Advanced data mining approaches in the assessment of urinary concentrations of bisphenols, chlorophenols, parabens and benzophenones in Brazilian children and their association to DNA damage

Early childhood exposures to phthalates in association with attention-deficit/hyperactivity disorder behaviors in middle childhood and adolescence in the ReCHARGE study

BACKGROUND

Early-life exposure to phthalates alters behaviors in animals. However, epidemiological evidence on childhood phthalate exposure and attention-deficit/hyperactivity disorder (ADHD) behaviors is limited.

METHODS

This study included 243 children from the ReCHARGE (Revisiting Childhood Autism Risks from Genetics and Environment) study, who were previously classified as having autism spectrum disorder (ASD), developmental delay, other early concerns, and typical development in the CHARGE case-control study. Twenty phthalate metabolites were measured in spot urine samples collected from children aged 2-5 years. Parents reported on children's ADHD symptoms at ages 8-18 years using Conners-3 Parent Rating Scale. Covariate-adjusted negative binomial generalized linear models were used to investigate associations between individual phthalate metabolite concentrations and raw scores. Weighted quantile sum (WQS) regression with repeated holdout validation was used to examine mixture effects of phthalate metabolites on behavioral scores. Effect modification by child sex was evaluated.

RESULTS

Among 12 phthalate metabolites detected in >75% of the samples, higher mono-2-heptyl phthalate (MHPP) was associated with higher scores on Inattentive (β per doubling = 0.05, 95% confidence interval [CI]: 0.02, 0.08) and Hyperactive/Impulsive scales (β = 0.04, 95% CI: 0.00, 0.07), especially among children with ASD. Higher mono-carboxy isooctyl phthalate (MCiOP) was associated with higher Hyperactivity/Impulsivity scores (β = 0.07, 95% CI: -0.01, 0.15), especially among typically developing children. The associations of the molar sum of high molecular weight (HMW) phthalate metabolites and a phthalate metabolite mixture with Hyperactivity/Impulsivity scores were modified by sex, showing more pronounced adverse associations among females.

CONCLUSION

Exposure to phthalates during early childhood may impact ADHD behaviors in middle childhood and adolescence, particularly among females. Although our findings may not be broadly generalizable due to the diverse diagnostic profiles within our study population, our robust findings on sex-specific associations warrant further investigations.

Application of the Key Characteristics of Carcinogens to Bisphenol A

The ten key characteristics (KCs) of carcinogens are based on characteristics of known human carcinogens and encompass many types of endpoints. We propose that an objective review of the large amount of cancer mechanistic evidence for the chemical bisphenol A (BPA) can be achieved through use of these KCs. A search on metabolic and mechanistic data relevant to the carcinogenicity of BPA was conducted and web-based software tools were used to screen and organize the results. We applied the KCs to systematically identify, organize, and summarize mechanistic information for BPA, and to bring relevant carcinogenic mechanisms into focus. For some KCs with very large data sets, we utilized reviews focused on specific endpoints. Over 3000 studies for BPA from various data streams (exposed humans, animals, in vitro and cell-free systems) were identified. Mechanistic data relevant to each of the ten KCs were identified, with receptor-mediated effects, epigenetic alterations, oxidative stress, and cell proliferation being especially data rich. Reactive and bioactive metabolites are also associated with a number of KCs. This review demonstrates how the KCs can be applied to evaluate mechanistic data, especially for data-rich chemicals. While individual entities may have different approaches for the incorporation of mechanistic data in cancer hazard identification, the KCs provide a practical framework for conducting an objective examination of the available mechanistic data without a priori assumptions on mode of action. This analysis of the mechanistic data available for BPA suggests multiple and inter-connected mechanisms through which this chemical can act.

Biomonitoring of benzophenones in guano samples of wild bats in Poland

Benzophenones (BPs) are substances used in the production of sunscreens, cosmetics, and personal care products. However, there is a lack of knowledge of BPs in wild animals. Therefore, the study aimed to assess the concentration of selected BPs commonly used in the cosmetic industry in guano samples collected from 4 colonies of greater mouse-eared bats (Myotis myotis). Liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used to determine guano concentrations of benzophenone 1 (BP-1), benzophenone 2 (BP-2), benzophenone 3 (BP-3) and benzophenone 8 (BP-8). BP-1 levels above the method quantification limit (MQL) were noted in 97.5% of samples and fluctuated from <0.1 ng/g to 259 ng/g (mean 41.50 ng/g, median 34.8). The second most common was BP-3, which fluctuated from <0.1 ng/g to 19 ng/g (mean 6.67 ng/g, median 5.05), and its levels higher than MQL were observed in 40% of samples. BP-2 and BP-8 concentrations did not exceed the method detection limit (0.04 ng/g) in any analyzed sample. There were visible differences in the BP-1 and BP-3 levels among the studied bat colonies. Mean BP-1 concentration fluctuated from 11.23±13.13 ng/g to 76.71±65.51 ng/g and differed significantly between the colonies. Mean BP-3 concentration fluctuated from 5.03±6.03 ng/g to 9.18±7.65 mg/g, but it did not differ significantly between the colonies. The results show that guano is a suitable matrix for the assessment of wildlife exposure to BPs. This could be particularly advantageous in protected species, where not disturbing and stressing the animals are crucial.

Effects of pharmaceutical and personal care products on pubertal development: Evidence from human and animal studies

Pharmaceutical and personal care products (PPCPs) include a wide range of drugs, personal care products and household chemicals that are produced and used in significant quantities. The safety of PPCPs has become a growing concern in recent decades due to their ubiquitous presence in the environment and potential risks to human health. PPCPs have been detected in various human biological samples, including those from children and adolescents, at concentrations ranging from several ng/L to several thousand μg/L. Epidemiological studies have shown associations between exposure to PPCPs and changes in the timing of puberty in children and adolescents. Animal studies have shown that exposure to PPCPs results in advanced or delayed pubertal onset. Mechanisms by which PPCPs regulate pubertal development include alteration of the hypothalamic kisspeptin and GnRH networks, disruption of steroid hormones, and modulation of metabolic function and epigenetics. Gaps in knowledge and further research needs include the assessment of environmental exposure to pharmaceuticals in children and adolescents, low-dose and long-term effects of exposure to PPCPs, and the modes of action of PPCPs on pubertal development. In summary, this comprehensive review examines the potential effects of exposure to PPCPs on pubertal development based on evidence from human and animal studies.

Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

BACKGROUND

A growing body of literature investigated childhood exposure to environmental chemicals in association with attention-deficit/hyperactivity disorder (ADHD) symptoms, but limited studies considered urinary mixtures of multiple chemical classes. This study examined associations of concurrent exposure to non-persistent chemicals with ADHD symptoms in children diagnosed with autism spectrum disorder (ASD), developmental delay (DD), and typical development (TD).

METHODS

A total of 549 children aged 2-5 years from the Childhood Autism Risks from Genetics and Environment (CHARGE) case-control study were administered the Aberrant Behavior Checklist (ABC). This study focused on the ADHD/noncompliance subscale and its two subdomains (hyperactivity/impulsivity, inattention). Sixty-two chemicals from four classes (phenols/parabens, phthalates, organophosphate pesticides, trace elements) were quantified in child urine samples, and 43 chemicals detected in > 70% samples were used to investigate their associations with ADHD symptoms. Negative binomial regression was used for single-chemical analysis, and weighted quantile sum regression with repeated holdout validation was applied for mixture analysis for each chemical class and all chemicals. The mixture analyses were further stratified by diagnostic group.

RESULTS

A phthalate metabolite mixture was associated with higher ADHD/noncompliance scores (median count ratio [CR] = 1.10; 2.5th, 97.5th percentile: 1.00, 1.21), especially hyperactivity/impulsivity (median CR = 1.09; 2.5th, 97.5th percentile: 1.00, 1.25). The possible contributors to these mixture effects were di-2-ethylhexyl phthalate (DEHP) metabolites and mono-2-heptyl phthalate (MHPP). These associations were likely driven by children with ASD as these were observed among children with ASD, but not among TD or those with DD. Additionally, among children with ASD, a mixture of all chemicals was associated with ADHD/noncompliance and hyperactivity/impulsivity, and possible contributors were 3,4-dihydroxy benzoic acid, DEHP metabolites, MHPP, mono-n-butyl phthalate, and cadmium.

CONCLUSIONS

Early childhood exposure to a phthalate mixture was associated with ADHD symptoms, particularly among children with ASD. While the diverse diagnostic profiles limited generalizability, our findings suggest a potential link between phthalate exposure and the comorbidity of ASD and ADHD.

Evaluation of exposure to multiple organic pollutants in riparian communities of the Brazilian Amazon: Screening levels and potential health risks

Organic pollutants are widely distributed in the environment. Due to their physical and chemical characteristics, they tend to be biomagnified in food chains, mainly in aquatic organisms. Therefore, food consumption is a significant route of lifelong exposure. Although the Amazon River basin contains the highest freshwater biodiversity on Earth, there is scarce literature focusing on the levels of organic pollutants in the local population. The present study was aimed at assessing the levels of several environmental pollutants (polycyclic aromatic hydrocarbons, bisphenols, parabens, and benzophenones) in urine samples from riverside communities along the Tapajós and Amazon Rivers in the Brazilian Amazon region. The results show a 100 % detection of naphthalene metabolites (namely, 1-hydroxy-naphthalene (1OH-NAP), 2-hydroxy-naphthalene (2OH-NAP)), with the highest levels belonging to benzylparaben (BzP) (17.3 ng/mL). Gender-specific analysis revealed that women had significantly higher levels of certain PAH metabolites (i.e., 1OH-NAP and 2-hydroxy-fluorene (2OH-FLU)) than men. In turn, most of the evaluated compounds were higher in urine samples from people living near the Amazon River, which presents increased traffic of boats and ships than the Tapajós River. On the other hand, the human health risk assessment suggested that all communities are at risk of suffering non-carcinogenic effects from exposure to PAHs. At the same time, they are also at risk of carcinogenic effects from exposure to benzo[a]pyrene metabolites. Thus, further studies are needed in order to evaluate the potential health effects of exposure to a mixture of these organic pollutants and other contaminants present in the area, such as mercury.

