Urinary concentrations of parabens amongst Iranian adults and their associations with socio-demographic factors

Human exposure characteristics of pharmaceutical and personal care product chemicals and associations with dietary habits

Considering the widespread presence of pharmaceutical and personal care products (PPCPs) in the environment and their adverse health effects, human exposure to PPCPs has caused worldwide concern. However, there remains insufficient information on the exposure assessment of the Chinese population. Based on this, the exposure levels of 13 PPCPs in the urine samples of 986 Chinese adults were measured, aiming to provide information on the prevalence of PPCP occurrence and investigate potential correlations between PPCP exposure and obesity. Results showed that the detection rates of these compounds in urine ranged from 28.12 % to 98.58 %, with median concentrations ranging below the limit of detection to 10.58 ng mL-1. Methyl-paraben (MeP) was the most dominant paraben and had the highest urinary concentration (median = 10.12 ng mL-1), while 4-hydroxy-benzophenone (4-OH-BP) was the dominant benzophenone derivative (median = 0.22 ng mL-1). In antibacterials, the urinary concentration of triclosan (mean = 42.00 ng mL-1) was much higher than that of triclocarban (mean = 0.63 ng mL-1). PPCP concentrations were significantly associated with sex, age, body mass index, education level, and annual household income (p < 0.050). Regression analysis of dietary habits showed that seafood and tea consumption may be significant exposure sources of PPCP exposure (p < 0.050). Furthermore, individual exposure to MeP (odds ratio (OR) < 1, p = 0.002) and 4-OH-BP (OR < 1, p = 0.009) exhibited a significantly negative association with obesity in females. Also, analysis results from quantile g-computation and Bayesian kernel machine regression models demonstrated that an inverse correlation between PPCP mixture exposure and obesity was significant in females. This study reports the extensive prevalence of PPCP exposure among adults from China, and may provide crucial insights into PPCP exposure dynamics. More epidemiological studies are need in the future, with a thorough knowledge of PPCP exposure.

A large-scale survey of urinary parabens and triclocarban in the Chinese population as well as the influencing factors and health risks

Parabens and triclocarban are widely applied as antimicrobial preservatives in foodstuffs, pharmaceuticals, cosmetics, and personal care products. However, few studies have been conducted on large-scale biomonitoring of parabens and triclocarban in the Chinese general population. In the present study, there were 1157 urine samples collected from 26 Chinese provincial capitals for parabens and triclocarban measurement to evaluate the exposure levels, spatial distribution, and influencing factors, as well as associated health risks in the Chinese population. The median concentrations of Σparabens and triclocarban were 14.0 and 0.03 μg/L, respectively. Methyl paraben was the predominant compound. Subjects in western China were more exposed to parabens, possibly due to climate differences resulting in higher consumption of personal care products. Subjects who were female, aged 18-44 years, or had a higher education level were found to have higher paraben concentrations. The frequency of drinking bottled water was positively associated with paraben exposure. The assessment of health risk based on urinary paraben concentrations indicated that 0.8 % of the subjects had a hazard index exceeding one unit, while Monte Carlo analysis suggested that 3.6 % of the Chinese population exposure to parabens had a potential non-carcinogenic risk. This large-scale biomonitoring study will help to understand the exposure levels of parabens and triclocarban in the Chinese general population and provide supporting information for government decision-making.

Associations of personal care products use with reproductive outcomes of IVF/ICSI treatment

Introduction

Personal care products (PCPs) contain a number of endocrine-disrupting chemicals (EDCs) that could potentially affect the reproductive function in women of childbearing age. However, studies focused on the effects of PCPs use on reproductive outcomes are very limited. The current study aimed to explore the relationships between PCPs use patterns and reproductive outcomes in women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.

Methods

A total of 1500 women from the Tongji Reproductive and Environmental (TREE) study between December 2018 and January 2020 were included in this study. Participants provided characteristics of PCPs use within the previous three months. Retrieved oocyte number, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, cleavage rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth were followed up as reproductive endpoints. Generalized linear regression model was utilized to assess the associations between various categories of PCPs use and reproductive endpoints of IVF/ICSI.

