Influence of household cleaning practices on the magnitude and variability of urinary monochlorinated bisphenol A

Assessment of Endocrine Disruptor Exposure in Hospital Professionals Using Hair and Urine Analyses: An Awareness Campaign

BACKGROUND

In 2021, French public authorities initiated the fourth National Environmental Health Plan to prevent environment-related health risks. This plan primarily focuses on the sensitization of health professionals and health care institutions. Endocrine disruptors (EDs) are environmental factors associated with several adverse health effects, such as reproductive disorders, obesity, and cancer. This study aimed to conduct an awareness campaign among professionals at a general hospital center on the risks related to EDs.

METHODS

Hospital professionals were directly involved in this study, and urine and hair samples were collected to determine bisphenol and paraben exposure levels. Analyses were performed using validated liquid chromatography-tandem mass spectrometry methods, enabling the simultaneous determination of bisphenols and parabens. A questionnaire on lifestyle habits was distributed to assess its relationship with the exposure profiles. Nineteen professionals were recruited for the study.

RESULTS

Bisphenol A was detected in 95% of the urine samples, and the chlorinated derivatives of bisphenol A were between 16% and 63%. parabens showed detection frequencies between 37% and 100%, and methylparaben was quantified at an average concentration of 0.45 ± 0.46 ng/mL. In hair samples, bisphenols A, F, and S were detected at 95%-100%, chlorinated derivatives of bisphenol A were detected at 37%-68%, and parabens were detected at 100%.

CONCLUSIONS

This awareness campaign may encourage health care institutions to adopt a policy of reducing endocrine disruptor exposure among their patients and professionals, who could be educated regarding the risks associated with EDs. Conducting a multicenter study to refine the results herein and establish a dynamic to prevent endocrine disruptor and environmental risks in health care systems would be valuable.

Quantification of the Conjugated Forms of Dichlorobisphenol A (3,3'-Cl 2 BPA) in Rat and Human Plasma Using HPLC-MS/MS

BACKGROUND

Bisphenol A (BPA) is a ubiquitous contaminant that has endocrine-disrupting effects. Chlorinated derivatives of BPA are formed during chlorination of drinking water and have higher endocrine-disrupting activity. Dichlorobisphenol A (Cl 2 BPA) is the most abundant chlorinated BPA derivative found in several human biological matrices. Recent in vitro experiments have shown that Cl 2 BPA is metabolized in sulpho- and glucuro-conjugated compounds. To date, no assay has been developed to quantify the sulfo- and glucuro-conjugates of 3,3'-Cl 2 BPA (3,3'-Cl 2 BPA-S and 3,3'-Cl 2 BPA-G, respectively).

METHODS

A high-performance liquid chromatography-tandem mass spectrometry assay for the determination of 3,3'-Cl 2 BPA conjugated forms in plasma samples was developed and validated according to the European Medicines Agency guidelines. Quantification was performed in the multiple reaction monitoring mode for all target analytes using a SCIEX 6500 + tandem mass spectrometer with an electrospray source operating in the negative ionization mode. Chromatographic separation was achieved using a C18 column maintained at 40°C and a binary mobile phase delivered in the gradient mode at a flow rate of 0.35 mL/min. Sample was prepared via simple precipitation using acetonitrile. The assay was validated and applied to rat and human plasma samples.

RESULTS

Linearity was demonstrated over the range of 0.006-25 ng/mL for 3,3'-Cl 2 BPA-G and 0.391-100 ng/mL for 3,3'-Cl 2 BPA-S. Intraday and interday bias values were in the 95%-109% range, and the imprecision <9%. Internal standard corrected matrix effects were also investigated. This method enabled quantification of the conjugated forms of 3,3'-Cl 2 BPA in plasma samples.

CONCLUSIONS

This is the first report on the development and validation of an analytical method for the quantification of 3,3'-Cl 2 BPA-G and 3,3'-Cl 2 BPA-S in the plasma matrix. This study is also the first report on the in vivo occurrence of these metabolites.