The evolution of endocrine disruptor chemical assessments worldwide in the last three decades

Endocrine Disrupting Chemicals (EDCs) encompass a wide variety of substances capable of interfering with the endocrine system, including but not limited to bisphenol A, organochlorines, polybrominated flame retardants, alkylphenols and phthalates. These compounds are widely produced and used in everyday modern life and have increasingly been detected in aquatic matrices worldwide. In this context, this study aimed to carry out a literature review to assess the evolution of EDCs detected in different matrices in the last thirty years. A bibliometric analysis was conducted at the Scopus, Web of Science, and Google Scholar databases. Data were evaluated using the Vosviewer 1.6.17 software. A total of 3951 articles in English were retrieved following filtering. The results demonstrate a gradual and significant growth in the number of published documents, strongly associated with the increasing knowledge on the real environmental impacts of these compounds. Studied were mostly conducted by developed countries in the first two decades, 1993 to 2012, but in the last decade (2013 to 2022), an exponential leap in the number of publications by countries such as China and an advance in research by developing countries, such as Brazil, was verified.

Machine Learning Assisted Discovery of Interactions between Pesticides, Phthalates, Phenols, and Trace Elements in Child Neurodevelopment

A growing body of literature suggests that developmental exposure to individual or mixtures of environmental chemicals (ECs) is associated with autism spectrum disorder (ASD). However, investigating the effect of interactions among these ECs can be challenging. We introduced a combination of the classical exposure-mixture Weighted Quantile Sum (WQS) regression and a machine-learning method termed Signed iterative Random Forest (SiRF) to discover synergistic interactions between ECs that are (1) associated with higher odds of ASD diagnosis, (2) mimic toxicological interactions, and (3) are present only in a subset of the sample whose chemical concentrations are higher than certain thresholds. In a case-control Childhood Autism Risks from Genetics and Environment (CHARGE) study, we evaluated multiordered synergistic interactions among 62 ECs measured in the urine samples of 479 children in association with increased odds for ASD diagnosis (yes vs no). WQS-SiRF identified two synergistic two-ordered interactions between (1) trace-element cadmium (Cd) and the organophosphate pesticide metabolite diethyl-phosphate (DEP); and (2) 2,4,6-trichlorophenol (TCP-246) and DEP. Both interactions were suggestively associated with increased odds of ASD diagnosis in the subset of children with urinary concentrations of Cd, DEP, and TCP-246 above the 75th percentile. This study demonstrates a novel method that combines the inferential power of WQS and the predictive accuracy of machine-learning algorithms to discover potentially biologically relevant chemical-chemical interactions associated with ASD.

Exploring environmental obesogenous effects of organic ultraviolet filters on children from a case-control study

It has been globally recognized that obesity has become a major public health concern, especially childhood obesity. There is limited information, however, regarding the exposure risk of organic ultraviolet (UV) filters, a kind of emerging contaminant, on childhood obesity. This study would be made on 284 obese and 220 non-obese Chinese children with eight organic UV filters at urinary levels. The eight organic UV filters, including 2-Ethylhexyl 4-aminobenzoate (PABA-E), octisalate (EHS), homosalate (HMS), 2-Ethylhexyl-p-methoxycinnamate (EHMC), benzophenone-3 (BP-3), amiloxate (IAMC), octocrylene (OC) and 4-Methylbenzylidene camphor (4-MBC) were identified in urine samples with detection rates ranged from 35.32% to 100%, among which PABA-E, HMS, IAMC and OC were firstly detected in children' s urine. And the urinary UV filters concentration was associated with genders, living sites, guardian education levels, household income, and dietary factors. Urinary EHMC concentrations and childhood obesity were positively associated for girls [Adjusted OR = 2.642 (95% CI: 1.019, 6.853)], while OC concentrations and childhood obesity were negatively associated for girls [Adjusted OR = 0.022 (95% CI: 0.001, 0.817)]. The results suggest that EHMC exposure may be an environmental obesogen for girls. Moreover, two statistical models were used separately to evaluate the impact of UV filter mixtures on childhood obesity, including the Bayesian kernel machine regression (BKMR) model and the quantile g-computation (qgcomp) model. The negative association between UV filter mixtures and childhood obesity was proposed from both BKMR and qgcomp models. Further experimental and epidemiological studies are called upon to discern the individual and mixture impacts of organic UV filters on childhood obesity.

Assessment of urinary aromatic amines in Brazilian pregnant women and association with DNA damage: Influence of genetic diversity, lifestyle, and environmental and socioeconomic factors

Aromatic amines (AAs) are polar organic chemicals with a wide environmental distribution originating from various sources, such as tobacco smoke, diesel exhaust, and dermal absorption from textile products with azo dyes. The toxicity profile of AAs is directly related to the amino group's metabolic activation and the generation of the reactive intermediate, forming DNA adducts and potential carcinogenicity. Urinary levels of 8-hydroxy-2'-deoxyguanosine (8OHdG) are an important biomarker of DNA damage. Since AAs have been shown to cross the placental barrier, being a risk factor for adverse birth outcomes, prenatal exposure is a great public health concern. The present study aimed to measure the urinary levels of 58 AAs in Brazilian pregnant women (n = 300) and investigated the impact of this exposure on DNA damage by quantifying 8OHdG levels. The influence of tobacco smoke exposure and dermal absorption of AAs by clothes on urinary levels was also assessed. The results showed a 100% detection rate for eight AAs, two of them regulated by the European Union (2,6-dimethylaniline and 2,4-diaminotolune). Hundreds of AAs may be derived from aniline, which here showed a median of 1.38 ng/mL. Aniline also correlated positively with 2,6-dimethylaniline, p-aminophenol, and other AAs, suggesting exposure to multiple sources. The present findings suggest that both tobacco smoke and dermal contact with clothes containing azo dyes are potential sources that might strongly influence urinary levels of AAs in Brazilian pregnant women. A multiple regression linear model (R2 = 0.772) suggested that some regulated AAs (i.e., 2-naphthylamine and 4-aminobiphenyl), nicotine, smoke habit, age, and Brazilian region could induce DNA damage occurrence, increasing the levels of 8OHdG. Given the limited available data on human exposure to carcinogenic AAs, as well as the lack of toxicological information on those non-regulated, further studies focused on measuring their levels in human fluids and the potential exposure sources are clearly essential.

Association between urinary methylparaben level and bone mineral density in children and adolescents aged 8-19 years

Previous epidemiological study has explored a positive association between methylparaben (Mep) and bone mineral density (BMD) in adults. Evidence linking Mep and BMD in children and adolescents is very limited. This study examined the association between Mep and BMD in children and adolescents aged 8-19 years. In this cross-sectional study, 1830 children and adolescents aged 8-19 years from NHANES 2011-2016 were analyzed. Mep was ln-transformed for analysis of the skewed distribution. Multiple linear regression analyses were performed to evaluate Mep's association with BMD (containing total BMD, trunk bone BMD, pelvis BMD, lumbar spine BMD, and thoracic spine BMD). Moreover, a generalized additive model (GAM) and a fitted smoothing curve (penalized spline method) were conducted to explore the exact shape of curve between them. In the fully adjusted model, ln-transformed Mep and BMD showed an independent and positive association (total BMD (β = 0.003, 95% CI (0.001, 0.005), P = 0.01), trunk bone BMD (β = 0.002, 95% CI (0.000, 0.005), P = 0.04), pelvis BMD (β = 0.004, 95% CI (0.001, 0.008), P = 0.02), lumbar spine BMD (β = 0.005, 95% CI (0.001, 0.008), P = 0.01), thoracic spine BMD (β = 0.003, 95% CI (0.001, 0.005), P = 0.02)) and a linear association. Subgroup analysis showed positive association between ln-transformed Mep and BMD. Furthermore, the positive association was significant in females and children aged 12-19 years (P for trend < 0.05). This study is the first study to find evidence demonstrating that exposure to Mep may be positively associated with BMD in children and adolescents aged 8-19 years. Validation of our findings will need further research.

Large-scale biomonitoring of bisphenol analogues and their metabolites in human urine from Guangzhou, China: Implications for health risk assessment

Bisphenol analogues (BPs) are ubiquitous in the environment and have gained significant attention regarding their associated health risks. However, there is a lack of comprehensive biomonitoring data on BPs and their metabolites in human urine. To address this, we conducted a study evaluate the exposure to BPs in the general population of Guangzhou, China. A total of 1440 urine samples were collected from volunteers and analyzed for the presence of BPs and their metabolites after being pooled into 36 groups based on age and gender. The findings revealed the common detection of ten free-form BPs, as well as the urinary metabolites of BPA and BPS, in the pooled urine samples. BPA was the predominant free-form compound, constituting 50% of the total BPs. The primary urinary metabolites of BPA and BPS are BPA-G and BPS-G, respectively, indicating glucuronidation as their primary metabolic pathway. The composition of urinary metabolites of BPA and BPS varied by age and sex, while the concentration of total BPs in urine was not significantly associated with age and sex. Enzymatic hydrolysis yielded a mean amplification of individual BPs concentrations in urine samples ranging from 1.8 times (BPA) to 4.6 times (BPS). Based on the outcomes, it was estimated that conjugated forms accounted for 96.9%, 96.2%, 94.7%, 94.1%, 92.6%, 89.1%, 87.3%, 87.2%, 87.1% and 85.8% of BPP, BPAF, BPZ, BPE, BPAP, BPF, BPA, BPC, BPS and BPF, respectively, in the pooled urine samples. Preliminary risk assessments indicated that the estimated daily intake of BPA was much higher than the latest proposed tolerable daily intake. Due to the unavailability of health-based guideline values for alternative BPs, some of them exhibit daily intakes comparable to BPA, implying that greater attention should be paid to health risks associated with exposure to BPs.