Results

After adjusting for relevant covariates, women who used skin care products ≥14 times per week had a reduction of 22.4% in the maturation rate (95% CI: -39.2%, -1.6%) compared to participants who did not use skin care products. After transferring fresh embryos, women who used cosmetics 1-2 times per week (adjusted OR = 2.2, 95% CI: 1.0, 4.8) or 3-7 times per week (adjusted OR = 2.5, 95% CI: 1.2, 5.2) had a higher possibility of miscarriage than those who did not use cosmetics. There was negative association between the use of gel or soap and the cleavage rate among women aged < 30 years old (P for interaction = 0.01). Among women with BMI ≥ 24 kg/m2, the use of gel or soap was negatively associated with the blastocyst formation rate (P for interaction = 0.04), while cosmetics use was negatively associated with the maturation rate (P for interaction = 0.001).

Conclusion

Our findings suggest that the use of PCPs in women of reproductive age have a potential adverse impact on IVF/ICSI outcomes, particularly skin care and cosmetic products.

New insights on the binding of butyl-paraben to trypsin: experimental and computational approaches

Butyl-paraben (BP) is one of the most widely used preservatives in numerous foodstuffs, skin care products, and a variety of drugs, and trypsin is the main digestive enzyme, the research on the binding between the two is essential for human health. In the present paper, the effect of BP on trypsin has been explored using experimental and computational techniques to evaluate BP toxicity at the protein level. The obtained results from molecular docking and kinetic assay revealed BP was embedded in the hydrophobic cavity-S1 binding pocket of the enzyme to inhibit its activity by a competitive model. Intrinsic fluorescence of trypsin after interaction with BP revealed the static mode of quenching. FRET indicated that the distance of the enzyme to BP is 1.89 nm with high energy efficiency. Thermodynamic results proved that BP spontaneously bound to trypsin in an enthalpy-driven manner, the van der Waals interactions and H-bonds serving as the predominant forces in binding processes. CD spectroscopy and molecular dynamics (MD) simulation revealed that the trypsin structure transformed from the β-Sheet structure to the unordered Coil structure upon interacting with BP. Resonance light scattering (RLS), synchronous fluorescence, and three-dimensional (3 D) spectroscopies further supported the alteration in the conformation of trypsin. Differential scanning calorimetry (DSC) showed that trypsin was somewhat destabilized in the presence of BP. Accordingly, all of the experimental data were confirmed by MD simulation.Communicated by Ramaswamy H. Sarma.

Presence of Parabens in Different Children Biological Matrices and Its Relationship with Body Mass Index

Parabens have been accepted almost worldwide as preservatives by the cosmetic, food, and pharmaceutical industries. Since epidemiological evidence of the obesogenic activity of parabens is weak, the aim of this study was to investigate the association between parabens exposure and childhood obesity. Four parabens (methylparaben/MetPB, ethylparaben/EthPB, propylparaben/PropPB, and butylparaben/ButPB) were measured in 160 children's bodies between 6 and 12 years of age. Parabens measurements were performed with ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). Logistic regression was used to evaluate risk factors for elevated body weight associated with paraben exposure. No significant relation was detected between children's body weight and the presence of parabens in the samples. This study confirmed the omnipresence of parabens in children's bodies. Our results could be a basis for future research about the effect of parabens on childhood body weight using nails as a biomarker due to the ease of its collection and its non-invasive character.

Within-day variability, predictors, and risk assessments of exposure to parabens among Chinese adult men

BACKGROUND

Parabens, as suspected endocrine disruptors, are widely used in personal care products and pharmaceuticals. However, variability, predictors, and risk assessments of human exposure to parabens are not well characterized.

OBJECTIVE

To evaluate within-day variability, predictors, and risk assessments of exposure to parabens among Chinese adult men.

METHODS

We measured four parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) in repeated urine samples from 850 Chinese adult men. We examined the variability by intraclass correlation coefficients (ICCs) and identified the predictors by multivariable linear mixed models. We assessed risks of paraben exposures based on the estimated daily intake (EDI).