Chlorobisphenol A activated kisspeptin/GPR54-GnRH neuroendocrine signals through ERα and GPER pathway in neuronal GT1-7 cells

Chlorobisphenol A (Cl_xBPA) is a kind of novel estrogenic compounds. The present study aims to investigate the effects of three Cl_xBPA compounds on the kisspeptin/G protein-coupled receptor 54 (GPR54, also named KissR1)-gonadotropin-releasing hormone (GnRH) (KGG) system in neuronal GT1-7 cells with mechanistic insights by estrogen receptor signaling pathways. The study demonstrated that low-concentration Cl_xBPA induced the cell proliferation, promoted GnRH secretion, upregulated the expression of KGG neuroendocrine signal-related proteins (KissR1, GnRH1 and kisspeptin) and genes including Kiss1, GnRH1, KissR1, luteinizing hormone receptor (Lhr) and follicle-stimulating hormone receptor (Fshr) in GT1-7 cells. Additionally, Cl_xBPA activated nuclear estrogen receptor alpha (ERα) and member estrogen receptor G protein-coupled estrogen receptor (GPER)-regulated phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and extracellular signal-regulated kinase (Erk1/2) signaling pathways. Pretreatment of GT1-7 cells with GPER inhibitor G15 and ERα inhibitor ICI reduced the expression of KissR1, GnRH1 and kisspeptin proteins, attenuated mRNA levels of Kiss1, GnRH1, KissR1, Fshr and Lhr genes, and decreased Cl_xBPA-induced GT1-7 cell proliferation. The results suggested that Cl_xBPA activated the KGG neuroendocrine signals and induced the proliferation of GT1-7 cells via ERα and GPER signaling pathways. This study provides a new perspective to explore the neuroendocrine toxicity mechanism of Cl_xBPA. CAPSULE: Cl_xBPA activated KGG neuroendocrine signaling pathway via ERα and GPER and induced the proliferation of GT1-7 cells.

An overview of the literature on emerging pollutants: Chlorinated derivatives of Bisphenol A (ClxBPA)

CONTEXT

Bisphenol A (BPA) is a ubiquitous contaminant with endocrine-disrupting effects in mammals. During chlorination treatment of drinking water, aqueous BPA can react with chlorine to form chlorinated derivatives of BPA (mono, di, tri and tetra-chlorinated derivatives) or Cl_xBPA.

OBJECTIVE

The aim of this study is to summarize and present the state of knowledge on human toxicological risk assessment of Cl_xBPA.

MATERIALS AND METHODS

A search on Cl_xBPA in the PubMed database was performed based on studies published between 2002 and 2021. Forty-nine studies on chlorinated derivatives of BPA were found. Available information on their sources and levels of exposure, their effects, their possible mechanisms of action and their toxicokinetics data was extracted and presented.

RESULTS

Cl_xBPA have been essentially detected in environmental aqueous media. There is evidence in toxicological and epidemiological studies that Cl_xBPA also have endocrine-disrupting capabilities. These emerging pollutants have been found in human urine, serum, breast milk, adipose and placental tissue and can constitute a risk to human health. However, in vitro and in vivo toxicokinetic data on Cl_xBPA are scarce and do not allow characterization of the disposition kinetics of these compounds.

CONCLUSION

More research to assess their health risks, specifically in vulnerable populations, is needed. Some water chlorination processes are particularly hazardous, and it is important to evaluate their chlorination by-products from a public health perspective.

Simultaneous determination of bisphenol A and its chlorinated derivatives in human plasma: Development, validation and application of a UHPLC-MS/MS method

Bisphenol A (BPA) is a well-known ubiquitous chemical found in polycarbonate, polysulfone and epoxy resins, used in mass production for many consumer products. BPA exhibits endocrine disruptor properties that can potentially induce adverse health effects. In aquatic environments, it can react with chlorine to produce chlorinated derivatives (ClxBPAs). ClxBPAs exhibit oestrogenic activity 10 to 105 times higher than BPA itself. Assessing human exposure to endocrine disrupting chemicals is mandatory to assess health risk. Blood, as well as urine matrix, are commonly used to perform human biomonitoring. We therefore developed, fully validated and applied a method based on Ultra High Performance Liquid Chromatography couples to a Triple Quad Mass Spectrometer to determine BPA, monochlorobisphenol A (MCBPA), dichlorobisphenol A (DCBPA), trichlorobisphenol A (TCBPA) and tetrachlorobisphenol A (TTCBPA) in human blood plasma. The European Medicines Agency guidelines for bioanalytical method validation have been applied. Precision and trueness of the method were <15% at medium and high levels of quality control and <20% at the limits of quantification (LOQs). The LOQs were settled at 0.1 ng/mL for BPA, 0.02 ng/mL for TTCBPA and 0.005 ng/mL for MCBPA, DCBPA, and TCBPA. The analytical method was applied to ten patients suffering from end stage renal disease. BPA was quantified in all ten patients while MCBPA, DCBPA and TTCBPA were determined in three and TCBPA in four. In conclusion, we have successfully developed a highly sensitive method to determine BPA and ClxBPAs in human plasma. Thanks to this method, for the first time, we could demonstrate ClxBPAs occurrence in human blood.

