Environmental endocrine disruption: an effects assessment and analysis

Oestrogens, adipose tissues and environmental exposures influence obesity and diabetes across the lifecycle

Endogenous oestrogens regulate essential functions to include menstrual cycles, energy balance, adipose tissue distribution, pancreatic β-cell function, insulin sensitivity and lipid homeostasis. Oestrogens are a family of hormones which include oestradiol (E2), oestrone (E1) and oestriol (E3). Oestrogens function by binding and activating oestrogen receptors (ERs). Phytoestrogens are plant-derived compounds which exhibit oestrogenic-like activity and can bind to ERs. Phytoestrogens exert potential oestrogenic-like benefits; however, their effects are context-dependent and require cautious consideration regarding generalised health benefits. Xenoestrogens are synthetic compounds which have been determined to disrupt endocrine function through binding to ERs. Xenoestrogens enter the body through various routes and given their chemical structure they can accumulate, posing long-term health risks. Xenoestrogens interfere with endogenous oestrogens and their functions contributing to conditions like cancer, infertility, and metabolic disorders. Understanding the interplay between endogenous and exogenous oestrogens is critical in order to determine their potential health consequences and requires further investigation. This manuscript provides a summary of the role endogenous oestrogens have in regulating metabolic functions. Additionally, we discuss the impact phytoestrogens and synthetic xenoestrogens have on biological systems across various life stages. We highlight their mechanisms of action, potential benefits, risks and discuss the need for further research to bridge gaps in understanding and mitigate exposure-related health risks.

Dietary pesticide exposure and non-communicable diseases and mortality: a systematic review of prospective studies among adults

BACKGROUND

Research on the effect of pesticide exposure on health has been largely focused on occupational settings. Few reviews have synthesized the associations between dietary pesticide exposure and health outcomes in non-occupationally exposed adults.

OBJECTIVE

We aim to summarize the evidence regarding dietary pesticide exposure and non-communicable diseases (NCD) in adults, using a systematic review of prospective studies.

METHODS

Electronic and manual searches were performed until July 2023. The inclusion criteria were the following: 1) adults aged ≥ 18years, 2) (non)-randomized trials, prospective cohort studies, 3) dietary exposure to pesticides. A bias analysis was carried out using the Nutrition Evidence Systematic Review guidelines based on the Cochrane ROBINS-I.

RESULTS

A total of 52 studies were retrieved and 6 studies that met the above criteria were included. Studies were conducted either in France or in the United States. The studies investigated the risk of cancer (n = 3), diabetes (n = 1), cardiovascular diseases (n = 1), and mortality (n = 1). The quality of the studies varied with overall grades derived from the bias analysis ranging from low to moderate bias. The level of evidence was estimated as low for the risk of cancer while the grading was not assignable for other outcomes, as only one study per outcome was available.

CONCLUSIONS

Although further research is warranted to examine more in depth the relationships between low-dose chronic exposure to pesticides through diet and NCD outcomes in non-occupationally-exposed adults, studies suggest a possible role of exposure to dietary pesticide on health. Standardized methodological guidelines should also be proposed to allow for comparison across studies.

A review of the occurrence, metabolites and health risks of butylated hydroxyanisole (BHA)

Butylated hydroxyanisole (BHA) is mainly used as a food additive due to its antioxidant properties, which prevent or delay oxidation reactions and extend the storage life of products. The widespread use of BHA has led to its extensive presence in various environmental matrices and human tissues. Food intake is the main route of human exposure to BHA. Under different conditions, BHA can produce different metabolites, with tert-butyl hydroquinone (TBHQ) being one of the major products. Several studies have shown that BHA could cause thyroid system damage, metabolic and growth disorders, neurotoxicity, and carcinogenesis. Mechanisms such as endocrine disruption, genotoxicity, disturbances of energy metabolism, reactive oxygen species (ROS) production, signaling pathways, and imbalances in calcium homeostasis appear to be associated with the toxic effects of BHA. Avoiding the toxic effects of BHA to the maximum extent possible is a top priority. Finding safe, non-toxic and environmentally friendly alternatives to BHA should be the focus of subsequent research. In all, this review summarized the current situation related to BHA and might make recommendations for future research directions. © 2023 Society of Chemical Industry.

Responses of signal crayfish Pacifastacus leniusculus to single short-term pulse exposure of pesticides at environmentally relevant concentrations

Although pesticides are often discharged into surface waters in pulses as opposed to a sustained release, the effect of episodic pollution events on freshwater crayfish is largely unknown. We monitored change in heart rate and distance moved to assess the response of signal crayfish Pacifastacus leniusculus to short-term exposure to environmentally relevant concentrations of metazachlor (MTZ), terbuthylazine (TER), and thiacloprid (TCL). Crayfish exposed to 20 µg/L of MTZ exhibited a significant increase in mean heart rate and distance moved. Increased heart rate was detected at 118 ± 74 s post-exposure to MTZ. There were no significant differences in mean heart rate and distance moved in crayfish exposed to 6 µg/L of TCL and 4 µg/L of TER. A significant correlation between heart rate and distance moved was found in all exposed groups. These results suggest that pulse exposure to MTZ impact crayfish physiology and behavior during short-term period. With pulse exposure to TCL and TER, crayfish not exhibiting a locomotor response may continue to be exposed to lower, but potentially harmful, levels of pollutants. Evidence of the impacts of pesticide pulse at environmentally relevant concentrations on crayfish is scarce. Further study is required to determine the ecological effects of such events on freshwater crayfish.

Pristane cadmium chloride nanoemulsion accelerates the onset of systemic lupus erythematosus in a C57BL/6 mouse model

OBJECTIVE

To accelerate the onset of systemic lupus erythematosus in C57BL/6 mice by injecting cadmium chloride nanoemulsion and shorten the traditional modeling time.

METHODS

Pristane cadmium chloride nanoemulsion was prepared, and 66 C57BL/6 mice were randomly divided into four groups. The pristane group was intraperitoneally injected with 0.6 mL of pristane blank nanoemulsion, the model group was injected with 0.6 mL of pristane cadmium chloride nanoemulsion, the Cadmium chloride control group was injected with 0.6 mL of cadmium chloride nanoemulsion, and the control group was injected with the same amount of 0.9% sodium chloride solution. Urine protein content, anti-dsDNA antibody content, Th1 cell/Th2 cell ratio, and kidney staining were detected in each group.

RESULTS

The model group began to develop disease in the 4th week, the anti-dsDNA antibody level reached 566.71 ± 1.44 ng/L, and the proteinuria reached 245.38 ± 30.54 ng/mL. The model group showed an onset at least 5 weeks earlier than that in the pristane group. There was no significant difference in anti-dsDNA antibody content between Cadmium chloride control group and blank group. At the 12th week, the Th1/Th2 cell ratio in the model group significantly decreased, and the pathological changes in the kidneys were consistent with the typical manifestations of lupus in mouse models.

CONCLUSION

These results suggest that cadmium chloride promotes earlier onset of pristane-induced systemic lupus erythematosus in a C57BL/6 mouse model.

