Estrogenicity profile and estrogenic compounds determined in river sediments by chemical analysis, ELISA and yeast assays

An effects-directed strategy was applied to bed sediments of a polluted tributary in order to isolate and identify the major estrogenic chemicals it discharges into the River Po, the principal Italian watercourse. Sediment extract was concentrated by solid phase extraction and then fractioned into 10 fractions by reversed phase high performance liquid chromatography (RP-HPLC). Estrogenic activity of whole extract and fractions were determined using a recombinant yeast assay containing the human estrogen receptor (YES). The 10 fractions and whole extract were analysed for target compounds, e.g. estrone (E1), 17beta-estradiol (E2), estriol (E3), 4-nonylphenol (NP), 4-tert-octylphenol (t-OP), bisphenol A (BPA), using both liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-competitive enzyme-linked immunosorbent assays (ELISA). The YES assay determined high estrogenic activity in whole sediment (15.6 ng/g EE2 equivalents), and positive results for fractions nr 1, 2, 6, 7 and 8. E1, E3 and NP were the main estrogenic chemicals, however, other unidentified compounds contributed to sediment estrogenicity, particularly for polar fractions nr 1 and 2. A GC-MS screening performed in scan mode identified other potential contributors such as phthalates (DBP, BBP), and OP isomers. A next sampling campaign extended to other tributaries and receiving stretches of the River Po confirmed E1, E3 and NP as major estrogenic chemicals potentially threatening other sites of the main river. In general, target compound ELISAs have been shown to be suitable tools for a rapid screening of wide areas or large numbers of environmental samples for estrogenic risk. The potential for interferences suggests however to use cautiously the concentration values obtained from some of the immunoassays.     

Biological assessment of bisphenol A degradation in water following direct photolysis and UV advanced oxidation

Endocrine disrupting compounds (EDCs) are exogenous environmental chemicals that can interfere with normal hormone function and present a potential threat to both environmental and human health. The fate, distribution and degradation of EDCs is a subject of considerable investigation. To date, several studies have demonstrated that conventional water treatment processes are ineffective for removal of most EDCs and in some instances produce multiple unknown transformation products. In this study we have investigated the use of direct photolysis with low-pressure (LP) Hg UV lamps and UV+hydrogen peroxide (H(2)O(2)) advanced oxidation process (AOP) for the degradation of a prototypic endocrine disrupter, bisphenol A (BPA), in laboratory water. Removal rates of BPA and formation of degradation products were determined by high performance liquid chromatography (HPLC) analysis. Changes in estrogenic activity were evaluated using both in vitro yeast estrogen screen (YES) and in vivo vitellogenin (VTG) assays with Japanese medaka fish (Oryzias latipes). Our results demonstrate that UV alone did not effectively degrade BPA. However, UV in combination with H(2)O(2) significantly removed BPA parent compound and aqueous estrogenic activity in vitro and in vivo. Removal rates of in vivo estrogenic activity were significantly lower than those observed in vitro, demonstrating differential sensitivities of these bioassays and that certain UV/AOP metabolites may retain estrogenic activity. Furthermore, the UV/H(2)O(2) AOP was effective for reducing larval lethality in treated BPA solutions, suggesting BPA degradation occurred and that the degradation process did not result in the production of acutely toxic intermediates.     

Determination of phenolic and steroid endocrine disrupting compounds in environmental matrices

