health assessment and in regulatory decision-making.

Biomonitoring bisphenols, parabens, and benzophenones in breast milk from a human milk bank in Southern Spain

BACKGROUND

Human breast milk is considered the optimal source of nutrition for infants. Milk from breast milk banks offers an alternative to infant formulas for vulnerable hospitalized neonates most likely to benefit from exclusive human milk feeding. However, breast milk can also be a source of exposure to environmental contaminants, including endocrine-disrupting chemicals (EDCs).

AIM

To evaluate concentrations of phenolic EDCs, including bisphenols, parabens (PBs), and benzophenones (BPs), in samples from a human milk bank in Granada, Southern Spain and to explore sociodemographic, reproductive, and lifestyle factors related to their concentrations in the milk.

METHODS

Concentrations of three bisphenols [bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS)], four PBs [methyl- (MeP), ethyl- (EtP), propyl- (n-PrP), and butyl-paraben (n-BuP)], and six BPs [BP-1, BP-2, BP-3, BP-6, BP-8, and 4-hydroxy-BP] were determined in milk samples from 83 donors. Information on potential explanatory variables was gathered using the milk bank donor form and an ad hoc questionnaire. Multiple linear and logistic regression models were fitted.

RESULTS

Detectable concentrations were found of at least one of the analyzed compounds in all donor breast milk samples and at least five compounds in one-fifth of them. The most frequently detected compounds were MeP (90.5%), BP-3 (75.0%), EtP (51.2%), n-PrP (46.4%), and BPA (41.7%). Median concentrations ranged between <0.10 ng/mL (n-PrP, n-BuP, BP-1) and 0.59 ng/mL (BP-3). No sample contained detectable concentrations of BPF, BPS, or most BPs (BP-2, BP-6, BP-8, and 4- hydroxy-BP). Breast milk phenol concentrations were associated with parity, the utilization of deodorants, mouthwash, skin care products, and cosmetics, and the intake of nutritional supplements.

CONCLUSIONS

Results reveal the widespread presence of BPA, PBs, and BP-3 in donor breast milk samples, highlighting the need for preventive measures to enhance the benefits of breast milk from milk banks and from breastfeeding women in general.

Co-exposure and health risks of several typical endocrine disrupting chemicals in general population in eastern China

Human exposure to endocrine disrupting chemicals (EDCs) is a health concern due to their wide use and interference with the human endocrine system. Parabens, bisphenols, benzophenones, triclosan (TCC), triclocarban (TCS), and tetrabromobisphenol-A (TBBPA) and its derivatives tetrachlorobisphenol-A (TCBPA) and tetrabromobisphenol-S (TBBPS), are typical EDCs that are frequently detected in environmental and human samples. However, only a few studies have assessed the co-exposure of these chemicals in humans. In this study, urine samples were collected from the general population in the city of Wuxi (n = 121) and a county, Taishun (n = 120), eastern China, and analyzed for these EDCs. Parabens, bisphenols, TCS, and benzophenones were frequently detected in urine, whereas TBBPA and its derivatives were not detected. The geometric mean concentrations of parabens, bisphenols, and benzophenones in urine from the Wuxi population were 25.7, 2.45, and 2.34 ng/mL, respectively, which were substantially higher than those from the Taishun population (17.2, 1.70, and 2.65 ng/mL). These results suggest an urban-rural difference in urinary EDCs. The exposure risks to these EDCs were estimated based on the measured urinary concentrations and acceptable daily intakes (ADIs). Hazard quotient values for EDCs in humans from both locations were generally less than 1, indicating a low exposure risk of EDCs in these regions. Nonetheless, the health risks caused by co-exposure to such EDCs cannot be ignored.

Occurrence, spatial distribution and ecological risk assessment of phthalate esters in water, soil and sediment from Yangtze River Delta, China

A total of 96 water, soil, and sediment samples, collected from 32 sampling sites in the Yangtze River Delta (YRD) region, were analyzed for 9 phthalate esters (PAEs). The sum concentrations of 9 PAEs (∑₉PAEs) in the water, soil, and sediment samples were 2.23-6.30 μg L^-1 (mean: 4.11 μg L^-1), 155-1410 μg kg^-1 (408 μg kg^-1), and 30.1-16,000 μg kg^-1 (1200 μg kg^-1), respectively. Among the 9 PAEs, di-n-butyl phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP), and di-isobutyl phthalate (DIBP) are the predominant congeners in the YRD region. DBP was the dominant PAE congener in water, accounting for 50.6% of the Σ₉PAEs, while DEHP was the predominant one in soil and sediment (accounting for 69.6% and 83.1% of the Σ₉PAEs, respectively). Soil and sediment samples collected from Wuxi city manifested relatively higher PAE concentrations. The partitioning of PAEs between water and sediment was attributed to the fact that low molecular weight PAEs (e.g., dimethyl phthalate (DMP) and diethyl phthalate (DEP)) were dominant in water, medium molecular weight PAEs (e.g., BzBP) were close to the equilibrium between sediment-water, and high molecular weight PAEs (e.g., DEHP) were more prevalent in sediment. The ecological risk assessment of PAEs in the surface water showed that the potential environmental risks followed the order of DEHP > DIBP > DBP > DMP > DEP. Comparatively, DEHP posed high ecological risk to sensitive algae, crustaceans and fish, while DMP and DEP exhibited low risk. In the sediment, DIBP exhibited a high risk to the sensitive fish, whereas DMP, DEP, DBP and DEHP displayed no risk.