Highly Sensitive and High-Throughput Method for the Analysis of Bisphenol Analogues and Their Halogenated Derivatives in Breast Milk

The structural analogs of bisphenol A (BPA) and their halogenated derivatives (together termed BPs) have been found in the environment, food, and even the human body. Limited research showed that some of them exhibited toxicities that were similar to or even greater than that of BPA. Therefore, adverse health effects for BPs were expected for humans with low-dose exposure in early life. Breast milk is an excellent matrix and could reflect fetuses' and babies' exposure to contaminants. Some of the emerging BPs may present with trace or ultratrace levels in humans. However, existing analytical methods for breast milk cannot quantify these BPs simultaneously with high sensitivity using a small sampling weight, which is important for human biomonitoring studies. In this paper, a method based on Bond Elut Enhanced Matrix Removal-Lipid purification, pyridine-3-sulfonyl chloride derivatization, and liquid chromatography electrospray tandem mass spectrometry was developed. The method requires only a small quantity of sample (200 μL) and allowed for the simultaneous determination of 24 BPs in breast milk with ultrahigh sensitivity. The limits of quantitation of the proposed method were 0.001-0.200 μg L^-1, which were 1-6.7 times lower than the only study for the simultaneous analysis of bisphenol analogs in breast milk based on a 3 g sample weight. The mean recoveries ranged from 86.11% to 119.05% with relative standard deviation (RSD) ≤ 19.5% (n = 6). Matrix effects were within 20% with RSD < 10% for six different lots of samples. The proposed method was successfully applied to 20 breast milk samples. BPA, bisphenol F (BPF), bisphenol S (BPS), and bisphenol AF (BPAF) were detected. BPA was still the dominant BP, followed by BPF. This is the first report describing the occurrence of BPF and BPAF in breast milk.

Human Exposures to Bisphenol A, Bisphenol F and Chlorinated Bisphenol A Derivatives and Thyroid Function

Although the increasing prevalence of thyroid nodular disease (TND) has been partially attributed to the more frequent usage of improved diagnostics, environmental factors, such as exposures to thyroid-disrupting chemicals may contribute to TND and altered thyroid function. We investigated the association between exposures to bisphenol A (BPA), its chlorinated derivatives (ClxBPA), and bisphenol F (BPF) with TND and thyroid measures in adult women. A case-control study in Cyprus and Romania (n = 212) was conducted, where cases were those with thyroid nodules (diameter >3mm), and controls without nodules. Serum TSH and free thyroxine and urinary levels of BPA, BPF and ClxBPA were measured using immunoassays and tandem mass spectrometry, respectively. The association between exposures to BPA compounds and TND, adjusting for age, BMI, thyroid hormones and urinary iodine was assessed using logistic regression. Linear regression was used to explore associations between urinary BPA, BPF and ClxBPA and serum thyroid hormones. With the exception of a chlorinated BPA compound (30%), the rest of bisphenols were quantified in 100% of urine samples. A positive and significant (p<0.05) association was observed between urinary BPA and serum TSH that remained after adjusting for urinary creatinine, age, BMI, study site and disease status; there was no significant association between BPF or ClxBPA with TSH. None of the BPA compounds were associated with higher odds of TND. Our study found associations of urinary BPA with TSH but not with BPF or ClxBPA. A larger study would be justified.