BACKGROUND, AIM AND SCOPE: Many pollutants have received significant attention due to their potential estrogenic effect and are classified as endocrine disrupting compounds (EDCs). EDCs comprise many classes of organic compounds. The development or optimization of analytical protocols for the simultaneous determination of EDCs in environmental samples is an analytical challenge because these compounds exhibit different physicochemical characteristics, they occur in the aquatic environment in relatively low concentrations and, furthermore, environmental samples are considered as complex matrices. The aim of this study is the development of analytical methods for the simultaneous determination of phenolic and steroid EDCs in aqueous and solid samples. The target compounds are 4-nonylphenol, 4-octylphenol, their ethoxylate oligomers (mono- and di-ethoxylates of nonylphenol and octylphenol), bisphenol A, the estrogens (estriol, estrone, 17beta-estradiol, 17alpha-estradiol) and the synthetic steroids (mestranol and 17alpha-ethynylestradiol). MATERIALS AND METHODS: Solid phase extraction employing Oasis HLB cartridges and different elution solvents was used for the recovery studies of the target compounds from various types of water samples (ultrapure water, artificial seawater, river water and seawater). Ultrasonic assisted extraction was applied for the recovery of the target EDCs from the solid samples. The recoveries were assessed using various solvents for the extraction and the elution of EDCs from different SPE cartridges used for clean up. Gas chromatography-mass spectrometry after derivatization with N,O-bis(trimethylsilyl)-trifluoroacetamide was employed for the determination of these compounds. RESULTS AND DISCUSSION: The recovery rates of three elution solvents (methanol, acetone and ethylacetate) for the extraction of target EDCs from artificial seawater were assessed after preconcentration on SPE cartridges. Acetone showed better recoveries and was further tested for its extraction efficiency in different water types (river water, seawater). Ultrasonic assisted extraction was used for the recovery of target EDCs from solid matrices. Acetone, methanol, mixture of acetone-methanol (1:1) and ethylacetate were used as extraction solvents. Ethylacetate and the mixture of acetone-methanol (1:1) exhibited better extraction efficiencies. An additional clean up step was necessary for sediment samples. Different SPE cartridges were employed for clean up of the extracts (Oasis HLB, C18, Florisil, silica, combination of silica and alumina). Florisil cartridges were finally used. The proposed methods were further validated on the determination of target EDCs in field collected samples (river water, seawater, wastewater, total suspended solids and sediments) from the major area of Thessaloniki, Greece. CONCLUSIONS: Efficient and accurate integrated methods for the simultaneous determination of alkylphenols (nonylphenol, octylphenol), their ethoxylate oligomers (mono- and di-ethoxylate of nonylphenol and octylphenol), bisphenol A and steroids (estriol, estrone, 17beta-estradiol, 17alpha-estradiol, mestranol and 17alpha-ethynylestradiol) in aqueous and solid samples were developed. The proposed methods were applied for the determination of the target compounds in representative environmental samples in the area of Thessaloniki, Northern Greece. RECOMMENDATIONS AND PERSPECTIVES: This study confirms the occurrence of selected EDCs in inland and marine waters in the area of Thessaloniki, Northern Greece. Since there is no previous data on the occurrence of the target EDCs in the major area, an extended survey is in progress to evaluate the occurrence and fate of these compounds.     

Overcoming the toxicity effects of municipal wastewater sludge and biosolid extracts in the Yeast Estrogen Screen (YES) assay

For nearly two decades, the Yeast Estrogen Screen (YES) has been used as a valuable tool for determining the total estrogenic potency of various environmental samples, including influent and effluent streams at municipal wastewater plants. However, applying the YES assay to wastewater sludges and stabilized biosolids has been problematic. This is due to co-extracted compounds from the solids either proving toxic to the yeast or masking the presence of estrogenic substances. The present research describes the development and validation of sample preparation steps that mitigate the toxicity effects of municipal wastewater sludge and biosolid samples in the YES assay, while allowing for reliable dose-dependent expression of estrogenic activity. A copper work-up for sulfur removal and chromatographic cleanup with silica and alumina were required in addition to solid-phase extraction to adequately remove interfering compounds. Sample stabilization methods such as autoclaving, lyophilization and formaldehyde treatment were found to be detrimental to the assay. Hence, heat-drying is recommended to prevent cytotoxicity and the degradation of estrogenic substances.     

Effects-directed analysis of organic toxicants in wastewater effluent from Zagreb, Croatia

