Revision of Biological Methods for Determination of EDC Presence and Their Endocrine Potential

Release of Selected Non-Intentionally Added Substances (NIAS) from PET Food Contact Materials: A New Online SPE-UHPLC-MS/MS Multiresidue Method

Food contact materials (FCMs) are an underestimated source of food chemical contaminants and a potentially relevant route of human exposure to chemicals that are harmful to the endocrine system. Foods and water are the main sources of exposure due to contact with the packaging materials, often of polymeric nature. European Regulation 10/2011 requires migration tests on FCMs and foodstuffs to evaluate the presence of listed substances (authorized monomers and additives) and non-intentionally added substances (NIAS) not listed in the regulation and not subjected to restrictions. The tests are required to ensure the compliance of packaging materials for the contained foods. NIAS are a heterogeneous group of substances classified with a potential estrogenic or androgenic activity. Subsequently, the evaluation of the presence of these molecules in foods and water is significant. Here we present an online SPE/UHPLC-tandem MS method to quantify trace levels of NIAS in food simulants (A: aqueous 3% acetic acid; B: aqueous 20% ethanol) contained in PET preformed bottles. The use of online SPE reduces systemic errors thanks to the automation of the technique. For the developed analytical method, we evaluate the limit of detection (LOD), the limit of quantitation (LOQ), selectivity, RSD% and BIAS% for LLOQ for a total of twelve NIAS, including monomers, antioxidants, UV-filters and additives. LOD ranged between 0.002 µg/L for bisphenol S and 13.6 µg/L for 2,6-di-tert-butyl-4-methylphenol (BHT). LOQs are comprised between 0.01 µg/L for bisphenol S and 42.2 µg/L for BHT. The online-SPE/UHPLC-tandem MS method is applied to the food simulants contained in several types of PET packaging materials to evaluate the migration of the selected NIAS. The results show the presence (µg/L) of NIAS in the tested samples, underlining the need for a new regulation for these potentially toxic molecules.

Estrogenic activity and ecological risk of steroids, bisphenol A and phthalates after secondary and tertiary sewage treatment processes

Effluents of sewage treatment plants (STPs) are an important source of estrogenic substances to the receiving water bodies affecting their ecological safety. In this study, steroids, bisphenol A (BPA) and phthalates were assessed in the secondary (SE) and tertiary effluent (TE) of three typical urban STPs in Beijing (China). In addition, the overall estrogenic activity in these effluents was assessed by an in-vitro bioassay (ERE-CALUX). Results showed that the concentrations and activities of estrogenic compounds in TE were lower than those in SE. The residual concentration of 17β-estradiol (E2) was the highest among the detected steroids, accounting for 51.6 ± 5.1% in SE and 57.5 ± 24.8% in TE. The residual level (25.2-41.6 ng/L) of BPA in effluents was significantly higher than that of steroids (0.2-28.8 ng/L). The residual concentration of diethyl phthalate was the highest among the detected phthalates accounting for 47.1 ± 5.1% in SE and 37.6 ± 11.5% in TE. Steroids and BPA had a higher removal rate (83.5% and 96.7%) in secondary and tertiary treatment than phthalates (68.8% and 83.1%). The hydrophobic characteristics of these estrogenic compounds determined the removal mechanism. The removal of steroids, BPA, dimethyl phthalate and diethyl phthalate (LogKow= 1.61-4.15) mainly occurred through biodegradation in the water phase, while the removal of dibutyl phthalate, butylbenzyl phthalate and di(2-ethylhexyl) phthalate (LogKow= 4.27-7.50) mainly occurred in the solid phase after adsorption on and sedimentation of the suspended particulate matter. According to ERE-CALUX, the estrogenic activity in the final STP effluents was 3.2-45.6 ng E2-equivalents/L, which is higher than reported levels in the effluents of European STPs. Calculation of estrogenic equivalents by using substance specific chemical analysis indicated that the dominant contributor was E2 (56.4-88.4%), followed by 17α-ethinylestradiol (EE2) (4.1-34.8%), both also exerting a moderate risk to the aquatic ecosystem. While the upgrade of treatment processes in STPs has efficiently reduced the emission of estrogenic substances, their ecological risk was not yet phased out.