Tebufenozide has limited direct effects on simulated aquatic communities

The use of insecticides to control undesirable pest species in forestry has undergone a shift from broad spectrum to narrow spectrum insecticides to reduce the risk of effects on non-target species. However, there is still risk of direct effects on non-target species as some insecticides function as hormone mimics, or through indirect pathways as the insecticide is broken down in the environment. Tebufenozide, an ecdysone hormone mimic, is the active ingredient in insecticides used in a variety of large scale pest control programs. An oft cited reason for the safety of Tebufenozide is that it is rapidly broken down in the environment by microbes. We investigated the potential non-target effects of two Tebufenozide formulations used in Canada, Mimic 240LV and Limit 240, on aquatic communities using an outdoor mesocosm experiment. We focus on direct effects on amphibian larvae (wood frog, Rana sylvaticus), zooplankton communities, and effects on biofilm and phytoplanktonic microbial communities that could arise from either direct toxicity, or from breaking down the insecticide as a nutrient and/or carbon source. There was limited evidence for direct effects on amphibian larvae or zooplankton communities. There were small but non-significant shifts in biofilm microbial communities responsible for nutrient cycling. Beta diversity in the plankton community was slightly higher among tanks treated with insecticide indicating a community dispersion/disbiosis effect. Overall, we found limited evidence of negative effects, however, subtle changes to microbial communities did occur and could indicate changes to ecosystem function.

Cytotoxicity evaluation and mechanism of endocrine-disrupting chemicals by the embryoid body test

Endocrine-disrupting chemicals (EDCs) are a structurally diverse class of synthetic and natural compounds. EDCs can cause non-communicable diseases such as obesity, type 2 diabetes, thyroid disorders, neurodevelopmental disease, hormone-dependent cancers, and reproductive disorders. The embryoid body test (EBT) is a developmental toxicity test method that determines the size of embryoid bodies (EBs) and the viability of mouse embryonic stem cells (mESCs) and fibroblasts (3T3 cells). The present study used the EBT to perform cytotoxicity evaluations of 10 EDCs and assessed the mechanistic relationship between endoplasmic reticulum (ER) stress and cytotoxicity. According to the statistical analysis and prediction model results, methylparaben, butylparaben, propylparaben, ethylparaben, triclosan, octylphenol, methoxychlor, bisphenol A, and diethylstilbestrol were classified as cytotoxic, but trichloroacetic acid was non-toxic. Classification accuracy was 90%. The mechanistic study showed that the cytotoxicities of butylparaben, propylparaben, octylphenol, and triclosan were induced by ER stress. The mRNA expressions of BiP, CHOP, and ATF4 were significantly higher following treatments with four EDCs compared to those after the control treatment. Compared to the control treatment, the mRNA levels of XBP1u and XBP1s increased significantly after butylparaben and propylparaben treatments, but did not increase with octylphenol and triclosan treatments. These results indicate that the EBT can be applied as an alternative toxicity test when evaluating the cytotoxicity of EDCs.

Preparation and evaluation of novel bio-based Bis-GMA-free dental composites with low estrogenic activity

OBJECTIVE

Although bisphenol Aglycidyl methacrylate (Bis-GMA) are widely used in the dental composite, its raw materials include the petroleum-based product bisphenol A (BPA) with high estrogenic activity (EA). In this study, two new BPA-free dimethacrylate monomers from bio-based material creosol were synthesized and evaluated.

METHODS

The renewable bisphenol monomer 5, 5'-methylenedicreosol (BCF) was prepared from bio-based material creosol. By the human breast cancer cells (MCF-7 cells) proliferation assay, a risk assessment of BCF was performed to determine if BCF possessed reduced EA in comparison to BPA. Then, the novel monomers 5, 5'-methylenedicreosol diglycidyl ether diacrylate (BCF-EA) and 5, 5'-methylenedicreosol diglycidyl ether dimethacrylate (BCF-GMA) were synthesized from BCF with epichlorohydrin and (meth)acrylate. All products were investigated by ¹H NMR and FT-IR spectra. The control resin was a mixture based on Bis-GMA and tri(ethyleneglycol) dimethacrylate (TEGDMA) with a weight ratio of 5:5 (5B5T). Similarly, experimental resin matrix was a mixture based on BCF-EA/TEGDMA (5E5T) and BCF-GMA/TEGDMA (5G5T). And their corresponding composites were then prepared with corresponding resin matrices and hybrid SiO₂ (5E5TC, 5G5TC and 5B5TC). The properties of these composites were investigated according to the standard or referenced methods. Each sample was evaluated for double bond conversion (DC), shrinkage stress (SS) and volumetric polymerization shrinkage (VS). Water sorption (WS), water solubility (SL), mechanical properties and cytotoxicity were also measured.

RESULTS

¹H NMR and FT-IR spectra confirmed the chemical structure of each monomer. EA test revealed that bio-based bisphenol monomer BCF as the precursor of BCF-EA and BCF-GMA showed lower EA than BPA. Cured resin matrix: Both 5E5T and 5G5T had nearly the same DC (p < 0.05), which was higher than 5B5T (p < 0.05); 5E5T and 5G5T had lower VS, SL and cytotoxicity than 5B5T (p < 0.05); mechanical properties of 5E5T and 5G5T were all better than those of 5B5T (p < 0.05). Cured composite: There was no significant difference in conversion (p < 0.05); 5E5TC and 5G5TC had significantly lower VS (p < 0.05); WS of 5E5TC and 5G5TC were similar (p < 0.05), but higher compared to 5B5TC (p < 0.05); 5E5TC and 5G5TC had the deeper depth of cure (p > 0.05); before water immersion, there was no significant difference in flexural strength between 5E5TC and 5G5TC (p > 0.05), and higher than 5B5TC (p < 0.05); 5E5TC and 5G5TC showed less cytotoxicity than 5B5TC (p < 0.05).

SIGNIFICANCE

The new BPA-free di(meth)acrylates are promising photocurable dental monomers owning to bio-based raw material, high degree of conversion coupled with low curing shrinkage and good mechanical properties. Therefore, BCF-EA and BCF-GMA has a potential to be used as the substitution for Bis-GMA to prepare Bis-GMA-free dental composite.

Shifting Perspectives of Translational Research in Bio-Bactericides: Reviewing the Bacillus amyloliquefaciens Paradigm

Simple Summary

The continuous reduction of approved conventional microbicides, due to health concerns and the development of plant-pathogen resistance, has been urged for the use of safe alternatives in crop protection. Several beneficial bacterial species, termed biological control agents, are currently used in lieu of chemical pesticides. The approach to select such bacterial species and manufacture commercial products has been based on their biocontrol effect under optimal growth conditions, which is far from the real nutrient-limited field conditions of plant niches. It’s important to determine the complex interactions that occur among BCAs, plant host and niche microbiome to fully understand and exploit the potential of biological control agents. Furthermore, it’s crucial to acknowledge the environmental impact of their long-term use.

Abstract

Bacterial biological control agents (BCAs) have been increasingly used against plant diseases. The traditional approach to manufacturing such commercial products was based on the selection of bacterial species able to produce secondary metabolites that inhibit mainly fungal growth in optimal media. Such species are required to be massively produced and sustain long-term self-storage. The endpoint of this pipeline is large-scale field tests in which BCAs are handled as any other pesticide. Despite recent knowledge of the importance of BCA-host-microbiome interactions to trigger plant defenses and allow colonization, holistic approaches to maximize their potential are still in their infancy. There is a gap in scientific knowledge between experiments in controlled conditions for optimal BCA and pathogen growth and the nutrient-limited field conditions in which they face niche microbiota competition. Moreover, BCAs are considered to be safe by competent authorities and the public, with no side effects to the environment; the OneHealth impact of their application is understudied. This review summarizes the state of the art in BCA research and how current knowledge and new biotechnological tools have impacted BCA development and application. Future challenges, such as their combinational use and ability to ameliorate plant stress are also discussed. Addressing such challenges would establish their long-term use as centerfold agricultural pesticides and plant growth promoters.

