Early pregnancy exposure to benzotriazoles and benzothiazoles in relation to gestational diabetes mellitus: A prospective cohort study

Occurrence, removal, and fate of benzothiazoles (BTHs) and benzotriazoles (BTRs) in two wastewater treatment plants in New York State, USA

Benzothiazoles (BTHs) and benzotriazoles (BTRs) are widely used in various consumer products. However, their occurrence and fate in wastewater treatment plants (WWTPs) in the United States remain poorly understood. In this study, wastewater and sludge samples were collected from two WWTPs from the Albany area of New York State (WWTPA and WWTPB) and the concentrations of three BTH derivatives (BTH, 2-OH-BTH, and 2-Me-S-BTH) and five BTR derivatives (1-OH-BTR, XTR, 4-OH-BTR, TTR, and BTR) were determined. The geometric mean (GM) concentrations of Σ(BTHs) and Σ(BTRs) in influent were in the range of 7550-8690 and 4590-6240 ng/L, whereas those in effluent were 6650-7150 and 4620-6800 ng/L, respectively. In the influent of two WWTPs, BTH, BTR, and TTR were identified as the major chemicals at respective GM concentrations of 8440, 4200, and 1280 ng/L in WWTPA, and 7300, 1180, and 2090 ng/L in WWTPB. The removal efficiencies of BTHs and BTRs following activated sludge treatment were < 80 %, and Σ(BTRs) showed a negative removal in both WWTPs. The respective mass loadings of Σ(BTHs) and Σ(BTRs) were 7240 and 5200 mg/d/1000 individuals in WWTPA, and 3530 and 2140 mg/d/1000 individuals in WWTPB. The environmental emissions of Σ(BTHs) and Σ(BTRs) from WWTP discharges were estimated at 3110-6030 and 2160-5700 mg/d/1000 individuals, respectively. Overall, BTHs and BTRs are not efficiently removed in WWTP processes. This study provides baseline information regarding the loading, fate, and discharge of BTHs and BTRs from WWTPs in the USA.

Exposure to benzotriazoles and benzothiazoles in Czech male population and its associations with biomarkers of liver function, serum lipids and oxidative stress

INTRODUCTION

Benzotriazoles and benzothiazoles (BTs) are high-production volume chemicals as well as widely distributed emerging pollutants with potential health risk. However, information about human exposure to BTs and associated health outcomes is limited.

OBJECTIVE

We aimed to characterise exposure to BTs among Czech men, including possible occupational exposure among firefighters, its predictors, and its associations with liver function, serum lipids and oxidative stress.

METHODS

165 participants (including 110 firefighters) provided urine and blood samples that were used to quantify the urinary levels of 8 BTs (high-performance liquid chromatography-tandem mass spectrometry), and 4 liver enzymes, cholesterol, low-density lipoprotein, and 8-hydroxy-2'-deoxyguanosine. Linear regression was used to assess associations with population characteristics and biomarkers of liver function, serum lipids and oxidative stress. Regression models were adjusted for potential confounding variables and false discovery rate procedure was applied to account for multiplicity.

RESULTS

The BTs ranged from undetected up to 46.8 ng/mL. 2-hydroxy-benzothiazole was the most predominant compound (detection frequency 83%; median 1.95 ng/mL). 1-methyl-benzotriazole (1M-BTR) was measured in human samples for the first time, with a detection frequency 77% and median 1.75 ng/mL. Professional firefighters had lower urinary 1M-BTR compared to non-firefighters. Urinary 1M-BTR was associated with levels of γ-glutamyl transferase (β = - 17.54%; 95% CI: - 26.127, - 7.962).

CONCLUSION

This is the first study to investigate BT exposure in Central Europe, including potentially exposed firefighters. The findings showed a high prevalence of BTs in the study population, the relevance of 1M-BTR as a new biomarker of exposure, and an urgent need for further research into associated adverse health outcomes.