Environmental and occupational exposure to bisphenol A and endometriosis: urinary and peritoneal fluid concentration levels

OBJECTIVES

The study aimed to give a first data set of bisphenol A (BPA) levels in the peritoneal fluid of patients suffering from endometriosis and to investigate the relationship between BPA exposure and endometriosis.

METHODS

A questionnaire investigating the occupational context, life environment, and habits was administered to 68 patients suffering from endometriosis and 60 endometriosis-free subjects (control group). Urine and peritoneal fluids samples were collected and analysed by GC/MSMS for BPA dosage.

RESULTS

Some of the investigated environmental/lifestyle risk factors (closeness to industries/activities at risk) were associated with an increase in endometriosis; smoking resulted as protective factor; others (use of food plastic boxes) did not seem to influence the onset of pathology. The association between the occupational exposure summarising all examined risk factors (working activity, personal protective equipment, seniority) and endometriosis was statistically significant (χ ² = 5.252, p = 0.02). Contrasting results were obtained when specific activities were examined. Detectable urinary BPA levels were found in all analysed samples (patients: 1.17-12.68 pg/µl; mean ± SD, 5.31 ± 3.36 pg/µl; control group: 1.28-2.35 pg/µl; mean ± SD, 1.64 ± 0.49 pg/µl; median; 1.46 pg/µl), with a statistically significant difference between patients and controls, showing an association between BPA exposure and endometriosis. Only a few subjects from the control group supplied peritoneal fluid; hence, no comparison test with patients (range 0.39-1.46 pg/µl; mean ± SD, 0.67 ± 0.30 pg/µl; median, 0.58 pg/µl) was carried out.

CONCLUSIONS

Results highlight the potential association between BPA exposure and endometriosis, as well as the current lack of knowledge regarding occupational exposure to BPA and the need of epidemiological studies focused on single activities/occupations, such as housewives, cleaners, students.

Occurrence and variability of iodinated trihalomethanes concentrations within two drinking-water distribution networks

Non-iodo-containing trihalomethanes (TTHM) are frequently detected in chlorinated tap water and currently regulated against their carcinogenic potential. Iodinated THM (ITHM) may also form in disinfected with chlorine waters that are high in iodine content, but little is known about their magnitude and variability within the drinking-water pipe distribution network of urban areas. The main objective of this study was to determine the magnitude and variability of ITHM and TTHM levels and their corresponding daily intake estimates within the drinking water distribution systems of Limassol and Nicosia cities of Cyprus, using tap samples collected from individual households (n=37). In Limassol, mean household tap water ITHM and TTHM levels was 0.58 and 38 μg L(-1), respectively. Dichloroiodomethane (DCIM) was the dominant species of the two measured ITHM compounds accounting for 77% of total ITHM and in the range of 0.032 and 1.65 μg L(-1). The range of DCIM concentrations in Nicosia tap water samples was narrower (0.032 - 0.848 μg L(-1)). Mean total iodine concentration in tap water samples from the seaside city of Limassol was 15 μg L(-1) and approximately twice to those observed in samples from the mainland Nicosia city. However, iodine concentrations did not correlate with the ITHM levels. The calculated chronic daily intake rates of ITHM were low when compared with those of TTHM, but because of their widespread occurrence in tap water and their enhanced mammalian cell toxicity, additional research is warranted to assess the magnitude and variability of human ITHM exposures.

Biomonitoring of human exposures to chlorinated derivatives and structural analogs of bisphenol A

The high reactivity of bisphenol A (BPA) with disinfectant chlorine is evident in the instantaneous formation of chlorinated BPA derivatives (ClxBPA) in various environmental media that show increased estrogen-activity when compared with that of BPA. The documented health risks associated with BPA exposures have led to the gradual market entry of BPA structural analogs, such as bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), etc. A suite of exposure sources to ClxBPA and BPA analogs in the domestic environment is anticipated to drive the nature and range of halogenated BPA derivatives that can form when residual BPA comes in contact with disinfectant in tap water and/or consumer products. The primary objective of this review was to survey all available studies reporting biomonitoring protocols of ClxBPA and structural BPA analogs (BPS, BPF, BPB, etc.) in human matrices. Focus was paid on describing the analytical methodologies practiced for the analysis of ClxBPA and BPA analogs using hyphenated chromatography and mass spectrometry techniques, because current methodologies for human matrices are complex. During the last decade, an increasing number of ecotoxicological, cell-culture and animal-based and human studies dealing with ClxBPA exposure sources and routes of exposure, metabolism and toxicity have been published. Up to date findings indicated the association of ClxBPA with metabolic conditions, such as obesity, lipid accumulation, and type 2 diabetes mellitus, particularly in in-vitro and in-vivo studies. We critically discuss the limitations, research needs and future opportunities linked with the inclusion of ClxBPA and BPA analogs into exposure assessment protocols of relevant epidemiological studies.