Exposure to Bisphenol A and Its Analogs among Thai School-Age Children

Bisphenol F (BPF) and bisphenol S (BPS) have become popular substitutes for bisphenol A (BPA) in the plastic industry due to concerns over BPA's adverse effects. However, there is limited information on children's exposure to these chemicals. This study aims to assess the extent of BPA, BPF, and BPS exposure and determine factors that influence such exposure. A group of Thai children (age 6-13 years, N = 358) were recruited between October 2019 and 2020. Two first-morning voids were collected one week apart. Demographic and exposure-related information was gathered. Urinary concentrations of bisphenols were analyzed by liquid chromatography and tandem mass spectrometry. Correlation between bisphenol concentrations with age, body weight, and sources of bisphenol exposure, was determined using generalized estimating equations with linear model. BPA, BPF, and BPS were detected at 79.6%, 31.0%, and 16.8%, with geometric mean (GM) concentrations of 1.41, 0.013, and 0.014 ng/mL, respectively. Younger children aged <10 years exhibited 1.3-1.6 times higher GM levels of all bisphenols compared to older children. Exposure to food stored in plastic containers was associated with higher levels of BPF and BPS. In conclusion, BPA was the most frequently detected bisphenol in urine samples from Thai children, followed by BPF and BPS.

Oxidative genomic damage in humans exposed to high indoor radon levels in Northeast Brazil

Radon gas inhalation is the main source of exposure to ionizing radiation by humans. There is still lack in knowledge concerning the chronic and indirect effects of exposure to this carcinogenic factor. Therefore, the aim of this work is to analyze the levels of oxidative genomic damage in inhabitants of a medium-high background radiation area (HBRA) (N = 82) in Northeastern Brazil and compare them with people living in a low background radiation area (LBRA) (N = 46). 8-hydroxy-2-deoxyguanosine (8-OHdG) was quantified in urine, Ser326Cys polymorphism was determined in the hOGG1 gene and indoor radon was measured. HBRA houses had 6.5 times higher indoor radon levels than those from LBRA (p-value < 0.001). The 8-OHdG mean (95% confidence interval) were significantly different, 8.42 (5.98-11.9) ng/mg creatinine and 29.91 (23.37-38.30) ng/mg creatinine for LBRA and HBRA, respectively. The variables representing lifestyle and environmental and occupational exposures did not have a significant association with oxidized guanosine concentrations. On the other hand, lower 8-OHdG values were observed in subjects that had one mutant allele (326Cys) in the hOGG1 gene than those who had both wild alleles (Ser/Ser (p-value < 0.05). It can be concluded that high radon levels have significantly influenced the genome oxidative metabolism and hOGG1 gene polymorphism would mediate the observed biological response.

Occurrence of bisphenol diglycidyl ethers and bisphenol analogs, and their associations with DNA oxidative damage in pregnant women

Bisphenol diglycidyl ethers (BDGEs) and Bisphenol A and its analogs (bisphenols) may have the same exposure routes and coexposure phenomenon in sensitive populations such as pregnant women. Previous biomonitoring studies on BDGEs are limited. Levels of fifteen bisphenols, six BDGEs and the DNA oxidative damage biomarker 8-hydroxy-2-deoxyguanosine (8-OHdG) were measured in the urine of pregnant women recruited in south China (n = 358). We aimed to provide the occurrence of bisphenols and BDGEs in pregnant women, and to investigate the potential relationship between their exposure and oxidative stress. Bisphenol A, bisphenol S, bisphenol F, bisphenol AP and all BDGEs (except for BADGE·2HCl) were frequently detected. The total concentrations of all bisphenols and BDGEs were 0.402-338 and 0.104-32.5 ng/mL, with geometric means of 2.87 and 2.48 ng/mL, respectively. BFDGE was the most abundant chemical of BDGEs, with a median concentration of 0.872 ng/mL, followed by BADGE·H2O·HCl (0.297 ng/mL). Except for pre-pregnancy obesity, maternal age/height, employment, fasting in the morning and parity did not affect the urinary concentrations of BDGEs. Significant and weak correlations were observed between concentrations (unadjusted) of total bisphenols and BDGEs (r = 0.389, p < 0.01), indicating their similar sources and exposure routes. The biomarker 8-OHdG was detected in all samples, with concentrations ranging from 1.98 to 32.6 ng/mL (median: 9.96 ng/mL). Levels of 8-OHdG were positively correlated with urinary several bisphenol concentrations (adjusted β range: 0.037-0.089, p < 0.05) but were not correlated with those of BDGEs. Further studies should focus on whether BDGEs and bisphenols exert combined effects on oxidative stress. Our study provided the first BDGEs exposure data in pregnant women and indicated that BDGEs exposure was highly prevalent in pregnant women as early as 2015 in south China.

Prenatal bisphenol A and S exposure and atopic disease phenotypes at age 6

BACKGROUND

Atopic disease may be influenced by prenatal and early life exposure to endocrine disrupting chemicals, including bisphenols, but results from epidemiological studies have been mixed. This study aimed to extend the epidemiological literature, hypothesizing that children with higher prenatal bisphenol exposure are more likely to have childhood atopic disease.

METHODS

Urinary bisphenol A (BPA) and S (BPS) concentrations were measured in each trimester from 501 pregnant women in a multi-center, prospective pregnancy cohort. Ever asthma, current asthma, wheeze, and food allergy) were assessed at age six via standardized ISAAC questionnaire. We constructed generalized estimating equations to examine BPA and BPS exposure jointly at each trimester for each atopy phenotype. BPA was modeled as a log-transformed continuous variable, whereas BPS was modeled as detected versus not detected. We also modeled pregnancy-averaged BPA values and a categorical indicator for number of detectable BPS values over pregnancy (0-3) in logistic regression models.

RESULTS

First trimester BPA was associated with inverse odds of food allergy among the entire study sample (OR = 0.78, 95% CI = 0.64-0.95, p = 0.01) and females only (OR = 0.69, 95% CI = 0.52-0.90, p = 0.006). The inverse relationship persisted in pregnancy-averaged models of BPA among females (OR = 0.56, 95% CI = 0.35-0.90, p = 0.006). Second trimester BPA was associated with greater odds of food allergy in the entire sample (OR = 1.27, 95% CI = 1.02-1.58, p = 0.03) and among males only (OR = 1.48, 95% CI = 1.02-2.14, p = 0.04). Odds of current asthma increased among males in the pregnancy-averaged BPS models (OR = 1.65, 95% CI = 1.01-2.69, p = 0.045).

CONCLUSION

We saw opposite effects of BPA on food allergy that were trimester- and sex-specific. These divergent associations warrant further investigation. There is some evidence to suggest that prenatal BPS is associated with asthma among males, but further research is required in cohorts with a greater proportion of prenatal urine samples with detectable BPS to validate these results.

The influence of the co-exposure to polycyclic aromatic hydrocarbons and toxic metals on DNA damage in brazilian lactating women and their infants: A cross-sectional study using machine learning approaches

Polycyclic aromatic hydrocarbons (PAHs) and toxic metals are widely spread pollutants of public health concern. The co-contamination of these chemicals in the environment is frequent, but relatively little is known about their combined toxicities. In this context, this study aimed to evaluate the influence of the co-exposure to PAHs and toxic metals on DNA damage in Brazilian lactating women and their infants using machine learning approaches. Data were collected from an observational, cross-sectional study with 96 lactating women and 96 infants living in two cities. The exposure to these pollutants was estimated by determining urinary levels of seven mono-hydroxylated PAH metabolites and the free form of three toxic metals. 8-Hydroxydeoxyguanosine (8-OHdG) levels in the urine were used as the oxidative stress biomarker and set as the outcome. Individual sociodemographic factors were also collected using questionnaires. Sixteen machine learning algorithms were trained using 10-fold cross-validation to investigate the associations of urinary OH-PAHs and metals with 8-OHdG levels. This approach was also compared with models attained by multiple linear regression. The results showed that the urinary concentration of OH-PAHs was highly correlated between the mothers and their infants. Multiple linear regression did not show a statistically significant association between the contaminants and urinary 8OHdG levels. Machine learning models indicated that all investigated variables did not present predictive performance on 8-OHdG concentrations. In conclusion, PAHs and toxic metals were not associated with 8-OHdG levels in Brazilian lactating women and their infants. These novelty and originality results were achieved even after applying sophisticated statistical models to capture non-linear relationships. However, these findings should be interpreted cautiously because the exposure to the studied contaminants was considerably low, which may not reflect other populations at risk.

Triclocarban triggers osteoarthritis via DNMT1-mediated epigenetic modification and suppression of COL2A in cartilage tissues

Triclocarban (TCC) is a widely used environmental endocrine-disrupting chemical (EDC). Articular injury of EDCs has been reported; however, whether and how TCCs damage the joint have not yet been determined. Herein, we revealed that exposure to TCC caused osteoarthritis (OA) within the zebrafish anal fin. Mechanistically, TCC stimulates the expression of DNMT1 and initiates DNA hypermethylation of the type II collagen coding gene, which further suppresses the expression of type II collagen and other extracellular matrices. This further results in decreased cartilage tissue and narrowing of the intraarticular space, which is typical of the pathogenesis of OA. The regulation of OA occurrence by TCC is conserved between zebrafish cartilage tissue and human chondrocytes. Our findings clarified the hazard and potential mechanisms of TCC towards articular health and highlighted DNMT1 as a potential therapeutic target for OA caused by TCC.