Comparison of 17β-Estradiol Adsorption on Corn Straw- and Dewatered Sludge-Biochar in Aqueous Solutions

Removal of steroid hormones from aqueous environment is of prevailing concern because of their adverse impact on organisms. Using biochar derived from biomass as adsorbent to remove pollutants has become more popular due to its low cost, effectiveness, and sustainability. This study evaluated the feasibility of applying corn straw biochar (CSB) and dewatered sludge biochar (DSB) to reduce 17β-estradiol (E2) from aquatic solutions by adsorption. The experimental results showed that the adsorption kinetics and isotherm behavior of E2 on the two biochars were well described by the pseudo-second-order (R2 > 0.93) and Langmuir models (R2 > 0.97). CSB has higher E2 adsorption capacity than DSB, and the maximum adsorption capacity was 99.8 mg/g obtained from Langmuir model at 298 K, which can be attributed to the higher surface area, porosity, and hydrophobicity of this adsorbent. Higher pH levels (>10.2) decreased the adsorption capacities of biochar for E2, while the ionic strength did not significantly affect the adsorption process. The regeneration ability of CSB was slightly better than that of DSB. The possible adsorption mechanism for E2 on biochar is suggested as π−π interactions, H−bonding, and micropores filling. These results indicated that CSB has more potential and application value than DSB on reducing E2 from aqueous solutions when considering economy and removal performance.

Hormones Nanofiltration in Carbon Nanotubes and Boron Nitride Nanotubes Using Uniform External Electric Field Through Molecular Dynamics

Hormones are a dangerous group of molecules that can cause harm to humans. This study based on classical molecular dynamics proposes the nanofiltration of wastewater contaminated by hormones from a computer simulation study, in which the water and the hormone were filtered in two single-walled nanotube compositions. The calculations were carried out by changing the intensities of the electric field that acted as a force exerting pressure on the filtration along the nanotube, in the simulation time of 100 ps. The hormones studied were estrone, estradiol, estriol, progesterone, ethinylestradiol, diethylbestrol, and levonorgestrel in carbon nanotubes (CNTs) and boron nitride (BNNTs). The most efficient nanofiltrations were for fields with low intensities in the order of 10-8 au and 10-7 au. The studied nanotubes can be used in membranes for nanofiltration in water treatment plants due to the evanescent field potential caused by the action of the electric field inside. Our data showed that the action of EF in conjunction with the van der Walls forces of the nanotubes is sufficient to generate the attractive potential. Evaluating the transport of water molecules in CNTs and BNNTs, under the influence of the electric field, a sequence of simulations with the same boundary conditions was carried out, seeking to know the percentage of water molecules filtered in the nanotubes.

Molecular Methods as Potential Tools in Ecohydrological Studies on Emerging Contaminants in Freshwater Ecosystems

Contaminants of emerging concern (CECs) present a threat to the functioning of freshwater ecosystems. Their spread in the environment can affect both plant and animal health. Ecohydrology serves as a solution for assessment approaches (i.e., threat identification, ecotoxicological assessment, and cause–effect relationship analysis) and solution approaches (i.e., the elaboration of nature-based solutions: NBSs), mitigating the toxic effect of CECs. However, the wide array of potential molecular analyses are not fully exploited in ecohydrological research. Although the number of publications considering the application of molecular tools in freshwater studies has been steadily growing, no paper has reviewed the most prominent studies on the potential use of molecular technologies in ecohydrology. Therefore, the present article examines the role of molecular methods and novel omics technologies as essential tools in the ecohydrological approach to CECs management in freshwater ecosystems. It considers DNA, RNA and protein-level analyses intended to provide an overall view on the response of organisms to stress factors. This is compliant with the principles of ecohydrology, which emphasize the importance of multiple indicator measurements and correlation analysis in order to determine the effects of contaminants, their interaction with other environmental factors and their removal using NBS in freshwater ecosystems.

