Urinary concentrations of environmental phenols and their association with type 2 diabetes in a population in Jeddah, Saudi Arabia

Covalent Organic Framework Nanofilm-Assisted Laser Desorption Ionization Mass Spectrometry for Rapid Screening of Parabens in Personal Care Products

RATIONAL

People are widely exposed to parabens in their daily life, but parabens are endocrine disrupting chemicals that pose a threat to human health. Therefore, establishing a rapid screening method to enhance monitoring of parabens is necessary. Herein, a covalent organic framework (COF) nanofilm-assisted laser desorption ionization mass spectrometry (LDI-MS) method was established to screen parabens in personal care products (PCPs).

METHODS

TAPB-TFPB-COF nanofilm was synthesized on indium tin oxide (ITO) glass and used as LDI-MS substrates. To observe the practicability of TAPB-TFPB-COF nanofilm-assisted LDI-MS, the results of this method for analyzing small molecules such as parabens, estrogens, and bisphenols were compared with those of the conventional organic matrix 9-aminoacridine (9-AA), and the reproducibility and detection limit were further verified. Finally, the method was applied to screen parabens in PCPs.

RESULTS

TAPB-TFPB-COF nanofilm-assisted LDI-MS analyzed small molecules such as parabens, estrogens, and bisphenols with higher mass spectral signals and cleaner mass spectral backgrounds compared with 9-AA. Meanwhile, the method analyzed methylparaben (MeP) with high reproducibility (RSD = 6.96%) and low detection limit (1.64 μM) and performed well for rapid screening of parabens in PCPs.

CONCLUSION

TAPB-TFPB-COF nanofilm-assisted LDI-MS for analyzing small molecules such as parabens, estrogens, and amino acids offered the advantages of rapid analysis, a clean background, and good reproducibility. The method was successfully applied to detecting parabens in PCPs, demonstrating the practical utility of LDI-MS based on TAPB-TFPB-COF nanofilm for analyzing parabens in complex samples.

Exposure of individuals aged 18-44 years to personal care products in Beijing, China: Exposure profiles, possible influencing factors, and risk assessment

Personal care products (PCPs) are a class of emerging pollutants that have attracted public concern owing to their harmful effects on humans and the environment. Biomonitoring data is valuable for insight the levels of PCPs in the human body and can be crucial for identifying potential health hazards. To gain a better understanding of timely exposure profiles and health risk of reproductive-age population to PCPs, we determined six parabens, six benzophenone-type ultraviolet filters, and three disinfectants in 256 urine samples collected from young adults aged 18-44 years in Beijing, China. The urinary levels of benzophenone-3 (BP-3) and 4-hydroxybenzophenone (4-OHBP) were significantly higher in summer compared to winter, suggesting these compounds have different seasonal usage patterns. Moreover, the total concentration of 15 PCPs in female was 430 ng/mL, approximately two times higher than that in male. P‑chloro-m-xylenol (PCMX), as a new type of antibacterial agent, has the greatest level among all target analytes, indicating the increasingly use of this antibacterial alternative recently. Five potential influencing factors that lead to the elevated exposure level of PCPs were identified. Over 19% of the target population had a high hazard index value (greater than 1) which was attributed to exposure to propyl paraben (PrP), benzophenone-1 (BP-1), BP-3 and PCMX, indicating that PCPs may pose a relatively high exposure risk at environmental levels that should be a cause for concern.

Triclocarban disrupts the activation and differentiation of human CD8+ T cells by suppressing the vitamin D receptor signaling

Triclocarban (TCC) is a widely applied environmental endocrine-disrupting chemical (EDC). Similar to most of EDCs, TCC potentially damages the immunity of various species. However, whether and how TCC impacts the adaptive immunity in mammals has yet to be determined. Herein, we discovered that TCC disrupts the activation and differentiation of CD8+ T cells in primary human peripheral blood samples, purified CD8+ T cells, and in mice in vivo. Mechanistically, TCC might block the activation of the vitamin D receptor (VDR) and reduce the synthesis of cholesterol, a precursor of vitamin D, resulting in inhibition of VDR signaling due to the suppression of both its ligand and the receptor itself by TCC. Our findings elucidate the hazard and potential mechanisms of TCC in mammalian adaptive immunity and highlighted VDR as a potential therapeutic target for the immunodeficiency caused by TCC.

SOCS3 Methylation Partially Mediated the Association of Exposure to Triclosan but Not Triclocarban with Type 2 Diabetes Mellitus: A Case-Control Study

This study aimed to evaluate the association of TCs (triclosan (TCS) and triclocarban) exposure with T2DM and glucose metabolism-related indicators and the mediating effect of SOCS3 methylation on their associations. A total of 956 participants (330 T2DM and 626 controls) were included in this case-control study. Logistic regression and generalized linear models were used to assess the effect of TCs on T2DM and glucose metabolism-related indicators. The dose-response relationship between TCs and T2DM was analyzed by restricted cubic spline. Finally, after evaluating the association between TCs and SOCS3 methylation levels, the mediating effect of SOCS3 methylation on the TC-associated T2DM was estimated. Each 1-unit increase in TCS levels was associated with a 13.2% increase in the risk of T2DM (OR = 1.132, 95% CI: 1.062, 1.207). A linear dose-response relationship was found between TCS and T2DM. TCS was negatively associated with Chr17:76356190 methylation. Moreover, mediation analysis revealed that Chr17:76356190 methylation mediated 14.54% of the relationship between TCS exposure and T2DM. Exposure to TCS was associated with a higher prevalence of T2DM. SOCS3 methylation partially mediated the association of TCS with T2DM. Our findings may provide new insights into the treatment of T2DM, and the study of the biological mechanisms of T2DM.

Co-exposure of parabens, benzophenones, triclosan, and triclocarban in human urine from children and adults in South China

Endocrine-disrupting chemicals (EDCs) are pervasive in the environment, prompting significant public concern regarding human exposure to these pollutants. In this study, we analyzed the levels of various endocrine-disrupting compounds, including parabens (PBs), benzophenones (BzPs), triclocarban (TCC) and triclosan (TCS), across 565 urine samples collected from residents of South China. All 11 target chemicals were detected at relatively high frequencies (41-100%), with the most prevalent ones being 3,4-dihydroxybenzoic acid (5.39 ng/mL), methyl-paraben (5.12 ng/mL), ethyl-paraben (3.11 ng/mL) and triclosan (0.978 ng/mL). PBs emerged as the most predominant group with a median concentration of 32.2 ng/mL, followed by TCs (sum of TCC and TCS, 0.998 ng/mL) and BzPs (0.211 ng/mL). Notably, urinary concentrations of PBs in adults were significantly higher (p < 0.01) compared to children, while BzPs and TCs were elevated in children (p < 0.001). The increased presence of BzPs and TCs in children is a cause for concern, given their heightened sensitivity and vulnerability to chemicals. Significant correlations were found between urinary target compounds and demographic factors, including gender, age and body mass index. Specifically, females, younger adults (18 ≤ age ≤ 35) and individuals with under/normal weight (16 ≤ BMI ≤ 23.9) were found to have higher exposure levels to EDCs, as indicated by the median values of their estimated daily intakes. Despite these higher levels still being lower than the acceptable daily intake thresholds, the health risks stemming from simultaneous exposure to these EDCs must not be overlooked.