Association between urinary levels of bisphenol A and its monochlorinated derivative and obesity

Population-based studies suggest the association between exposures to bisphenol A (BPA) and obesity. However, no human studies are available that link exposures to chlorinated derivatives of BPA with obesity biomarkers. The objective of this exploratory post hoc analysis of our cross-sectional study's dataset was to evaluate the association between urinary levels of BPA and monochlorinated BPA (mono-ClBPA) with body mass index (BMI) in a random sample of 223 adults (≥18 years) from the general population in Cyprus. Univariate analysis and multiple logistic regressions were performed for descriptive statistics and estimating odds ratio (OR) of above normal BMI, respectively. We observed a relatively weak positive association between urinary mono-ClBPA and BMI, such as (i) 76 ng g(-1) in participants with above normal BMI (≥25 kg m(-2)) versus 55 ng g(-1) in those with normal BMI (<25 kg m(-2)) (P for mean difference = 0.053) and (ii) higher percentage of participants with above normal BMI in the high urinary mono-ClBPA tertile (63% in tertile 3 and 57% in tertile 2 versus 50% in tertile 1, P for trend = 0.056). Similar tests of association between urinary BPA and BMI showed null outcome. A dichotomously-classified group analysis showed an increased odds ratio (OR) for higher BMI in the group with high creatinine-adjusted urinary levels of BPA and mono-ClBPA when compared with the participants group with low levels for both compounds [logistic model adjusted for gender and health status as potential confounders; adjusted OR (95% CI): 2.34 (1.10, 5.10), P = 0.027]. Measurements of both BPA and its trace chlorinated derivative in human matrices may be warranted for a comprehensive exposure assessment towards improving our understanding of their obesogenic effects.

Preliminary evidence of the association between monochlorinated bisphenol A exposure and type II diabetes mellitus: A pilot study

Evidence for the association of bisphenol A (BPA) with type II diabetes mellitus (T2DM) has been inconsistent in human studies. In-vitro and animal studies indicate that chlorinated BPA derivatives aggravate BPA health effects via higher estrogenic activity and alteration of membrane-initiating signaling pathways. We evaluated the association between urinary monochlorinated BPA (mono-ClBPA) concentrations and the incidence of T2DM. In our cross-sectional study, we identified 20 adult participants (≥18 yr) who reported having T2DM (doctor-diagnosed) and 131 adults with normal health. First morning void urine samples were analyzed for total BPA and mono-ClBPA. Detection limits of the analytical method were 95 ng L(-1) for BPA and 32 ng L(-1) for mono-ClBPA. Multivariable logistic regression analyses and additive Bayesian network modeling were performed. After adjusting for age, gender, BMI, urinary total BPA and other confounders, the odds of having T2DM was 3.29 times higher (95% confidence interval, CI: 1.10, 11.4; P < 0.05) per unit increase in log-transformed and creatinine-adjusted urinary mono-ClBPA levels (n = 151); this relation did not hold for total BPA. The globally optimum Bayesian model corroborated the results of the logistic regression by expressing mono-ClBPA in the pathway of T2DM, and not for total BPA. An age-matched sensitivity analysis confirmed the increase in OR of T2DM by 3.04 times (95% CI: 1.10, 11.0; P < 0.05) per unit increase in log-transformed and creatinine-adjusted urinary mono-ClBPA concentration (n = 68). The urinary monochlorinated BPA derivative was significantly associated with T2DM, whereas the parent compound (total BPA) was not. Caution should be applied in interpreting these findings, as this is the first study to report this association and the sample size of participants with T2DM is small. Additional research with a larger sample size coupled with relevant toxicological studies is warranted.