The organic toxicants present in the effluent of the main sewer of the city of Zagreb, Croatia were isolated and identified through the use of effects-directed characterisation techniques. At the time of investigation, the wastewater effluent received no treatment and was comprised of a mixture of effluent from domestic and industrial sources. The organic load of the wastewater was isolated by solid phase extraction and toxicity profiles obtained using reverse-phase HPLC. All procedures were evaluated through the analysis of a series of reference compounds of widely differing polarity. Toxicity profiles for EROD activity (CYP1A induction), vitellogenin induction (estrogenic activity), cytotoxicity (membrane stability and metabolic inhibition) were obtained using a rainbow trout (Oncorhynchus mykiss) primary hepatocyte bioassay. The suite of bioassays showed biological responses after exposure to the raw extracts for all the endpoints tested. However, a combination of mixture toxicity and cytotoxicity in the complex raw extract had some masking effect on the sub-lethal responses of vitellogenin and EROD induction. Bioassay testing of the fine fractions obtained by HPLC produced a range of endpoint-specific toxicity profiles for each sample. A number of compounds were identified by the use of GC-MS and LC-MS/MS as responsible for the observed effects. The steroid estrogens 17 beta-estradiol and estriol were identified by LC-MS/MS as estrogen receptor agonists in two of the estrogenic fractions. In addition, GC-MS analysis identified different alkylphenols, benzophenone and methylparaben which also contributed to the estrogenic activity of the sample. Polycyclic aromatic hydrocarbons (PAHs), alkyl substituted PAHs, nitro-polycyclic aromatic compounds (nitro-PACs), carbazoles and alkyl substituted carbazoles and other known CYP1A inducers were identified by GC-MS analysis as responsible for some of the observed EROD activity. Some active compounds remain unidentified.     

Evaluation of an extraction method for a mixture of endocrine disrupters in sediment using chemical and in vitro biological analyses

Aquatic sediments are contaminated by a wide diversity of organic pollutants such as endocrine-disrupting chemicals (EDCs) which encompass a broad range of chemical classes having natural and anthropogenic origins. The use of in vitro bioassays is now widely accepted as an alternative method for their detection in complex samples. However, based on the diversity of EDC chemical properties, their common extraction is difficult and comprehensive validation of extraction methods for a bioanalysis purpose is still weakly documented. In this study, we compared the performance of several organic solvents, i.e., acetone, methanol, dichloromethane, heptane, dichloromethane/acetone (50:50, v/v), dichloromethane/methanol (50:50, v/v), heptane/acetone (50:50, v/v), and heptane/methanol (50:50, v/v), to extract a diversity of active chemicals from a spiked sediment matrix using pressurized liquid extraction. For this purpose, we defined a mixture of 12 EDCs with a wide range of polarity (2?<?log Kow?<?8) (i.e., estrone, 17β-estradiol, bisphenol A, o,p′DDT, 4-tert-octylphenol, fenofibrate, triphenyl phosphate, clotrimazole, PCB-126, 2,3,7,8 TCDD, benzo[k]fluoranthene, and dibenzo[a,h]anthracene). Working concentrations of each individual compound in the mixture were determined as equipotent concentrations on the basis of the concentration-addition (CA) model applied to in vitro estrogenic, dioxin-like, and pregnane X receptor (PXR)-like activities. Extraction efficiencies based on both chemical and biological analyses were assessed in triplicate in artificial blank sediment spiked with this mixture and in natural sediment contaminated by native EDCs. In both spiked and natural sediment, MeOH/DCM yields the best recovery while heptane was the least efficient solvent. Our study provided the validation of a sediment extraction methodology for EDC bioanalysis purposes, which can be used for comprehensive environmental contamination characterization.     

Analysis of estrogenic activity in coastal surface waters of the Baltic Sea using the yeast estrogen screen

In the present study, the yeast estrogen screen (YES) has been used to assess the estrogenic activity in surface waters of a coastal region in the German Baltic Sea. Solid-phase extraction using the copolymer Oasis HLB followed by a clean-up on silica was carried out on approximately 50-l water samples. From the final 400 μl extract volume, 100 μl aliquots were used for the measurement of estrogenic activity and for chemical analysis, which was performed by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). From 29 samples taken during two campaigns (2003 and 2004) at five different stations 27 samples showed an estrogenic response higher than 10%. The response in the YES was expressed as measured estradiol equivalents (EEQs), which were in the range of 0.01 (Darss Peninsula) to 0.82 ng/l (Inner Wismar Bay). Samples from stations located in inner coastal waters showed higher estrogenic activities than those from outer located stations. A comparison of measured estrogenicity (YES) and calculated estrogenicity (chemical analysis) showed significant differences, probably due to the presence of anti-estrogenic compounds and/or the estrogenic activity of unknown, not identified contaminants. The main contributors to the overall estrogenic activity were synthetic and natural hormones.     