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

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

Endocrine disrupting effects of parabens in zebrafish (Danio rerio): New insights from transcriptomics, metabolomics, and molecular dynamics simulation

Parabens (PBs), a group of widely used synthetic preservatives with potential endocrine disrupting activity, have been detected with increasing frequency in organisms and environmental matrices. This study assessed the hormone interference effects of four typical PBs, namely methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP), in zebrafish and elucidated the probable underlying mechanisms. Transcriptomic and metabolomic analyses showed that the differentially expressed genes and metabolites were associated with the tyrosine metabolism, arachidonate metabolism, and glycerophospholipid metabolism, indicating they were essential precursors of steroid hormone biosynthesis and metabolism. Histopathological analysis revealed impaired gonad development in the zebrafish exposed to PBs, as evidenced by the significantly increased vitellogenin (VTG) and estradiol (E2) levels. Furthermore, molecular dynamics simulation suggested that the four PBs could preferentially activate the zebrafish estrogen receptor, zfERβ2, to regulate the downstream pathways. Disruption of the amino acid metabolism and lipid metabolism, and activation of zfERβ2 signaling pathway were found to be the key mechanisms for the endocrine disrupting effects of PBs. The hormone interference effects of PBs were apparently dependent on the shared oxybenzene on their structures, with the degree of interference determined largely by the length of their alkyl chains. These findings provide new insights into the endocrine disrupting effects of PBs and could help better assess their risk to human health.

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.

Methylparaben induces hepatic glycolipid metabolism disorder by activating the IRE1α-XBP1 signaling pathway in male mice

Methylparaben (MP), a preservative widely used in daily supplies, exists in both the environment and the human body. However, the potential health risks posed by MP remain unclear. This study aimed to unravel the mechanisms by which MP disrupts glucose and lipid homeostasis. For this, we administered MP to mice and observed changes in glucose and lipid metabolism. MP exposure led to hyperglycemia, hyperlipidemia, visceral organ injury, and hepatic lipid accumulation. RNA sequencing results from mice livers indicated a close association between MP exposure and endoplasmic reticulum (ER) stress, inflammatory response, and glucose and lipid homeostasis. Western blotting and quantitative reverse transcription-polymerase chain reaction revealed that MP activated ER stress, particularly the inositol-requiring enzyme 1 (IRE1)/X-box binding protein 1 (XBP1) pathway, which further promoted the activation of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. The activation of these pathways phosphorylated insulin receptor substrate-1 (IRS1) (ser 307), resulting in decreased phosphorylation of protein kinase B (Akt) (ser 473), leading to insulin resistance. Additionally, MP exposure promoted lipogenesis through ER stress. To explore potential remedies, we administered the ER stress inhibitor 4-phenylbutyric acid (4-PBA) and the IRE1α-XBP1 pathway inhibitor toyocamycin to mice, both of which protected against metabolic disorders and organ injury caused by MP. These findings suggest that MP induces disruptions in glucose and lipid metabolism through ER stress, primarily through the IRE1α-XBP1 pathway.

Effect of pH on UV/H2O2-mediated removal of single, mixed and halogenated parabens from water

Adjusting pH values in aqueous environments can significantly improve the efficiency by which parabens and halo-parabens are removed. In this study, 20 neutral and deprotonated species were selected as models to investigate their pH-dependent removal mechanisms and kinetics by a UV/H2O2 process using density functional theory (DFT). Compared to neutral species, deprotonated species exhibit higher reactivity to HO• due to their high electron cloud density. H atom abstraction (HAA) reactions on the substitution groups are the most favorable pathways for neutral species, while radical adduct formation (RAF) reactions are the most favorable for deprotonated species. Single electron transfer (SET) reactions can be neglected for neutral species, while these reactions become a viable route for deprotonated molecules. The total reaction rate constants range from 1.63 × 109 to 3.74 × 1010 M- 1 s- 1 at pH 7.0, confirming the experimental results. Neutral and weakly alkaline conditions are favorable for the degradation of MeP and halo-parabens in the UV/H2O2 process. The order of removal efficiency at optimum pH is dihalo-parabens > mono-halo-parabens ≈ F, F-MeP > MeP. Furthermore, the transformation products must undergo oxidative degradation due to their high toxicity. Our findings provide new insights into the removal of parabens and their halogenated derivatives from wastewater.

Bisphenol A (BPA) and Cardiovascular or Cardiometabolic Diseases

Bisphenol A (BPA; 4,4'-isopropylidenediphenol) is a well-known endocrine disruptor. Most human exposure to BPA occurs through the consumption of BPA-contaminated foods. Cardiovascular or cardiometabolic diseases such as diabetes, obesity, hypertension, acute kidney disease, chronic kidney disease, and heart failure are the leading causes of death worldwide. Positive associations have been reported between blood or urinary BPA levels and cardiovascular or cardiometabolic diseases. BPA also induces disorders or dysfunctions in the tissues associated with these diseases through various cell signaling pathways. This review highlights the literature elucidating the relationship between BPA and various cardiovascular or cardiometabolic diseases and the potential mechanisms underlying BPA-mediated disorders or dysfunctions in tissues such as blood vessels, skeletal muscle, adipose tissue, liver, pancreas, kidney, and heart that are associated with these diseases.

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.

Exposure to parabens and dysglycemia: Insights from a Chinese population

BACKGROUND

Parabens, a widely exposed environmental endocrine disruptor, were reported to disturb glucose metabolism through various pathways in animal models, but epidemiologic studies are limited. Therefore, this study aimed to investigate the plasma parabens level in rural populations and their effects of single and mixed paraben exposure on T2DM based on the Henan Rural Cohort.

METHODS

A total of 1713 participants (880 T2DM and 833 controls) from the Henan Rural Cohort Study were included in this case-control study. Generalized linear regression models were performed to assess the single and joint effects of parabens on T2DM and glucose metabolism indicators. In addition, the dose-response relationship of plasma parabens with T2DM and glucose metabolism indicators were explored by the restricted cubic splines. Bayesian kernel machine regression (BKMR) and quantile g-computation models were utilized to assess overall associations of paraben mixtures with T2DM and glucose metabolism indicators.

RESULTS

Σparabens and methylparaben (MeP) exposure significantly increased the risk of T2DM (P < 0.01). However, ethylparaben (EtP) and butylparaben (BuP) were negatively related to T2DM (P < 0.01). Notably, non-linear relationships of EtP and BuP with T2DM were observed. When the level of EtP or BuP was above the inflection point observed in dose-response curve, the ORs and 95% CIs were 1.453 (1.252, 1.686) and 1.982 (1.444, 2.721), respectively. Moreover, the result of quantile g-computation also showed that exposure to high concentration of parabens mixture was positively related to the risk of T2DM. BKMR model indicated that parabens mixture was associated with glycometabolism following a U-shape and parabens mixture increased the risk of dysglycemia when all parabens concentrations were at or above their 55th percentile compared with the median.