Associations between urinary concentrations of benzothiazole, benzotriazole, and their derivatives and lung cancer: A nested case-control study

Benzothiazole (BTH), benzotriazole (BTR), and their respective derivatives (BTHs and BTRs) are emerging environmental pollutants with widespread human exposure and oncogenic potential. Studies have demonstrated adverse effects of exposure to certain BTHs and BTRs on the respiratory system. However, no study has examined the associations between exposure to BTHs and BTRs and lung cancer risk. We aimed to examine the associations between urinary concentrations of BTHs and BTRs and the risk of lung cancer in the general population from Quzhou, China. We conducted a nested case-control study in an ongoing prospective Quzhou Environmental Exposure and Human Health (QEEHH) cohort, involving 20, 694 participants who provided urine samples during April 2019-July 2020. With monthly follow-up until November 2022, 212 lung cancer cases were recruited and 1:1 matched with healthy controls based on age and sex. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of lung cancer risk associated with urinary BTHs and BTRs concentrations using conditional logistic regression models after controlling for potential covariates. We also examined effect modification by several covariates, including sex, socioeconomic status, smoking status, alcohol consumption, and dietary habit. Creatinine-corrected urinary BTH and 2-hydroxy-benzothiazole (2-OH-BTH) levels were significantly associated with the risk of lung cancer, after adjusting for a variety of covariates. Participants in the highest quartile of BTH had a 95% higher risk of lung cancer, compared with those in the lowest quartile (adjusted OR = 1.95, 95% CI: 1.08-3.49; p for trend = 0.01). Participants with higher levels of urinary 2-OH-BTH had an 83% higher risk of lung cancer than those with lower levels (adjusted OR = 1.83, 95% CI: 1.16-2.88; p for trend = 0.01). Exposure to elevated levels of BTH and 2-OH-BTH may be associated with an increased risk of lung cancer. These associations were not modified by socio-demographic characteristics.

Progress in research on the safety of silicone rubber products in food processing

Silicone rubber (SR) is widely used in the food processing industry due to its excellent physical and chemical properties. However, due to the differences in SR product production formulas and processes, the quality of commercially available SR products varies greatly, with chemical and biological hazard potentials. Residual chemicals in SR, such as siloxane oligomers and 2,4-dichlorobenzoic acid, are non-intentionally added substances, which may migrate into food during processing so the safe use of SR must be guaranteed. Simultaneously, SR in contact with food is susceptible to pathogenic bacteria growing and biofilm formation, like Cronobacter sakazakii, Staphylococcus aureus, Salmonella enteritidis, and Listeria monocytogenes, posing a food safety risk. Under severe usage scenarios such as high-temperature, high-pressure, microwave, and freezing environments with long-term use, SR products are more prone to aging, and their degradation products may pose potential food safety hazards. Based on the goal of ensuring food quality and safety to the greatest extent possible, this review suggests that enterprises need to prepare high-quality food-contact SR products by optimizing the manufacturing formula and production process, and developing products with antibacterial and antiaging properties. The government departments should establish quality standards for food-contact SR products and conduct effective supervision. Besides, the reusable SR products should be cleaned by consumers immediately after use, and the deteriorated products should be replaced as soon as possible.

Environmental pollutants exposure and gestational diabetes mellitus: Evidence from epidemiological and experimental studies