Luminescence-Sensing Tb-MOF Nanozyme for the Detection and Degradation of Estrogen Endocrine Disruptors

Using flexible structures and components of metal-organic framework (MOF) materials, we designed and developed an artificial nanozyme with dual functions of a catalyst and luminescent sensor specifically for the determination and degradation of hormone 17β-estradiol (E2) and its derivatives (E1, E3, and EE2), a class of disruptors with strong effect on the human endocrine system. This nanozyme composed of the luminescent Tb³⁺ ion, catalytic coenzyme factor hemin, and light-harvesting ligand can be used to both degrade E2 like natural horseradish peroxidase (HRP) and sense E2 as low as 50 pM by its luminescence. The nanozyme catalyzes the decomposition of E2 and its derivatives through a mechanism of active hydroxyl radicals and oxidative high-valent iron-oxo intermediates. The prepared nanozyme is pluripotent, stable, and cheap and can replace the widely used combination of natural enzyme and chromogenic substrate. The present strategy of constructing artificial enzymes directly from functional units provides a new way for the design and development of smart, multifunctional artificial enzymes.

Bisphenols (A, S, and F) affect the basic hormonal activity determined for pharmaceuticals - Study of Saccharomyces cerevisiae

Pharmaceuticals and analogs of bisphenol A (BPA) are increasingly threatening environmental pollutants. In this study, mixtures of selected pharmaceuticals (diclofenac sodium salt, chloramphenicol, oxytetracycline hydrochloride, fluoxetine hydrochloride, estrone, ketoprofen, progesterone, gemfibrozil and androstenedione) were prepared with BPA and its two analogs (namely, bisphenols F and S) at such ratios to reflect environmentally detectable levels. Then, the mixture solutions were studied with a XenoScreen YES/YAS assay to determine the variations in the initial hormonal response of each pharmaceutical compound due to the presence of a bisphenol analog. The results obtained were modeled with the concentration addition (CA) and independent action (IA) approaches, the trueness of which was studied with model deviation ratios (MDR). The estrogenic agonistic activity of the drugs studied was most strongly affected by the presence of BPA in solution (twenty-one cases of synergy observed for CA models versus twelve cases of antagonism in the case of IA predictions). BPS shows a strong agonistic estrogenic impact on most of the drugs studied at medium and high concentration levels; androgenic agonistic activity was also impaired with elevated concentrations of BPS. Increasing the concentration of BPF in a reaction mixture also increased the number of YES + synergism incidences (for CA modeling). Estrone, progesterone and androstenedione were mostly affected by the highest BPF concentrations studied in the case of androgenic agonistic research performed.

Assessment of ecotoxicity and total volatile organic compound (TVOC) emissions from food and children's toy products

The development of new methods for identifying a broad spectrum of analytes, as well as highly selective tools to provide the most accurate information regarding the processes and relationships in the world, has been an area of interest for researchers for many years. The information obtained with these tools provides valuable data to complement existing knowledge but, above all, to identify and determine previously unknown hazards. Recently, attention has been paid to the migration of xenobiotics from the surfaces of various everyday objects and the resulting impacts on human health. Since children are among those most vulnerable to health consequences, one of the main subjects of interest is the migration of low-molecular-weight compounds from toys and products intended for children. This migration has become a stimulus for research aimed at determining the degree of release of compounds from popular commercially available chocolate/toy sets. One of main objectives of this research was to determine the impact of time on the ecotoxicity (with Vibrio fischeri bioluminescent bacteria) of extracts of products intended for children and to assess the correlation with total volatile organic compound emissions using basic chemometric methods. The studies on endocrine potential (with XenoScreen YES/YAS) of the extracts and showed that compounds released from the studied objects (including packaging foils, plastic capsules storing toys, most of toys studied and all chocolate samples) exhibit mostly androgenic antagonistic behavior while using artificial saliva as extraction medium increased the impact observed. The impact of time in most cases was positive one and increased with prolonging extraction time. The small-scale stationary environmental test chambers - μ-CTE™ 250 system was employed to perform the studies aimed at determining the profile of total volatile organic compounds (TVOCs) emissions. Due to this it was possible to state that objects from which the greatest amounts of contaminants are released are plastic containers (with emission rate falling down from 3273 to 2280 ng/g of material at 6 h of conditioning in elevated temperature).