CONCLUSION

MeP or paraben mixture exposure levels showed a linear positive association with risk of T2DM. EtP and BuP were nonlinearly associated with glucose metabolism and moderate-high exposure contributed to T2DM.

Environmental exposure to paraben and its association with blood pressure: A cross-sectional study in China

Parabens (PBs) are the most widely used preservatives. Recent epidemiological studies have indicated that environmental exposure to parabens has adverse health effects, such as increased metabolic diseases risk. However, limited information is available on the cardiovascular effect of paraben exposure. Hence, we conducted a cross-sectional study investigating the associations between exposure to parabens with high blood pressure risk and blood pressure levels among the general Chinese population. In this study, we enrolled 1405 individuals from a medical center in Wuhan, China. Urinary methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP) and butylparaben (BuP) concentrations were determined. Multivariable logistic and linear regression models were applied to analyze the associations between urinary parabens and high blood pressure risk and blood pressure level changes. Bayesian kernel machine regression (BKMR) models were applied to estimate the combined effect of the four parabens. Compared with the first quartile group, participants with the fourth quartile of EtP, PrP, and ∑parabens (∑PBs) concentrations had a 2.10-fold (95% CI: 1.40, 3.00), 1.83-fold (95% CI: 1.27, 2.62) and 1.84-fold (95% CI: 1.27, 2.65) increased the risk of hypertension, respectively. High urinary EtP, PrP, and ∑PBs levels were found to increase the levels of systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), and mid-blood pressure (MBP). BKMR models indicated the overall effects of the paraben mixture were significantly associated with high blood pressure risk and blood pressure level changes. Furthermore, after stratification by sex, the associations of EtP exposure and blood pressure levels were more pronounced in males. Our results suggest that environmental exposure to parabens might elevate blood pressure levels and increase the risk of high blood pressure.

New environmental factors related to diabetes risk in humans: Emerging bisphenols used in synthesis of plastics

BACKGROUND

Diabetes mellitus (DM) is one of the largest global health emergencies of the 21st century. In recent years, its connection with environmental pollutants, such as bisphenol A (BPA), has been demonstrated; consequently, new structurally similar molecules are used to replace BPA in the plastics industry (BPS, BPF and BPAF).

AIM

To carry out a systematic review to allow coherent evaluation of the state of the art. Subsequently, a meta-analysis was performed to unify the existing quantitative data.

METHODS

Firstly, a systematic review was carried out, using the terms "(bisphenol) AND (Diabetes OR Hyperglycemia)", to maximize the number of results. Subsequently, three authors analyzed the set of articles. Finally, a meta-analysis was performed for each BP, using RevMan software. In addition, funnel plots were developed to study publication bias.

RESULTS

The systematic analysis of the literature revealed 13 recent articles (2017-2023) related to the study paradigm. The qualitative analysis showed interesting data linking diabetes to the three most widely used substitute BPs in the industry: BPS, BPF and BPAF. Finally, the meta-analysis determined a positive relationship with BPS, BPF and BPAF, which was only statistically significant with BPS.

CONCLUSION

There is a need to apply the precautionary principle, regulating the use of new BPs. Therefore, replacing BPA with BPS, BPF or BPAF is unlikely to protect the population from potential health risks, such as DM.

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.

Food contaminants and potential risk of diabetes development: A narrative review

The number of people diagnosed with diabetes continues to increase, especially among younger populations. Apart from genetic predisposition and lifestyle, there is increasing scientific and public concern that environmental agents may also contribute to diabetes. Food contamination by chemical substances that originate from packaging materials, or are the result of chemical reactions during food processing, is generally recognized as a worldwide problem with potential health hazards. Phthalates, bisphenol A (BPA) and acrylamide (AA) have been the focus of attention in recent years, due to the numerous adverse health effects associated with their exposure. This paper summarizes the available data about the association between phthalates, BPA and AA exposure and diabetes. Although their mechanism of action has not been fully clarified, in vitro, in vivo and epidemiological studies have made significant progress toward identifying the potential roles of phthalates, BPA and AA in diabetes development and progression. These chemicals interfere with multiple signaling pathways involved in glucose and lipid homeostasis and can aggravate the symptoms of diabetes. Especially concerning are the effects of exposure during early stages and the gestational period. Well-designed prospective studies are needed in order to better establish prevention strategies against the harmful effects of these food contaminants.

Safety of benzophenone-type UV filters: A mini review focusing on carcinogenicity, reproductive and developmental toxicity

Consumer products containing benzophenone-type ultraviolet (UV) filters (BPs) have been widely accepted by the public, resulting in the widely existence of various BPs in the human body and environment. In recent years, more and more evidences show that BPs are endocrine disruptors. In view of the continuous exposure risk of BPs and their endocrine disrupting characteristics, the carcinogenicity of BPs and their effects on reproduction and development are of particular concern. However, due to the wide varieties of BPs and the scattered toxicity studies on BPs, people have a limited understanding on the safety of BPs. Therefore, this paper systematically reviews the carcinogenicity, reproductive and developmental toxicity of BPs in order to expand people's knowledge on the health risks of BPs and screen for more safe BPs. Although existing toxicological studies are insufficient, it can be determined that BPs have different potentials for carcinogenicity, and reproductive and developmental toxicity. Among those BPs, 2-hydroxyl-4-methoxyl benzophenone needs to be used with caution due to its adverse effects on cancer cell proliferation and migration, reproductive ability, sex differentiation, neurodevelopment, and so on. It is worth noting that functional group substitutions significantly affect the interaction between BPs and biomolecules such as DNA, cancer cells, and seminal fluid, resulting in different levels of toxicity. In short, it is very necessary to evaluate the carcinogenicity, reproductive and developmental toxicity of BPs, which is of great significance for establishing reasonable BPs content standards in cosmetics, water quality treatment standards for BPs, and so on.

The binding mechanism of benzophenone-type UV filters and human serum albumin: The role of site, number, and type of functional group substitutions

