Occurrence of hormones in the Scheldt estuary: an analytical challenge!

In recent years, scientific concern, public debate and media attention has risen about the presence of natural and synthetic compounds in the environment. This is due to the observation that low environmental concentrations may affect human and wildlife. The aim of the presented study was to develop and evaluate analytical approaches for the detection of different groups of endocrine disrupting chemicals in environmental matrices, e.g. water, sediments, suspended solids and biota. More specific, the aim was to develop analytical methods for the detection of these compounds in the low ng.l-1 or ng.g-1 level. At first, the issue of endocrine disruption will be introduced. This study was carried out within an interdisciplinary research project, Endis-Risks (http://www.vliz.be/projects/endis). This four-year project focused on the distribution, exposure and effects of endocrine disrupting chemicals in the Scheldt Estuary (B-Nl). In this presentation, the emphasis will be laid on the detection of estrogens. In order to understand the possible risks of the environmental occurrence of these compounds, their chemistry, their use, their potential for endocrine disruption and their environmental occurrence will be presented. Next, the development and validation procedure for the analytical methods that enable (routine) analysis of environmental samples for estrogens in concentrations in the low ng.l-1 or ng.g-1 range will be described. The methods included speedisk or ASE extraction and detection with gas chromatography coupled to multiple mass spectrometry (GC-MS²). Finally, the results of a four-year-(2002-2005) research on the occurrence of oestrone (E1), estradiol (E2) and ethinylestradiol (EE2) in the Scheldt Estuary will be presented. Similar to what has been reported for fresh water environments and waste waters, it was demonstrated that estuarine waters and the associated suspended matter and sediments are contaminated with the same estrogenic compounds and within the same order of magnitude. Oestrone (E1), the degradation product of E2, the most important female hormone was detected most frequently and in the highest concentrations. Low ng.l-1 and ng.g-1of E1 and ß-E2 (ß isomer of E2) were detected both in water, sediment and suspended matter samples, whereas concentrations of EE2 were below the limit of quantification (LOQ)

Analytiek van hormoon verstorende stoffen in milieumatrices = Analytics of endocrine disrupting chemicals in environmental matrices