Exploiting the Potential of Supported Magnetic Nanomaterials as Fenton-Like Catalysts for Environmental Applications

In recent years, the application of magnetic nanoparticles as alternative catalysts to conventional Fenton processes has been investigated for the removal of emerging pollutants in wastewater. While this type of catalyst reduces the release of iron hydroxides with the treated effluent, it also presents certain disadvantages, such as slower reaction kinetics associated with the availability of iron and mass transfer limitations. To overcome these drawbacks, the functionalization of the nanocatalyst surface through the addition of coatings such as polyacrylic acid (PAA) and their immobilization on a mesoporous silica matrix (SBA15) can be factors that improve the dispersion and stability of the nanoparticles. Under these premises, the performance of the nanoparticle coating and nanoparticle-mesoporous matrix binomials in the degradation of dyes as examples of recalcitrant compounds were evaluated. Based on the outcomes of dye degradation by the different functionalized nanocatalysts and nanocomposites, the nanoparticles embedded in a mesoporous matrix were applied for the removal of estrogens (E1, E2, EE2), accomplishing high removal percentages (above 90%) after the optimization of the operational variables. With the feasibility of their recovery in mind, the nanostructured materials represented a significant advantage as their magnetic character allows their separation for reuse in different successive sequential batch cycles.

Cypermethrin induces Sertoli cell apoptosis through mitochondrial pathway associated with calcium

Cypermethrin, one kind of pyrethroid pesticides, has been shown to act as endocrine-disrupting chemicals (EDCs). The purpose of this study was to explore the roles of Sertoli cell apoptosis through mitochondrial pathway associated with calcium (Ca²⁺) in cypermethrin-induced male reproductive toxicology. The mouse Sertoli cells TM4 were cultured with 0 μM, 10 μM, 20 μM, 40 μM and 80 μM of cypermethrin. We used flow cytometry, Fluo-4 AM, western blot and JC-1 Assay Kit to examine apoptosis, intracellular Ca²⁺, expressions of mitochondrial apoptotic pathway-related proteins and mitochondrial membrane potential. We found cypermethrin increased apoptosis rate of TM4 cells significantly and with a significant increase in intracellular Ca²⁺ concentration. Cypermethrin significantly decreased the protein expressions of cytosolic B-cell lymphoma-2 (Bcl-2) and mitochondrial cytochrome c (Cyt-c). The protein expressions of cytosolic Bcl-2-associated x (Bax), Cyt-c, cleaved caspase-3, calmodulin (CaM), Ca²⁺/CaM-dependent protein kinases II (CaMKII) and phosphorylated CaMKII were increased significantly in cypermethrin-exposed TM4 cells. Cypermethrin decreased mitochondrial membrane potential significantly. Then, Bcl-2 family and Ca²⁺/CaM/CaMKII pathway participate in cypermethrin-induced homeostasis. Ca²⁺ overload activates mitochondrial pathway by increasing permeability of mitochondrial membrane and decreasing mitochondrial membrane potential. We suggest cypermethrin induces Sertoli cell apoptosis involving mitochondrial pathway associated with Ca²⁺ regulated by Bcl-2 family and Ca²⁺/CaM/CaMKII pathway. The study provides a new insight into mechanisms involved in cypermethrin-induced male reproductive toxicology.

Preparation of a Novel Resin Based Covalent Framework Material and Its Application in the Determination of Phenolic Endocrine Disruptors in Beverages by SPE-HPLC

A new type of economical covalent organic framework material(COF), namely resin based covalent organic framework material, was prepared by combining resin and covalent organic framework material by hydrothermal synthesis, which was based on the preparation of traditional COF material(TpBD COF). The properties of the material and covalent organic framework material were compared in the way of characterization, and the possible reaction mechanism was analyzed. The solid phase extraction separation (SPE) ability of this material for four kinds of phenolic endocrine disrupting compounds (bisphenol F, bisphenol A, octylphenol and nonylphenol) in beverage samples was investigated. The results showed that the prepared COF materials had abundant internal channels, ordered structure, large specific surface area (TpBD COF: 814.6 m2/g and resin based COF: 623.9 m2/g) and good thermal stability (pyrolysis temperature was 443 °C and 437 °C, respectively). Solid phase extraction experiments demonstrated that the two COF materials as adsorbent of solid phase extraction column had ideal adsorption separation effect and good anti-interference ability, and had strong anti-interference ability. The SPE effect was superior to the traditional solid phase extraction column. The precision RSD of this method was less than 3%. This SPE method had high recovery and could be reused (carbonated beverage: 98.18-102.18% and beverage: 98.52-101.79%), In addition, the recovery of the material did not change significantly in the 50 cycles of solid phase extraction, indicating that the material had good stability and could be reused, which could meet the requirements for the detection and analysis of trace pollutants in environmental samples. The resin based COF material prepared in this study could reduce the cost of monomer uses and provide a possibility for its industrial production. At the same time, as an efficient SPE adsorbent, it also provided a new research scheme for the enrichment of trace phenolic endocrine disruptors in beverage samples.

A Review of the Impact of Selected Anthropogenic Chemicals from the Group of Endocrine Disruptors on Human Health

BACKGROUND

The aim of the study was to review data on the impact of anthropogenic chemicals (endocrine disruptors) on various diseases, which, consequently, may facilitate their prevention and be used as a tool for managing public healthcare. Every day, humans are exposed to chemicals, including xenoestrogens, which are similar to female hormones.

METHODS

This manuscript was prepared based on a meta-analysis of research on the impacts of selected EDCs on human health.

RESULTS

Special attention should be paid to bisphenol A (BPA), benzo-α-pyrene, and phthalates due to their proven endocrine activity and presence in our daily lives. Xenoestrogens are absorbed by human organisms through the digestive system since they can migrate to food from food packages and drinks as well as from plastic products used daily. The presence of these chemicals in human organisms is considered a potential cause for some diseases commonly referred to as 'diseases of civilization'.

CONCLUSIONS

The biomonitoring of xenoestrogens, which are chemicals with unfavorable impacts on human health, is a crucial tool for assessing the risk from the pollution of the environment. The novelty is a holistic approach to assessing the occurrence of risk factors for civilization diseases.