Occurrence of multiple bisphenol S analogues in children from Shantou, China

Emerging bisphenol S analogues (BPSs) have gained their application perspectives to replace bisphenol A (BPA) and BPA analogues (BPAs). However, the extent of human exposure and potential health risk from BPSs is rarely known yet. We hypothesized that children living in Shantou, China, a well-known e-waste recycling city, may expose to emerging BPSs together with BPA and BPAs. In this study, BPA, six commonly used BPAs and 11 emerging BPSs were determined simultaneously in 240 urine samples collected from children residing in Shantou. BPA, BPS, bisphenol F, bisphenol AF and three BPSs of 2,4'-bis(hydroxyphenyl)sulfone, 4-((4-(allyloxy)phenyl)sulfonyl)phenol and diphenylsulfone (DPS) were the urinary predominant bisphenols with detection frequencies of 67-100% in the children. BPA was found at the highest median concentration (3.36 µg/g creatinine) followed by BPS (0.313) and DPS (0.187). It is interesting to find that the girls and children in the younger group (2 ≤ age < 5) had consistently higher concentrations of the seven dominant bisphenols than the boys and these of the older group (5 ≤ age ≤ 10), respectively. The children with under/overweight suffered higher burdens of bisphenol exposure based on medians of estimated daily intakes. Association analysis results indicated that the Shantou children exposed themselves to multiple BPSs along with BPA and BPAs from assumed consumer products and/or contaminated environments.

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 μg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Urinary pentachlorophenol in general population of central China: reproducibility, predictors, and associations with oxidative stress biomarkers

Pentachlorophenol (PCP) is a ubiquitous environmental persistent organic pollutant and a Group 1 carcinogen. Human exposure level of PCP was reported to be relatively higher in China than in many other countries, because sodium pentachlorophenate was abused as molluscicide in China. PCP can induce oxidative stress; however, the relationship of PCP exposure with oxidative stress biomarkers (OSBs) in human beings has rarely been documented. In this study, 404 first-morning urine samples (including repeated samples in three days donated by 74 participants) were collected from 128 healthy adults (general population without occupational exposure to PCP) in autumn and winter of 2018, respectively, in Wuhan, central China. Urinary concentrations of PCP and three select OSBs [including 8-OHG (abbreviation of 8-hydroxy-guanosine), 8-OHdG (8-hydroxy-2'-deoxyguanosine), and 4-HNEMA (4-hydroxy-2-nonenal mercapturic acid), which reflect oxidative damage of RNA, DNA, and lipid, respectively] were determined. PCP was detectable in 100% of the urine samples (specific gravity-adjusted median concentration: 0.44 ng/mL; range: 0.02-14.2 ng/mL). Interday reproducibility of urinary PCP concentrations was excellent (intraclass correlation coefficient: 0.88) in three days. Significant differences in PCP concentrations were found among different age groups; the group of participants aged 20-45 y (median: 0.72 ng/mL) had higher concentrations than those in the elders (aged 45-60 y and > 60 y). Spatial disparity was observed in autumn, and urban residents had higher PCP concentrations than rural residents (median: 0.60 vs. 0.31 ng/mL), whereas such disparity was not found in winter. There were no season-, sex-, or BMI-related differences between the corresponding subgroups. The urinary PCP concentrations were found to be associated with increases in 8-OHdG and 8-OHG rather than 4-HNEMA. An interquartile range increase in urinary PCP concentration was associated with a 23.5% (95% CI: 9.18-39.6) increase in 8-OHdG and a 21.3% (95% CI: 9.18-32.4) increase in 8-OHG, implied that PCP exposure at environmental relevant dose might be associated with nucleic acid oxidative damage in the general population. This pilot study reported associations between PCP exposure and OSBs in human beings. Future studies are needed to elucidate the mediating roles of OSBs in the association between PCP exposure and certain adverse health outcomes.

Benzophenone-3: Comprehensive review of the toxicological and human evidence with meta-analysis of human biomonitoring studies

BACKGROUND

Benzophenone-3 (BP-3) and its major metabolite benzophenone-1 (BP-1) are widely used as UV filters in sunscreens and cosmetics to prevent sunburn and skin damage, or as stabilizers to prevent photodegradation in many commercial products. As a result, their presence is ubiquitous in the environment, wildlife and humans. Based on endocrine disruption concerns, international regulatory agencies are performing a closer evaluation.

OBJECTIVE AND METHODS

This work aimed to comprehensively review the available human relevant evidence for safety issues in MEDLINE/PubMed in order to create a structured database of studies, as well as to conduct an integrative analysis as part of the Human Biomonitoring for Europe (HBM4EU) Initiative.

RESULTS

A total of 1,635 titles and abstracts were screened and 254 references were evaluated and tabulated in detail, and classified in different categories: i) exposure sources and predictors; ii) human biomonitoring (HBM) exposure levels to perform a meta-analysis; iii) toxicokinetic data in both experimental animals and humans; iv) in vitro and in vivo rodent toxicity studies; and v) human data on effect biomarkers and health outcomes. Our integrative analysis showed that internal peak BP-3 concentrations achieved after a single whole-body application of a commercially available sunscreen (4% w/w) may overlap with concentrations eliciting endocrine disrupting effects in vitro, and with internal concentrations causing in vivo adverse female reproductive effects in rodents that were supported by still limited human data. The adverse effects in rodents included prolonged estrous cycle, altered uterine estrogen receptor gene expression, endometrium hyperplasia and altered proliferation and histology of the mammary gland, while human data indicated menstrual cycle hormonal alterations and increased risk of uterine fibroids and endometriosis. Among the modes of action reported (estrogenic, anti-androgenic, thyroid, etc.), BP-3 and especially BP-1 showed estrogenic activity at human-relevant concentrations, in agreement with the observed alterations in female reproductive endpoints. The meta-analysis of HBM studies identified a higher concern for North Americans, showing urinary BP-3 concentrations on average 10 and 20 times higher than European and Asian populations, respectively.

DISCUSSION AND CONCLUSIONS

Our work supports that these benzophenones present endocrine disrupting properties, endorsing recent European regulatory efforts to limit human exposure. The reproducible and comprehensive database generated may constitute a point of departure in future risk assessments to support regulatory initiatives. Meanwhile, individuals should not refrain from sunscreen use. Commercially available formulations using inorganic UV filters that are practically not absorbed into systemic circulation may be recommended to susceptible populations.

Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

Background

Agrowing body of literature investigated childhood exposure to environmental chemicals in association with attention deficit hyperactivity disorder (ADHD) symptoms, but limited studies considered urinary mixtures of multiple chemical classes. This study examined associations of concurrent exposure to non-persistent chemicals with ADHD symptoms in children diagnosed with autism spectrum disorder (ASD), developmental delay, and typical development.

Methods

A total of 574 children aged 2-5 years from the Childhood Autism Risks from Genetics and Environment (CHARGE) case-control study was administered the Aberrant Behavior Checklist (ABC). This study focused on the Hyperactivity subscale and its two subdomains (hyperactivity/impulsivity, inattention). Sixty-two chemicals from four classes (phenols/parabens, phthalates, organophosphate pesticides, trace elements) were quantified in child urine samples, and 43 chemicals detected in >70% samples were used in statistical analyses. Weighted quantile sum regression for negative binomial outcomes with repeated holdout validation was performed to investigate covariate-adjusted associations between mixtures and ABC scores in 574 children. The mixture analyses were further restricted to 232 children with ASD.

Results

Phthalate metabolite mixtures, weighted for mono-n-butylphthalate (MNBP), mono-2-heptyl phthalate, and mono-carboxy isononyl phthalate, were associated with the Hyperactivity subscale (mean incidence rate ratio [mIRR] = 1.11; 2.5th, 97.5th percentile: 1.00, 1.23), especially the hyperactivity/impulsivity subdomain (mIRR = 1.14; 2.5th, 97.5th percentile: 1.06, 1.26). These associations remained similar after restricting to children with ASD. The inattention subdomain was associated with a phenols/parabens mixture, weighted for several parabens and bisphenols (mIRR = 1.13; 2.5th, 97.5th percentile: 1.00, 1.28) and a total mixture, weighted for 3,4-dihydroxy benzoic acid, MNBR and mono-(2-ethyl-5-carboxypentyl) phthalate (mIRR = 1.11; 2.5th, 97.5th percentile: 1.01,1.25) only among children with ASD.

Conclusions

Concurrent exposure to phthalate mixtures was associated with hyperactivity in early childhood. Though causal inference cannot be made based on our cross-sectional findings, this study warrants further research on mixtures of larger number of chemicals from multiple classes in association with ADHD-related behaviors in young children.

Triclosan is associated with breast cancer via oxidative stress and relative telomere length

Introduction

Triclosan (TCS), a widely prescribed broad-spectrum antibacterial agent, is an endocrine-disrupting chemical. The relationship and biological mechanisms between TCS exposure and breast cancer (BC) are disputed. We aimed to examine the correlation between urinary TCS exposure and BC risk and estimated the mediating effects of oxidative stress and relative telomere length (RTL) in the above association.

Methods

This case-control study included 302 BC patients and 302 healthy individuals in Wuhan, China. We detected urinary TCS, three common oxidative stress biomarkers [8-hydroxy-2-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F_2α (8-isoPGF_2α), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)], and RTL in peripheral blood mononuclear cells.