In recent years, scientific concern, public debate and media attention has risen about the environmental presence of natural and synthetic compounds due to the observation that environmental concentrations in the low ng.l-1 and ng.g-1 level may affect human and wildlife. The aim of this doctoral thesis was to develop and to evaluate analytical approaches for the detection of estrogens en chlorotriazines, two important groups of endocrine disrupting chemicals (EDCs), in different environmental matrices, e.g. water, sediments, suspended solids and biota. More specifically, the aim was to develop analytical methods for the detection of these compounds in the low ng.l-1 and ng.g-1 level. Environmental concentrations in an estuarine ecosystem like the Scheldt estuary (Belgium-The Netherlands) were established. In chapter I, the issue of endocrine disruption is introduced and the recent developments in environmental chemistry are discussed. This doctoral thesis was carried out within an interdisciplinary research project, Endis-Risks. This 4 year project focussed on the distribution, exposure and effects of endocrine disrupting chemicals in the Scheldt estuary. In this doctoral research, the emphasis is laid on the estrogens and the chlorotriazine herbicides. In order to understand the possible risks of the environmental occurrence of these compounds, their chemistry, their use, their potential for endocrine disruption and their environmental occurrence is described. Also the legislation in relation to their environmental occurrence and their possible abuse in veterinary practice is introduced. In short, the risk assessment procedure is presented. Finally, the conceptual framework and the outline of this doctoral thesis are formulated. In chapter II.1., the development and validation procedure of an analytical method that enables the routine analysis of (estuarine) water samples for estrogens (E1, E2, E3 and EE2) in concentrations in the low ng.l-1 range is described. The method included extraction of water samples using solid phase extraction disks and detection with gas chromatography coupled to multiple mass spectrometry in the electron impact mode (GC-EI-MS-MS). Method performance characteristics (according to 2002/657/EC), e.g. trueness, recovery, calibration, precision, accuracy, limits of detection and quantification and the compound stability are presented for each of the targeted estrogens. Quantification limits of 0.25 ng.l-1 are achieved. Application of this Belac accredited procedure to water samples from the Scheldt estuary revealed that E1 was detected most frequently. In chapter II.2. the results of a 4-year (2002-2005) research on the occurrence of E1, E2 and EE2 in the Scheldt-estuary are presented. Chemical analysis of the water samples was performed using Speedisk extraction as described in chapter II.1.. Suspended matter, sediment and biota samples were extracted with Accelerated Solvent Extraction (ASE). Chromatographic analysis of the extracts was carried out with GC-EI-MS-MS. Detected concentrations were in the low ng.l-1 or ng.g-1 range. In all matrices considered, E1 and E2 were detected, whereas concentrations of E3 and EE2 were below the limit of quantification (LOQ). E1 was observed most frequently and at the highest concentrations. This research demonstrates that estuarine waters and associated sediments and suspended solids are contaminated with the same estrogens which were found within the same concentration range as those reported for freshwater and wastewater. In chapter II.3., a case-study is described concerning the detection of estrogens in an unknown aqueous sample found during a raid. Therefore, different analytical techniques were combined. At first, in vivo techniques (mice trials with anatomical and histological research) were carried out by administration (orally and subcutaneously) of the unknown water solution. To determine the estrogenic potency an in vitro technique, the yeast estrogenic screen, YES was used. After extraction of the water sample (based on the method described in chapter II.1.) and HPLC-fractionation, analysis of the extracts was performed using both Liquid Chromatography and Gas Chromatography coupled to multiple Mass Spectrometry (LC- and GC-MS-MS). The result of this investigation was the detection of both E1 and EE2 at low ng.l-1 concentrations. Chapter II.4. describes the development of an analytical routine approach for the determination of low ng.l-1 levels of EGAs (Estrogens, Gestagens, Androgens) and corticosteroids in aqueous preparations (i.e. drinking water, drinking water supplements) brought on the ‘black’ market. For this, after speedisk extraction of the samples (see chapter II.1.), HPLC fractionation was performed using a methanol:water gradient program (see chapter II.3.). GC-EI-MS-MS screening was used for the EGAs, whereas GC-NCI-MS was used for the screening for corticosteroids. Confirmation of the latter (when dexamethasone (Dxm) or betamethasone (Btm) was suspected) was done by LC-ESI-MS-MS. The combined use of GC and LC coupled to MS enabled the identification and quantification of anabolics and corticosteroids at the low ng.l-1 level. In this chapter 2 case-studies are described of the detection of medroxyprogesterone acetate (MPA) and Btm at low ng.l-1 levels in unknown aqueous solutions. In chapter III the occurrence of the chlorotriazine herbicides atrazine, simazine and terbutylazine in water, sediment and suspended matter over a period of 4 years (2002-2005) is described. Atrazine was found to be the herbicide exhibiting the highest concentration in the different targeted matrices. Simazine and terbutylazine were detected at lower concentrations. Traces of the targeted pesticides were detected in sediments, but these were below the LOQ. As part of an ecotoxicological assessment, the potential acute effect (mortality) and chronic effects (growth, molting) of atrazine on the mysid Neomysis integer (Crustacea:Mysidacea), a resident invertebrate in the Scheldt estuary were studied. This study concluded that atrazine could be toxic to mysids at high concentrations, but at present environmental concentrations (as measured in the Scheldt estuary), acute or chronic effects will probably not result in mortality or decline of the mysid population. In chapter IV, general conclusions and future research perspectives are formulated. Summarising, the major goal of this doctoral thesis was the development of analytical approaches to detect EDCs in different complex matrices at ng.l-1 and ng.g-1 levels

Occurrence of pharmaceuticals in environmental samples: a multi-analyte approach

Pharmaceuticals and their residues in the environment have been recently recognized as one of the emerging research areas in the environmental chemistry and toxicology and caused them to be viewed as a new class of priority substances. It has been reportedthat they are introduced continuously in the environment via household use, effluents from Sewage Treatment Plants (STPs) and animal excreta. Up to date, the potential human, animal and ecological risk associated with the occurrence of these compounds in the environment is not well documented. There is an increased attention due to the fact that they are designed to have specific effects at low doses and to be resistant to Moreover, the science of mixture toxicity is complex and to date quite unknown (Bound et al., 2006; Hernando et al., 2006).Despite the increased research and regulatory interest in the occurrence of pharmaceuticals and their degradation products in STPs effluents and freshwater ecosystems (Hernando et al., 2006), the occurrence, the distribution between the different environmental compartments (i.e. water, sediments, suspended solids and aqueous organisms), the trophic transfer and their potential toxicity is to date far less documented (Emblidge and DeLorenze, 2006).In this sense, this study will present a detection method for the determination of a large group of pharmaceuticals (i.e. antibiotics, beta-agonists, painkillers, tranquilizers, nonsteroidal anti-inflammatory drugs) used both in human and veterinary practice in environmental samples using Liquid Chromatography coupled to multiple Mass Spectrometry