Exposure of men and lactating women to environmental phenols, phthalates, and DINCH

Phthalates and 1,2-Cyclohexane dicarboxylic acid diisononyl ester (DINCH), bisphenols (BPs), parabens (PBs), and triclosan (TCS) are high-production-volume chemicals of pseudo-persistence that are concerning for the environment and human health. This study aims to assess the exposure to 10 phthalates, DINCH, and environmental phenols (3 BPs, 7 PBs, and TCS) of Slovenian men (n = 548) and lactating primiparous women (n = 536). We observed urinary concentrations comparable to studies from other countries and significant differences among the sub-populations. In our study, men had significantly higher levels of phthalates, DINCH, and BPs, whereas the concentrations of PBs in urine were significantly higher in women. The most significant determinant of exposure was the area of residence and the year of sampling (2008-2014) that mirrors trends in the market. Participants from urban or industrialized sampling locations had higher levels of almost all monitored analytes compared to rural locations. In an attempt to assess the risk of the population, hazard quotient (HQ) values were calculated for individual compounds and the chemical mixture. Individual analytes do not seem to pose a risk to the studied population at current exposure levels, whereas the HQ value of the chemical mixture is near the threshold of 1 which would indicate a higher risk. We conclude that greater emphasis on the risk resulting from cumulative exposure to chemical mixtures and additional studies are needed to estimate the exposure of susceptible populations, such as children.

In utero exposure to parabens and early childhood BMI z-scores - Associations between placental ethyl paraben, longitudinal BMI trajectories and cord blood metabolic biomarkers

BACKGROUND

Parabens are used as antimicrobial preservatives in personal care products. Few studies have dealt with adverse health outcomes, transplacental transfer, and obesogenic effects of prenatal exposure to parabens. We examined the association between placental paraben levels and cord blood metabolic biomarkers, considering modulating effects of maternal pre-pregnancy BMI and underlying epigenetic mechanisms, and investigated longitudinal effects of in utero paraben exposure on early childhood trajectories of BMI z-scores.

METHODS

Placental concentrations of four parabens [methyl (MeP), ethyl (EtP), propyl (PrP), and butyl (BuP)] were measured by ultra-performance liquid chromatography/tandem mass spectrometry in 229 placentas of the ENVIRONAGE birth cohort. The association with cord blood metabolic biomarkers [glucose, insulin, γ-glutamyltransferase (GGT), high-density and low-density lipoprotein (HDL and LDL)] was analyzed in multiple regression models with two different sets of, a priori selected potential confounders, additionally stratified for different maternal BMI groups and assessed by causal mediation analysis. The association between placental paraben concentration and differential DNA methylation of CpGs annotated to GGT and longitudinal measurements of BMI z-scores were investigated with adjusted linear mixed models.

RESULTS

The geometric means of placental MeP, EtP, PrP, and BuP levels above the limit of detection (LOD) were 4.42, 1.32, 1.51, and 0.35 ng/g respectively, with only EtP showing sufficient (88%) measurements above LOD for further analyses. An interquartile ratio (IQR) increase in placental EtP was associated with an increase of 12.61 % (95% CI: 1.80 24.57) in the geometric mean of cord GGT activity, and with a decrease of -3.64 % (95% CI: -6.80 to -0.39) in the geometric mean of cord glucose. Placental EtP levels were significantly associated with hypermethylation of cg08612779 annotated to GGT7 after correcting for multiple testing (ß = 0.0017, p = 0.049). An interquartile ratio (IQR) increment in placental EtP was associated with a decrease in longitudinal BMI z-score of 0.27 points (95% CI: -0.46 to -0.088).

CONCLUSION

Prenatal EtP exposure may affect early childhood BMI. The association of placental EtP with cord blood GGT and glucose levels provides a starting point for further research on mechanisms of paraben-related metabolic processes in utero.

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.

Parabens as chemicals of emerging concern in the environment and humans: A review

Parabens are one of the most widely used preservatives in food, pharmaceuticals and personal care products (PCPs) because of their advantageous properties and low toxicity based on the early assessments. However, recent research indicates that parabens may act as endocrine-disrupting chemicals (EDCs) and thus, are considered as chemicals of emerging concern that have adverse human health effects. To provide the basis for future human health studies, we reviewed relevant literature, published between 2005 and 2020, regarding the levels of parabens in the consumer products (pharmaceuticals, PCPs and food), environmental matrices and humans, including susceptible populations, such as pregnant women and children. The analysis showed that paraben detection rates in consumer products, environmental compartments and human populations are high, while the levels vary greatly by country and paraben type. The concentrations of parabens reported in pregnant women (~20-120 μg/L) were an order of magnitude higher than in the general population. Paraben concentrations in food and pharmaceuticals were at the ng/g level, while the levels in PCPs reached mg/g levels. Environmental concentrations ranged from ng/L-μg/L in surface waters to tens of μg/g in wastewater and indoor dust. The levels of human exposure to parabens appear to be higher in the U.S. and EU countries than in China and India, which may change with the increasing production of parabens in the latter countries. The review provides context for future studies to connect paraben exposure levels with human health effects.