Benzophenone-type UV filters (BPs) are common in natural aquatic environments. They can cause endocrine disruption or other adverse effects once they enter the human body via the food chain or drinking water. The primary cause of BPs accumulation and toxicity is the transport of BPs into the human body. Functional group substitutions can have a significant impact on the interactions of BPs and transporters, resulting in a variety of impact effects. Therefore, we explored the interaction between human serum albumin (HSA, a typical transporter) and ten typical BPs [benzophenone (BP1), 2-hydroxybenzophenone (BP2), 4-hydroxybenzophenone (BP3), 2,2'-dihydroxybenzophenone (BP4), 2,4-dihydroxybenzophenone (BP5), 4,4'-dihydroxybenzophenone (BP6), 2,4,4'-trihydroxybenzophenone (BP7), 2,2',4,4'-tetrahydroxybenzophenone (BP8), 2-hydroxy-4-methoxybenzophenone (BP9), and 2,2'-dihydroxy-4-methoxybenzophenone (BP10)] to study the role of functional group substitutions in binding. The results showed that BPs could bind to HSA at site 2, with binding constants ranging from 2.01 × 10³ to 4.57 × 10⁵ L/mol. Compared to BP1, hydroxyl and methoxy substitutions enhanced the BPs-HSA binding. The combined effect of the number and site of hydroxyl substitution at BPs determined the binding strength between BPs and HSA. It was more accessible to bind HSA when BPs were substituted with para-hydroxyl (4-hydroxyl) groups than with ortho-hydroxyl (2-hydroxyl) groups. Moreover, the additional para-methoxy (4-methoxy) group increased the BP-HSA binding strength by approximately 47 times under the same hydroxyl substitution conditions. Theoretical calculations revealed that functional group substitutions increased the intermolecular binding force by increasing the negative electrostatic potential surface area of BPs, which significantly increased the electrostatic and dispersion forces between the BPs and HSA. This BPs-HSA binding decreased the α-helix of HSA and influenced the ratio of other secondary structures, including β-sheet, β-turn, and random coil of HSA. This study provides a theoretical and experimental foundation for understanding the human health risks associated with BPs.

Bisphenol F induced hyperglycemia via activation of oxidative stress-responsive miR-200 family in the pancreas

Bisphenol F (BPF), BPS and BPAF are gaining popularity as main substitutes to BPA, but there is no clear evidence that these compounds disrupt glycemic homeostasis in the same way. In this study, four bisphenols were administered to C57BL/6 J mice, and showed that the serum insulin was elevated in the BPA and BPS exposed mice, whereas BPF exposed mice exhibited lower serum insulin and higher blood glucose. BPF decreased oxidized glutathione/reduced glutathione ratio (GSSG/GSH) and N6-methyladenosine (m6A) levels, which was responsible for pancreatic apoptosis in mice. Additionally, the downregulation of Nrf2 and the aberrant regulation of the p53-lncRNA H19 signaling pathway further increased miR-200 family in the BPF-exposed pancreas. The miR-200 family directly suppressed Mettl14 and Xiap by targeting their 3' UTR, leading to islet apoptosis. Antioxidant treatment not only elevated m6A levels and insulin contents but also suppressed the miR-200 family in the pancreas, ultimately improving BPF-induced hyperglycemia. Taken together, miR-200 family could serve as a potential oxidative stress-responsive regulator in the pancreas. And moreover, we demonstrated a novel toxicological mechanism in that BPF disrupted the Keap1-Nrf2 redox system to upregulate miR-141/200b/c which controlled pancreatic insulin production and apoptosis via Mettl14 and Xiap, respectively. As the major surrogates of BPA in various applications, BPF was also diabetogenic, which warrants attention in future research.

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.

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.

Challenges in the Analytical Preparation of a Biological Matrix in Analyses of Endocrine-Disrupting Bisphenols

Endocrine-disrupting chemicals (EDCs) are xenobiotics presented in a variety of everyday products that may disrupt the normal activity of hormones. Exposure to bisphenol A as EDC at trace and ultra-trace levels is associated with adverse health effects, and children are recognized as the most vulnerable group to EDCs exposure. In this review, a summary is presented of up-to-date sample preparation methods and instrumental techniques applied for the detection and quantification of bisphenol A and its structural analogues in various biological matrices. Biological matrices such as blood, cell-free blood products, urine, saliva, breast milk, cordial blood, amniotic and semen fluids, as well as sweat and hair, are very complex; therefore, the detection and later quantification of bisphenols at low levels present a real analytical challenge. The most popular analytical approaches include gas and liquid chromatography coupled with mass spectrometry, and their enhanced reliability and sensitivity finally allow the separation and detection of bisphenols in biological samples, even as ultra-traces. Liquid/liquid extraction (LLE) and solid-phase extraction (SPE) are still the most common methods for their extraction from biological matrices. However, many modern and environmentally safe microextraction techniques are currently under development. The complexity of biological matrices and low concentrations of analytes are the main issues for the limited identification, as well as understanding the adverse health effects caused by chronical and ubiquitous exposure to bisphenols and its analogues.

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.

Occurrence of emerging bisphenol S analogues in urine from five occupational populations in South China

Bisphenol S (BPS) and its 11 emerging analogues were investigated in 325 urine samples from five occupational populations in South China. Besides BPS, ten emerging BPS analogues were newly identified and detected in the urine. It should be noted that urinary concentrations of dominant BPS analogues of 2,4'-bis(hydroxyphenyl)sulfone (2,4-BPS), bis(3-allyl-4-hydroxyphenyl)sulfone (TGSA) and diphenylsulfone (DPS) were 1.1-2.3 times higher than that of BPS, with overall detection frequencies at 74-91 %. The median sum concentrations of the target 12 bisphenols (ng/mL) were found highest in urine from cashiers (1.12), followed by water plant staffs (0.994), teachers (0.552), doctors (0.408) and power plant staffs (0.333). The composition profile of the urinary dominant bisphenols was occupational-dependent, with 2,4-BPS accounting for 45-73 % in cashiers and power plant staffs, and with DPS and TGSA for 74-82 % among doctors, teachers and water plant staffs. Significant correlations were found among the most frequently detected bisphenols in cashiers, indicating their common application and emission pathways. The median exposures based on estimated daily intakes (EDIs, ng/kg bw/day) for the 12 bisphenols in cashiers and water plant staffs (31.6-35.6) were 1.8-3.4 times higher than those of teachers, doctors and power plant staffs (10.6-17.5). This is the first study to identify multiple emerging BPS analogues in urine from occupational populations, especially cashiers and water plant staffs.

Combined effect of polystyrene microplastics and bisphenol A on the human embryonic stem cells-derived liver organoids: The hepatotoxicity and lipid accumulation

Human are exposed to microplastics (MP) via inhalation or ingestion daily and inevitably. The liver is an important target organ of MP. Bisphenol A (BPA) is one of commonly used plasticizers. It is added in plastics, but also generally detected in the biological samples of human beings. However, the combined toxic effect of MP and BPA on human liver is unclear. In this study, a novel 3D in vitro model, the liver organoid (LO) derived from human-pluripotent stem cells, has been utilized to explore the 1 μm polystyrene (PS)-induced hepatotoxicity with BPA individually and jointly. Conclusively, all the changes in the cytotoxicity, cellular and molecular makers regarding the energy supplement, hepatic injury, oxidative stress, inflammatory response, disruption in the lipid accumulation, as well as epigenetics regulation induced by BPA or PS on the LOs individually were comparable to previous study. The BPA levels in the culture medium were declined by the added PS. The combined adverse effect of PS and BPA on the LOs was identified to be synergistic upon deteriorated hepatotoxicity and interfered the gene panels related to multiple processes of lipid metabolism, together with the proteins of HNF4A, CD36, ACC1, CPT1A, CYP2E1, ERα and ERβ. Specifically, PS didn't change the ERα or ERβ individually, but when the LOs were co-exposed to PS and BPA, the ERα further elevated significantly and synergistically. Our findings highlight the metabolic-related health risk due to co-exposure to MP and BPA, even at low-doses equivalent to human internal exposure level. Based on these findings, the potential adverse outcome pathway related to PS and BPA singly and jointly were proposed, predicting two possible outcomes to be hepatic steatosis. Moreover, the ERα and HNF4A were proposed to be potential candidate markers to investigate the "vector-like effect" of PS in the present of BPA.