ENDIS-RISKS: endocrine disruption in the Scheldt estuary - a field study

ENDIS-RISKS, a multidisciplinary research project with five institutes, evaluates the distribution, exposure and effects of endocrine disruptors in the Scheldt Estuary. This estuary is known to be one of the most polluted estuaries in the world. Untreated domestic wastewater and effluents of the industrial areas of Ghent and Antwerp are to a large extent responsible for this pollution. During an intensive field study of four years, eight sampling campaigns were executed on seven sampling points along the Scheldt Estuary. A detailed analysis of the distribution of endocrine disrupting substances in the Scheldt Estuary was executed. Water, sediment, suspended solids and biota were analysed for seven groups of chemicals: estrogens, pesticides, organotins, polyaromatic components, polyaromatic hydrocarbons and phenols. Special attention was given to the estuarine mysid shrimp Neomysis integer. Its ecotoxicology and population characteristics were studied in detail. A selection of results of this field study is put forward. Water samples, tested in vitro for their potential to bind with estrogen, revealed more estrogenic activity in the more upstream stations. Concentrations of chlorotriazine herbicides in water samples, were higher in the upstream reaches compared to the downstream sites. Analyses of TBT in mysid shrimps revealed high concentrations (>2mg.kg-1 dry weight) which suggests a high bioaccumulation capacity. Population characteristics results of N. integer show that it has a broader distribution range, with a shift more upstream, in comparison with historical data (Mees et al., 1995). On the other hand, length distribution of developmental stages of N. integer along the estuary indicates some environmental stress, caused by the estuarine gradient or by pollutants. Some hypotheses will be put forward to explain these patterns

Endocrine disruption in the Scheldt estuary distribution, exposure and effects (ENDIS-RISKS). Final report

ENDIS-RISKS is a multidisciplinary, research project conducted by five institutes. This project aimed to assess the distribution, exposure and effects of endocrine disruptors in the Scheldt estuary, with specific attention to invertebrates. The Scheldt estuary is known to be one of the most polluted estuaries in the world. The industrial areas of Ghent and Antwerp are to a large extent responsible for this pollution. To achieve these goals detailed knowledge of the distribution and long-term effects of these substances is needed. This information is crucial for the development of future-oriented policy measures at the national and European level. The project can be divided into four different research phases. In Phase I the occurance and distribution of endocrine disrupting substances in the Scheldt estuary was studied. Water, sediment, suspended solids and biota were sampled 3 times a year for a period of 4 years (2002-2006). In all these matrices, 7 groups of chemicals were analysed: estrogens, pesticides, phthalates, organotins, polyaromatic components (PCBs, PBDEs), polyaromatic hydrocarbons (PAHs) and phenols. All the analyzed chemicals are on the OSPAR list of priority chemicals or are indicated as endocrine disruptors on this list. The different water samples were also tested using in vitro assays to assess their potential to bind to the (human) estrogen and androgen receptor. Phase II evaluated the exposure of biota occuring in the Scheldt estuary to endocrine disrupting substances. Based on the results of the chemical analysis, priority substances were selected. Phase III studied the effects of endocrine disrupting substances occurring in the Scheldt estuary on resident mysid shrimp populations (laboratory and field studies). Substances of concern were selected and tested in the laboratory to evaluate their effects on the estuarine mysid Neomysis integer. In the context of this project, three new assays using invertebrate-specific endpoints were developed to examine the effect of endocrine disrupting chemicals (EDCs) on molting, embryogenesis and vitellogenesis of N. integer. Finally, in Phase IV laboratory and field results were used to perform a preliminary environmental risk assessment of endocrine disruptors in the Scheldt estuary. Samples were collected along the salinity gradiënt of the Scheldt estuary with the RV Belgica. Water samples were taken with Teflon-coated Go-Flo bottles (10L), sediment samples with Van Veen Grab, biota with a hyperbentic sledge, and suspended particulate matter (SPM) was continuously sampled with an Alfa Laval flow-through centrifuge. For the chemical analysis, protocols were developed to analyse estrogens, organotriazine herbicides, organochlorine pesticides, phtalates, organotins, PAHs, PCBs, and PBDEs in the different matrices: i.e. water, sediment, SPM and biota.Experimental studies were performed to analyse growth, molting, embryogenesis and vitellogenesis of N. integer. These studies were needed to develop ecotoxicological assays to evaluate EDCs on these physiological processes. To study growth of N. integer, organisms were individually transferrred in exposure solutions and molts were collected to measure the growth after each molting. To study embryogenesis, embryos were taking out of the marsupium and placed in multiwell plates. Each day survival, developmental stages and hatching was analysed. To study vitellogenesis, vitellin was isolated from eggs with gelfitration and polyclonal antibodies were developed (in rabbits). With the isolated vitellin and the antibodies an enzyme-linked immunosorbent assay (ELISA) was developed. Vitellin was quatified in ovigerous females exposed to test compound in the laboratory and in females collected from the different sampling sites of the Scheldt estuary. In addition to vitellin levels, energy allocation and testosterone metabolism was examined in field collected mysids. Finally, results from population stu