Web-based behavioral intervention to reduce exposure to phthalate metabolites, bisphenol A, triclosan, and parabens in mothers with young children: A randomized controlled trial

In this study, a web-based behavioral intervention was designed, which aimed to reduce exposure to phthalate metabolites, bisphenol A, triclosan, and parabens in mothers with young children. A randomized controlled design with two groups was used to verify the effects of the intervention pre- and post-test. In total, 51 mothers participated in the study, categorizing 26 and 25 in the intervention and control groups, respectively. The web-based behavioral intervention focused on changes in diet, personal care products, and health behavior and reinforced behavior through encouragement. This program included an educational video, a game for locating endocrine disruptors at home, a method for locating facilities potentially emitting endocrine disruptors, resources, and a questions and answers mode. Data were collected from May 18 to June 30, 2020. Participants allocated to the intervention group were provided access to the behavioral intervention website via a computer or smartphone. Participants allocated to the control group were sent written information about endocrine disruptors via mail. For both the intervention and control groups, questionnaire results and maternal urine samples were assessed at baseline, during the intervention, and after one month. After the intervention, the urinary concentrations of mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), bisphenol A (BPA), methylparaben (MP), ethylparaben (EP), and propylparaben (PP) were found to be significantly decreased in the intervention group. Compared with the control group, the intervention group showed significantly decreased urinary geometric mean values of MEHP, MEOHP, BPA, MP, and PP after one month compared with those during the intervention (3.8%, 16.3%, 28.4%, 9.2%, and 24.4%, respectively). Hence, the web-based behavioral intervention was effective at reducing the exposure to endocrine disruptors in mothers with young children.

Prenatal Exposure to Butyl Paraben Is Associated With Fat Percentage in 7-Year-Old Boys

CONTEXT

Parabens are used as preservatives in consumer products but are suspected of having endocrine-disrupting properties. A recent study reported an association between in utero exposure to butyl paraben and overweight in childhood, with a stronger trend in girls.

OBJECTIVE

We therefore studied the association between parabens in maternal urine in third trimester and fat percentage in children aged 7 years.

DESIGN, SETTING, AND PARTICIPANTS

We used data from the Odense Child Cohort, a mother-child cohort with enrollment from 2010 to 2012, in which the children are followed. Paraben concentration was assessed in maternal urine at median gestational week 28.7 and body composition measured as total, gynoid, and android fat percentages assessed by dual X-ray absorptiometry in their children at age 7 years.

MAIN OUTCOME MEASUREMENTS

Total, gynoid, and android fat percentages and z-score for body mass index.

INTERVENTIONS

None.

RESULTS

Paraben exposure was low. In multivariate linear regressions, detection of butylparaben in maternal urine was associated with an increase of 17% [95% confidence intervals (CI) 3.0%, 32%] in total body fat percentage and an increase of 23% (95% CI 5.1%, 43%) in android fat percentage in boys, compared to boys whose mother had no detectable butylparaben in urine. No significant associations between in utero exposure to methyl-, ethyl- or propyl parabens and body composition were found, and no significant associations were seen in girls.

CONCLUSION

Our findings suggest that parabens, which are believed to have low toxicity, may affect obesity development at vulnerable time periods during development.

Temporal exposure and consistency of endocrine disrupting chemicals in a longitudinal study of individuals with impaired fasting glucose

Endocrine disrupting chemicals (EDCs) include non-persistent exogenous substances such as parabens, bisphenols and phthalates which have been associated with a range of metabolic disorders and disease. It is unclear if exposure remains consistent over time. We investigated change in indicators of EDC exposure between 2009 and 2016 and assessed its consistency between and within individuals over a median follow-up time of 47 months in a sample of Dutch individuals. Of 500 Dutch individuals, two 24 h urine samples were analysed for 5 parabens, 3 bisphenols and 13 metabolites of in total 8 different phthalates. We calculated per-year differences using meta-analysis and assessed temporal correlations between and within individuals using Spearman correlation coefficients, intra-class correlation coefficients (ICC) and kappa-statistics. We found a secular decrease in concentrations of methyl, ethyl, propyl and n-butyl paraben, bisphenol A, and metabolites of di-ethyl phthalate (DEP), di-butyl phthalate (DBP), di-(2-ethyl-hexyl) phthalate (DEHP), and butylbenzyl phthalate (DBzP) which varied from 8 to 96% (ethyl paraben, propyl paraben) between 2009 and 2016. Within-person temporal correlations were highest for parabens (ICC: 0.34 to 0.40) and poorest for bisphenols (ICC: 0.15 to 0.23). For phthalate metabolites, correlations decreased most between time periods (ICC < 48 months: 0.22 to 0.39; ≥48 months: 0.05 to 0.32). When categorizing EDC concentrations, 33-54% of individuals remained in the lowest or highest category and temporal correlations were similar to continuous measurements. Exposure to most EDCs decreased between 2009 and 2016 in a sample of individuals with impaired fasting glucose from the Dutch population. Temporal consistency was generally poor. The inconsistency in disease associations may be influenced by individual-level or temporal variation exhibited by EDCs. Our findings call for the need for repeated measurements of EDCs in observational studies before and during at-risk temporal windows for the disease.

Prenatal paraben exposure and anogenital distance and reproductive hormones during mini-puberty: A study from the Odense Child Cohort

BACKGROUND

Parabens are added to personal care products as antimicrobial preservatives. They have been suggested to have endocrine disrupting abilities. Prenatal exposure to parabens has been associated with reproductive endpoints including reduced male anogenital distance (AGD, distance from anus to genitals), which is sensitive to prenatal anti-androgenic exposure.

OBJECTIVES

To study the associations between maternal paraben concentrations in second trimester urine and AGD and reproductive hormone concentrations at 3 months of age in offspring.