Results

Significant associations were observed between log-transformed urinary concentrations of TCS, 8-OHdG, HNE-MA, 8-isoPGF_2α, RTL, and BC risk, with the odds ratios (95% confidence intervals) being 1.58 (1.32-1.91), 3.08 (1.55-6.23), 3.39 (2.45-4.77), 3.99 (2.48-6.54), and 1.67 (1.35-2.09), respectively. Continuous TCS exposure was significantly positively correlated with RTL, HNE-MA, and 8-isoPGF_2α (all p<0.05) but not with 8-OHdG (p = 0.060) after adjusting for covariates. The mediated proportions of 8-isoPGF2_2α and RTL in the relationship between TCS and BC risk were 12.84% and 8.95%, respectively (all p<0.001).

Discussion

In conclusion, our study provides epidemiological evidence to confirmed the deleterious effects of TCS on BC and indicated the mediating effect of oxidative stress and RTL on the correlation between TCS and BC risk. Moreover, exploring the contribution of TCS to BC can clarify the biological mechanisms of TCS exposure, provide new clues for the pathogenesis of BC, which is of great significance to improving public health systems.

Occurrence and profile characteristics of environmental phenols in human urine from a rural area in Northwestern China

Many environmental phenols, such as bisphenols, benzophenones and parabens, are known as endocrine disruptors and can adversely affect human health. However, the knowledge of human exposure to common environmental phenols in Chinese rural areas is insufficient. In this context, 181 urine samples were collected from participants in a rural area in Northwest China and were analyzed for nine bisphenols, three benzophenones and four parabens. Bisphenol A (BPA), bisphenol S, benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-hydroxybenzophenone, methylparaben (MeP), ethylparaben and propylparaben (PrP) were detected in more than 50% of the urine samples, with median concentrations of 0.938 ng/mL, 0.0111 ng/mL, 0.191 ng/mL, 1.30 ng/mL, 0.0320 ng/mL, 25.9 ng/mL, 4.31 ng/mL and 1.94 ng/mL, respectively. A significant positive correlation was observed between BP-1 and BP-3, as well as between MeP and PrP, indicating metabolic transformation and combined use, respectively. The concentrations of MeP and PrP in females were significantly higher than those in males, suggesting that females were exposed to more MeP and PrP than males. Urinary concentrations of BPA, BP-3, MeP and PrP could be influenced by age. Other demographic information, such as annual household income, education and occupation was not associated with the exposure level of the targeted phenols in adults. The estimated daily intakes of the analytes except BPA were all below their respective tolerable/acceptable daily intake levels. This study profiles the demographic differences in the exposure to environmental phenols in general populations from rural areas and provides information on risk assessments.

Urinary profile of PAHs and related compounds in women working in beauty salons

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemical compounds which interest to human biological monitoring researches because of their potential carcinogenic, mutagenic, and teratogenic properties. However, the exposure of female beauticians to these contaminants is not well-reported. For biomonitoring of potential exposure of female cosmeticians to PAHs in beauty salons, urine samples were taken from cosmetologist women (n = 50.00) and housewives (n = 35.00) as the exposure group (EG) and control group (CG), respectively. Next, unmetabolized PAHs levels as well as the concentration of - 1-hydroxypyrene (1-OHP) were analyzed in these specimens. In addition, since benzene has some common source with PAHs, in this study t, t'-Muconic acid (TTMA) level was also determined as the metabolite and indicator of exposure to benzene. The results indicated a high detection frequency of the target compounds (PAHs, 1-OHP and TTMA) in the urine specimens of beauticians. The results also showed that there is a significant difference between the concentration of these pollutants in the urine specimens of the exposure and control groups. The median concentration of ΣPAHs, 1-OHP, and TTMA in the before exposure (BE) specimens collected from the exposure group were 337.42 ng/L, 593.92 ng/L, and 247.90 μg/L, respectively. However, a higher concentration of these contaminants was observed in the after exposure specimens with a median concentration of 423.29 ng/L, 745.03 ng/L, and 310.97 μg/L, respectively. In terms of contribution of PAHs compounds in total toxic equivalents, DahA, BaP, and IndP with 59.03, 28.73, and 2.86 % had the largest share. In this study, it was also observed that some kidney damage biomarkers as well as some oxidative stress injury biomarkers are positively and significantly correlated with the urinary values of ∑PAHs. Thus, it can be concluded that high health risks threaten the female beauticians regarding kidney injury and DNA oxidative stress.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

Associations between repeated measurements of childhood triclosan exposure and physical growth at 7 years

BACKGROUND

Epidemiological studies suggested that triclosan (TCS) exposure was ubiquitous among children and could affect their physical growth. However, most studies relied on TCS exposure at single time point, and the impacts of multiple time points TCS exposure were unclear.

OBJECTIVES

To estimate the associations between repeated TCS measurements in childhood (at ages 1, 2, 5, and 7 years) and physical growth at 7 years.

METHODS

This study included 206 children from Laizhou Wan Birth Cohort (LWBC), China. Urinary TCS concentrations were detected at age of 1, 2, 5, and 7 years, and physical growth including height, weight, waist circumference, and fat percentage was measured at 7 years. Multiple informant models were applied to examine the relationships of repeated TCS measurements in childhood with physical growth, and stratified analysis by gender was performed.

RESULTS

The detection rates of TCS at age of 1, 2, 5, and 7 years were above 60%, with median declining from 0.89 to 0.33 μg/g creatinine. We found TCS at 5 years was positively associated with waist-to-height ratio, and TCS at 7 years was positively associated with physical growth, including weight z-score, BMI z-score, waist circumference, waist-to-height ratio, and fat percentage. Moreover, the above associations for weight z-score, BMI z-score, and fat percentage significantly varied by the period of exposure (pint ˂ 0.05). After stratified by gender, positive associations were only found among boys.

CONCLUSIONS

In our study, TCS levels decreased as children's age increased. TCS exposures at age of 5 and 7 years were positively associated with physical growth at 7 years, and these associations were only significant in boys. Given the relatively small sample size, our findings should be interpreted with caution until confirmed by further investigation.

Inter-method reliability of silicone exposome wristbands and urinary biomarker assays in a pregnancy cohort

Silicone wristbands act as passive environmental samplers capable of detecting and measuring concentrations of a variety of chemicals. They offer a noninvasive method to collect complex exposure data in large-scale epidemiological studies. We evaluated the inter-method reliability of silicone wristbands and urinary biomarkers in the New Hampshire Birth Cohort Study. A subset of study participants (n = 96) provided a urine sample and wore a silicone wristband for 7 days at approximately 12 gestational weeks. Women were instructed to wear the wristbands during all their normal activities. Concentrations of urinary compounds and metabolites in the urine and parent compounds in wristbands were compared. High detection rates were observed for triphenyl phosphate (76.0%) and benzophenone (78.1%) in wristbands, although the distribution of corresponding urinary concentrations of chemicals did not differ according to whether chemicals were detected or not detected in wristbands. While detected among only 8.3% of wristbands, median urinary triclosan concentrations were higher among those with triclosan detected in wristbands (9.04 ng/mL) than without (0.16 ng/mL). For most chemicals slight to fair agreement was observed across exposure assessment methods, potentially due to low rates of detection in the wristbands for chemicals where observed urinary concentrations were relatively low as compared to background concentrations in the general population. Our findings support the growing body of research in support of deploying silicone wristbands as an important exposure assessment tool.

Comprehensive assessment of estrogenic activities of parabens by in silico approach and in vitro assays

Parabens are ubiquitous pollutants in the environment and humans due to their wide applications in food, pharmaceuticals, and personal care products. Although the estrogenic activity of some parabens has been confirmed, the underlying mechanisms and the structure-estrogenic activity relationship are still largely unclear. Here, we systematically used in silico and in vitro approaches to investigate the estrogenic potency of typical parabens, including methyl-, ethyl-, propyl-, iso-propyl-, butyl-, iso-butyl- and benzyl-paraben. Molecular dynamics simulations and binding free energy calculations were combined to investigate the atomic-level mechanism of paraben binding to estrogen receptors (ERs). Computational analysis showed that ER were the targets of tested parabens and kept a stable agonist conformation. The calculated total binding free energies suggested that van der Waals interactions were the major driving forces for paraben-ER interaction and correlated with the structure of paraben side chains. In in vitro assays, paraben with an aromatic side chain, benzyl-paraben, showed the strongest estrogenic activity at 0.01 μM and the EC₅₀ at 0.796 ± 0.307 μM, on par with levels commonly detected in human organs. Among tested parabens with an alkyl side chain, the estrogenicity increased as the side chain length increased from 1 to 4, but no significant difference appeared between parabens with isomeric alkyl side chains (propyl- vs isopropyl and butyl- vs iso-butylparaben). The estrogenic activity of parabens was significantly related to the calculated binding energies (R² = 0.94, p = 0.0012), depending on the side chains of parabens. Our findings provide a significant mechanism for parabens to disrupt estrogenic function and considerations for structural optimization from the perspective of environmental protection.