Chronic Exposure to 4-Nonylphenol Alters UDP-Glycosyltransferase and Sulfotransferase Clearance of Steroids in the Hard Coral, Pocillopora damicornis

The effects of the xenoestrogen 4-nonylphenol (4NP) on endocrine and metabolic homeostasis in the reef building coral, Pocillopora damicornis were investigated. The aim was to understand if ubiquitous nonylphenol ethoxylate contaminants in the marine environment result in altered homeostatic function. Coral colonies were chronically exposed (6 weeks) to a sublethal concentration (1 ppb) of 4NP and sampled over the coral's lunar reproductive cycle. Although activity of steroidogenic enzymes [cytochrome P450 (CYP) 17, CYP 19, and 3-β-Hydroxysteroid dehydrogenase] and the conjugation enzyme glutathione-S-transferase was not altered, significant increases in the activity of the steroid clearing enzyme UDP-glycosyltransferase (UGT) were observed. The natural fluctuation of UGT activity with the lunar cycle was replaced with consistently high UGT activity throughout the reproductive cycle during 4NP exposure. No effect of 4NP on the reverse reaction, mediated by β-glucuronidase, was observed. Thus, 4NP shifts the UGT:β-glucuronidase ratio toward greater clearance at points in the lunar cycle where retention of compounds is typically favored. Additionally, 4NP reduced activity of the steroid regeneration enzyme steroid sulfatase, further shifting the system toward clearance rather than regeneration. These data imply that environmentally relevant levels of 4NP may be impacting the reproductive health of corals and threatening the persistence of coral reefs.

Efficient photocatalytic destruction of recalcitrant micropollutants using graphitic carbon nitride under simulated sunlight irradiation

The ubiquity of micropollutants (MPs) in aquatic environments has attracted increasing concern for public health and ecological security. Compared to conventional biological treatment, photocatalytic processes show more efficiency in degrading MPs, but they require expensive materials and complicated synthesis processes. This study developed an economic photocatalytic process to degrade micropollutants. We synthesized urea-based graphitic carbon nitride (g-C3N4) by a facile one-step pyrolysis method and evaluated the photocatalytic efficiency of carbamazepine (CBZ). Under simulated solar irradiation, g-C3N4 could achieve 100% removal efficiency of 0.1 mg/L CBZ in spiked wastewater effluent within 15 min, and 86.5% removal efficiency in wastewater influent after 20 min of irradiation. The porous structure of g-C3N4 promoted effective charge separation and mass transport of CBZ near the catalyst surface, enabling a high kinetic rate (0.3662 min -1). Reactive oxygen species trapping experiments revealed that superoxide radicals (O2 •-) and holes (h+) were the major active radicals. Electron paramagnetic resonance (EPR) further confirmed the presence of O2 •-, • OH, 1O2 and holes. The pH, light intensity and initial CBZ concentration were found to have significant impacts on the removal efficiency of CBZ. Possible reaction intermediates were identified and the degradation pathway was proposed. Multiple MPs were selected to further demonstrate photocatalytic efficiency of g-C3N4. The facile synthesis, superior efficiency, and versatility of g-C3N4 make it a promising catalyst for application in tertiary wastewater treatment processes.

Fluorescent methylammonium lead halide perovskite quantum dots as a sensing material for the detection of polar organochlorine pesticide residues

Methylammonium lead halide perovskite quantum dots (MAPB-QDs) have been widely used for photovoltaic devices due to their special electronic structures. In this work, MAPB-QDs were used for the first time to detect polar organochlorine pesticides (OCPs) based on the phenomenon that the fluorescence spectra of MAPB-QDs were blue-shifted in the presence of polar OCPs. Furthermore, ¹H NMR, FTIR, XPS and XRD were performed first to illustrate the sensing mechanism. In the presence of polar OCPs, the MAPB-QDs' capping ligands, oleic acid (OA) and oleylamine (OAm), were replaced with OCPs and then the chlorine element was adequately doped into QDs, resulting in the increase of the MAPB-QDs' bandgap. As result of the insufficient stability of MAPB-QDs in the presence of moisture, MAPB-QDs were mixed with PDMS and used as the colorimetric cards for fast detection of OCPs in real samples.

Sex-Specific Differences of Steroid Receptors Following Exposure to Environmentally Relevant Concentrations of Phenothiazine in Fundulus heteroclitus

Phenothiazine (PTZ) is a heterocyclic thiazine compound used for industrial and medical purposes. Through environmental surveillance studies, PTZ was found being discharged into a local river in Connecticut. Phenothiazine has been shown to act similarly to endocrine disrupting chemicals. This study sought to identify sex specific hormone receptor changes in Fundulus heteroclitus in response to PTZ exposure. Fundulus heteroclitus, also known as mummichog, are small fish native to the Atlantic coast of the United States and Canada. They reside in brackish waters and can survive harsh toxic environments. This model organism is native to the polluted waters found in Connecticut. In this study, fish were exposed to PTZ concentrations of 0.5 ppm, 1.0 ppm, and 2.0 ppm for 1 week. Following exposure, brain, liver, and gonad tissues were harvested; cDNA was synthesized; and mRNA expression was assessed for 6 different hormone receptors. Compared with vehicle control (ethanol) differences in mRNA expression, levels of hormone receptors were observed in various tissues from male and female fish. Many of the tissues assessed showed changes in expression level, while only female liver and testis showed no change. These results implicate PTZ as a potential endocrine disrupting compound to mummichog at environmentally relevant concentrations.

Developmental polychlorinated biphenyl exposure influences adult zebra finch reproductive behaviour

Polychlorinated biphenyls (PCBs) are worldwide chemical pollutants that have been linked to disrupted reproduction and altered sexual behaviour in many organisms. However, the effect of developmental PCB-exposure on adult passerine reproductive behaviour remains unknown. A commercial PCB mixture (Aroclor 1242) or an estrogenic congener (PCB 52) were administered in sublethal amounts to nestling zebra finches (Taeniopygia guttata) in the laboratory to identify effects of developmental PCB-exposure on adult zebra finch reproductive parameters. Results indicate that although traditional measures of reproductive success are not altered by this PCB dosage, PCBs do alter sexual behaviours such as male song and nesting behaviour. Males treated with PCB 52 in the nest sang significantly fewer syllables than control males, while females treated with Aroclor 1242 in the nest showed the strongest song preferences. PCB treatment also caused an increase in the number of nesting attempts and abandoned nests in the Aroclor 1242 treatment relative to the PCB 52 treatment, and offspring with control fathers fledged significantly earlier than those with fathers treated with Aroclor 1242. Behavioural differences between males seem to best explain these reproductive effects, most notably aggression. These findings suggest that sublethal PCB-exposure during development can significantly alter key reproductive characteristics of adult zebra finches, likely reducing fitness in the wild.

The dark side of the breastfeeding: In the light of endocrine disruptors

Breastfeeding plays an essential role in the healthy development of a newborn, but human milk is obviously compromised by pollutants from our environment. The main contaminants of human milk with endocrine-disrupting compound (EDCs) have raised concern for public and environmental health. Bisphenol A (BPA), which can leach from plastics, are among the most well-studied. Since EDs are known to cross the mammary gland barrier and BPA may accumulate in the neonate, “BPA-free” products have been introduced to the market. However, recent studies have shown that alternative bisphenols (e.g. BPS, BPF) can be detected in breast milk, have ED activities and may have developmental effects similar to BPA.

