Endocrine Disruptors: Time to Act

Bismuth-Based Z-Scheme Heterojunction Photocatalysts for Remediation of Contaminated Water

Agricultural runoff, fuel spillages, urbanization, hospitalization, and industrialization are some of the serious problems currently facing the world. In particular, byproducts that are hazardous to the ecosystem have the potential to mix with water used for drinking. Over the last three decades, various techniques, including biodegradation, advanced oxidation processes (AOPs), (e.g., photocatalysis, photo-Fenton oxidation, Fenton-like oxidation, and electrochemical oxidation process adsorption), filtration, and adsorption techniques, have been developed to remove hazardous byproducts. Among those, AOPs, photocatalysis has received special attention from the scientific community because of its unusual properties at the nanoscale and its layered structure. Recently, bismuth based semiconductor (BBSc) photocatalysts have played an important role in solving global energy demand and environmental pollution problems. In particular, bismuth-based Z-scheme heterojunction (BBZSH) is considered the best alternative route to overhaul the limitations of single-component BBSc photocatalysts. This work aims to review recent studies on a new type of BBZSH photocatalysts for the treatment of contaminated water. The general overview of the synthesis methods, efficiency-enhancing strategies, classifications of BBSc and Z-scheme heterojunctions, the degradation mechanisms of Z- and S-schemes, and the application of BBZSH photocatalysts for the degradation of organic dyes, antibiotics, aromatics compounds, endocrine-disrupting compounds, and volatile organic compounds are reviewed. Finally, challenges and the future perspective of BBZSH photocatalysts are discussed.

Brief postnatal exposure to bisphenol A affects apoptosis and gene expression in the medial prefrontal cortex and social behavior in rats with sex specificity

Bisphenol A (BPA) is an endocrine disruptor found in polycarbonate plastics and exposure in humans is nearly ubiquitous and it has widespread effects on cognitive, emotional, and reproductive behaviors in both humans and animal models. In our laboratory we previously found that perinatal BPA exposure results in a higher number of neurons in the adult male rat prefrontal cortex (PFC) and less play in adolescents of both sexes. Here we examine changes in the rate of postnatal apoptosis in the rat prefrontal cortex and its timing with brief BPA exposure. Because an increased number of neurons in the PFC is a characteristic of a subtype of autism spectrum disorder, we tested social preference following brief BPA exposure and also expression of a small group of genes. Males and females were exposed to BPA from postnatal days (P) 6 through 8 or from P10 through 12. Both exposures significantly decreased indicators of cell death in the developing medial prefrontal cortex in male subjects only. Additionally, males exposed to BPA from P6 - 8 showed decreased social preference and decreased cortical expression of Shank3 and Homer1, two synaptic scaffolding genes that have been implicated in social deficits. There were no significant effects of BPA in the female subjects. These results draw attention to the negative consequences following brief exposure to BPA during early development.

Determination of bisphenols, parabens, and benzophenones in placenta by dispersive liquid-liquid microextraction and gas chromatography-tandem mass spectrometry

Human exposure to endocrine disrupting chemicals (EDCs) is of particular concern during development. Bisphenols, parabens, and benzophenones are EDCs widely used in the manufacture of numerous goods, personal care products, and cosmetics. The aim of this study was to develop a new and practical method for determining three bisphenols, four parabens, and five benzophenones in placenta samples. It uses dispersive liquid-liquid microextraction (DLLME) in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS). Several chemometric approaches were employed to optimize the experimental parameters. Limits of detection ranged from 0.04 to 0.08 ng g^-1 and inter-day variabilities (evaluated as relative standard deviation) from 4.2% to 13.4%. The method was validated using matrix-matched standard calibration followed by a recovery assay with spiked samples. Recovery percentages ranged from 87.1% to 113.2%. Finally, the method was used to measure target compounds in 20 placental tissue samples from voluntary donors. This analytical procedure can provide information on the exposure of the fetus to non-persistent EDCs.

Recent Advances in the Rejection of Endocrine-Disrupting Compounds from Water Using Membrane and Membrane Bioreactor Technologies: A Review

Water is a critical resource necessary for life to be sustained, and its availability should be secured, appropriated, and easily obtainable. The continual detection of endocrine-disrupting chemicals (EDCs) (ng/L or µg/L) in water and wastewater has attracted critical concerns among the regulatory authorities and general public, due to its associated public health, ecological risks, and a threat to global water quality. Presently, there is a lack of stringent discharge standards regulating the emerging multiclass contaminants to obviate its possible undesirable impacts. The conventional treatment processes have reportedly ineffectual in eliminating the persistent EDCs pollutants, necessitating the researchers to develop alternative treatment methods. Occurrences of the EDCs and the attributed effects on humans and the environment are adequately reviewed. It indicated that comprehensive information on the recent advances in the rejection of EDCs via a novel membrane and membrane bioreactor (MBR) treatment techniques are still lacking. This paper critically studies and reports on recent advances in the membrane and MBR treatment methods for removing EDCs, fouling challenges, and its mitigation strategies. The removal mechanisms and the operating factors influencing the EDCs remediation were also examined. Membranes and MBR approaches have proven successful and viable to eliminate various EDCs contaminants.