Except for known sociodemographic factors, long-term exposure to environmental pollutants has been shown to contribute to the development of gestational diabetes mellitus (GDM), but the conclusions remain controversial. To provide a comprehensive overview of the association between environmental pollutants and GDM, we performed a systematic review and meta-analysis. Several electronic databases (PubMed, Embase, Web of Science, Medline and Cochrane) were searched for related epidemiological and experimental studies up to September 2022. For epidemiological studies, a meta-analysis was carried out to appraise the effect of environmental pollutants, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), per- and polyfluoroalkyl substances (PFASs), phenols, phthalates (PAEs), polybrominated diphenyl ethers (PBDEs) and parabens exposure on GDM. Moreover, we also summarized possible biological mechanisms linking pollution exposure and GDM based on the included experimental studies. A total of 80 articles were enrolled, including 38 epidemiological studies and 42 experimental studies. Meta-analysis results showed that exposure to PAEs [OR (95%CI) = 1.07 (1.00, 1.14)], PFASs [OR (95%CI) = 1.10 (1.01, 1.19)], as well as PCBs [OR (95%CI) = 1.18 (1.02, 1.36)] and PBDEs [OR (95%CI) = 1.33 (1.17, 1.50)] significantly increased the risk of GDM, but no significant effects were found for phenols, OCPs, and parabens. In addition, experimental studies suggested that the potential biological mechanisms of environmental pollutants contributing to GDM may involve insulin resistance, β-cell dysfunction, neurohormonal dysfunction, inflammation, oxidative stress, epigenetic modification, and alterations in gut microbiome. In conclusion, long-term environmental pollutants exposure may induce the development of GDM, and there may be a synergistic effect between the homologs. However, studies conducted on the direct biological link between environmental pollutants and GDM were few. More prospective studies and high-quality in vivo and in vitro experiments were needed to investigate the specific effects and mechanisms.

Prenatal exposure to benzotriazoles and benzothiazoles and child neurodevelopment: A longitudinal study

Benzotriazoles (BTRs) and benzothiazoles (BTHs) are emerging benzo-heterocyclic compounds that may induce neurotoxicity. However, the effect of prenatal exposure to BTs (BTRs and BTHs) on child neurodevelopment has not been elucidated. We aimed to explore the associations between maternal urinary concentrations of BTs in single or in mixture with child neurodevelopment at the age of two. This study recruited 513 mother-child pairs based on a birth cohort from 2014 to 2015 in Wuhan. Maternal urinary concentrations of eight BTs (four BTRs and four BTHs) in the first, second, and third trimesters were measured. The mental development index (MDI) and psychomotor development index (PDI) of children, as two indexes of neurodevelopment, were assessed at two years old by the Bayley Scales. In the analyses of single BTs, prenatal average tolyltriazole (TTR) exposure level was associated with decreased boys' MDI scores (β = -2.84, 95 % CI: -5.11, -0.57) and prenatal average 1-H-benzotriazole (1-H-BTR) exposure level was associated with decreased boys' PDI scores (β = -1.44, 95 % CI: -2.70, -0.17), respectively. Maternal urinary concentrations of benzothiazole (BTH) in the 1^st trimester (β = -1.79, 95 % CI: -2.78, -0.80), 2^nd trimester (β = -1.14, 95 % CI: -2.19, -0.09), and the prenatal average exposure (β = -2.15, 95 % CI: -3.69, -0.61) were also negatively associated with boys' PDI scores. However, no significantly negative association was observed among girls. In the further mixture analysis, the quantile g-computation model found a significant negative association between prenatal average concentrations of BTs in mixture and boys' PDI scores [β = -4.80 (95 % CI: -9.08, -0.52)], and BTH weighted the highest in the negative association. As far as we know, this is the first research to estimate the effect of prenatal exposure to BTs on child neurodevelopment. The findings showed that prenatal exposure to BTs was negatively associated with neurodevelopment among boys, suggesting that the associations may be modified by infant sex.

A preliminary report on the association between maternal serum organophosphate ester concentrations and gestational diabetes mellitus