Impacts of the synthetic androgen Trenbolone on gonad differentiation and development - comparisons between three deeply diverged anuran families

Using a recently developed approach for testing endocrine disruptive chemicals (EDCs) in amphibians, comprising synchronized tadpole exposure plus genetic and histological sexing of metamorphs in a flow-through-system, we tested the effects of 17β-Trenbolone (Tb), a widely used growth promoter in cattle farming, in three deeply diverged anuran families: the amphibian model species Xenopus laevis (Pipidae) and the non-models Bufo(tes) viridis (Bufonidae) and Hyla arborea (Hylidae). Trenbolone was applied in three environmentally and/or physiologically relevant concentrations (0.027 µg/L (10-10 M), 0.27 µg/L (10-9 M), 2.7 µg/L (10-8 M)). In none of the species, Tb caused sex reversals or masculinization of gonads but had negative species-specific impacts on gonad morphology and differentiation after the completion of metamorphosis, independently of genetic sex. In H. arborea and B. viridis, mounting Tb-concentration correlated positively with anatomical abnormalities at 27 µg/L (10-9 M) and 2.7 µg/L (10-8 M), occurring in X. laevis only at the highest Tb concentration. Despite anatomical aberrations, histologically all gonadal tissues differentiated seemingly normally when examined at the histological level but at various rates. Tb-concentration caused various species-specific mortalities (low in Xenopus, uncertain in Bufo). Our data suggest that deep phylogenetic divergence modifies EDC-vulnerability, as previously demonstrated for Bisphenol A (BPA) and Ethinylestradiol (EE2).

Effect-based environmental monitoring for thyroid disruption in Swedish amphibian tadpoles

It is well-known that the metamorphosis process in amphibians is dependent on thyroid hormones. Laboratory studies have shown that several environmental contaminants can affect the function of thyroid hormones leading to alterations in the amphibian metamorphosis. The basic idea of the present study was to elucidate if the amphibian metamorphosis might be a useful tool as biomarker for effect-based environmental monitoring, examining wild tadpoles for potential thyroid hormone disruption. A laboratory test was performed to identify the responses from exposure to 6-propylthiouracil (PTU), which has a well-known mechanism on the thyroid system, on Swedish tadpoles from the Rana genus. This was followed by an environmental monitoring study where tadpoles of Rana arvalis, R. temporaria, and Bufo bufo were sampled from various sites in Sweden. Morphological data such as body weight, histopathological measurements of the thyroid glands, and environmental parameters were recorded. The results revealed that Rana tadpoles respond similar as other amphibians to PTU exposure, with interrupted development and increased size relative to the developmental stage. Data on some wild tadpoles showed similar features as the PTU exposed, such as high body weight, thus suggesting potential thyroid disrupting effects. However, histological evaluation of thyroid glands and pesticide analyses of the water revealed no clear evidence of chemical interactions. To a minor degree, the changes in body weight may be explained by natural circumstances such as pH, forest cover, and temperature. The present study cannot fully explain whether the high body weights recorded in some tadpoles have natural or chemical explanations. However, the study reveals that it is clearly achievable to catch tadpoles in suitable stages for the use in this type of biomonitoring and that the use of these biomarkers for assessment of thyroid disruption seems to be highly relevant.

Marker-assisted selection of YY supermales from a genetically improved farmed tilapia-derived strain

Genetically improved farmed tilapia (GIFT) and GIFT-derived strains account for the majority of farmed tilapia worldwide. As male tilapias grow much faster than females, they are often considered more desirable in the aquacultural industry. Sex reversal of females to males using the male sex hormone 17-α-methyltestosterone (MT) is generally used to induce phenotypic males during large-scale production of all male fingerlings. However, the widespread use of large quantities of sex reversal hormone in hatcheries may pose a health risk to workers and ecological threats to surrounding environments. Breeding procedures to produce genetically all-male tilapia with limited or no use of sex hormones are therefore urgently needed. In this study, by applying marker-assisted selection (MAS) for the selection of YY supermales from a GIFT-derived strain, we identified 24 XY pseudofemale and 431 YY supermale tilapias. Further performance evaluation on the progenies of the YY supermales resulted in male rates of 94.1%, 99.5% and 99.6%, respectively, in three populations, and a daily increase in body weight of 1.4 g at 3 months (n=997). Our study established a highly effective MAS procedure in the selection of YY supermales from a GIFT-derived strain. Furthermore, the development of MAS-selected YY supermales will help reduce the utilization of hormones for controlling sex in the tilapia aquaculture.

Prenatal Exposure to Endocrine Disruptors and Cardiometabolic Risk in Preschoolers: A Systematic Review Based on Cohort Studies

Background:

Follow-up studies have reported both positive and negative associations between prenatal exposure to endocrine disrupting chemicals (EDCs) and some anthropometric indicators of overweight and obesity in children. However, few studies have evaluated the effect of this exposure on cardiometabolic risk factors in preschool-age children. The health and disease development paradigm (DOHaD) proposes that the physiological and metabolic adaptations triggered by the exposure to these compounds, coupled with postnatal conditions, can modify the risk of disease. In this context, cardiometabolic risk factors in children are not only an important outcome derived from prenatal exposure but a predictor/mediator of the children’s future health.

Objective:

To conduct a systematic review of the evidence published in the last 10 years from cohort studies on the association between prenatal exposure to EDCs and cardiometabolic risk factors in preschoolers.

Design:

Studies published from January 1, 2007 to May 1, 2017 in PubMed were analyzed. The research strategy was based on specified keywords and following the application of strict inclusion/exclusion criteria, 16 studies were identified and reviewed. Data were extracted and aspects of quality were assessed using an adapted Newcastle–Ottawa scale for cohort studies.

Results:

Only 5 of the 16 studies reviewed analyzed cardiometabolic risk factors in addition to anthropometric measures in children. The cohort studies included in this review suggest that prenatal exposure to low concentrations of EDCs has an impact on anthropometric variables and biochemical parameters in preschool-age children. Positive associations between prenatal exposure to EDCs and percentage of fat mass, body mass index, waist circumference, skinfolds and risk of overweight persisted after adjustment for important confounding variables. No association was found with lipid profile and glucose levels.

Conclusions:

Evidence was found to suggest that prenatal exposure to EDCs is positively associated with cardiometabolic risk factors in preschool children.

Comprehensive Screening Links Halogenated Organic Compounds with Testosterone Levels in Male Delphinus delphis from the Southern California Bight

While environmental pollutants have been associated with changes in endocrine health in cetaceans, efforts to link contaminant exposure with hormones have largely been limited to a list of known, targeted contaminants, overlooking minimally characterized or unknown compounds of emerging concern. To address this gap, we analyzed a suite of potential endocrine disrupting halogenated organic compounds (HOCs) in blubber from 16 male short-beaked common dolphins ( Delphinus delphis) with known maturity status collected from fishery bycatch in the Southern California Bight. We employed a suspect screening mass spectrometry-based method to investigate a wide range of HOCs that were previously observed in cetaceans from the same region. Potential endocrine effects were assessed through the measurement of blubber testosterone. We detected 167 HOCs, including 81 with known anthropogenic sources, 49 of unknown origin, and 37 with known natural sources. The sum of 11 anthropogenic and 4 unknown HOC classes were negatively correlated with blubber testosterone. Evidence suggests that elevated anthropogenic HOC load contributes to impaired testosterone production in mature male D. delphis. The application of this integrative analytical approach to cetacean contaminant analysis allows for inference of the biological consequences of accumulation of HOCs and prioritization of compounds for future environmental toxicology research.