Assessment of parabens and ultraviolet filters in human placenta tissue by ultrasound-assisted extraction and ultra-high performance liquid chromatography-tandem mass spectrometry

Increasing concerns have been raised over recent decades about human exposure to Endocrine Disrupting Chemicals (EDCs), especially about their possible effects on embryo, foetus, newborn, and child. Parabens (PBs) and ultraviolet filters (UV-filters) are prevalent EDCs widely used as additives in cosmetics and personal care products (PCPs). The objective of this study was to determine the presence of four PBs and ten UV-filters in placental tissue samples using a novel analytical method based on ultrasound-assisted extraction (UAE) and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Multivariate optimization strategies were used to accurately optimize extraction and clean-up parameters. Limits of quantification ranged from 0.15 to 0.5μgkg^-1, and inter-day variability (evaluated as relative standard deviation) ranged from 3.6% to 14%. The method was validated using matrix-matched standard calibration followed by a recovery assay with spiked samples. Recovery percents ranged from 94.5% to 112%. The method was satisfactorily applied for the determination of the target compounds in human placental tissue samples collected at delivery from 15 randomly selected women. This new analytical procedure can provide information on foetal exposure to compounds, which has been little studied.

Total Effective Xenoestrogen Burden in Serum Samples and Risk for Breast Cancer in a Population-Based Multicase-Control Study in Spain

BACKGROUND

Most studies on endocrine-disrupting chemicals and breast cancer have focused on single compounds and have produced inconclusive findings.

OBJECTIVES

We assessed the combined estrogenic effects of mixtures of xenoestrogens in serum and their relationship to breast cancer risk.

METHODS

A total of 186 incident pretreatment breast cancer cases and 196 frequency-matched controls were randomly sampled from a large population-based multicase-control study in Spain. The total effective xenoestrogen burden attributable to organohalogenated xenoestrogens (TEXB-α) and endogenous hormones and more polar xenoestrogens (TEXB-β) was determined in serum samples using high-performance liquid chromatography and E-Screen bioassay. Odds ratios for breast cancer comparing tertiles of serum TEXB-α and TEXB-β were estimated using logistic models, and smooth risk trends were obtained using spline models.

RESULTS

Cases had higher geometric mean TEXB-α and TEXB-β levels (8.32 and 9.94 Eeq pM/mL, respectively) than controls (2.99 and 5.96 Eeq pM/mL, respectively). The fully adjusted odds ratios for breast cancer (95% confidence intervals) comparing the second and third tertiles of TEXB-α with the first tertile were 1.77 (0.76, 4.10) and 3.45 (1.50, 7.97), respectively, and those for TEXB-β were 2.35 (1.10, 5.03) and 4.01 (1.88, 8.56), respectively. A steady increase in risk was evident across all detected TEXB-α levels and a sigmoidal trend was observed for TEXB-β. Individual xenoestrogens showed weak and opposing associations with breast cancer risk.

CONCLUSIONS

This is the first study to show a strong positive association between serum total xenoestrogen burden and breast cancer risk, highlighting the importance of evaluating xenoestrogen mixtures, rather than single compounds, when studying hormone-related cancers.

CITATION

Pastor-Barriuso R, Fernández MF, Castaño-Vinyals G, Whelan D, Pérez-Gómez B, Llorca J, Villanueva CM, Guevara M, Molina-Molina JM, Artacho-Cordón F, Barriuso-Lapresa L, Tusquets I, Dierssen-Sotos T, Aragonés N, Olea N, Kogevinas M, Pollán M. 2016. Total effective xenoestrogen burden in serum samples and risk for breast cancer in a population-based multicase-control study in Spain. Environ Health Perspect 124:1575-1582; http://dx.doi.org/10.1289/EHP157.

Determination of endocrine-disrupting chemicals in human milk by dispersive liquid–liquid microextraction

Aim: Human populations are widely exposed to numerous so-called endocrine-disrupting chemicals, exogenous compounds able to interfere with the endocrine system. This exposure has been associated with several health disorders. New analytical procedures are needed for biomonitoring these xenobiotics in human matrices. A quick and inexpensive methodological procedure, based on sample treatment by dispersive liquid–liquid microextraction, is proposed for the determination of bisphenols, parabens and benzophenones in samples. Results: LOQs ranged from 0.4 to 0.7 ng ml-1 and RSDs from 4.3 to 14.8%. Conclusion: This methodology was satisfactorily applied in the simultaneous determination of a wide range of endocrine-disrupting chemicals in human milk samples and is suitable for application in biomonitoring studies.

Hormone Use in Food Animal Production: Assessing Potential Dietary Exposures and Breast Cancer Risk

In recent years, increasing attention has been paid to the role of hormones in breast cancer etiology, following reports that heightened levels of endogenous hormones and exposure to exogenous hormones and other endocrine-disrupting chemicals through food and the environment are associated with increased breast cancer risk. Seven hormone drugs (testosterone propionate, trenbolone acetate, estradiol, zeranol, progesterone, melengestrol acetate, and bovine somatotropin) are approved by the U.S. Food and Drug Administration for use in food animals. There is concern that these drugs or their biologically active metabolites may accumulate in edible tissues, potentially increasing the risk of exposure for consumers. To date, the potential for human exposure to residues of these compounds in animal products, as well as the risks that may result from this exposure, is poorly understood. In this paper, we discuss the existing scientific evidence examining the toxicological significance of exposure to hormones used in food animal production in relation to breast cancer risk. Through a discussion of U.S. federal regulatory programs and the primary literature, we interpret the state of surveillance for residues of hormone drugs in animal products and discuss trends in meat consumption in relation to the potential for hormone exposure. Given the lack of chronic bioassays of oral toxicity of the seven hormone compounds in the public literature and the limitations of existing residue surveillance programs, it is not currently possible to provide a quantitative characterization of risks that result from the use of hormonal drugs in food animal production, complicating our understanding of the role of dietary hormone exposure in the population burden of breast cancer.