Organophosphate esters (OPEs) are extensively manufactured and used in China. Whether exposure to OPEs during pregnancy increases the risk of gestational diabetes mellitus (GDM) is unknown. Between 2011 and 2012, a case-control study including 130 and 67 women with and without GDM, respectively, was conducted in Hangzhou, China. The levels of 10 OPEs in maternal serum samples at delivery were quantified, and the relationships between the OPE concentrations and GDM risk were investigated. The results show that in all participants, tri-n-butyl phosphate (TNBP, median: 2.02 ng/mL) was the most common OPE present in the serum, followed by tri-phenyl phosphate (TPHP, median: 1.74 ng/mL) and tri-iso-butyl phosphate (median: 1.68 ng/mL). With one-unit elevation in the tris (2-chloroethyl) phosphate, TNBP, TPHP, and tris (2-butoxy ethyl) phosphate (TBOEP) concentrations in maternal serum, 1-h glucose levels increased by 0.19 (95% confidence interval (CI): -0.01, 0.29), 0.11 (95% CI: -0.18, 0.62), 0.29 (95% CI: 0.12, 0.58), and 0.20 units (95% CI: 0.01, 0.44), respectively. In addition, a unit increase in TBOEP levels in maternal serum was associated with an increase of 0.26 units (95% CI: 0.09, 0.61) in 2-h glucose levels. After adjusting for covariate factors, serum TNBP (odds ratio (OR) = 2.07; 95% CI: 1.27, 3.41), TBOEP (OR = 2.63; 95% CI: 1.68, 4.11), and TPHP (OR = 1.03; 95% CI: 1.05, 1.51) concentrations were associated with GDM incidence in pregnant women. Overall, TNBP, TBOEP, and TPHP exposure during pregnancy is associated with GDM risk and increased glucose levels.

Pollution characteristics, exposure assessment and potential cardiotoxicities of PM2.5-bound benzotriazole and its derivatives in typical Chinese cities

Benzotriazole and its derivatives (BTRs), classified as high-volume production chemicals, have been widely detected in various environmental media, including the atmosphere, water, soil and dust, as well as organisms. However, studies on the pollution characteristics and health impact of PM_2.5 related BTRs are so far limited. This study is the first to demonstrate the regional scale distribution of PM_2.5-bound BTRs and their potential cardiotoxicities. Optimized methods of extraction, purification and GC-EI-MS/MS were applied to characterize and analyze PM_2.5-bound BTRs from three cities in China during the winter of 2018. The concentration of ∑BTRs in Taiyuan (6.28 ng·m^-3) was more than three times that in Shanghai (1.53 ng·m^-3) and Guangzhou (1.99 ng·m^-3). Benzotriazole (BTR) and 5-methyl-1H-benzotriazole (5TTR) contributed more than 80% of ∑BTRs concentration as the major pollutants among three cities. The correlation analysis indicated that there was a positive correlation between temperature and concentration of BTR and a negative correlation between temperature and concentration of 5TTR. In addition, the risk of BTRs exposure to toddlers should be paid more attention in Taiyuan by the human exposure assessment. Furthermore, toxicity screening by experimental methods indicated that 4-methyl-1H-benzotriazole (4TTR) was the most harmful to cardiomyocytes. The western blot assay showed a ROS-mediated mitochondrial apoptosis signaling pathway was activated after exposure to 4TTR in neonatal rat cardiomyocytes (NRCMs). On the other hand, metabolomics revealed that exposure of 4TTR to NRCMs disturbed mitochondrial energy metabolism by disturbing pantothenate and coenzyme A synthesis pathway. Our study not only clarifies the contamination profiles of PM_2.5-bound BTRs in typical Chinese cities but also reveals their cardiotoxicities associated with mitochondrial dysfunction.

Determination of benzotriazole and benzothiazole derivatives in tea beverages by deep eutectic solvent-based ultrasound-assisted liquid-phase microextraction and ultrahigh-performance liquid chromatography-high resolution mass spectrometry

Benzotriazole (BTRs) and benzothiazole (BTHs) derivatives are a group of high production volume chemicals with emerging health concern, which found in tea beverages raising potential risks for food safety and human health. The present work describes a simple method using a "green" deep eutectic solvent (DES) based-ultrasound-assisted liquid-phase microextraction (UALPME) to rapidly extract BTRs and BTHs from tea beverages, and then applying UHPLC-electrospray ionization (+)-quadrupole time-of-flight mass spectrometry for detection and quantification. To overcome the challenges related to different experimental conditions, a Factorial Multilevel Categoric Design and a Face Centered Central Composite Design were applied to screen and optimize the parameters for the DES-UALPME procedure, respectively. After optimization, the method was validated and shown to possess low limits of quantification (LOQs; 1.5-12 ng mL^-1), high precision (3-13%), and satisfactory accuracy (65-107%). The developed method was then successfully applied for the analysis of some selected BTRs and BTHs in tea beverages.