Cumulative risk assessment and exposure characteristics of parabens in the general Taiwanese using multiple hazard indices approaches

Parabens, a group of endocrine disrupting chemicals (EDCs), are well known preservatives in pharmaceuticals and personal care products (PPCPs). However, studies on parabens exposure and their cumulative effects in Asian population are limited. This study aimed to identify the exposure characteristics and estimate the cumulative risk of four parabens in the general Taiwanese. We have collected urine samples including 271 adults (18-97 yrs old) and 95 minors (7-17 yrs old), from Taiwan Environmental Survey for Toxicants 2013, and analyzed for four urinary parabens including methyl (MeP)-, ethyl (EtP)-, propyl (PrP)-, and butylparaben (BuP) by using ultraperformance liquid chromatography-tandem mass spectrometry. The health-based guidance value (HBGV) and the antiandrogenic properties of parabens were used to calculate the hazard index (HI) for cumulative risk. MeP and PrP were most abundant compounds and startlingly higher than those in other countries. Adults had a higher geometric mean level of four parabens than minors (adults: MeP, 381.7; PrP, 108.6; EtP, 39.6 and BuP 6.3 ng/mL; minors: MeP, 65.7; PrP, 7.9, EtP, 2.6 and BuP 2.2 ng/mL). Participants who used a higher number of personal care products had a significantly higher risk with higher concentrations of PrP (above 75th %tile) [adjusted odds ratio (aOR): 1.79, 95 % CI: 1.01-3.15] and BuP [aOR: 1.78, 95 % CI: 1.03-3.07]. The median and 95th %tile HI (the sum of the HQs of each paraben) was as 1.10 and 4.39-fold higher than acceptable cumulative threshold (HI <1) and PrP accounted for 90 % of the HI. Our results indicate omnipresent exposure to parabens among the Taiwanese population, which might cause certain level of concerns. These significant increasing trends of HI with age dependence were observed, which mainly driven by PPCPS used. Routine survey of parabens in PPCPs and continued biomonitoring needs to be urgently addressed.

Urinary levels of monohydroxylated polycyclic aromatic hydrocarbons in Brazilian children and health risk assessment: a human biomonitoring-based study

Monitoring human exposure to polycyclic aromatic hydrocarbons (PAHs) is a public health concern. Children are a vulnerable subgroup of the population with limited human biomonitoring data worldwide. Thus, this study aimed to measure the levels of seven PAH metabolites in urine from Brazilian children and provide risk assessment values for this exposure. Our data show naphthalene was the major contributor to children's exposure to PAHs, with a 100% detection rate. Children in urban regions presented higher exposure to PAHs, with higher concentrations of 2-naphthol in the southeast (1.09 ng/mL, p < 0.05). Furthermore, the highest concentration of 2-naphthol was found in older children (p = 0.02), suggesting a possible difference in dietary habits. Exposure to the carbaryl insecticide is suggested based on the high concentrations of 1-naphthol (1.29 ng/mL) and considering the ratio 1-naphthol/2-naphthol (1.78). Moreover, the positive correlation between the metabolites of fluorine and pyrene also suggests exposure to PAHs by petrol combustion. The risk assessment of the PAH exposure was evaluated using the estimated daily intake (EDI) for two naphthalene metabolites in the study with a 100% detection rate. The EDI was 14.47 ng/kg BW/day. The risk assessment to the PAH exposure revealed a non-carcinogenic risk profile, with a hazard quotient of 0.71. To the best of our knowledge, this study is the first to provide levels of PAHs in Brazilian children.

Urinary paraben derivatives in pregnant women at three trimesters: Variability, predictors, and association with oxidative stress biomarkers

Exposure to parabens has been shown to increase oxidative stress, which has a vital impact on the development of numerous diseases. However, few studies reported the effects of the paraben derivatives on oxidative stress, particularly among pregnant women. This study, using repeated measurements, aimed to understand the exposure profiles of urinary paraben derivative concentrations and their relationships with oxidative stress biomarkers (OSBs). A total of 861 pregnant women, who provided spot urine samples at three trimesters, were included, and 2583 urine samples were used to measure four paraben derivatives [p-hydroxybenzoic acid (p-HB), 3,4-dihydroxybenzoic acid (3,4-DHB), methyl protocatechuate, and ethyl protocatechuate], four parabens (methyl, ethyl, propyl, and butyl), and three OSBs [8-hydroxy-2'-deoxyguanosine (for DNA), 8-hydroxyguanosine (for RNA), and 4-hydroxy nonenal mercapturic acid (for lipid)]. Pregnant women were extensively exposed to parabens and paraben derivatives with detection frequencies (DFs) of 86.1%-100%, except for butylparaben with a DF of 14.9%. p-HB and 3,4-DHB had relatively high urinary concentrations (specific gravity-adjusted median values: 1394 and 74.5 ng/mL, respectively). Low reproducibility in paraben derivatives was found across the three trimesters. Sampling season, pre-pregnancy body mass index, and infant sex were predictors of some paraben derivatives/parabens. Linear mixed model analyses showed that all target compounds (if DF > 50%) were associated with increases in all the selected OSBs, where the percent change in OSBs with an interquartile range increase in paraben concentration ranged from 9.85% to 24.7%, while those in paraben derivative concentration ranged from 13.8% to 72.1%. Weighted quantile sum model showed that joint exposure was significantly associated with increased OSBs, and paraben derivatives were stronger contributors to OSBs compared with parabens. Overall, urinary paraben derivatives were associated with increased oxidative stress of nucleic acids and lipid in pregnant women.

Bisphenol A and its analogues in paired urine and house dust from South China and implications for children's exposure

Following the restriction of bisphenol A (BPA) in certain products, a number of bisphenol analogues (BPs) have been used as BPA replacements in different applications, raising environmental and health concerns. The present study determined a total of 13 bisphenol analogues in house dust and children urine from South China families (n = 46). Among all BPs, BPA, bisphenol S (BPS) and bisphenol F (BPF) were frequently detected in house dust, with concentrations ranging from 0.54 to 26.2 μg/g (median: 2.60 μg/g), 0.07-11.5 μg/g (median: 0.32 μg/g) and 0.02-2.4 μg/g (median: 0.29 μg/g), respectively. BPA (median: 2.43 ng/mL) was also the dominant BP in children urine samples, accounting for 75.2 ± 27.4% of the total concentrations of urinary BPs, followed by BPS (0.23 ng/mL), whereas BPF was only detected in less than 30% of urine samples. Children's daily intake of bisphenols through dust ingestion and total daily intakes were estimated based on the dust and urine concentrations, respectively. The estimated intake of BPA, BPS and BPF via house dust ingestion accounted for 9%, 12% and 38% of the total intakes predicted based on urinary concentrations, respectively, and exhibited very low exposure risks.

Urinary parabens and their derivatives associated with oxidative stress biomarkers in children from South and Central China: Repeated measures

Previous studies implied that elevated exposure to parabens may result in increased oxidative stress. However, the association between exposure to paraben derivatives and oxidative stress biomarkers in children has been rarely studied. This study examined the associations between exposure to paraben derivatives and oxidative stress biomarkers in Chinese children. Nine targeted compounds of parabens and their derivatives including methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP), butyl paraben (BuP), p-hydrox4ybenzoic acid (p-HB), 3,4-dihydroxy benzoic acid (3,4-DHB), benzoic acid, methyl 3,4-dihydroxybenzoate (rOH-MeP), and ethyl 3,4-dihydroxybenzoate (rOH-EtP) were detected in urine collected from 139 children from South and Central China. Additionally, 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), and 4-hydroxy-2-nonenal mercapturic acid (HNE-MA) were measured as oxidative stress biomarkers. All targeted compounds (except for BuP) were frequently detected in urine (detection frequencies ranged 80.8%-100%). Linear mixed effects model revealed that all targeted compounds (with detection frequencies >50%), except for EtP, were significantly associated with an increase in 8-OHdG. rOH-EtP was found to be significantly associated with 8-OHG (β = 0.12; 95% confidence interval [95% CI]: 0.08, 0.16) positively. In addition, PrP and benzoic acid were associated with elevated levels of HNE-MA. Weighted quantile sum regression revealed that co-exposure to the targeted compounds was positively associated with 8-OHdG (β = 0.17; 95% CI: 0.12, 0.22), 8-OHG (β = 0.14; 95% CI: 0.10, 0.18), and HNE-MA (β = 0.43; 95% CI: 0.27, 0.59); rOH-EtP and benzoic acid were the major contributors for the combined effects on oxidative stress of nucleic acids and lipid, respectively. Our findings provide new evidence for the effects of exposure to paraben derivatives on nucleic acid oxidative damage and lipid peroxidation in children.

Diurnal Variation in Biomarkers of Exposure to Endocrine-Disrupting Chemicals and Their Association with Oxidative Damage in Norwegian Adults: The EuroMix Study

Much evidence on the adverse health effects of endocrine-disrupting chemicals (EDCs) has accumulated during recent decades. EDCs are commonly found in various foods and personal care products (PCP). Data documenting a diurnally varying EDC metabolism in humans is scarce. This study examined (i) the time-of-day effect on the diurnal magnitude and variance of urinary biomarkers of exposure to EDCs, and (ii) the association between EDC exposures and oxidative damage in a Norwegian adult subpopulation. This was a cross-sectional panel study using biobanked samples from the EuroMix project. During a typical weekday, participants were asked to collect all day’s urine voids and record dietary and PCP habitual uses in a diary. Collected time stamps of urine voids were classified into three distinct periods in the day (morning 6 a.m.−12 p.m., mid-day 12 p.m.−6 p.m., evening 6 p.m.−6 a.m.). Questionnaires regarding demographic characteristics, personal care product usage, and dietary habits were completed. Urinary levels of EDCs (phthalates, parabens, and bisphenols) were measured using mass spectrometry and adjusted for urinary volume using specific gravity. Urinary 4-hydroxynonenal (4HNE), a lipid peroxidation marker, was measured using an immunoassay kit. Linear mixed-effect models identified EDCs under the influence of a diurnal variation effect that was adjusted for dietary habits and PCP use and examined associations between EDC and 4HNE. p-values were FDR-adjusted. Most phthalates appeared to be diurnally varying with higher urinary levels towards the evening (q < 0.001) than those measured during mid-day; this strong diurnal variation effect was not present for parabens and bisphenols. Significant (q < 0.001) positive associations were observed between all phthalates, parabens, and bisphenols (except bisphenol S) and 4HNE. This study’s findings highlighted the diurnal variation of excretion for certain EDC, but not for others, in real-life conditions. The degree of EDC chronotoxicity in distinct diurnal windows of the day warrants further investigation with longitudinal human studies.