METHODS

Pregnant women from Odense, Denmark were included in early pregnancy from 2010 to 12, and their children are being followed up. Fasting spot urine samples from 536 pregnant women were analyzed for methylparaben (MeP), ethyl-paraben (EtP), iso-propylparaben (i-PrP), n-propylparaben (n-PrP), n-butylparaben (n-BuP) and benzylparaben (BzP) by liquid chromatography tandem mass spectrometry and thereafter osmolarity adjusted. Three months after expected date of birth, AGD was measured in 452 children, and serum concentrations of follicle stimulating hormone (FSH), luteinizing (LH), testosterone, dehydroepiandrosterone-sulphate (DHEAS), androstenedione and 17-hydroxyprogesterone (17-OHP) were measured in 198 children. Maternal paraben exposure was categorized into tertiles or below and above level of detection, and sex-stratified multiple linear regression analyses were performed with AGD or reproductive hormones as outcomes.

RESULTS

Most pregnant women had low concentrations of parabens in urine, but 10% exceeded the threshold for adverse estrogenic effects. Higher maternal paraben exposure was associated with shorter AGD in male offspring and longer AGD in girls, although only significant for MeP in boys. In addition, FSH, LH, DHEAS, 17-OHP concentrations were lower in girls with high prenatal paraben exposure, whereas no consistent pattern was found in boys.

DISCUSSION

The endocrine disrupting abilities of parabens may affect humans at vulnerable time periods during development, which may have long term impact on reproductive function. This is the first study to find these associations in girls and our findings need confirmation.

Parabens in urine of children and adolescents in Germany - human biomonitoring results of the german environmental survey 2014-2017 (GerES V)

Parabens are antimicrobial preservatives used in a wide range of consumer products such as personal care products, cosmetics, pharmaceuticals, and food. Consequently, the general population is ubiquitously exposed to these substances via dermal absorption, ingestion, and inhalation. Parabens promote estrogenic activity and are hence under assessment as endocrine disrupting substances. Urine samples from 3- to 17-year-old children and adolescents (N = 516) living in Germany were analysed for concentrations of nine parabens in the population representative German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Detection rates and urinary concentrations of the parabens decreased with increasing length of the alkyl chain. Methyl paraben was quantified in 97% of the samples with a geometric mean (GM) concentration of 7.724 μg/L (6.714 μg/g_creatinine), ethyl paraben was quantified in 69% (GM: 0.943 μg/L and 0.825 μg/g_crea), and n-propyl paraben in 31% (GM: 0.563 μg/L and 0.493 μg/g_crea). Concentrations of iso-propyl paraben, butyl paraben, iso-butyl paraben, and benzyl paraben were below the limit of quantification in most samples. Pentyl paraben and heptyl paraben were not detected in any of the samples. Paraben concentrations in urine were found to be associated with frequent usage of leave-on personal care products and cosmetics. Cumulative exposure to parabens (back-calculated daily intakes, expressed as hazard index) was found to be on a level raising concern in up to 14% of the population, mainly driven by n-propyl paraben, and depending on the level of conservativeness and point-of departures used for calculation.

Human metabolism and urinary excretion kinetics of di-n-butyl adipate (DnBA) after oral and dermal administration in three volunteers

Di-n-butyl adipate (DnBA) is used as a plasticizer and in various consumer products (e.g. personal care products) replacing, in part, the endocrine disruptor di-n-butyl phthalate (DnBP). We provide quantitative in vivo data on human DnBA metabolism and excretion after oral dose (105-185 μg/kg bw) and dermal application to three volunteers each as a tool for exposure and risk assessment. Complete and consecutive urine samples were collected for two (oral) and four days (dermal), respectively, and analyzed for the metabolites mono-n-butyl adipate (MnBA), 3- and tentative 4-hydroxy-mono-n-butyl adipate (3OH-MnBA, 4OH-MnBA), and 3-carboxy-mono-n-propyl adipate (3cx-MnPrA), as well as the hydrolysis product adipic acid (AA) using stable isotope dilution quantification. Metabolites were excreted within 24 h after oral dose with one or two concentration maxima at 0.8-3.0 h (n = 3) and 4.8-6.3 h (n = 2). AA was the major but unspecific metabolite with urinary excretion fractions (F_UEs) of 14-26 %. Mean F_UEs (range) of 3cx-MnPrA, MnBA, 3OH-MnBA, and tentative 4OH-MnBA were low, but consistent between volunteers (0.47 % (0.35-0.63 %), 0.079 % (0.065-0.091 %), 0.012 % (0.006-0.016 %), and 0.005 % (0.002-0.009 %), respectively). MnBA and 3OH-MnBA seem to be suitable, specific exposure biomarkers for DnBA, whereas 3cx-MnPrA and 4OH-MnBA seem to originate also from other, unknown sources not related to DnBA. Compared to the oral study, metabolite excretion in the dermal study was delayed and MnBA excretion was somewhat higher compared to the oxidized metabolites. Based on urinary concentrations and the above excretion fractions, calculated uptakes in the dermal study did not exceed the adipate ester ADI of 5 mg/(kg bw*day).

Human biomonitoring in urine samples from the Environmental Specimen Bank reveals a decreasing trend over time in the exposure to the fragrance chemical lysmeral from 2000 to 2018

2-(4-tert-butylbenzyl)propionaldehyde (trade names, e.g. lysmeral or lilial) is a fragrance chemical frequently used in cosmetic products where it is labelled as Butylphenyl methylpropional. A recently developed LC-MS/MS method for the analysis of four lysmeral metabolites (tert-butylbenzoic acid (TBBA), lysmerol, lysmerylic acid, and hydroxy-lysmerylic acid) was applied to 329 urine samples from the Environmental Specimen Bank collected between 2000 and 2018. The two major metabolites TBBA and lysmerol were found in quantifiable concentrations in almost all samples in this study and correlated significantly. Hence, both analytes proved to be specific biomarkers indicating the broad exposure to lysmeral. A significant decline was found for TBBA and lysmerol for the monitored years with the most pronounced decrease from 2012 to 2015. The daily intake (DI) was used to evaluate potential health risks with respect to the derived no-effect level (DNEL) as a threshold for exposure of the general population. The median DI (1.63 μg/kg bw/d) and the 95th percentile (4.69 μg/kg bw/d) corresponded to 2.6% and 7.5% of the lowest DNEL (62.5 μg/kg bw/d for oral administration), respectively. Even though a decreasing trend in exposure was observed the data still calls for efforts to reduce the exposure towards lysmeral since metabolites of lysmeral were detected in nearly all samples and adverse effects cannot be excluded. Clearly, these results need to be substantiated by HBM campaigns in population representative samples like the German Environmental Survey in adults (GerES VI) to provide more robust data for the adult population.