Subchronic exposure to kalach 360 SL-induced endocrine disruption and ovary damage in female rats

Kalach 360 SL (KL), glyphosate (G) surfactant-based herbicides, is a systemic herbicide effective against weeds. It was applied in agriculture in Tunisia and throughout the world, which can represent a risk to non-target organisms. The aim of this study was to investigate the morphological and biochemical aspects of ovary injury after exposure to KL. Female Wistar rats were divided into three groups: group 1 was used as a control; group 2 orally received 0.07 ml of KL, (126 mg of G/kg) and group 3 orally received 0.175 ml of KL (315 mg of G/kg) each day for 60 days. The subchronic exposure of KL induces impaired folliculogenesis, ovary development, decreased oestrogen secretion, promoted oxidative stress and impairments of ovary histological aspects. Histological finding shows necrosis cell, vacuolisation of follicles, dissociated oocytes and granulosa cell, associated with several atretic follicles. We conclude that KL induces endocrine disruption and ovary damage in female rats.

Premature Immunosenescence Impairs Immune Surveillance Allowing the Endometriotic Stem Cell to Migrate: The Cytokine Profile as a Common Denominator

While endometriosis, one of the most common reasons for infertility, remains a multifactorial condition and its exact cause highly speculative, there are data pointing to novel pathways of disease initiation which involve a stem cell and its ability to migrate and implant after it differentiates into an endometriotic stem cell. Thus, the mechanisms conferring immune surveillance, which would also normally expel the mesenchymal endometriotic cell, impairing its migration and implantation, appear to be negatively influenced by a state of endometriotic premature immunosenescence. This interplay between the two immunological mechanisms and endometriosis is influenced by a number of common factors having an active role in the host's protection process that inhibits harmful diseases and maintains cellular homeostasis. It appears more than coincidental that production/inhibition of IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-15, IL-18, TNF-α, VEGF, ICAM-1, and the number of Tolllike receptors is the same in immunosenescent states and in conditions with reduced immune surveillance, while the same variations are recorded in endometriotic patients. It is probable that these are common to all process signals, guide the endometriotic stem cell and dictate its fate according to the stochastic, transdifferentiation (plasticity) or deterministic model to become capable of migration and tissue invasion. It is currently unknown whether the pathway taken by the hemopoietic stem cell to become endometriotic represents a normal or aberrant route of development. This prompts research into its isolation and in vitro study of its behavior in order to reveal its potential function and role in endometriosis. (Journal of Endometriosis 2010; 2: 7–18)

Risks and benefits related to alimentary exposure to xenoestrogens

Xenoestrogens are widely diffused in the environment and in food, thus a large portion of human population worldwide is exposed to them. Among alimentary xenoestrogens, phytoestrogens (PhyEs) are increasingly being consumed because of their potential health benefits, although there are also important risks associated to their ingestion. Furthermore, other xenoestrogens that may be present in food are represented by other chemicals possessing estrogenic activities, that are commonly defined as endocrine disrupting chemicals (EDCs). EDCs pose a serious health concern since they may cause a wide range of health problems, starting from pre-birth till adult lifelong exposure. We herein provide an overview of the main classes of xenoestrogens, which are classified on the basis of their origin, their structures and their occurrence in the food chain. Furthermore, their either beneficial or toxic effects on human health are discussed in this review.

Identification of candidate reference chemicals for in vitro steroidogenesis assays

The Endocrine Disruptor Screening Program (EDSP) is transitioning from traditional testing methods to integrating ToxCast/Tox21 in vitro high-throughput screening assays for identifying chemicals with endocrine bioactivity. The ToxCast high-throughput H295R steroidogenesis assay may potentially replace the low-throughput assays currently used in the EDSP Tier 1 battery to detect chemicals that alter the synthesis of androgens and estrogens. Herein, we describe an approach for identifying in vitro candidate reference chemicals that affect the production of androgens and estrogens in models of steroidogenesis. Candidate reference chemicals were identified from a review of H295R and gonad-derived in vitro assays used in methods validation and published in the scientific literature. A total of 29 chemicals affecting androgen and estrogen levels satisfied all criteria for positive reference chemicals, while an additional set of 21 and 15 chemicals partially fulfilled criteria for positive reference chemicals for androgens and estrogens, respectively. The identified chemicals included pesticides, pharmaceuticals, industrial and naturally-occurring chemicals with the capability to increase or decrease the levels of the sex hormones in vitro. Additionally, 14 and 15 compounds were identified as potential negative reference chemicals for effects on androgens and estrogens, respectively. These candidate reference chemicals will be informative for performance-based validation of in vitro steroidogenesis models.

Adsorption Removal of 17β-Estradiol from Water by Rice Straw-Derived Biochar with Special Attention to Pyrolysis Temperature and Background Chemistry

Rice straw biochar that produced at three pyrolysis temperatures (400, 500 and 600 °C) were used to investigate the adsorption properties of 17β-estradiol (E2). The biochar samples were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), elemental analysis and BET surface area measurements. The influences of pyrolysis temperature, E2 concentration, pH, ionic strength, background electrolyte and humic acid were studied. Kinetic and isotherm results illustrated that the adsorption process could be well described by pseudo-second-order and Freundlich models. Experimental results showed that ionic strength had less influence on the adsorption of E2 by 500 and 600 °C rice straw biochar. Further, multivalent ions had positive impact on E2 removal than monovalent ions and the influence of the pyrolysis temperature was unremarkable when background electrolyte existed in solutions. The adsorption capacity of E2 decreased with the pH ranged from 3.0 to 12.0 and the humic acid concentration from 2 to 10 mg L-1. Electrostatic attractions and π-π interaction were involved in the adsorption mechanisms. Compared to low-temperature biochar, high-temperature biochar exhibited a better adsorption capacity for E2 in aqueous solution, indicated it had a greater potential for E2 pollution control.

Occurrence and risk assessment of estrogenic compounds in the East Lake, China

Forty two surface water samples were collected in May and June of 2013 in five lakelets of the East Lake, China. Four steroid hormones (17β-estradiol (βE2), estrone (E1), 17α-estradiol (αE2) and 17α-ethinylestradiol (αEE2)) were analyzed in these samples. Determination of four estrogenic compounds was performed on high performance liquid chromatography/mass spectrometry (HPLC/MS). βE2 was detected with the highest detection frequency of 62% and its concentration range was from nd to 17.58ng/L. The mean total concentration of four compounds increased with the order: Houhu lake (L5) (8.91ng/L)<Niuchao lake (L1) (19.92ng/L)<Guozheng lake (L2) (20.03ng/L)<Tangling lake (L4) (22.65ng/L)<Guandu lake (L3) (35.68ng/L). Pollution sources of four compounds were mainly from municipal wastewater and water washed out from farm land fertilized with the waste of livestock or irrigated with water from livestock farm. The proportion of sample sites at high risk that compounds had effect on fish population were 58.3% in Guozheng (L2) lake, 100% in Guandu (L3) lake, and 62.5% in Tangling (L4), Niuchao (L1) and Houhu (L5) lake, respectively. The mean βE2 equivalent concentrations was at relatively high levels in L3 with 8.6ng/L, L1 with 6.1ng/L, L4 with 4.62ng/L, L2 with 4.58ng/L and L5 with 2.62ng/L, respectively. Meanwhile, sampling sites at high risk generally were surrounded with hospitals, hotels and residential buildings where had high population density.