RESULTS

The four parabens were detected in >76% of urinary samples. We observed fair to good to high reproducibility (ICCs: 0.71 to 0.86) for urinary paraben concentrations within one day. Use of facial cleanser was associated with higher four urinary paraben concentrations. Increasing age, taking medicine, intravenous injection, and interior decoration in the workplace were related to higher urinary concentrations of specific parabens. Smoking and drinking were associated with lower urinary concentrations of specific parabens. The maximum EDIs for the four parabens ranged from 13.76 to 848.68 μg/kg bw/day, and 0.9% of participants had the hazard quotient values > 1 driven by PrP exposure.

CONCLUSIONS

Urinary paraben concentrations were less variable within one day. Several lifestyle characteristics including use of facial cleanser and pharmaceuticals may contribute to paraben exposures.

Impact of Paraben Exposure on Adiposity-Related Measures: An Updated Literature Review of Population-Based Studies

Parabens are alkyl esters of p-hydroxybenzoic acid that are commonly used in pharmaceutical and cosmetic products. Humans are exposed to parabens when they use these products and through diet. There are growing concerns that paraben exposure can adversely impact human health. The endocrine-disrupting and obesogenic properties of parabens have been observed in animal studies and in vitro, prompting the increase in population-based studies of paraben exposure and adiposity-related endpoints. In this review, we summarize epidemiological studies published between 2017 and 2022 that examined paraben exposure in utero, between birth and adolescence, and in adulthood, in relation to adiposity-related measures. Overall, these studies provide some evidence that suggests that paraben exposure, especially during critical development windows, is associated with adiposity-related measures. However, we have noted several limitations in these studies, including the predominance of cross-sectional studies, inconsistent sample collection procedures, and small sample sizes, which should be addressed in future studies.

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.

Parabens and Menopause-Related Health Outcomes in Midlife Women: A Pilot Study

Background: Parabens are antimicrobial agents prevalently found in daily-use products that can interfere with the endocrine and reproductive systems. In this study, we examined the cross-sectional associations of parabens with hot flashes, hormone concentrations, and ovarian volume in a subsample of 101 nonsmoking, non-Hispanic 45- to 54-year-old women from the Midlife Women's Health Study. Materials and Methods: Women self-reported their hot flash history and underwent a transvaginal ultrasound to measure ovarian volume. Participants provided blood for quantification of serum hormones (by enzyme-linked immunosorbent assay or radioimmunoassay) and urine samples for measurements of urinary paraben biomarker levels (by high-performance liquid chromatography negative-ion electrospray ionization-tandem mass spectrometry). Linear or logistic regression models evaluated associations of specific gravity-adjusted paraben biomarker concentrations with hot flashes, hormone concentrations, and ovarian volume. Results: We observed marginal associations of propylparaben, methylparaben, and ∑parabens biomarkers (molar sum of four parabens) with hot flashes and follicle-stimulating hormone (FSH) concentrations, and of these paraben biomarkers and ethylparaben with ovarian volume. For example, women tended to have 32% (95% confidence intervals [CI]: 0.9 to 1.81), 40% (95% CI: 1.0 to 1.95), and 40% (95% CI: 0.98 to 2.01) higher odds of having recent, monthly, and mild hot flashes, respectively, for every two-fold increase in ∑parabens. Similarly, women tended to have 14.54% (95% CI: -0.10 to 31.32) higher FSH concentrations, but 5.67% (95% CI: -12.54 to 1.75) reduced ovarian volume for every two-fold increase in ∑parabens Conclusions: Overall, our preliminary findings suggest that urinary paraben biomarkers may be associated with menopause-related outcomes in midlife women. Additional studies in larger and diverse populations are needed to expand on these findings.

Risk of thyroid cancer and benign nodules associated with exposure to parabens among Chinese adults in Wuhan, China

Parabens are widely used as preservatives, which have been found to affect thyroid function in toxicological studies. However, population studies on whether they are associated with thyroid tumors remain unclear. This study aims to investigate the relationship between environmental paraben exposure and thyroid cancer and benign nodules. We recruited participants from the Department of Thyroid and Breast Surgery at Wuhan Central Hospital, Wuhan, China. The detectable percentages of methyl paraben, ethyl paraben, and propyl paraben in the urinary samples of 425 study subjects were 99.1%, 95.3%, and 92.0%, respectively. All uncorrected and creatinine-corrected parabens were moderately correlated with one another. After adjusting for possible confounders, all three parabens were associated with an increased risk of thyroid cancer. Furthermore, the mixture pollutant analysis of parabens found positive associations with risk of thyroid cancer (OR = 0.24, 95% CI: 0.18, 0.31) and benign nodules (OR = 1.33, 95% CI: 0.86, 1.80). We observed that individual exposure to paraben mixtures may be associated with the risk of thyroid cancer and benign nodules.