Biologically directed environmental monitoring, fate, and transport of estrogenic endocrine disrupting compounds in water: A review

Endocrine disrupting compounds (EDCs) are contaminants that may be hormonally active at low concentrations and are emerging as a major concern for water quality. Estrogenic EDCs (e-EDCs) are a subclass of EDCs that, when organisms are exposed to them, function as estrogens. Given that there are numerous e-EDCs that can negatively affect humans and wildlife, general screening techniques like biologically based assays (BBAs) may provide major advantages by estimating the total estrogenic effects of many e-EDCs in the environment. These techniques may potentially be adapted for field portable biologically directed sampling and analyses. This article summarizes available BBAs used to measure estrogenic e-EDCs in the environmental samples and also presents results relating to fate and transport of e-EDCs. Estrogenic EDCs appear to be almost ubiquitous in the environment, despite low solubility and high affinity of organic matter. Potential transport mechanisms may include: (1) transport of more soluble precursors, (2) colloid facilitated transport, (3) enhanced solubility through elevated pH, and (4) the formation of micelles by longer-chain ethoxylates. Due to their persistent and ubiquitous nature, source control strategies for e-EDCs may reduce influent concentration to wastewater treatment plants so that the post treatment effluent will decrease concentrations to estrogenically inactive levels. Alternatively if source reduction is not possible, then more testing is needed on tertiary treatment technologies and treatment efficiencies for e-EDCs. There is still a need for research on remediation and restoration approaches for habitats disturbed by elevated e-EDC concentrations.     

Determination of estrogenic activity by LYES-assay (yeast estrogen screen-assay assisted by enzymatic digestion with lyticase)

In order to enhance the sensitivity and the speed of the yeast estrogen screen (YES)-assay, which has been established in many laboratories for the determination of estrogenic activity of compounds and environmental samples, the LYES-assay, a modified version of the YES-assay including a digestion step with the enzyme lyticase, was developed. With the LYES-assay the estrogenic activities of natural (17β-estradiol E2 and estrone), synthetic (17-ethinylestradiol EE2) and pharmaceutical estrogens (diethylstilbestrol DES) as well as xenoestrogens (4-nonylphenol NP and five parabens) were determined and compared with the results obtained by other in vitro-assays namely the conventional YES-assay, the E-Screen-assay (MCF-7 breast tumor cell proliferation) and a receptor binding-assay (RB) with human estrogen receptors hER- and hER-β. In the case of E2 the LYES-assay had a significantly lower limit of quantification (LOQ) than the conventional YES-assay and even two orders of magnitude lower than the RB-assay. Compared to the E-Screen-assay the LOQ of the LYES-assay was almost one order of magnitude higher. The time required to perform the LYES-assay was as little as seven hours compared to three to five days for the conventional YES-assay. Thus, the LYES-assay is a very good alternative to existing estrogenic in vitro-assays, since it has a good sensitivity, is cheap and much faster than the other assays.     

Toxic masking and synergistic modulation of the estrogenic activity of chemical mixtures in a yeast estrogen screen (YES)

Background, aim and scope

Estrogenic and non-estrogenic chemicals typically co-occur in the environment. Interference by non-estrogenic chemicals may confound the assessment of the actual estrogenic activity of complex environmental samples. The aim of the present study was to investigate whether, in which way and how seriously the estrogenic activity of single estrogens and the observed and predicted joint action of estrogenic mixtures is influenced by toxic masking and synergistic modulation caused by non-estrogenic chemical confounders.

Materials and methods

The yeast estrogen screen (YES) was adapted so that toxicity and estrogenicity could be quantified simultaneously in one experimental run. Mercury, two organic solvents (dimethyl sulfoxide (DMSO) and 2,4-dinitroaniline), a surfactant (LAS-12) and the antibiotic cycloheximide were selected as toxic but non-estrogenic test chemicals. The confounding impact of selected concentrations of these toxicants on the estrogenic activity of the hormone 17ß-estradiol was determined by co-incubation experiments. In a second step, the impact of toxic masking and synergistic modulation on the predictability of the joint action of 17ß-estradiol, estrone and estriol mixtures by concentration addition was analysed.