Association of urinary triclosan, methyl triclosan, triclocarban, and 2,4-dichlorophenol levels with anthropometric and demographic parameters in children and adolescents in 2020 (case study: Kerman, Iran)

Endocrine-disrupting chemicals (EDCs) can be a major risk factor for noncommunicable illnesses, especially when children are exposed to them. The purpose of this study was to assess the urine concentrations of triclosan (TCS), methyl triclosan (MTCS), triclocarban (TCC), and 2,4-dichlorophenol (2,4-DCP) and its association with anthropometric and demographic parameters in children and adolescents aged 6-18 living in Kerman, Iran, in 2020. A GC/MS instrument was used to measure the concentrations of the analytes. TCS, MTCS, TCC, and 2,4-DCP geometric mean concentrations (µg/L) were 4.32 ± 2.08, 1.73 ± 0.88, 4.66 ± 10.25, and 0.19 ± 0.14, respectively. TCS, MTCS, TCC, and 2,4-DCP were shown to have a positive and significant association with BMI z-score and BMI (p-value < 0.01). TCS and MTCS have a positive, strong, and substantial association (p-value < 0.01, r = 0.74). There was no significant association between the waist circumference (WC) and the analytes studied. In addition, there was a close association between analyte concentration and demographic parameters (smoking, education, income, etc.) overall. In Kerman, Iran, the current study was the first to look into the association between TCS, MTCS, TCC, and 2,4-DCP analytes and anthropometric and demographic data. The levels of urinary TCS, MTCS, TCC, 2,4-DCP, and anthropometric parameters in children and adolescents are shown to have a significant association in this study. However, because the current study is cross-sectional and it is uncertain if a single experiment accurately reflects long-term exposure to these analytes, more research is needed to determine the impact of these analyses on the health of children and adolescents.

Environmental exposures to pesticides, phthalates, phenols and trace elements are associated with neurodevelopment in the CHARGE study

OBJECTIVE

To determine if higher exposures measured in early childhood to environmental phenols, phthalates, pesticides, and/or trace elements, are associated with increased odds of having a diagnosis of Autism Spectrum Disorder (ASD), Developmental Delay (DD), or Other Early Concerns (OEC) compared to typically developing children (TD).

METHODS

This study included 627 children between the ages of 2-5 who participated in the Childhood Autism Risks from Genetics and Environment (CHARGE) study. Urine samples were collected at the same study visit where diagnostic assessments to confirm diagnosis indicated during the recruitment process were performed. Adjusted multinomial regression models of each chemical with diagnosis as the outcome were conducted. Additionally, two methods were used to analyze mixtures: repeated holdout multinomial weighted quantile sum (WQS) regression for each chemical class; and a total urinary mixture effect was assessed with repeated holdout random subset WQS.

RESULTS

Many urinary chemicals were associated with increased odds of ASD, DD or OEC compared to TD; however, most did not remain significant after false discovery rate adjustment. Repeated holdout WQS indices provided evidence for associations of both a phenol/paraben mixture effect and a trace element mixture effect on DD independently. In analyses adjusted for confounders and other exposures, results suggested an association of a pesticide mixture effect with increased risk for ASD. Results also suggested associations of a total urinary mixture with greater odds of both ASD and DD separately.

CONCLUSION

Higher concentrations of urinary biomarkers were associated with ASD, DD, and OEC compared to TD, with consistency of the results comparing single chemical analyses and mixture analyses. Given that the biospecimens used for chemical analysis were generally collected many months after diagnoses were made, the direction of any causal association is unknown. Hence findings may reflect higher exposures among children with non-typical development than TD children due to differences in behaviors, metabolism, or toxicokinetics.

Determination of Parabens, Bisphenol A and Its Analogs, Triclosan, and Benzophenone-3 Levels in Human Urine by Isotope-Dilution-UPLC-MS/MS Method Followed by Supported Liquid Extraction

The development of a rapid analytical approach for determining levels of antibacterial agents, plasticizers, and ultraviolet filters in biosamples is crucial for individual exposure assessment. We developed an analytical method to determine the levels of four parabens—bisphenols A (BPA) and its analogs, triclosan (TCS), triclocarban, and benzophenone-3 (BP-3)—in human urine. We further measured the levels of these chemicals in children and adolescents. We used a supported liquid extraction (SLE) technique coupled with an isotope-dilution ultraperformance liquid chromatography-tandem mass spectrometry (ID-UPLC-MS/MS) method to assess the detection performance for these chemicals. Forty-one urine samples from 13 children and 28 adolescents were assessed to demonstrate the capability and feasibility of our method. An acceptable recovery (75.6–102.4%) and matrix effect (precision < 14.2%) in the three-level spiked artificial urine samples were achieved, and good performance of the validated ID-UPLC-MS/MS method regarding linearity, limits of detection, and quantitation was achieved. The within-run and between-run accuracy and precision also demonstrated the sensitivity and stability of this analytical method, applied after SLE. We concluded that the ID-UPLC-MS/MS method with SLE pretreatment is a valuable analytical method for the investigation of urinary antibacterial agents, plasticizers, and ultraviolet filters in humans, useful for human biomonitoring.

Benzophenone-1 induced aberrant proliferation and metastasis of ovarian cancer cells via activated ERα and Wnt/β-catenin signaling pathways

Benzophenone-1 (BP-1) belongs to personal care product-related contaminants of emerging concern and has been recently reported to induce xenoestrogenic effects. However, the underlying mechanisms leading to the activation of target receptors and subsequent various adverse outcomes remain unclear, which is beneficial to safety and health risk assessment of benzophenone-type ultraviolet filters with their widespread occurrence. Herein, we investigated disrupting effects of BP-1 at environmentally relevant concentrations (10^-9-10^-6 M) on estrogen receptor (ER) α-associated signaling pathways. Molecular dynamics simulations together with yeast-based assays revealed the steady binding of BP-1 to ERα ligand binding domain (LBD) and hence the observed agonistic activity. BP-1 triggered interaction between ERα and β-catenin in human SKOV3 ovarian cancer cells and caused translocation of β-catenin from the cytoplasm to the nucleus, leading to aberrant activation of Wnt/β-catenin. BP-1 consequently induced dissemination of SKOV3 via regulating epithelial-mesenchymal transitions (EMT) biomarkers including minimally downregulating ZO-1 gene to 78.0 ± 10.1% and maximally upregulating MMP9 gene to 144.1 ± 29.7% and promoted 1.03-1.83 fold proliferation, migration and invasion of SKOV3. We provide the first evidence that the BP-1 activated ERα triggers crosstalk between ERα and Wnt/β-catenin pathway, leading to the abnormal stimulation and progression of SKOV3 cancer cells.

Urinary level of un-metabolized parabens in women working in beauty salons

Parabens are a group of chemical additive extensively utilized in various health care products and ubiquitously observed in the different environmental matrixes. Nevertheless, the exposure of women working in beauty salons to these pollutants is not well-documented. For this purpose, 50.00 women working in beauty salons were chosen as the exposed group (EG) and 35.00 housewives were chosen as the control group (GC). The concentration of methyl paraben (MeP), ethyl paraben (EtP), butyl paraben (BuP), propyl paraben (PrP), benzyl paraben (BzP), heptyl paraben (HepP), and para-hydroxybenzoic acid (4-HB) metabolite were quantified in the collected urine samples. It was seen that paraben sexist with a high detection frequency (DF) in the urine of women working in beauty salons. The results also revealed that the significant difference between the urinary parabens level in the EG and CG (P value < 0.05). The median concentration of Σparaben and HB-4 metabolite in the before exposure (BE) samples was 124.00 and 219.00 μg/L, while in the after exposure (AE) samples, it was 156.00 and 249.00 μg/L, respectively. Moreover, the parabens levels in the AE samples were considerably higher than in BE samples in women working in beauty salons (P value < 0.05). This research also documented that "personal care products (PCPs) usage" can be known as a leading factor for the urinary paraben level in the studied individuals. The median total estimated daily intakes (TEsDI) for MeP, EtP, and PrP for the studied women were obtained as 8.02, 4.57, and 7.88 μg/L respectively. Also, a significant and positive association was observed between EtP, PrP as well as BuP and 8-OhdG (as a DNA oxidative stress biomarker) (P value < 0.01). Further, a significant and positive association was found between EtP as well as BuP and some biomarkers of kidney damage (like uTIMP-1 and uKim-1). Accordingly, it can be stated that women working in beauty salons are at a high risk in terms of DNA oxidative stress and kidney damage.

Human-Biomonitoring derived exposure and Daily Intakes of Bisphenol A and their associations with neurodevelopmental outcomes among children of the Polish Mother and Child Cohort Study

BACKGROUND

Bisphenol A (BPA) is an industrial chemical mostly used in the manufacture of plastics, resins and thermal paper. Several studies have reported adverse health effects with BPA exposures, namely metabolic disorders and altered neurodevelopment in children, among others. The aim of this study was to explore BPA exposure, its socio-demographic and life-style related determinants, and its association with neurodevelopmental outcomes in early school age children from Poland.

METHODS

A total of 250 urine samples of 7 year-old children from the Polish Mother and Child Cohort Study (REPRO_PL) were analyzed for BPA concentrations using high performance liquid chromatography with online sample clean-up coupled to tandem mass spectrometry (online-SPE-LC-MS/MS). Socio-demographic and lifestyle-related data was collected by questionnaires or additional biomarker measurements. Emotional and behavioral symptoms in children were assessed using mother-reported Strengths and Difficulties Questionnaire (SDQ). Cognitive and psychomotor development was evaluated by Polish adaptation of the Intelligence and Development Scales (IDS) performed by trained psychologists.