A survey of parabens in aquatic environments in Hanoi, Vietnam and its implications for human exposure and ecological risk

Seven parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), iso-propylparaben (iPrP), butylparaben (BuP), benzylparaben (BzP), and heptylparaben (HepP) were determined in bottled water, tap water, river water, lake water, and wastewater samples collected from Hanoi, Vietnam, using solid phase extraction (SPE) followed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The highest total concentration of parabens were measured in wastewater (range, 27.3-1050 ng/L; mean/median, 268/175 ng/L), followed by lake water (range, 18.0-254 ng/L; mean/median, 51.7/58.5 ng/L), river water (range, 16.5-52.1 ng/L; mean/median, 32.1/42.6 ng/L), tap water (range, 5.01-54.3 ng/L; mean/median, 28.6/41.1 ng/L), and bottled water (range, 1.56-39.9 ng/L; mean/median, 6.92/9.19 ng/L). Methylparaben and propylparaben were the predominant compounds found in all samples. The mean estimated human exposure dose of parabens through drinking bottled water was 0.27 ng/kg-bw/day, which is 6 orders of magnitude below the safety threshold recommended by the Joint FAO/WHO Expert Committee on Food Additive in 1974 (10 mg/kg-bw/day). Concentrations of parabens measured in river water, lake water, and wastewater samples were assessed to pose low to moderate ecological risks to aquatic organisms (0.1 < RQ < 1). Methyl, ethyl, and propyl parabens exhibited significant correlations in water samples.

Patterns of environmental exposure to phenols in couples who plan to become pregnant

Phenols are widely used in consumer products and known for their reproductive toxicities. Little is known regarding the environmental exposure to phenols in couples prior to conception, a key period affecting fertility. We measured the urinary concentrations of six parabens and seven bisphenols in 903 pre-conception couples in China. We investigated the occurrence, distribution, source and health risk of phenols in husbands and wives separately, and the correlation and difference in phenol concentrations between couples. Similar distribution profiles of urinary phenols were observed between females and males. Methyl 4-hydroxybenzoate (MeP) and bisphenol A (BPA) were the predominant compounds. The level of urinary phenols in our population was mostly lower than the global levels. Exposure to phenols was linked to processed food and personal care products. The correlations between phenols in males and females were moderate (0.218-0.686), while the correlation in phenols between husband and wife was low (0.009-0.215). Female had a significantly higher urinary phenol levels than male (P < 0.05). Urinary phenols in couples were associated with family income, type of drinking water and frequency of household cleaning. Household factors accounted for ≤1.5% of variance in phenol levels between couples, suggesting that individual variations may be the major factor. Risk assessment showed that exposure to phenols posed a low hazard to 17.5% of the couples in our population. Our findings provide important evidence of environmental exposure to phenols in couples of child-bearing age.

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.

Dietary exposure to parabens and body mass index in an adolescent Spanish population

Parabens are alkyl esters of p-hydroxybenzoic acid which are extensively used in cosmetics, pharmaceuticals and foodstuffs due to their antimicrobial properties. The most commonly used parabens are methyl-(MeP), ethyl-(EtP), propyl-(PrP) and butyl-(BuP) paraben. Most human exposure to parabens is achieved through the consumption of food or pharmaceutical products and the use of personal care products. However, studies on dietary parabens exposure and the associated factors are very scarce. The main aim of the present study was to explore factors associated with dietary exposure to parabens in Spanish adolescents according to gender. Dietary data and anthropometric measures were collected from 585 adolescents (53.4% boys) aged 12-16 years. Parabens exposure through diet was assessed using a food frequency questionnaire with food products providing more than 95% of energy and macronutrient intake being included in analysis. Stepwise regression was used to identify the foods that most contributed to parabens intake. Logistic regression was used to evaluate factors predicting higher dietary exposure to parabens. The main contributors to dietary MeP, EtP, PrP and BuP exposure in adolescent boys were eggs (41.9%), canned tuna (46.4%), bakery and baked goods products (57.3%) and pineapple (61.1%). In adolescent girls, the main contributors were apples and pears (35.3%), canned tuna (42.1%), bakery and baked goods products (55.1%) and olives (62.1%). Overweight/obese girls were more likely to belong to the highest tertile of overall parabens intake (odds ratio [OR]: 3.32; 95% confidence interval [95% CI]: 1.21-9.15) and MeP (OR: 3.05; 95% CI: 1.14-8.12) than those with a body mass index lower than 25 kg/m². These findings suggest a positive association between dietary exposure to parabens and overweight/obesity in adolescent girls.