Exposure of the French population to bisphenols, phthalates, parabens, glycol ethers, brominated flame retardants, and perfluorinated compounds in 2014-2016: Results from the Esteban study

BACKGROUND

As part of the French Human Biomonitoring (HBM) programme, the Esteban study described, among other things, biomarkers levels of various chemicals in adults (18-74 years old) and children (6-17 years old). This paper describes the design of the study and provides, for the first time, data on the biological exposure of the general French population to a wide range of contaminants posing a threat to human health which are currently found in domestic environments.

METHODS

Esteban is a cross-sectional study conducted on a nationwide sample of the French general population. Exposure biomarkers of six families of contaminants deemed detrimental to adults' and children's health were measured in biological samples collected either at participants' homes by a nurse, or brought to a National Health Insurance examination centre. All participants were randomly selected (2503 adults and 1104 children). The geometric mean and percentiles of the distribution of levels were estimated for each biomarker. Most of the descriptive statistical analyses were performed taking into account the sampling design.

RESULTS

Results provided a nationwide description of biomarker levels. Bisphenols (A, S and F), and some metabolites of phthalates and perfluorinated compounds (PFCs) (specifically, PFOS and PFOA) were quantified in almost all the biological samples analysed. Higher levels were observed in children (except for PFCs). Levels were coherent with international studies, except for bisphenols S and F, brominated flame retardants (BFRs) and parabens (with higher levels reported in the USA than in France).

CONCLUSION AND PERSPECTIVES

This study is the first to provide a representative assessment of biological exposure to domestic contaminants at the French population level. Our results show that the French general population was exposed to a wide variety of pollutants in 2014-2016, and identify the determinants of exposure. These findings will be useful to stakeholders who wish to advocate an overall reduction in the French population's exposure to harmful substances. Similar future studies in France will help to measure temporal trends, and enable public policies focused on the reduction of those chemicals in the environment to be evaluated.

A Novel HPLC Method for Simultaneous Determination of Methyl, Ethyl, n-propyl, Isopropyl, n-butyl, Isobutyl and Benzyl Paraben in Pharmaceuticals and Cosmetics

INTRODUCTION

The alkyl esters of p-hydroxybenzoic acid at the C-4 position, "the parabens," including methyl, ethyl, propyl, and butyl, are widely used as antimicrobial preservatives in foods, cosmetics, and pharmaceuticals. Official regulations on the use of these compounds make their analysis essential for the estimation of their exposure.

METHODS

On this basis, the presented study was realized to develop a simple, selective and cheap high-performance liquid chromatographic method for the quantitative determination of methylparaben, ethylparaben (EP), n-propyl paraben (NPP), isopropyl paraben (IPP), n-butyl paraben (NBP), isobutyl paraben (IBP) and benzyl paraben (BP) in pharmaceuticals and cosmetic products.

RESULTS

The chromatographic separation of the analytes was achieved under flow rate gradient elution conditions using a C18-bonded core-shell silica particle column (2.6 μm particle size, 150 × 3.0 mm from Phenomenex Co.). The samples were injected into the system as aliquots of 1.0 μL, and the compounds were detected by using a photodiode array detector set at 254 nm wavelength. With this technique, seven paraben derivatives can be determined in the concentration range of 250-2000 ng/mL. The recovery of the method is in the range of 99.95-13.84%, and the RSD is at a maximum value of 3.95%.

CONCLUSION

The proposed method was fully validated and successfully applied to different pharmaceutical and cosmetic samples (n=16), including syrups, suspensions, oral sprays, gels, etc. At least one paraben derivative was detected in six samples and was determined quantitatively. The maximum amount of a paraben derivative found in the analyzed samples was 321.7 ng/mL, which was MP. To the best of our knowledge, this is the first LC method, which is applicable both on pharmaceutical and cosmetic samples.

N-methylmalonamic acid (NMMA) as metabolite of methylisothiazolinone and methylchloroisothiazolinone in 24-h urine samples of the German Environmental Specimen Bank from 2000 to 2017 - exposure and time trends

Methylisothiazolinone (MI) and the mixture of methylchloroisothiazo¬linone/methylisothiazolinone (MCI/MI, 3:1) are widespread biocides used in cosmetics, household products, paints or as disinfectant in air-conditioning systems. Exposure to these compounds has raised concerns due to their sensitizing potential, as rates of skin sensitization were reported to increase in the last decade. We have analyzed N-methylmalonamic acid (NMMA), a common metabolite of MI and MCI in 24-h urine samples of the German Environmental Specimen Bank collected from 480 participants (240 male/240 female) between the years 2000 and 2017. Using these data, we were able to calculate the overall daily intake of MI and/or MCI/MI (3:1) of the study participants and point out time trends. NMMA was determined in all urine samples investigated above the LOQ of 0.5 μg/L urine. Median and 95th percentile level of NMMA in all 24-h urine samples was 4.1 μg/g creatinine and 8.5 μg/g creatinine, respectively. This would correspond to a median and 95th percentile daily intake of 0.35 μg/kg bw and 0.71 μg/kg bw for exclusive uptake of MI and 0.64 μg/kg bw and 1.28 μg/kg bw for exclusive uptake of MCI/MI (3:1). We noted only slight variations over time for median exposures, but an increasing time trend in the 95th percentile exposure between 2006 and 2011 with a decrease in recent years, probably reflecting regulatory measures on MI and MCI/MI (3:1) in cosmetic products. Increasing knowledge on determinants of exposure to MI and/or MCI/MI (3:1) would be necessary to further lower exposure to these sensitizing compounds.