Placental transfer of bisphenol diglycidyl ethers (BDGEs) and its association with maternal health in a population in South of China

Despite high production and usage, little is known about exposure to bisphenol diglycidyl ethers (BDGEs) and their derivatives in pregnant women and fetuses. In this study, we determined nine BDGEs in 106 paired maternal and cord serum samples collected from e-waste dismantling sites in South of China. Bisphenol A bis (2,3-dihydroxypropyl) glycidyl ether (BADGE·2H2O), bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) glycidyl ether (BADGE·HCl·H2O), and bisphenol F diglycidyl ether (BFDGE) were the major BDGEs, with median concentrations of 0.57, 4.07, and 1.60 ng/mL, respectively, in maternal serum, and of 3.58, 5.61, and 0.61 ng/mL, respectively, in cord serum. The transplacental transfer efficiencies (TTEs) were estimated for BDGEs found in samples, and median values were in the range of 0.98 (BFDGE) to 5.91 (BADGE·2H2O). Our results suggested that passive diffusion plays a role in the placental transfer of BADGE·HCl·H2O and BFDGE, whereas several mechanisms contribute to the high accumulation of BADGE·2H2O in cord serum. Multiple linear regression analysis indicated significant associations between maternal serum concentrations of BDGEs and blood clinical biomarkers, especially those related to liver injuries, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and adenosine deaminase (ADA) (P < 0.05). To our knowledge, this is the first study to report the occurrence of BDGEs in paired maternal-fetal serum samples and provide new insights into prenatal and fetal exposures. The newly discovered TTEs in maternal-fetal pairs contribute to a fuller inventory of the transmission activity of pollutants in the human body, ultimately adding to a more significant comprehensive risk evaluation.

Determination of Metabolomics Profiling in BPA-Induced Impaired Metabolism

Exposure to bisphenol A (BPA) is unavoidable and it has far-reaching negative effects on living systems. This study aimed to explore the toxic effects of BPA in an experimental animal model through a metabolomics approach that is useful in measuring small molecule perturbations. Beside this, we also examined the ameliorative effects of resveratrol (RSV) against BPA-induced disturbances in experimental mice. This study was conducted for 28 days, and the results showed that BPA indeed induced an impairment in amino acid metabolism, taking place in the mitochondria by significantly (p < 0.05) decreasing the levels of certain amino acids, i.e., taurine, threonine, asparagine, leucine, norleucine, and glutamic acid in the mice plasma. However, the administration of RSV did prove effective against the BPA-induced intoxication and significantly (p < 0.05) restored the level of free amino acids. Lipid metabolites, L-carnitine, sphinganine, phytosphingosine, and lysophosphatidylcholine were also determined in the mice serum. A significant (p < 0.05) decline in glutathione peroxidase (GPx), superoxide dismutase (SOD,) glutathione, and catalase levels and an elevation in malondialdehyde level in the BPA group confirmed the generation of oxidative stress and lipid peroxidation in experimental mice exposed to BPA. The expression of Carnitine palmitoyltransferase I (CPT-I), carnitine palmitoyltransferase II (CPT-II), lecithin−cholesterol acyltransferase (LCAT), carnitine O-octanoyltransferase (CROT), carnitine-acylcarnitine translocase (CACT), and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) genes was significantly upregulated in the liver tissue homogenates of experimental mice exposed to BPA, although RSV regulated the expression of these genes when compared with BPA treated experimental mice. CPT-I, CPT-II, and CACT genes are located in the mitochondria and are involved in the metabolism and transportation of carnitine. Hence, this study confirms that BPA exposure induced oxidative stress, upregulated gene expression, and impaired lipid and amino acid metabolism in experimental mice.

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.

Assessment of human exposure to benzophenone-type UV filters: A review

To avoid the harmful effects of UV radiation, benzophenone-type UV filters (BPs) are widely used in personal care products and other synthetic products. Biomonitoring studies have shown the presence of BPs in various human biological samples, raising health concerns. However, there is a paucity of data on the global human exposure to this group of contaminants. In this study, we compiled data on the body burden of BPs along with the possible exposure routes and biotransformation pathways. BPs can easily penetrate the skin barrier and thus, they can be absorbed through the skin. In the human body, BPs can undergo Phase I (mainly demethylation and hydroxylation) and Phase II (mainly glucuronidation and sulfation) biotransformations. From a total of 158 studies, most of the studies are related to urine (concentration up to 92.7 mg L^-1), followed by those reported in blood (up to 0.9 mg L^-1) and milk (up to 0.8 mg L^-1). Among BPs, benzophenone-1 and benzophenone-3 are the most commonly detected congeners. The body burden of BPs is associated with various factors, including the country of residence, lifestyle, income, education level, and ethnicity. The presence of BPs in maternal urine (up to 1.1 mg L^-1), placenta (up to 9.8 ng g^-1), and amniotic fluid (up to 15.7 μg L^-1) suggests potential risks of prenatal exposure. In addition, transplacental transfer of BPs is possible, as demonstrated by their presence in maternal serum and cord serum. The possible association of BPs exposure and health effects was discussed. Future human biomonitoring studies and studies on the potential health effects are warranted. Overall, this review provides a summary of the global human exposure to BPs and can serve as supporting evidence to guide usage in order to protect humans from being exposed to BPs.

Natural Products in Mitigation of Bisphenol A Toxicity: Future Therapeutic Use

Bisphenol A (BPA) is a ubiquitous environmental toxin with deleterious endocrine-disrupting effects. It is widely used in producing epoxy resins, polycarbonate plastics, and polyvinyl chloride plastics. Human beings are regularly exposed to BPA through inhalation, ingestion, and topical absorption routes. The prevalence of BPA exposure has considerably increased over the past decades. Previous research studies have found a plethora of evidence of BPA’s harmful effects. Interestingly, even at a lower concentration, this industrial product was found to be harmful at cellular and tissue levels, affecting various body functions. A noble and possible treatment could be made plausible by using natural products (NPs). In this review, we highlight existing experimental evidence of NPs against BPA exposure-induced adverse effects, which involve the body’s reproductive, neurological, hepatic, renal, cardiovascular, and endocrine systems. The review also focuses on the targeted signaling pathways of NPs involved in BPA-induced toxicity. Although potential molecular mechanisms underlying BPA-induced toxicity have been investigated, there is currently no specific targeted treatment for BPA-induced toxicity. Hence, natural products could be considered for future therapeutic use against adverse and harmful effects of BPA exposure.