RESULTS

Urinary BPA concentrations and back-calculated daily intakes (medians of 1.8 μg/l and 46.3 ng/kg bw/day, respectively) were similar to other European studies. Urinary cotinine levels and body mass index, together with maternal educational level and socio-economic status, were the main determinants of BPA levels in Polish children. After adjusting for confounding factors, BPA has been found to be positively associated with emotional symptoms (β: 0.14, 95% CI: 0.022; 0.27). Cognitive and psychomotor development were not found to be related to BPA levels.

CONCLUSIONS

This study represents the first report of BPA levels and their determinants in school age children in Poland. The exposure level was found to be related to child emotional condition, which can have long-term consequences including social functioning and scholastic achievements. Further monitoring of this population in terms of overall chemical exposure is required.

Estimating household exposure to moth repellents p-dichlorobenzene and naphthalene and the relative contribution of inhalation pathway in a sample of Japanese children

p-Dichlorobenzene (DCB) and naphthalene (NP) used as moth repellents in indoor environments are suspected to be carcinogenic. To evaluate their adverse effects on health with chronic exposure in the general population, especially children, we need to know their amounts absorbed by the body and the relationships between their amounts and air quality in residences. At present, little is known worldwide about them. This study examined the daily intakes of DCB and NP by Japanese children via all exposure pathways and the contribution of indoor air quality to the intakes. First-morning void urine samples from the subjects aged 6 to 15 years and air samples in their bedrooms were collected. Airborne NP and DCB and their urinary metabolites were measured. Significant correlations were detected between their airborne concentrations and the urinary excretion amounts of their corresponding metabolites. The absorption amounts of DCB and NP by inhalation of the children while at home were calculated to be 26 and 2.0 ng/kg b.w./h, respectively, as median values. The daily intake was estimated to be 2.4 and 0.90 μg/kg b.w./d (median), respectively. The fractions (median) of inhalation absorption amounts to overall absorption amounts for DCB and NP were 30% and 5%, respectively. In children living in residences where the indoor air concentrations of these compounds were more than half the level of each guideline value for indoor air quality, the main exposure route for their absorption was considered to be inhalation while at home. The indoor concentrations of DCB exceeded the lifetime excess cancer risk level of 10^-4 in 22% of the residences and 10^-3 in 9% of them. Our findings indicate the need to further reduce airborne concentrations of DCB in Japanese residences to prevent its adverse effects on the health of Japanese children.

Investigation of endocrine disruptor pollutants and their metabolites along the Romanian Black Sea Coast: Occurrence, distribution and risk assessment

In recent years, the occurrence of organic UV-filters (UVFs) and bisphenol derivatives (BPs) in the marine environment has raised high concerns all over the world, due to the potentially adverse impacts on marine organism and, indirectly on human health. This paper reports, for the first time in Romania, the occurrence, distribution pattern and environmental risk assessment of UVFs, BPs and their metabolites in seawater, sediment and algae collected from the Romania Black Sea coastal region. BP-3 (2-hydroxy-4-methoxy-benzophenone) was the most abundant contaminant in seawater samples, with detection frequency of 100 %. Sediment samples were dominated by ES (Ethylhexyl salicylate), with concentration values up to 5823 ng/g d.w., while for algae, concentrations of several hundreds of ng/g d.w. were determined for BP-3, BS (Benzyl salicylate) and BPE (Bisphenol E). Environmental risk assessment revealed that some UVFs and BPs detected in seawater samples were hazardous to the marine organism of the Black Sea.

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.

Urinary parabens, bisphenol A and triclosan in primiparas from Shenzhen, China: Implications for exposure and health risks

The usage of parabens, bisphenol A and triclosan in diverse consumer products is in widespread. Nevertheless, there are limited data concerning exposure to these chemicals in human being, especially in primiparas. Biomonitoring of chemicals in primiparas is useful for the estimation of chemical exposure risks for both primiparas and their offspring. This study aims to investigate urinary levels of parabens, bisphenol A and triclosan of 84 primiparas from Shenzhen, China and to evaluate their potential health risks. Methyl, ethyl, and n-propyl parabens bisphenol A and triclosan exhibited high detection rates (DRs) (> 97%) in urine samples, suggesting that primiparas are exposed to them widely. The median concentrations of methyl, ethyl, and n-propyl parabens, bispenol A and triclosan in urine were 2.14, 4.10, 0.46, 1.30 and 3.00 µg/L, respectively. Ethyl paraben was the predominant paraben accounting for nearly half of Σ₃parabens (The sum concentrations of methyl, ethyl, n-propyl parabens). Positive associations with significance (p < 0.05) were found between the usage of plastic containers and urinary concentrations of ethyl paraben or BPA, indicating plastic containers might be an important factor influencing primipara exposure to these two chemicals. Urinary concentrations of methyl paraben were positively associated (p < 0.05) with the time of computer use by participant, suggesting that indoor dust might constitute an important source of parabens. The estimated daily intakes of parabens, bisphenol A and triclosan contrasted with the acceptable daily intakes in a comparatively low level. The hazard quotients (HQs) of these chemicals were all less than 1, suggesting no health risks for primiparas from South China.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40201-020-00599-1.

The Different Facets of Triclocarban: A Review

In the late 1930s and early 1940s, it was discovered that the substitution on aromatic rings of hydrogen atoms with chlorine yielded a novel chemistry of antimicrobials. However, within a few years, many of these compounds and formulations showed adverse effects, including human toxicity, ecotoxicity, and unwanted environmental persistence and bioaccumulation, quickly leading to regulatory bans and phase-outs. Among these, the triclocarban, a polychlorinated aromatic antimicrobial agent, was employed as a major ingredient of toys, clothing, food packaging materials, food industry floors, medical supplies, and especially of personal care products, such as soaps, toothpaste, and shampoo. Triclocarban has been widely used for over 50 years, but only recently some concerns were raised about its endocrine disruptive properties. In September 2016, the U.S. Food and Drug Administration banned its use in over-the-counter hand and body washes because of its toxicity. The withdrawal of triclocarban has prompted the efforts to search for new antimicrobial compounds and several analogues of triclocarban have also been studied. In this review, an examination of different facets of triclocarban and its analogues will be analyzed.

Acute Toxicity and DNA Instability Induced by Exposure to Low Doses of Triclosan and Phthalate DEHP, and Their Combinations, in vitro

Triclosan (TCS) is an antimicrobial agent widely used in personal care products (PCP) and the di-(2-ethyl hydroxy-phthalate) (DEHP) is a chemical compound derived from phthalic acid, used in medical devices and plastic products with polyvinyl chloride (PVCs). As result of their extensive use, TCS and DEHP have been found in the environment and previous studies demonstrated the association between their exposure and toxic effects, mostly in aquatic organisms, but there is a shortage in the literature concerning the exposure of TCS and DEHP in human cells. The aim of the present study was to assess the impact of exposure to TCS and DEHP, as well as their combinations, on biomarkers related to acute toxicity and DNA instability, in HepG2 cells, by use of cytokinesis-block micronucleus cytome (CBMNCyt) assay. For that, the cultures were exposed to TCS, DEHP and combinations at doses of 0.10, 1.0, and 10 μM for the period of 4 h and the parameters related to DNA damage (i.e., frequencies of micronuclei (MN) and nuclear buds (NBUDs), to cell division (i.e., nuclear division index (NDI) and nuclear division cytotoxic index (NDCI) and to cell death (apoptotic and necrotic cells) were scored. Clear mutagenic effects were seen in cells treated with TCS, DEHP at doses of 1.0 and 10 μM, but no combined effects were observed when the cells were exposed to the combinations of TCS + DEHP. On the other hand, the combination of the toxicants significantly increased the frequencies of apoptotic and necrotic cells, as well as induced alterations of biomarkers related to cell viability (NDI and NDCI), when compared to the groups treated only with TCS or DEHP. Taken together, the results showed that TCS and DEHP are also able to induce acute toxicity and DNA damage in human cells.

Enhanced Disrupting Effect of Benzophenone-1 Chlorination Byproducts to the Androgen Receptor: Cell-Based Assays and Gaussian Accelerated Molecular Dynamics Simulations

Benzophenone-1 (BP-1), one of the commonly used ultraviolet filters, has caused increasing public concern due to frequently detected residues in environmental and recreational waters. Its susceptibility to residual chlorine and the potential to subsequently trigger endocrine disruption remain unknown. We herein investigated the chlorination of BP-1 in swimming pool water and evaluated the endocrine disruption toward the human androgen receptor (AR). The structures of monochlorinated (P1) and dichlorinated (P2) products were separated and characterized by mass spectrometry and ¹H-¹H NMR correlation spectroscopy. P1 and P2 exhibited significantly higher antiandrogenic activity in yeast two-hybrid assays (EC₅₀, 6.13 μM and 9.30 μM) than did BP-1 (12.89 μM). Our 350 ns Gaussian accelerated molecular dynamics simulations showed the protein dynamics in a long-time scale equilibrium, and further energy calculations revealed that although increased hydrophobic interactions are primarily responsible for enhanced binding affinities between chlorinated products and the AR ligand binding domain, the second chloride in P2 still hinders the complex motion because of the solvation penalty. The mixture of BP-1-P1-P2 elicited additive antiandrogenic activity, well fitted by the concentration addition model. P1 and P2 at 1 μM consequently downregulated the mRNA expression of AR-regulated genes, NKX3.1 and KLK3, by 1.7-9.1-fold in androgen-activated LNCaP cells. Because chlorination of BP-1 occurs naturally by residual chlorine in aquatic environments, our results regarding enhanced antiandrogenic activity and disturbed AR signaling provided evidence linking the use of personal care products with potential health risks.