Influence of Vegetarian Dietary Intervention on Urinary Paraben Concentrations: A Pilot Study with 'Temple Stay' Participants

Personal care products and cosmetics have been identified as major sources of paraben exposure among humans. However, the contribution of dietary factors has not been well understood. We recruited temple stay participants (n = 25) who followed a strict Buddhist vegetarian diet during a five-day period, and assessed the influence of this lifestyle change, employing their urine samples collected before and after the temple stay. Before the temple stay, methylparaben (MeP) was detected at the highest levels, followed by ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP), and benzophenones (BPs) in the urine samples. Following the temple stay, the urinary EtP concentrations remarkably increased from 14.0 to 105 μg/L, and were around two orders of magnitude higher than those reported from other countries. Dietary factors associated with the temple diet may partly explain the increase, because EtP is allowed in Korea for seasoning and condiments, which are frequently added in vegetarian diets. Following the temple stay, however, MeP, PrP, and BPs did not show significant decreasing trends. In contrast, BuP levels decreased significantly, especially in male urine samples, that is, from 3.60 to 1.03 μ/L, suggesting a reduced use of certain personal care products during the temple stay. Our observations outline the potential importance of dietary factors on EtP exposure, and might help explain its high exposure levels among Korean population.

Parabens in breast milk and possible sources of exposure among lactating women in Korea

Parabens, broad-spectrum antimicrobial preservatives widely used in various consumer products and food, are suspected to be linked with several adverse health effects in humans, especially newborn babies, infants, and young children. While human exposure to parabens has been frequently reported by measuring the concentration of parabens in urine, similar measurements in breast milk have rarely been made. To determine paraben concentrations in breast milk and possible sources of exposure, four major parabens, including methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) were measured in breast milk samples collected from 260 lactating women in South Korea. Demographic, socioeconomic, and behavioral factors associated with the presence of parabens in breast milk were determined. EP concentrations were detected at the highest levels in breast milk samples, followed by MP, PP, and BP. Pre-pregnancy BMI, parity, use of basic skin care products, use of cosmetics, canned beverage, and type of milk consumption were associated with higher frequencies of paraben detection. In addition, type of milk, parity, and drinking status were significantly associated with the concentration of EP. Multiple regression analyses showed that colostrum and transitional milk samples had higher levels of EP than mature milk samples. The estimated daily intake of parabens in infants via breastfeeding appears to be negligible when compared to the acceptable daily intake values set forth by the European Food Safety Authority (EFSA); however, considering the vulnerability of breastfed infants and ubiquitous sources of exposure from daily use of household and personal toiletries, efforts to identify sources and mitigate exposure are warranted.

German Environmental Specimen Bank: 24-hour urine samples from 1999 to 2017 reveal rapid increase in exposure to the para-phthalate plasticizer di(2-ethylhexyl) terephthalate (DEHTP)

The worldwide plasticizer markets are facing constant substitution processes. Many classic ortho-phthalate plasticizers like di(2-ethylhexyl) phthalate (DEHP) are phased out, due to their proven toxicity to reproduction. Assumedly less critical, less regulated plasticizers such as di(2-ethylhexyl) terephthalate (DEHTP) are increasingly applied in consumer near products like toys, food contact materials, and medical devices. With the increasing use of DEHTP, increasing exposures of the general population have to be expected likewise. Human biomonitoring is a well-established tool to determine population exposures. In the present study we investigate the time trend of exposure to DEHTP using 24-hour urine samples of the German Environmental Specimen Bank (ESB) collected from 1999 to 2017. In these samples (60 per odd-numbered year, 600 samples in total) collected from young German adults (20-29 years, equal gender distribution) we determined four specific urinary metabolites as biomarkers of DEHTP exposure. From 1999 to 2009, the main specific urinary metabolite 5cx-MEPTP was quantifiable in <10% of the samples. Thereafter, detection rates and levels constantly increased, in line with rapidly increasing DEHTP consumption volumes. In 2017, all samples had 5cx-MEPTP levels above the limit of quantification (LOQ) with a median concentration of 3.35 μg/L (95th percentile: 12.8 μg/L). The other metabolites were detected less frequently and at lower levels but correlated well with 5cx-MEPTP robustly confirming the increasing DEHTP exposure. All 5cx-MEPTP concentrations were well below the German health based guidance value (HBM-I) of 2800 μg/L for adults. Likewise, the median calculated daily intake, based on 5cx-MEPTP measured in 2017, was 0.74 μg/kg bw∗d (95th percentile: 3.86 μg/kg bw∗d), still well below the tolerable daily intake (TDI) of 1000 μg/kg bw∗d. Based on current toxicological knowledge we can hence conclude that for the population investigated, DEHTP exposure gives no reason for immediate concern. However, the steep ongoing increase of DEHTP exposure warrants further close monitoring in the future, preferably also in sub-populations with known higher exposures to plasticizers, especially children.