Combined effects of bisphenol A and diabetes genetic risk score on incident type 2 diabetes: A nested case-control study

Observational studies reported inconsistent results on the association between bisphenol A (BPA) and type 2 diabetes (T2D) risk. Whether genetic factors modified the association remains unclear. The present nested case-control study prospectively investigated the association of BPA with T2D risk, and the interaction and combined effects of diabetes genetic risk score (GRS) and serum BPA on T2D risk. Based on the Dongfeng-Tongji cohort study, 995 incident diabetes cases and 1:1 age- and gender-matched controls were included. T2D was diagnosed based on the American Diabetes Association criteria. Serum BPA concentration was measured at baseline. Diabetes GRS was constructed by 88 diabetes-related SNPs selected from large-scale GWASs. A U-shaped association was observed between serum BPA levels and T2D risk, with the lowest odds of T2D at the serum BPA levels of 1.00 ng/mL (P = 0.001 for nonlinearity). Compared with the middle group, the multivariate-adjusted ORs of T2D in the lowest group and the highest group of serum BPA were 1.52 (95% CI: 1.04, 2.22) and 1.40 (95% CI: 1.08, 1.81), respectively. Both serum BPA levels (β = 0.107, P = 0.001) and weighted-GRS (w-GRS) (β = 0.072, P = 0.02) were significantly associated with baseline FPG levels. Participants with both highest w-GRS and serum BPA levels had highest risk of T2D (OR = 2.53, 95%CI: 1.49, 4.31, P = 0.001) and higher baseline FPG levels (β = 0.218, P = 0.01), compared with those with both lowest w-GRS and serum BPA levels. Non modified effects of serum BPA levels and w-GRS on T2D, baseline FPG levels, and 5-y changes of FPG levels were detected (All P_interaction > 0.05). Our results suggested a U-shaped association between serum BPA levels and T2D risk. Participants with higher serum BPA levels and diabetes genetic risk had higher FPG levels and higher risk of T2D.

Pentachlorophenol exposure in early pregnancy and gestational diabetes mellitus: A nested case-control study

Pentachlorophenol (PCP) is an endocrine-disrupting chemical that is ubiquitously found in the environment. Few studies have reported PCP exposure in pregnant women and its association with gestational diabetes mellitus (GDM). This nested case-control study aimed to determine the concentration of urinary PCP in early pregnancy and explore the association between PCP exposure and GDM risk. This study included 293 GDM cases and 586 non-GDM controls matched by fetal sex and maternal age from a birth cohort in Wuhan, China. PCP concentrations in spot urine samples collected between 8 and 16 weeks of gestation were measured by ultra-performance liquid chromatography-tandem mass spectrometry. Conditional logistic regression was used to assess the association between PCP exposure and the odds ratio of GDM. The median concentrations of specific gravity-adjusted PCP in controls and cases were 0.70 and 0.80 ng/mL, respectively, with no significant differences (P > 0.05). The multivariate-adjusted odds ratios (ORs) (95% confidence intervals) for GDM across quartiles of urinary PCP were 1 (reference), 1.63 (1.06-2.50), 1.70 (1.11-2.61), and 1.35 (0.87-2.08), respectively, showing a potential "inverted-U" shaped association. In addition, PCP levels and maternal age or fetal sex had significant interactions with GDM risk (both P for interaction < 0.05). Among older women and those carrying female fetuses, the ORs of GDM risk were higher. This study suggests that pregnant women in central China are widely exposed to PCP, and this is the first time to report that PCP exposure may increase the risk of GDM (with potential effect modifications by maternal age and fetal sex). The association observed is in agreement with PCP's "inverted-U" anti-estrogenic effect in vivo; thus, such an effect in humans at environmentally relevant doses should be studied further.

BPS and BPF are as Carcinogenic as BPA and are Not Viable Alternatives for its Replacement

BACKGROUND

Plastic polymers are omnipresent, and life without them is virtually impossible. Despite the advantages provided by the material, conventional plastic also has harmful effects on the environment and human health. Plastics release microplastics and compounds, such as BPA, which is a xenoestrogen and once absorbed by the body, have an affinity for estrogen receptors α and β, acting as an agonist on human cells, being an endocrine disrupter able to cause various diseases and acting as a potential neoplastic inducer. BPS and BPF are BPA's analogs, a proposed solution to solve its harmful effects incorporated into the market. The analogs can be found in daily use products and are used in several industrial applications.

OBJECTIVES

In the present work, the researchers aimed to develop a revisional study of BPA's harmful effects on human health, focusing on its carcinogenic potential, discussing its mechanisms of action, as well as its analogs effects, and identifying if they are a viable alternative to BPA's substitution in plastic polymers' production.

METHODS

In this review, articles published in the last 15 years related to the different aspects of conventional plastics and BPA were analyzed and revised with precision. The subjects ranged from conventional plastics and the problems related to their large-scale production, BPA, its negative aspects, and the feasibility of using its analogs (BPS and BPF) to replace the compound. The articles were extensively reviewed and concisely discussed.

RESULTS

This study demonstrated that BPA has a high carcinogenic potential, with known mechanisms to trigger breast, ovarian, prostate, cervical, and lung cancers, thus elucidating that its analogs are also xenoestrogens, that they can exert similar effects to BPA and, therefore, cannot be considered viable alternatives for its replacement. Conclusion This study suggests that new research should be carried out to develop such alternatives, allowing the substitution of plastic materials containing BPA in their composition, such as developing economically viable and sustainable biodegradable bioplastics for socio-environmental well-being.

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.

Maternal Benzophenone Exposure Impairs Hippocampus Development and Cognitive Function in Mouse Offspring

Benzophenones are widely supplemented in personal care products, but little is known about its neurodevelopmental toxicity. The previous epidemiological study discovered a negative correlation between maternal exposure to a benzophenone metabolite 4-hydroxybenzophenone (4HBP) and child's neurodevelopment, yet the causal relationship and detailed mechanism remain to be defined. Here, it is reported that prenatal, but not postnatal, exposure to environmentally relevant level of 4HBP impairs hippocampus development and causes cognitive dysfunction in offspring mice. Transcriptomic analyses reveal that 4HBP induces the endoplasmic reticulum stress-induced apoptotic signaling and inflammatory response in hippocampal neural stem cells. Mechanistically, 4HBP exposure activates protein kinase R-like ER kinase (PERK) signaling, which induces CHOP, inhibits IκB translation, and transactivates p65, thereby promoting inflammation and apoptosis on multiple levels. Importantly, genetic or pharmacological inhibition of PERK pathway significantly attenuates 4HBP-induced NFκB signaling and neurodevelopmental abnormalities in mice and in a human brain organoid model. The study uncovers the neurodevelopmental toxicity of BP and cautions its exposure during pregnancy.

Urinary concentrations of phenols and parabens and incident diabetes in midlife women: The Study of Women's Health Across the Nation

BACKGROUND

Environmental phenols have been suggested as diabetogens but evidence from prospective cohort studies is limited. We examined associations between urinary concentrations of phenols and parabens, assessed at two time-points, and incident diabetes in the Study of Women's Health Across the Nation (SWAN).