Modeling and MANOVA studies on toxicity and endocrine potential of packaging materials exposed to different extraction schemes

The stability of the linings of packaging that is in contact with the goods stored has been of major concern during decades of the development of packaging materials. In this work, an attempt was undertaken to assess the applicability of using two bioassays (Microtox^® and XenoScreen YES/YAS) in estimating the stability of packaging (cans, caps, multilayer material) and the impact of their degradation on the toxicity of some simulated media. The assessment of the impact of packaging storage conditions (temperature, disinfection, preservation, extracting and washing solvents) was planned and performed with i) regression modeling of the experimental effects on the ecotoxicity readings, ii) ANOVA and MANOVA estimation of the experimental conditions as significant factors affecting the toxicity results and iii) FTIR analysis of the packages. It is shown that the effects of temperature and extraction solvents could be quantitatively assessed by the agreement between all methods applied. It can be stated that temperature and acidity as well as the alcohol content in the sensitive media have the greatest impact on the toxicity of the extract and thus on the stability of the internal lining and the extractability of xenobiotics.

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.

Estrogenic Activity Measurements in Water Using Diffusive Gradients in Thin-Film Coupled with an Estrogen Bioassay

A novel type of diffusive gradients in thin-film (DGT) was combined with a chemically activated luciferase gene expression bioassay (CALUX) to measure estrogens in aquatic systems. The performance of this novel method was assessed with 17β-estradiol (E2) as the model steroid hormone, XAD 18 resin gel as the binding phase in the DGT method and VM7Luc4E2 cells (formerly BG1Luc4E2) for the Estrogen Responsive Element (ERE)-CALUX bioassay. The measured effective diffusion coefficient of E2 in agarose diffusive gel was 4.65 ± 0.37 × 10^-6 cm² s^-1 at 25 °C. The detection limit of this combined DGT/ERE-CALUX method for 1 day of sampling (0.026 ± 0.003 ng L^-1 of E2) is significantly lower than that obtained by spot sampling combined with GC-MS/MS or LC-MS/MS analysis (0.1-7.0 ng L^-1). The method is independent of pH (5-8), ionic strength (0.001-0.5 M), and dissolved organic matter (DOM; concentrations up to 30 mg L^-1). Field applications of this novel DGT in effluents of three sewage treatment plants in Beijing city (China) showed comparable results to conventional spot (grab) sampling. This study demonstrates that the combined DGT/ERE-CALUX approach is an effective and sensitive tool for in situ monitoring of estrogenic activity in waters and wastewaters.

Endocrine disruption in aquatic systems: up-scaling research to address ecological consequences

Endocrine‐disrupting chemicals (EDCs) can alter biological function in organisms at environmentally relevant concentrations and are a significant threat to aquatic biodiversity, but there is little understanding of exposure consequences for populations, communities and ecosystems. The pervasive nature of EDCs within aquatic environments and their multiple sub‐lethal effects make assessments of their impact especially important but also highly challenging. Herein, we review the data on EDC effects in aquatic systems focusing on studies assessing populations and ecosystems, and including how biotic and abiotic processes may affect, and be affected by, responses to EDCs. Recent research indicates a significant influence of behavioural responses (e.g. enhancing feeding rates), transgenerational effects and trophic cascades in the ecological consequences of EDC exposure. In addition, interactions between EDCs and other chemical, physical and biological factors generate uncertainty in our understanding of the ecological effects of EDCs within aquatic ecosystems. We illustrate how effect thresholds for EDCs generated from individual‐based experimental bioassays of the types commonly applied using chemical test guidelines [e.g. Organisation for Economic Co‐operation and Development (OECD)] may not necessarily reflect the hazards associated with endocrine disruption. We argue that improved risk assessment for EDCs in aquatic ecosystems urgently requires more ecologically oriented research as well as field‐based assessments at population‐, community‐ and food‐web levels.