A review of environmental metabolism disrupting chemicals and effect biomarkers associating disease risks: Where exposomics meets metabolomics

Humans are exposed to an ever-increasing number of environmental toxicants, some of which have gradually been elucidated to be important risk factors for metabolic diseases, such as diabetes and obesity. These metabolism-sensitive diseases typically occur when key metabolic and signaling pathways were disrupted, which can be influenced by the exposure to contaminants such as endocrine disrupting chemicals (EDCs), along with genetic and lifestyle factors. This promotes the concept and research on environmental metabolism disrupting chemicals (MDCs). In addition, identifying endogenous biochemical markers of effect linked to disease states is becoming an important tool to screen the biological targets following environmental contaminant exposure, as well as to provide an overview of toxicity risk assessment. As such, the current review aims to contribute to the further understanding of exposome and human health and disease by characterizing environmental exposure and effect metabolic biomarkers. We summarized MDC-associated metabolic biomarkers in laboratory animal and human cohort studies using high throughput targeted and nontargeted metabolomics techniques. Contaminants including heavy metals and organohalogen compounds, especially EDCs, have been repetitively associated with metabolic disorders, whereas emerging contaminants such as perfluoroalkyl substances and microplastics have also been found to disrupt metabolism. In addition, we found major limitations in the effective identification of metabolic biomarkers especially in human studies, toxicological research on the mixed effect of environmental exposure has also been insufficient compared to the research on single chemicals. Thus, it is timely to call for research efforts dedicated to the study of combined effect and metabolic alterations for the better assessment of exposomic toxicology and health risks. Moreover, advanced computational and prediction tools, further validation of metabolic biomarkers, as well as systematic and integrative investigations are also needed in order to reliably identify novel biomarkers and elucidate toxicity mechanisms, and to further utilize exposome and metabolome profiling in public health and safety management.

Machine Learning for Investigation on Endocrine-Disrupting Chemicals with Gestational Age and Delivery Time in a Longitudinal Cohort

Endocrine-disrupting chemicals (EDCs) are widespread environmental chemicals that are often considered as risk factors with weak activity on the hormone-dependent process of pregnancy. However, the adverse effects of EDCs in the body of pregnant women were underestimated. The interaction between dynamic concentration of EDCs and endogenous hormones (EHs) on gestational age and delivery time remains unclear. To define a temporal interaction between the EDCs and EHs during pregnancy, comprehensive, unbiased, and quantitative analyses of 33 EDCs and 14 EHs were performed for a longitudinal cohort with 2317 pregnant women. We developed a machine learning model with the dynamic concentration information of EDCs and EHs to predict gestational age with high accuracy in the longitudinal cohort of pregnant women. The optimal combination of EHs and EDCs can identify when labor occurs (time to delivery within two and four weeks, AUROC of 0.82). Our results revealed that the bisphenols and phthalates are more potent than partial EHs for gestational age or delivery time. This study represents the use of machine learning methods for quantitative analysis of pregnancy-related EDCs and EHs for understanding the EDCs' mixture effect on pregnancy with potential clinical utilities.

Determination of benzotriazole and benzothiazole derivatives in human urine by eco-friendly deep eutectic solvent-based ultrasound-assisted liquid-liquid microextraction followed by ultrahigh performance liquid chromatography quadrupole-time-of-flight mass spectrometry