Results

Each of the non-estrogenic chemicals reduced the apparent estrogenicity of both single estrogens and their mixtures if applied at high, toxic concentrations. Besides this common pattern, a highly substance- and concentration-dependent impact of the non-estrogenic toxicants was observable. The activity of 17ß-estradiol was still reduced in the presence of only low or non-toxic concentrations of 2,4-dinitroaniline and cycloheximide, which was not the case for mercury and DMSO. A clear synergistic modulation, i.e. an enhanced estrogenic activity, was induced by the presence of slightly toxic concentrations of LAS-12. The joint estrogenic activity of the mixture of estrogens was affected by toxic masking and synergistic modulation in direct proportion to the single estrogens, which allowed for an adequate adaptation of concentration addition and thus unaffected predictability of the joint estrogenicity in the presence of non-estrogenic confounders.

Discussion

The modified YES proved to be a reliable system for the simultaneous quantification of yeast toxicity and estrogen receptor activation. Experimental results substantiate the available evidence for toxic masking as a relevant phenomenon in estrogenicity assessment of complex environmental samples. Synergistic modulation of estrogenic activity by non-estrogenic confounders might be of lower importance. The concept of concentration addition is discussed as a valuable tool for estrogenicity assessment of complex mixtures, with deviations of the measured joint estrogenicity from predictions indicating the need for refined analyses.

Conclusions

Two major challenges are to be considered simultaneously for a reliable analysis of the estrogenic activity of complex mixtures: the identification of known and suspected estrogenic compounds in the sample as well as the substance- and effect-level-dependent confounding impact of non-estrogenic toxicants.

Recommendations and perspectives

The application of screening assays such as the YES to complex mixtures should be accompanied by measures that safeguard against false negative results which may be caused by non-estrogenic but toxic confounders. Simultaneous assessments of estrogenicity and toxicity are generally advisable.     

Combining passive samplers and biomonitors to evaluate endocrine disrupting compounds in a wastewater treatment plant by LC/MS/MS and bioassay analyses

Two types of integrative sampling approaches (passive samplers and biomonitors) were tested for their sampling characteristics of selected endocrine disrupting compounds (EDCs). Chemical analyses (LC/MS/MS) were used to determine the amounts of five EDCs (nonylphenol, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol) in polar organic chemical integrative samplers (POCIS) and freshwater mussels (Unio pictorum); both had been deployed in the influent and effluent of a municipal wastewater treatment plant (WWTP) in Genoa, Italy. Estrogenicity of the POCIS samples was assessed using the yeast estrogen screen (YES). Estradiol equivalent values derived from the bioassay showed a positive correlation with estradiol equivalents calculated from chemical analyses data. As expected, the amount of estrogens and EEQ values in the effluent were lower than those in the influent. Passive sampling proved to be the preferred method for assessing the presence of these compounds since employing mussels had several disadvantages both in sampling efficiency and sample analyses.     

A Biomimetic Approach to the Detection and Identification of Estrogen Receptor Agonists in Surface Waters Using Semipermeable Membrane Devices (SPMDs) and Bioassay-Directed Chemical Analysis (12 pp)