METHODS

We examined 1,299 women, aged 45-56 years, who were diabetes-free at baseline of the SWAN Multi-Pollutant Study (MPS) (1999-2000) and were followed through January 2017. Urinary concentrations of bisphenol-A, bisphenol-F, triclosan, 2,4-dichlorophenol, 2,5-dichlorophenol, benzophenone-3, methyl-paraben, ethyl-paraben, propyl-paraben, and butyl-paraben were measured twice at MPS baseline and 3 years later (2002-2003), and the two average concentrations were used as exposure variables. Associations of incident diabetes with individual phenols and parabens were examined using Cox regression. We evaluated the overall joint effects using quantile-based g-computation.

RESULTS

Adjusted hazard ratios (HRs) for incident diabetes of the third tertile compared with the first tertile of urinary concentrations were 0.40 (95% confidence interval [CI] = 0.29, 0.56) for methyl-paraben; 0.42 (0.30, 0.58) for propyl-paraben; 0.53 (0.38, 0.75) for 2,5-diclrorophenol; and 0.55 (0.39, 0.80) for benzophenone-3. Nonlinear associations were found for bisphenol-A and 2,4-dichlorophenol (significant positive associations in the second tertile but no associations in the third tertile compared with the first tertile). No significant associations were observed for the other individual chemicals or the joint effect of mixtures.

CONCLUSIONS

Our findings do not support diabetogenic effects of urinary parabens which were inversely associated with incident diabetes among mid-life women. Epidemiologic findings for biomarkers with short half-lives and high within-person variability need to be interpreted with caution.

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.

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.

Risks of organic UV filters: a review of environmental and human health concern studies

Organic UV filters are compounds that absorb UV irradiation by their highly conjugated structure. With the developing consciousness over the last century of the skin damage UV radiation can cause, the demand for organic UV filters has risen, for use not only in sunscreens, but also in other personal care products. The massive production and usage of these organic UV filters has resulted in extensive release into the aquatic environment, and thereby making an important group of emerging contaminants. Considering the widespread occurrence of organic UV filters in not only ambient water, but also sediment, soil and even indoor dust, their threats towards the health of living organisms have been a subject of active investigation. In this review article, we present an overall review of existing knowledge on the risks of organic UV filters from the aspects of both environmental and human health impacts. As for the environment, some organic UV filters are proven to bioaccumulate in various kinds of aquatic organisms, and further to have adverse effects on different kinds of animal models. Toxicological studies including in vivo and in vitro studies are important and effective means to ascertain the effects and mechanisms of organic UV filters on both the ecosystem and humans. Subsequent concerns arise that these compounds will affect human health in the long term. This review concludes by suggesting future lines of research based on the remaining knowledge gaps.

Bisphenol A and Type 2 Diabetes Mellitus: A Review of Epidemiologic, Functional, and Early Life Factors

Type 2 diabetes mellitus (T2DM) is characterised by insulin resistance and eventual pancreatic β-cell dysfunction, resulting in persistent high blood glucose levels. Endocrine disrupting chemicals (EDCs) such as bisphenol A (BPA) are currently under scrutiny as they are implicated in the development of metabolic diseases, including T2DM. BPA is a pervasive EDC, being the main constituent of polycarbonate plastics. It can enter the human body by ingestion, through the skin, and cross from mother to offspring via the placenta or breast milk. BPA is a xenoestrogen that alters various aspects of beta cell metabolism via the modulation of oestrogen receptor signalling. In vivo and in vitro models reveal that varying concentrations of BPA disrupt glucose homeostasis and pancreatic β-cell function by altering gene expression and mitochondrial morphology. BPA also plays a role in the development of insulin resistance and has been linked to long-term adverse metabolic effects following foetal and perinatal exposure. Several epidemiological studies reveal a significant association between BPA and the development of insulin resistance and impaired glucose homeostasis, although conflicting findings driven by multiple confounding factors have been reported. In this review, the main findings of epidemiological and functional studies are summarised and compared, and their respective strengths and limitations are discussed. Further research is essential for understanding the exact mechanism of BPA action in various tissues and the extent of its effects on humans at environmentally relevant doses.

Associations of urinary concentrations of phthalate metabolites, bisphenol A, and parabens with obesity and diabetes mellitus in a Korean adult population: Korean National Environmental Health Survey (KoNEHS) 2015-2017

Phthalates and bisphenol A (BPA) have been suspected as risk factors for obesity and diabetes mellitus (DM) among humans. However, associations between phthalates and environmental phenols are often inconsistent across different populations. In this study, we recruited the adult population (n = 3782) of the Korean National Environmental Health Survey (KoNEHS) 2015-2017 (Cycle 3) and assessed the associations between urinary biomarkers of phthalate, BPA, and paraben exposure with obesity and DM. A potential collider issue with the use of urinary creatinine (Cr) or specific gravity (SG) exists when adjusting urinary dilution; therefore, a covariate-adjusted standardization (CAS) was employed for adjustment, and the results were compared. In the present population, the direction of the association often varied depending on the choices made to adjust urinary dilution. When using CAS, the direction of association resembled those of previously reported experimental observations. With Cr or SG adjustment, ORs for obesity decreased in the highest quartiles of monocarboxyoctyl phthalate (MCOP) [OR (95% CI) = Cr: 0.71 (0.54, 0.93); SG: 0.68 (0.52, 0.90)], monocarboxy-isononyl phthalate (MCNP) [OR (95% CI) = Cr: 0.67 (0.52, 0.87); SG: 0.68 (0.52, 0.89)], and mono(3-carboxylpropyl) phthalate (MCPP) in the urine [OR (95% CI) = Cr: 0.60 (0.47, 0.76); SG: 0.61 (0.48, 0.77)]; however, with CAS, these negative associations disappeared. Instead, mono-benzyl phthalate (MBzP) [OR (95% CI) = 1.31 (1.03, 1.66)], BPA [OR (95% CI) = 1.62 (1.27, 2.06)], or ethyl paraben (EtP) [OR (95% CI) = 1.51 (1.19, 1.91)] concentrations in the highest quartile showed positive associations with a higher risk of obesity. On the other hand, for DM, an overall decrease in ORs was observed for phthalate metabolites and BPA following SG adjustment and disappeared with CAS adjustment. In addition, the highest quartiles of BPA, methyl paraben (MeP), and ethyl paraben (EtP) showed a significantly higher risk of DM than those in the lowest quartiles following CAS [OR (95% CI) = BPA: 1.65 (1.06, 2.59); MeP: 1.68 (1.08, 2.60); and EtP: 2.74 (1.77, 4.24), respectively]. The present observations outline the importance of using an appropriate adjustment method for urinary dilution in association studies on obesity and DM. In addition, several phthalates, BPA, and parabens were identified as potential chemical risk factors for these outcomes. Further studies are warranted in other populations to confirm these observations.