Metabolites of the alkyl pyrrolidone solvents NMP and NEP in 24-h urine samples of the German Environmental Specimen Bank from 1991 to 2014

PURPOSE

The aim of this study was to get a first overview of the exposure to the solvents and reproductive toxicants N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP) in Germany. NMP and NEP metabolite concentrations were determined in 540 24-h urine samples of the German Environmental Specimen Bank collected from 1991 to 2014. With these data we were able to investigate NMP/NEP exposures over time and to evaluate associated risks.

METHODS

NMP metabolites 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methylsuccinimide (2-HMSI) and NEP metabolites 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI) were determined by stable isotope dilution analysis using solid phase extraction followed by derivatization (silylation) and GC-EI-MS/MS.

RESULTS

We were able to quantify 5-HNMP and 2-HMSI in 98.0 and 99.6% and 5-HNEP and 2-HESI in 34.8 and 75.7% of the samples. Metabolite concentrations were rather steady over the timeframe investigated, even for NEP which has been introduced as an NMP substitute only in the last decade. Calculated median daily intakes in 2014 were 2.7 µg/kg bw/day for NMP and 1.1 µg/kg bw/day for NEP. For the combined risk assessment of NMP and NEP exposure, the hazard index based on the human biomonitoring assessment I values (HBM I values) was less than 0.1.

CONCLUSIONS

Based on the investigated subpopulation of the German population, individual and combined NMP and NEP exposures were within acceptable ranges in the investigated timeframe. Sources of NEP exposure in the 90s and 00s remain elusive.

Parabens in human urine from several Asian countries, Greece, and the United States

Parabens, esters of para-hydroxybenzoic acid, are commonly used as antimicrobial preservatives in cosmetics and personal care products. Although several studies report exposure of humans to parabens in Western countries, little is known about exposure of humans to parabens in Asian countries. In this study, we determined concentrations of six parabens in spot urine samples collected from nine countries and estimated daily intakes (DI) and potential health risks of parabens. Ethyl-paraben, methyl-paraben, and propyl-paraben were detected frequently at 100, 98.0, and 80.3%, respectively, with representative median concentrations of 0.68, 7.02, and 1.21 ng/mL, respectively, for all nine countries. Urine samples from females (total median concentration: 32.3 ng/mL) contained significantly higher concentrations of parabens than did those from males (5.46 ng/mL). Urine samples from Korea (total median paraben concentration: 227 ng/mL) had the highest concentrations, which were one to two orders of magnitude higher than those found in other countries (3.67-29.1 ng/mL). The estimated DI of parabens (on the basis of concentrations measured in urine) varied widely, and several samples had propyl-paraben exposures above the acceptable DI. Our results suggest that paraben exposure is ubiquitous in Asian countries, and further assessment of potential health risk of these chemicals is needed.

[Integration of sex/gender into environmental health research. Results of the interdisciplinary research network Sex/Gender-Environment-Health (GeUmGe-NET)]

The comprehensive consideration of sex/gender in health research is essential to increase relevance and validity of research results. Contrary to other areas of health research, there is no systematic summary of the current state of research on the significance of sex/gender in environmental health. Within the interdisciplinary research network Sex/Gender-Environment-Health (GeUmGe-NET) the current state of integration of sex/gender aspects or, respectively, gender theoretical concepts into research was systematically assessed within selected topics of the research areas environmental toxicology, environmental medicine, environmental epidemiology and public health research on environment and health. Knowledge gaps and research needs were identified in all research areas. Furthermore, the potential for methodological advancements by using gender theoretical concepts was depicted. A dialogue between biomedical research, public health research, and gender studies was started with the research network GeUmGe-NET. This dialogue has to be continued particularly regarding a common testing of methodological innovations in data collection and data analysis. Insights of this interdisciplinary research are relevant for practice areas such as environmental health protection, health promotion, environmental justice, and environmental health monitoring.

Urinary concentrations of parabens and reproductive parameters in young men

Parabens are a group of alkyl esters of p-hydroxybenzoic acid that are commonly added to personal care products, cosmetics, pharmaceuticals and beverage and food processing as antimicrobial preservatives. Parabens have been reported to show estrogenic effects and affect male reproduction function in animal models, but human epidemiologic studies are still scarce. The objective of this study was to examine associations between urinary concentrations of parabens and semen quality and reproductive hormone levels. This was a cross-sectional study with 215 young university students (18-23years old) recruited between 2010 and 2011 in Southern Spain (Murcia Region). All men provided a urine, blood and semen sample on a single day. Urinary paraben concentrations (methylparaben, ethylparaben, propylparaben and butylparaben) were measured by dispersive liquid-liquid microextraction and ultra-high performance liquid chromatography with tandem mass spectrometry detection. Semen quality was evaluated by measuring volume, sperm concentration, total sperm count (TSC), motility and morphology following WHO guidelines. Serum samples were analyzed for reproductive hormones, including follicle-stimulating hormone, luteinizing hormone, testosterone, inhibin B and estradiol using immunoassays. Associations between urinary concentrations of parabens and semen quality parameters and reproductive hormone levels were examined using linear regression, adjusting for potential covariates. Ninety-four percent of the men had detectable urinary concentrations of parabens. After taking into account important covariates, urinary concentrations of parabens or their molar sum were not significantly associated with any semen parameters or any of the reproductive hormone levels. Relative to men in the lowest quartile of sum of urinary paraben concentrations, the adjusted difference (95% CI) of TSC (millions) for men in the 2nd, 3rd, and 4th quartiles were 4.1% (-37.1;45.3), -1.6% (-41.9;38.8), and -9.8% (-52.5;32.8), respectively (P-trend=0.55). Our results suggest that, in young men, urinary parabens may not adversely impact reproductive function, but further research is warranted to confirm these findings in other male populations.