The sex-specific association between maternal urinary paraben levels and offspring size at birth

Parabens are a group of antimicrobial preservatives applied in an extensive range of products and are suspected to impair fetal growth because of their disrupting effect on the endocrine system. We aimed to examine maternal urinary paraben concentrations and their neonates' outcome indexes. Methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) concentrations were measured in 105 maternal urine samples collected before delivery. Length, weight, and head circumference at birth were extracted from the mothers' delivery files. A multivariable linear regression analysis was performed to evaluate the association between paraben levels and neonatal anthropometric indices. The median levels of urinary parabens, especially BP, were higher than those in other countries. Prenatal urinary concentration of MP and BP showed a significantly positive association with birth weight in all neonates (β = 0.79, 95% CI: 0.16, 1.41, and β = 8.56, 95% CI: 3.95, 13.17, respectively), while these chemicals showed a significant negative association with head circumference (β = - 0.002, 95% CI: - 0.004, - 0.000, and β = - 0.016, 95% CI: - 0.030, - 0.002, respectively). A significant positive association between MP and birth length was also found (β = 0.004, 95% CI: 0.00, 0.00) in all the neonates. In sex-stratified adjusted models, MP and BP were found to be associated, respectively, with higher birth length and weight in male neonates (β = 0.008, 95% CI: - 0.001, 0.017, and β = 7.948, 95% CI: 1.045, 14.851). In girls, maternal urinary MP, PP, and BP were associated with increased birth weight (β = 0.831, 95% CI: 0.043, 1.620; β = 4.178, 95% CI: 0.877, 7.480; and β = 10.821, 95% CI: 3.545, 18.097, respectively), and MP and BP were associated with reduced head circumference at birth (β = - 0.003, 95% CI: - 0.005, - 0.001, and β = - 0.035, 95% CI: - 0.055, - 0.016). These results revealed potential impacts between neonatal growth and maternal exposure to parabens. However, these findings should be interpreted while considering the limitations of the present study.

Exposure to Parabens Through The Use of Personal Care Products Among Iranian Men

Despite the widespread use of parabens as antimicrobial preservatives in personal care products (PCP) and foodstuffs, recent studies have shown that exposure to parabens can play a role in the endocrine disruption process. In the present study, the urinary concentrations of methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) were measured among 125 men, and their relationship with the use of 13 distinct PCPs was examined. MP, EP, PP, and BP were detected with a median concentration of 60.12, 8.40, 9.74, and 7.19 μg/L, respectively. The difference of urinary MP and PP between three groups of users of PCPs (low, medium, and high users) was significant (p < 0.05), and the higher levels were found in the high-users' group. The total number of PCP applications was associated with higher urinary MP and PP. Furthermore, the urinary concentration of parabens was found to be dependent of the types of products used. Participants who reported the use of sunscreen, lotions, and deodorant had significantly higher urinary MP (76-185%) than nonusers. Bodywash users had higher levels of urinary MP and PP (112-160%). The use of mouthwash, perfume/cologne, and toothpaste also had urinary PP concentration (73-412%) higher than nonusers. The use of handwashing products remarkably increased the urinary levels of parabens (158-520%). Our findings showed that the use of certain types of PCP is an important source of paraben exposure among Iranian men. These findings can serve as a basis for more extensive studies to investigate the extent of exposure to parabens and to apply appropriate strategies for reduction of their exposure.