Male-male marriage in Sinophone and Anglophone Harry Potter danmei and slash

The aim of this study is to compare Sinophone and Anglophone fan fiction consisting of female-oriented male-male romance: danmei and slash, respectively. To increase comparability, we analysed Harry Potter fan fiction in which the characters Harry and Draco are married. Male-male marriage was selected because our online Sinophone and Anglophone BL fandom surveys indicate this to be the most popular story element of the nine options we provided. We analysed five stories originally written in Chinese and five originally written in English which subsequently had been fan-translated into Chinese. Using Thematic Analysis (Braun & Clarke, 2006) we found some robust patterns. In contrast to the Anglophone fiction, the Sinophone tended to: stress the importance of family approval for the marriage; incorporate a wedding ceremony; employ clearly gendered roles between partners; utilise extended, as opposed to nuclear, families; and showed the couple to produce children, particularly boys. Hence, the stories mirror the relative social conservatism and social liberalism of their cultures of origin. However, in reading and writing such danmei young Chinese women are still pushing at the boundaries of the traditional family

Testosterone metabolism in Neomysis integer following exposure to benzo(a)pyrene

Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 144 (2006): 405-412, doi:10.1016/j.cbpb.2006.04.001.Cytochromes P450 (CYPs) are important enzymes involved in the regulation of hormone synthesis and in the detoxification and/or activation of xenobiotics. CYPs are found in virtually all organisms, from archae, and eubacteria to eukaryota. A number of endocrine disruptors are suspected of exerting their effects through disruption of normal CYP function. Consequently, alterations in steroid hormone metabolism through changes in CYP could provide an important tool to evaluate potential effects of endocrine disruptors. The aim of this study was to investigate the potential effects of the known CYP modulator, benzo(a)pyrene (B(a)P), on the testosterone metabolism in the invertebrate Neomysis integer (Crustacea; Mysidacea). N. integer were exposed for 96h to 0.43, 2.39, 28.83, 339.00 and 1682.86μg B(a)P L-1 and a solventcontrol, and subsequently their ability to metabolize testosterone was assessed. Identification and quantification of the produced phase I and phase II testosterone metabolites was performed using liquid chromatography coupled with multiple mass spectrometry (LC-MS2). Significant changes were observed in the overall ability of N. integer to metabolize testosterone when exposed to 2.39, 28.83, 339.00 and 1682.86μg B(a)P L-1 as compared to the control animals.This research was supported by a research grant of the Ghent University Research Fund (BOF, 011.072.02). Dr. Tim Verslycke was supported by a Postdoctoral Fellowship of the Belgian American Educational Foundation

Observation of the Early Structural Changes Leading to the Formation of Protein Superstructures.

Formation of superstructures in protein aggregation processes has been indicated as a general pathway for several proteins, possibly playing a role in human pathologies. There is a severe lack of knowledge on the origin of such species in terms of both mechanisms of formation and structural features. We use equine lysozyme as a model protein, and by combining spectroscopic techniques and microscopy with X-ray fiber diffraction and ab initio modeling of Small Angle X-ray Scattering data, we isolate the partially unfolded state from which one of these superstructures (i.e., particulate) originates. We reveal the low-resolution structure of the unfolded state and its mechanism of formation, highlighting the physicochemical features and the possible pathway of formation of the particulate structure. Our findings provide a novel detailed knowledge of such a general and alternative aggregation pathway for proteins, this being crucial for a basic and broader understanding of the aggregation phenomena.This is the author's accepted manuscript and will be under embargo until the 3rd of September 2015. The final version is published by ACS in The Journal of Physical Chemistry Letters here: http://pubs.acs.org/doi/abs/10.1021/jz501614e