Disruption of normal adipocyte development and function by methyl- and propyl- paraben exposure

Methyl- and propyl- parabens are generally regarded as safe by the U.S Food and Drug Administration and as such are commonly used in personal care products. These parabens have been associated with increased white adipogenesis in vitro and methyl paraben also increased the white adipose mass of mice. Given brown adipose also plays a role in energy balance, we sought to evaluate whether the effects of methyl- and propyl- parabens on white adipocytes extended to brown adipocytes. We challenged white and brown pre-adipocytes at low doses of both parabens (up to 1 μM) during the differentiation process and examined adipogenesis with the ORO assay. The impact of each paraben on glucose uptake and lipolytic activity of adipocytes were measured with a fluorescent glucose analog and enzymatically, respectively. Methyl- and propyl- parabens increased adipogenesis of 3T3-L1 white adipocytes but not brown adipocytes. In white adipocytes, methyl paraben increased glucose uptake and both parabens reduced basal lipolysis. However, in brown adipocytes, parabens had no effect on basal lipolysis and instead attenuated isoproterenol induced lipolysis. These data indicate that methyl- and propyl- parabens target the differentiation and metabolic processes of multiple types of adipocytes in a cell autonomous manner.

Endocrine-disrupting chemicals: implications for human health

Since reports published in 2015 and 2016 identified 15 probable exposure-outcome associations, there has been an increase in studies in humans of exposure to endocrine-disrupting chemicals (EDCs) and a deepened understanding of their effects on human health. In this Series paper, we have reviewed subsequent additions to the literature and identified new exposure-outcome associations with substantial human evidence. Evidence is particularly strong for relations between perfluoroalkyl substances and child and adult obesity, impaired glucose tolerance, gestational diabetes, reduced birthweight, reduced semen quality, polycystic ovarian syndrome, endometriosis, and breast cancer. Evidence also exists for relations between bisphenols and adult diabetes, reduced semen quality, and polycystic ovarian syndrome; phthalates and prematurity, reduced anogenital distance in boys, childhood obesity, and impaired glucose tolerance; organophosphate pesticides and reduced semen quality; and occupational exposure to pesticides and prostate cancer. Greater evidence has accumulated than was previously identified for cognitive deficits and attention-deficit disorder in children following prenatal exposure to bisphenol A, organophosphate pesticides, and polybrominated flame retardants. Although systematic evaluation is needed of the probability and strength of these exposure-outcome relations, the growing evidence supports urgent action to reduce exposure to EDCs.

Bisphenol A-induced metabolic disorders: From exposure to mechanism of action

Bisphenol A (BPA) is considered as ubiquitous xenooestrogen and an endocrine disrupting chemical which has deleterious effects on endocrine functions. Human populations are continuously exposed to BPA as it is abundant in daily life. It has been found to be associated with wide range of metabolic disorders notably type 2 diabetes mellitus (DM). Numerous epidemiological studies have been conducted to find its role in development of DM. Experimental studies have found that BPA exposure is associated with pathogenesis of DM and also considered as a risk factor for gestational diabetes. Being a lipophilic compound, BPA is preferably accumulated in adipose tissues where it alters the production of adipokines that play important roles in insulin resistance. BPA induces apoptosis by caspase activation after mitochondrial damage and it impairs insulin signaling pathways by altering associated ion channel activity especially potassium channels. Perinatal exposure of BPA makes offspring more susceptible to develop DM in early years. Epigenetic modifications are the key mechanisms for BPA-induced metabolic re-programming, where BPA alters the expression of DNA methyltransferases involved in methylation of various genes. In this way, DNA methyltransferase controls the expression of numerous genes including genes important for insulin secretion and signaling. Furthermore, BPA induces histone modifications and alters miRNA expression. In this article, we have briefly described the sources of BPA exposure to human being and summarized the evidence from epidemiological studies linking DM with BPA exposure. Additionally, we have also highlighted the potential molecular pathways for BPA-induced DM.

Historical exposure to non-persistent environmental pollutants and risk of type 2 diabetes in a Spanish sub-cohort from the European Prospective Investigation into Cancer and Nutrition study

BACKGROUND

Environmental factors are believed to account for a substantial burden of type 2 diabetes mellitus (T2DM). Non-persistent environmental pollutants (npEPs) are a group of widely-used chemicals identified as endocrine/metabolic disrupting chemicals and obesogens. The aim of this study was to analyse the potential associations of serum levels of three groups of npEPs with the risk of incident T2DM.

METHODS

This is a longitudinal study within a sub-sample of Granada EPIC-Spain cohort (n = 670). We quantified serum concentrations of 7 npEPs: four parabens (Methylparaben (MP) ethylparaben (EP), propylparaben (PP) and butilparaben (BP); two benzophenones: Benzophenone 1 (BP1), Benzophenone 3 (BP3); and Bisphenol A (BPA). Exposure was assessed by means of chemical analyses of serum samples collected at recruitment, and information on potential confounders was gathered by using validated questionnaires at baseline. Follow-up was performed by review of patients' clinical records. Cox Proportional Hazards Models were used for the statistical analyses.

RESULTS

Median follow-up time was 23 years. There were 182 (27%) incident T2DM diagnoses in our sub-cohort. MP was the most frequently detected npEP, 88.42% samples above the limit of detection, and BP showed the lowest percentage of detection (19.21%). Those individuals within the fourth PP quartile (0.53-9.24 ng/ml) showed a statistically significant increased risk of T2DM (HR = 1.668 p = 0.012), while BP1 concentrations showed an inverse non-significant trend with the risk.

CONCLUSIONS

We evidenced a potential contribution of npEP exposure on T2DM, but no clear trend was observed. However, limitations in relation to exposure estimation might influence our findings and further research is warranted to confirm our results.

Urinary phenols and parabens and diabetes among US adults, NHANES 2005-2014

BACKGROUND AND AIMS

Phenols and parabens are ubiquitous and have been associated with markers of cardiovascular health. However, the literature lacks population-based studies examining the link between these endocrine disruptors and diabetes. We examined the association between paraben/phenol concentrations and diabetes among a nationally representative sample of US adults.

METHODS AND RESULTS

We utilized data from the 2005-2014 National Health and Nutrition Examination Surveys (N = 8498). Total urinary concentrations of BPA, triclosan, BP-3, and propyl, butyl, ethyl, and methyl parabens were measured from urine specimens collected during the examination session. Diabetes status was based on self-report of a previous diagnosis or HbA1c≥6.5%. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CI) associated with the difference in log-transformed values of the 75th and 25th percentiles for each phenol/paraben, adjusting for potential confounders. The adjusted ORs (95% CI) of diabetes comparing the 75th to 25th percentiles of each paraben/phenol were 1.09 (0.96-1.23) for BPA, 0.84 (0.72-0.98) for triclosan, 0.69 (0.61-0.79) for BP-3, 0.71 (0.61-0.83) for propyl paraben, 0.66 (0.54-0.80) for butyl paraben, 0.60 (0.51-0.71) for ethyl paraben, and 0.79 (0.68-0.91) for methyl paraben.

CONCLUSIONS

Higher concentrations of triclosan, BP-3, and propyl, butyl, ethyl, and methyl parabens were associated with lower odds of diabetes. These findings warrant further investigation into the potential mechanism behind the observed associations and the temporal direction of the associations, given that we cannot rule out reverse causation. Future studies of these endocrine disruptors may improve the understanding of their relationship with diabetes.