Application of chemometric techniques in studies of toxicity of selected commercially available products for infants and children

The goal of the present study is to assess the impact of the experimental conditions for extraction procedures (time of extraction, thermal treatment and type of extraction media) as applied to several baby and infant products checked for their possible ecotoxicological response when tested by various ecotoxicity tests (Microtox^®, Ostracodtoxkit F™ and Xenoscreen YES/YAS™). The systems under consideration are multidimensional by nature and, therefore, the appropriate assessment approach was intelligent data analysis (chemometrics). Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were selected as reliable data mining methods for the interpretation of the ecotoxicity data. We show that the different experimental conditions have a significant impact on the ecotoxicity levels observed, especially those measured by Microtox^® and Ostracodtoxkit F™ tests. The time of contact proves to be a very significant factor for all extraction media and ecotoxicity test procedures. The present study is a pioneering effort to offer a specific expert approach for analysing links between the type of test measurement methodology and imposed experimental conditions to mimic real-life circumstances in the use of baby and infant products.

Assessment of toxic and endocrine potential of substances migrating from selected toys and baby products

Analysis of literature data shows that there is limited information about the harmful biological effects of mixture of compounds from the EDC group that are released from the surface of toys and objects intended for children and infants. One of the tools that can be used to obtain such information is appropriate bioanalytical tests. The aim of this research involved determining whether tests that use living organisms as an active element (Vibrio fischeri-Microtox®, Heterocypris incongruens-Ostrocodtoxkit F™ and the XenoScreen YES/YAS™ test of oestrogenic/androgenic activity) can be a tool for estimating the combined toxic effects induced by xenobiotics released from objects intended for children. To reproduce the conditions to which objects are exposed during their use, liquids with a composition corresponding to that of human bodily fluids (artificial sweat and saliva) were used. This research focused on the main parameters influencing the intensification of the migration process (temperature, contact time and composition of the extraction mixture). The studies aimed to estimate the endocrine potential of the extracts showed that compounds released from the surface of studied objects exhibit antagonistic androgenic activity. While on the basis of the results of Microtox® test, one can state that the largest quantity of toxic compounds are released in the first 2 h of using the object. The FTIR spectra analyses confirmed that no degradation of polymeric material took place. On the basis of the results obtained, it was unanimously concluded that contact of the object with bodily fluids may result in the release of a large number of xenobiotics, which has disadvantageous effects on the metabolic processes of the indicator organisms.

Environmental risk assessment of Polish wastewater treatment plant activity

Wastewater treatment plants (WWTPs) play an extremely important role in shaping modern society's environmental well-being and awareness, however only well operated and supervised systems can be considered as environmentally sustainable. For this reason, an attempt was undertaken to assess the environmental burden posed by WWTPs in major Polish cities by collecting water samples prior to and just after wastewater release points. Both classical and biological methods (Microtox(®), Ostracodtoxkit F™ and comet assay) were utilized to assess environmental impact of given WWTP. Interestingly, in some cases, water quality improvement indicated as a toxicity decrement toward one of the bio-indicating organisms makes water worse for others in the systems. This fact is particularly noticeable in case of Silesian cities where heavy industry and high population density is present. It proves that WWTP should undergo individual evaluation of pollutant removal efficiency and tuned to selectively remove pollutants of highest risk to surrounding regional ecosystems. Biotests again proved to be an extremely important tool to fully assess the impact of environmental stressors on water bodies receiving effluents from WWTPs.

Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP

Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.

Effect of inorganic nanoparticles on 17β-estradiol and 17α-ethynylestradiol adsorption by multi-walled carbon nanotubes

With extensive application of diverse engineered nanoparticles (NPs), multiple NPs would inevitably be released into the environment. However, much emphasis in most previous studies on the interactions of pollutants with NPs has been placed on only one type of NPs at a time. This study investigated the impact of inorganic NPs (I-NPs) on the adsorption of 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) by multi-walled carbon nanotubes (CNTs). The presence of I-NPs inhibited the adsorption and increased the equilibrium time of E2 and EE2 by CNTs. Moreover, the effect of Al2O3 was stronger than that of SiO2, because electrostatic attraction enhanced the interaction between oppositely charged Al2O3 and CNTs. The addition sequence of I-NPs and pollutant also influences adsorption. This is among the first studies investigating the effect of I-NPs on pollutants adsorption by CNTs, which is useful for understanding the transport and fate of CNTs and contaminants in natural aquatic systems.