Benzotriazole (BTRs) and benzothiazole (BTHs) derivatives have been classified as high production volume pollutants of emerging concern. The present work describes a rapid and simple process using an eco-friendly deep eutectic solvent (DES) based-ultrasound-assisted liquid-liquid microextraction (DES-UALLME) technique to effectively extract five BTRs and four BTHs in human urine samples, and then applying ultrahigh-performance liquid chromatography and electrospray ionization (+)-quadrupole time-of-flight mass spectrometry (UHPLC-ESI(+)-QTOF-MS) for their detection and quantification. DESs are a group of novel "green" solvents, and their applications in sample pretreatment are appropriate for the requirements for green chemistry, environmental protection and sustainable development. Furthermore, to overcome the challenges related to different experimental conditions, multivariate experimental design approaches conducted by means of a multilevel categorical design and a Box-Behnken Design were applied to screen and optimize parameters that have significant influences on the extraction efficiency of DES-UALLME. After optimization, the method was validated and shown to possess low limits of quantitation (LOQs; 0.4 - 9 ng mL^-1), high precision (3-12%), and high accuracy (mean spiked recoveries; 80-101%). The developed method was then successfully applied for the analysis of BTRs and BTHs in human urine samples. Interestingly, 5,6-dimethyl-1H-benzotriazole (XTR) was detected in almost all of the urine samples, which correlates with its high production and widely applications in industry processes and consumer products in Taiwan. These target analytes could potentially be used as biomarkers to assess exposure of BTRs and BTHs in biomonitoring programs and studies.

Impact of gestational exposure to endocrine disrupting chemicals on pregnancy and birth outcomes

With the advent of industrialization, humans are exposed to a wide range of environmental chemicals, many with endocrine disrupting potential. As successful maintenance of pregnancy and fetal development are under tight hormonal control, the gestational exposure to environmental endocrine disrupting chemicals (EDC) have the potential to adversely affect the maternal milieu and support to the fetus, fetal developmental trajectory and birth outcomes. This chapter summarizes the impact of exposure to EDCs both individually and as mixtures during pregnancy, the immediate and long-term consequences of such exposures on the mother and fetus, the direct and indirect mechanisms through which they elicit their effects, factors that modify their action, and the research directions to focus future investigations.

Prenatal exposure to benzotriazoles and benzothiazoles and cord blood mitochondrial DNA copy number: A prospective investigation

BACKGROUND

Mitochondria are sensitive to environmental toxicants due to the limited repair capacity. Exposure to benzotriazoles (BTRs) and benzothiazoles (BTHs) may contribute to adverse health outcomes through oxidative stress, which may interfere with mitochondrial function. However, the mitochondrial effects of exposure to BTs (BTRs and BTHs) have not yet been elucidated, particularly in human investigations.

OBJECTIVES

We examined the associations between trimester-specific urinary BTRs and BTHs concentrations and cord blood mitochondrial DNA copy number (mtDNAcn) in a prospective birth cohort.

METHODS

The present study included 742 mother-infant pairs who participated in a birth cohort between 2014 and 2015 in Wuhan and had data on urinary concentrations of BTRs and BTHs and mtDNAcn in cord blood. Concentrations of BTs were repeatedly measured in maternal urine samples at different trimesters using high performance liquid chromatography-tandem mass spectrometry. Relative mtDNAcn in umbilical cord blood was analyzed by quantitative real-time polymerase chain reaction. Generalized estimating equations were used to evaluate the associations between BTs exposure across gestation and mtDNAcn in cord blood.

RESULTS

In the present study, we observed a positive association between urinary 2-methylthio-benzothiazole (2-MeS-BTH) concentrations in the first trimester and cord blood mtDNAcn, with marginal significance [percent changes (%Δ) = 3.97, 95% confidence interval (CI): -0.05, 8.16, p = 0.05], while urinary 2-amino-benzothiazole concentrations in the third trimester were significantly negatively associated with cord blood mtDNAcn (%Δ = -5.89, 95% CI: -10.32, -1.24). Similar patterns of associations were demonstrated between urinary 1-H-benzotriazole (1-H-BTR) and xylyltriazole concentrations in the third trimester and cord blood mtDNAcn (%Δ = -4.18 to -3.23). In sex-specific analysis, we identified that maternal urinary 1-H-BTR in the first trimester and 2-MeS-BTH in the third trimester were positively associated with cord blood mtDNAcn among male infants but not female (P for interaction = 0.05 for 1-H-BTR, P for interaction = 0.05 for 2-MeS-BTH, respectively).

CONCLUSIONS

We found evidence that prenatal exposure to BTRs and BTHs were associated with cord blood mtDNAcn alternation, and these associations were modified by infant gender. Further investigations are needed to corroborate these findings.