Computational study involving identification of endocrine disrupting potential of herbicides: Its implication in TDS and cancer progression in CRPC patients

Several environmental pollutants, including herbicides, act as endocrine disrupting chemicals (EDCs). They can cause cancer, diabetes, obesity, metabolic diseases and developmental problems. Present study was conducted to screen 608 herbicides for evaluating their endocrine disrupting potential. The screening was carried out with the help of endocrine disruptome docking program, http://endocrinedisruptome.ki.si (Kolsek et al., 2013). This program screens the binding affinity of test ligands to 12 major nuclear receptors. As high as 252 compounds were capable of binding to at least three receptors wherein 10 of them showed affinity with at-least six receptors based on this approach. The latter were ranked as potent EDCs. Majority of the screened herbicides were acting as antagonists of human androgen receptor (hAR). A homology modeling approach was used to construct the three dimensional structure of hAR to understand their binding mechanism. Docking results reveal that the most potent antiandrogenic herbicides would bind to hydrophobic cavity of modeled hAR and may lead to testicular dysgenesis syndrome (TDS) on fetal exposure. However, on binding to T877 mutant AR they seem to act as agonists in castration-resistant prostate cancer (CRPC) patients.

Reversible Reduction of Estrone to 17β-Estradiol by , , and Isolates from the Las Vegas Wash

Environmental endocrine-disrupting compounds (EDCs) are a growing concern as studies reveal their persistence and detrimental effects on wildlife. Microorganisms are known to affect the transformation of steroid EDCs; however, the diversity of estrogen-degrading microorganisms and the range of transformations they mediate remain relatively little studied. In mesocosms, low concentrations of added estrone (E1) and 17β-estradiol (E2) were removed by indigenous microorganisms from Las Vegas Wash water within 2 wk. Three bacterial isolates, sp. strain LVW-9, sp. strain LVW-12, and sp. strain LVW-PC, were enriched from Las Vegas Wash water on E1 and E2 and used for EDC transformation studies. In the presence of alternative carbon sources, LVW-9 and LVW-12 catalyzed near-stoichiometric reduction of E1 to E2 but subsequently reoxidized E2 back to E1; whereas LVW-PC minimally reduced E1 to E2 but effectively oxidized E2 to E1 after a 20-d lag. In the absence of alternative carbon sources, LVW-12 and LVW-PC oxidized E2 to E1. This report documents the rapid and sometimes reversible microbial transformation of E1 and E2 and the slow degradation of 17α-ethinylestradiol in urban stream water and extends the list of known estrogen-transforming bacteria to the genera and . These results suggest that discharge of steroid estrogens via wastewater could be reduced through tighter control of redox conditions and may assist in future risk assessments detailing the environmental fate of estrogens through evidence that microbial estrogen transformations may be affected by environmental conditions or growth status.

Hormonally active agents in the environment: a state-of-the-art review

After the Second World War, infatuation with modern products has exponentially widened the spectrum of chemicals used. Some of them are capable of hijacking the endocrine system by blocking or imitating a hormone and are referred to as hormonally active chemicals or endocrine disruptors. These are chemicals that the body was not designed for evolutionarily and they are present in every matrix of the environment. We are living in a chemical world where the exposures are ubiquitous and take place in combinations that can interact with the endocrine system and some other metabolic activities in unexpected ways. The complexity of interaction of these compounds can be understood by the fact that they interfere with gene expression at extremely low levels, consequently harming an individual life form, its offspring or population. As the endocrine system plays a critical role in many biological or physiological functions, by interfering body's endocrine system, endocrine disrupting compounds (EDCs) have various adverse effects on human health, starting from birth defects to developmental disorders, deadly deseases like cancer and even immunological disorders. Most of these compounds have not been tested yet for safety and their effects cannot be assessed by the available techniques. The establishment of proper exposure measurement techniques and integrating correlation is yet to be achieved to completely understand the impacts at various levels of the endocrine axis.

Human Elimination of Organochlorine Pesticides: Blood, Urine, and Sweat Study

Background. Many individuals have been exposed to organochlorinated pesticides (OCPs) through food, water, air, dermal exposure, and/or vertical transmission. Due to enterohepatic reabsorption and affinity to adipose tissue, OCPs are not efficiently eliminated from the human body and may accrue in tissues. Many epidemiological studies demonstrate significant exposure-disease relationships suggesting OCPs can alter metabolic function and potentially lead to illness. There is limited study of interventions to facilitate OCP elimination from the human body. This study explored the efficacy of induced perspiration as a means to eliminate OCPs. Methods. Blood, urine, and sweat (BUS) were collected from 20 individuals. Analysis of 23 OCPs was performed using dual-column gas chromatography with electron-capture detectors. Results. Various OCPs and metabolites, including DDT, DDE, methoxychlor, endrin, and endosulfan sulfate, were excreted into perspiration. Generally, sweat samples showed more frequent OCP detection than serum or urine analysis. Many OCPs were not readily detected in blood testing while still being excreted and identified in sweat. No direct correlation was found among OCP concentrations in the blood, urine, or sweat compartments. Conclusions. Sweat analysis may be useful in detecting some accrued OCPs not found in regular serum testing. Induced perspiration may be a viable clinical tool for eliminating some OCPs.

A survey of parabens in commercial pharmaceuticals from China and its implications for human exposure

Parabens are widely used as antimicrobial preservatives during pharmaceutical production. However, little information is available regarding the occurrence of parabens in commercial pharmaceuticals and their implications for human exposure. In this study, six commonly used parabens were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry with 100 commercial pharmaceuticals collected from China. Almost all of the pharmaceutical samples contained at least one kind of parabens with the detection frequency of 97%. The concentrations of Σ6parabens (sum of the six parabens) ranged from below MDL to 1256ng/g, with mean and median values of 94.8 and 119ng/g, respectively. Methyl paraben (MeP), ethyl paraben (EtP) and propyl paraben (PrP) were the predominant compounds. Significant positive correlation was observed between concentrations of MeP and PrP, indicating their co-applications in pharmaceuticals. Levels of Σ6parabens varied in different categories of pharmaceuticals and increased with their shelf lives. Based on the measured concentrations and daily ingestion rates of pharmaceuticals, the estimated daily intake (EDI) of parabens was calculated. The median values of EDIpharmaceutical for male adults, female adults and children were 4.05, 4.75 and 9.73ng/kg-bw/day, respectively, which were three orders of magnitude lower than those from foodstuffs and personal care products (PCPs). It was firstly reported that the total exposure dose was 0.326mg/kg-bw/day via foodstuffs, PCPs, and pharmaceuticals for Chinese female adults.

Distribution and estrogenic potential of endocrine disrupting chemicals (EDCs) in estuarine sediments from Mumbai, India

Endocrine disrupting chemicals (EDCs) are responsible for inappropriate development and they alter the hormonal and homeostatic systems of organism. Phthalates (PAEs), bisphenol A (BPA) and other EDCs were monitored in surface sediments at different stations across Thane Creek, India. Analysis of PAEs was carried out using GC-MS technique, while BPA and other EDCs were analyzing on UPLC-PDA instrument. Di-n-butyl phthalate (DBP) had the highest concentration among all fourteen analyzed phthalates ranges between 0.13 and 0.4 mg kg(-1); and was detectable in all sediment samples. Strong correlation (r = 0.95, p < 0.01) was observed between total organic carbon (TOC, %) and total PAEs. BPA was also detected in all samples; average BPA concentration varies from 16.3 to 35.79 μg kg(-1) with mean value 25.15 μg kg(-1) dry weight of sediment. Synthetic EDCs such as 4-para-nonylphenol (NP) and 4-tert-octylphenol (OP) were also analyzed; and their average concentrations were founds to be 356.5 and 176 μg kg(-1), respectively. Estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) were the main contributors to the overall estradiol equivalent concentration (EEQs) in sediment, their average total percentage contributions is more than 90 %.