Exposure to benzophenones, parabens and triclosan among pregnant women in different trimesters

Humans are potentially exposed to many environmental pollutants, many of which may cause adverse health effects, especially to pregnant women and their fetuses. In this study, 11 environmental pollutants from three different chemical classes, including benzophenones, parabens and triclosan were measured in 627 urine samples collected from 209 pregnant women to evaluate exposure and trends as a function of pregnancy stage. Methylparaben (MeP), ethylparaben, propylparaben (PrP), butylparaben, 2,4-dihydroxybenzophenone (BP-1), 2-hydroxy-4-methoxybenzophenone (BP-3) and 4-hydroxybenzophenone were detected in >50% samples. The concentrations of BP-1 and BP-3 (Spearman's r=0.57, p<0.01) and those of MeP and PrP (Spearman's r=0.68, p<0.01) were found to be correlated. The urinary concentrations of BP-1 and BP-3 in the first trimester were significantly higher than those in the second or third trimester (Mann-Whitney U test, p<0.05). These findings provide valuable information for improving the prediction of maternal exposure to these emerging pollutants and for assessing their potential health risks to the mother as well as the offspring.

Daily intake and hazard index of parabens based upon 24 h urine samples of the German Environmental Specimen Bank from 1995 to 2012

In recent years, exposure to parabens has become more of a concern because of evidence of ubiquitous exposure in the general population, combined with evidence of their potency as endocrine disruptors. New human metabolism data from oral exposure experiments enable us to back calculate daily paraben intakes from urinary paraben levels. We report daily intakes (DIs) for six parabens based on 660 24 h urine samples from the German Environmental Specimen Bank collected between 1995 and 2012. Median DI values ranged between 1.1 μg/kg bw/day for iso-butyl paraben and 47.5 μg/kg bw/day for methyl paraben. The calculated DIs were compared with acceptable levels of exposure to evaluate the hazard quotients (HQs) that indicate that acceptable exposure is exceeded for values of >1. Approximately 5% of our study population exceeded this threshold for individual paraben exposure. The hazard index (HI) that takes into account the cumulative risk of adverse estrogenic effects was 1.3 at the 95th percentile and 4.4 at maximum intakes, mainly driven by n-propyl paraben exposure. HI values of >1 indicate some level of concern. However, we have to point out that we applied most conservative assumptions in the HQ/HI calculations. Also, major exposure reduction measures were enacted in the European Union after 2012.

Considering common sources of exposure in association studies - Urinary benzophenone-3 and DEHP metabolites are associated with altered thyroid hormone balance in the NHANES 2007-2008

Epidemiological studies have shown that thyroid hormone balances can be disrupted by chemical exposure. However, many association studies have often failed to consider multiple chemicals with possible common sources of exposure, rendering their conclusions less reliable. In the 2007-2008 National Health and Nutrition Examination Survey (NHANES) from the U.S.A., urinary levels of environmental phenols, parabens, and phthalate metabolites as well as serum thyroid hormones were measured in a general U.S. population (≥12years old, n=1829). Employing these data, first, the chemicals or their metabolites associated with thyroid hormone measures were identified. Then, the chemicals/metabolites with possible common exposure sources were included in the analytical model to test the sensitivities of their association with thyroid hormone levels. Benzophenone-3 (BP-3), bisphenol A (BPA), and a metabolite of di(2-ethylhexyl) phthalate (DEHP) were identified as significant determinants of decreased serum thyroid hormones. However, significant positive correlations were detected (p-value<0.05, r=0.23 to 0.45) between these chemicals/metabolites, which suggests that they might share similar exposure sources. In the subsequent sensitivity analysis, which included the chemicals/metabolite with potentially similar exposure sources in the model, we found that urinary BP-3 and DEHP exposure were associated with decreased thyroid hormones among the general population but BPA exposure was not. In association studies, the presence of possible common exposure sources should be considered to circumvent possible false-positive conclusions.

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.

Urinary paraben concentrations and their associations with anthropometric measures of children aged 3 years

Parabens, known as ubiquitous preservatives, have been linked to adverse health outcomes in humans. This study aimed to examine urinary paraben concentrations of children at 3 years of age and evaluate their associations with anthropometric parameters. Urinary parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP) and benzylparaben (BeP) were measured among 436 children in a birth cohort using gas chromatography with tandem mass spectrometry. Generalized linear models were performed to evaluate associations of paraben exposures with age- and sex-specific z scores, including weight, height, weight for height and body mass index. MeP, EtP and PrP were the dominant parabens in urinary samples, with the median concentrations of 6.03 μg/L, 3.17 μg/L, 2.40 μg/L, respectively. The median values of estimated daily intake (EDI_urine) of five urinary paraben concentrations were 12.10, 5.68, 4.50, 0.06 and 0.17 μg/kg-body weight/day, respectively. Urinary EtP concentrations were positively associated with weight z scores [regression coefficient β = 0.16, 95% confidence interval (CI): 0.04, 0.29; p = 0.01] and height z scores (β = 0.15, 95% CI: 0.03, 0.27; p = 0.01). Positive associations were found between the sum of molar concentrations of five parabens and height z scores among all children (β = 0.24, 95% CI: 0.04, 0.45; p = 0.02). These significant associations were only observed in boys. Our findings suggest that exposure to parabens may be adversely associated with physical growth in 3-year-old boy children. Further prospective studies are warranted to understand the toxicological mechanisms of paraben exposures and potential risk of children.