From BPA to its analogues: Is it a safe journey?

Bisphenol-A (BPA) is one of the most abundant synthetic chemicals in the world due to its uses in plastics. Its widespread exposure vis-a-vis low dose effects led to a reduction in its safety dose and imposition of ban on its use in infant feeding bottles. This restriction paved the way for the gradual market entry of its analogues. However, their structural similarity to BPA has put them under surveillance for endocrine disrupting potential. The application of these analogues is increasing and so are the studies reporting their toxicity. This review highlights the reasons which led to the ban of BPA and also reports the exposure and toxicological data available on its analogues. Hence, this compilation is expected to answer in a better way whether the replacement of BPA by these analogues is safer or more harmful?

The potential reproductive effects of exposure of domestic ruminants to endocrine disrupting compounds

Chemical compounds that mimic or block some of the actions of the steroid hormone oestradiol, have created public concern primarily because of potential adverse reproductive effects in wildlife and humans. Many studies, in vivo and in vitro, have revealed abnormal reproductive function following exposure to these compounds. The number of chemicals known to have the potential to modulate endocrine functions is increasing. In contrast to humans and wildlife, the potential reproductive effects of exposure of domestic animals to endocrine disrupting compounds (EDC) have been studied little. The aim of this overview is to evaluate the possible contribution of EDC to reproductive failure in domestic ruminants.

Sources and classes of EDC are discussed as well as their structure and the modes of hormone disruption. Endocrine disrupting agents may interfere with the reproductive processes of both males and females at several points of the reproductive cycle and through a range of physiological mechanisms. Extrapolating from the results obtained with laboratory animals, the mechanisms whereby infertility in domestic ruminants might be expressed by exposure to EDC through contaminated food and drinking water are addressed.

A preliminary risk assessment is included and it is concluded that under certain circumstances there may be a significantly enhanced intake of oestrogenic hormones and EDC through sewage-contaminated water or soil-contaminated herbage. The physiological consequences for domestic ruminants of EDC ingestion, at the rates estimated, are largely unknown. However, the levels of exposure to oestrogenic hormones and phthalates in grazing ruminants are such that when studying fertility problems in high-yielding dairy cattle the impacts of exposure to endocrine disruptors via the food and drinking water cannot be neglected.

An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors

BACKGROUND

Simultaneous or sequential exposure to multiple environmental stressors can affect chemical toxicity. Cumulative risk assessments consider multiple stressors but it is impractical to test every chemical combination to which people are exposed. New methods are needed to prioritize chemical combinations based on their prevalence and possible health impacts.

OBJECTIVES

We introduce an informatics approach that uses publicly available data to identify chemicals that co-occur in consumer products, which account for a significant proportion of overall chemical load.

METHODS

Fifty-five asthma-associated and endocrine disrupting chemicals (target chemicals) were selected. A database of 38,975 distinct consumer products and 32,231 distinct ingredient names was created from online sources, and PubChem and the Unified Medical Language System were used to resolve synonymous ingredient names. Synonymous ingredient names are different names for the same chemical (e.g., vitamin E and tocopherol).

RESULTS

Nearly one-third of the products (11,688 products, 30%) contained ≥ 1 target chemical and 5,229 products (13%) contained > 1. Of the 55 target chemicals, 31 (56%) appear in ≥ 1 product and 19 (35%) appear under more than one name. The most frequent three-way chemical combination (2-phenoxyethanol, methyl paraben, and ethyl paraben) appears in 1,059 products. Further work is needed to assess combined chemical exposures related to the use of multiple products.

CONCLUSIONS

The informatics approach increased the number of products considered in a traditional analysis by two orders of magnitude, but missing/incomplete product labels can limit the effectiveness of this approach. Such an approach must resolve synonymy to ensure that chemicals of interest are not missed. Commonly occurring chemical combinations can be used to prioritize cumulative toxicology risk assessments.

CITATION

Gabb HA, Blake C. 2016. An informatics approach to evaluating combined chemical exposures from consumer products: a case study of asthma-associated chemicals and potential endocrine disruptors. Environ Health Perspect 124:1155-1165; http://dx.doi.org/10.1289/ehp.1510529.

Sex reversal assessments reveal different vulnerability to endocrine disruption between deeply diverged anuran lineages

Multiple anthropogenic stressors cause worldwide amphibian declines. Among several poorly investigated causes is global pollution of aquatic ecosystems with endocrine disrupting compounds (EDCs). These substances interfere with the endocrine system and can affect the sexual development of vertebrates including amphibians. We test the susceptibility to an environmentally relevant contraceptive, the artificial estrogen 17α-ethinylestradiol (EE2), simultaneously in three deeply divergent systematic anuran families, a model-species, Xenopus laevis (Pipidae), and two non-models, Hyla arborea (Hylidae) and Bufo viridis (Bufonidae). Our new approach combines synchronized tadpole exposure to three EE2-concentrations (50, 500, 5,000 ng/L) in a flow-through-system and pioneers genetic and histological sexing of metamorphs in non-model anurans for EDC-studies. This novel methodology reveals striking quantitative differences in genetic-male-to-phenotypic-female sex reversal in non-model vs. model species. Our findings qualify molecular sexing in EDC-analyses as requirement to identify sex reversals and state-of-the-art approaches as mandatory to detect species-specific vulnerabilities to EDCs in amphibians.

Occurrence and removal of phenolic endocrine disrupting chemicals in the water treatment processes

This paper evaluated the occurrence and removal efficiency of four selected phenolic endocrine disrupting chemicals (bisphenol A (BPA), octylphenol (OP), nonylphenol (NP) and diethylstilbestrol (DES)) in two drinking waterworks in Jiangsu province which take source water from Taihu Lake. The recombined yeast estrogen screen (YES) and liquid chromatography tandem mass spectrometry (LC-MS/MS) were applied to assess the estrogenicity and detect the estrogens in the samples. The estrogen equivalents (EEQs) ranged from nd (not detected) to 2.96 ng/L, and the estrogenic activities decreased along the processes. Among the 32 samples, DES prevailed in all samples, with concentrations ranging 1.46-12.0 ng/L, BPA, OP and NP were partially detected, with concentrations ranging from nd to 17.73 ng/L, nd to 0.49 ng/L and nd to 3.27 ng/L, respectively. DES was found to be the main contributor to the estrogenicity (99.06%), followed by NP (0.62%), OP (0.23%) and BPA (0.09%). From the observation of treatment efficiency, the advanced treatment processes presented much higher removal ratio in reducing DES, the biodegradation played an important role in removing BPA, ozonation and pre-oxidation showed an effective removal on all the four estrogens; while the conventional ones can also reduce all the four estrogens.