Goal, Scope and Background Some anthropogenic pollutants posses the capacity to disrupt endogenous control of developmental and reproductive processes in aquatic biota by activating estrogen receptors. Many anthropogenic estrogen receptor agonists (ERAs) are hydrophobic and will therefore readily partition into the abiotic organic carbon phases present in natural waters. This partitioning process effectively reduces the proportion of ERAs readily available for bioconcentration by aquatic biota. Results from some studies have suggested that for many aquatic species, bioconcentration of the freely-dissolved fraction may be the principal route of uptake for hydrophobic pollutants with logarithm n-octanol/water partition coefficient (log Kow) values less than approximately 6.0, which includes the majority of known anthropogenic ERAs. The detection and identification of freely-dissolved readily bioconcentratable ERAs is therefore an important aspect of exposure and risk assessment. However, most studies use conventional techniques to sample total ERA concentrations and in doing so frequently fail to account for bioconcentration of the freely-dissolved fraction. The aim of the current study was to couple the biomimetic sampling properties of semipermeable membrane devices (SPMDs) to a bioassay-directed chemical analysis (BDCA) scheme for the detection and identification of readily bioconcentratable ERAs in surface waters. Methods SPMDs were constructed and deployed at a number of sites in Germany and the UK. Following the dialytic recovery of target compounds and size exclusion chromatographic clean-up, SPMD samples were fractionated using a reverse-phase HPLC method calibrated to provide an estimation of target analyte log Kow. A portion of each HPLC fraction was then subjected to the yeast estrogen screen (YES) to determine estrogenic potential. Results were plotted in the form of 'estrograms' which displayed profiles of estrogenic potential as a function of HPLC retention time (i.e. hydrophobicity) for each of the samples. Where significant activity was elicited in the YES, the remaining portion of the respective active fraction was subjected to GC-MS analysis in an attempt to identify the ERAs present. Results and Discussion Estrograms from each of the field samples showed that readily bioconcentratable ERAs were present at each of the sampling sites. Estimated log Kow values for the various active fractions ranged from 1.92 to 8.63. For some samples, estrogenic potential was associated with a relatively narrow range of log Kow values whilst in others estrogenic potential was more widely distributed across the respective estrograms. ERAs identified in active fractions included some benzophenones, various nonylphenol isomers, benzyl butyl phthalate, dehydroabietic acid, sitosterol, 3-(4-methylbenzylidine)camphor (4-MBC) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (AHTN). Other tentatively identified compounds which may have contributed to the observed YES activity included various polycyclic aromatic hydrocarbons (PAHs) and their alkylated derivatives, methylated benzylphenols, various alkylphenols and dialkylphenols. However, potential ERAs present in some active fractions remain unidentified. Conclusions and Outlook Our results show that SPMD-YES-based BDCA can be used to detect and identify readily bioconcentratable ERAs in surface waters. As such, this biomimetic approach can be employed as an alternative to conventional methodologies to provide investigators with a more environmentally relevant insight into the distribution and identity of ERAs in surface waters. The use of alternative bioassays also has the potential to expand SPMD-based BDCA to include a wide range of toxicological endpoints. Improvements to the analytical methodology used to identify ERAs or other target compounds in active fractions in the current study could greatly enhance the applicability of the methodology to risk assessment and monitoring programmes.     

Cell bioassays for detection of aryl hydrocarbon (AhR) and estrogen receptor (ER) mediated activity in environmental samples

In vitro cell bioassays are useful techniques for the determination of receptor-mediated activities in environmental samples containing complex mixtures of contaminants. The cell bioassays determine contamination by pollutants that act through specific modes of action. This article presents strategies for the evaluation of aryl hydrocarbon receptor (AhR)-(hereafter referred as dioxin-like) or estrogen receptor (ER)-mediated activities of potential endocrine disrupting compounds (EDCs) in complex environmental mixtures. Extracts from various types of environmental or food matrices can be tested by this technique to evaluate their 2,3,7,8-tetrachlorodibenzop-dioxin equivalents (TCDD-EQs) or estrogenic equivalents (E₂-EQs) and to identify contaminated samples that need further investigation using resource-intensive instrumental analyses. Fractionation of sample extracts exhibiting significant activities, and subsequent reanalysis with the bioassays can identify important classes of contaminants that are responsible for the observed activity. Effect-directed chemical analysis is performed only for the active fractions to determine the responsible compounds. Mass-balance estimates of all major compounds contributing to the observed effects can be calculated to determine if all of the activity has been identified, and to assess the potential for interactions such as synergism or antagonism among contaminants present in the complex mixtures. The bioassay approach is an efficient (fast and cost effective) screening system to identify the samples of interest and to provide basic information for further analysis and risk evaluation.     

Occurrence, distribution, and sources of six phenolic endocrine disrupting chemicals in the 22 river estuaries around Dianchi Lake in China

The objectives of this study are to track the occurrence, distribution, and sources of phenolic endocrine disrupting compounds (EDCs) in the 22 rivers around Dianchi Lake in China, to estimate the input and output amounts of phenolic EDCs in the water system, and to provide more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment. Six phenolic EDCs were systematically evaluated in water and surface sediment in the estuaries of those rivers. The water and sediment samples were preconcentrated by solid-phase extraction system and microwave-assisted extraction system, respectively. Phenolic EDCs were analyzed by GC-MS (Thermo Fisher Scientific, USA) after derivatization. Phenolic EDCs were found ubiquitously in the aquatic environment. The total concentrations ranged from 248 to 4,650 ng/L in water, and 113 to 3,576 ng/g dry weight in surface sediment. The residue amount of phenolic EDCs in Dianchi Lake was 258 kg/a. Concentrations of the phenolic EDCs in the Lake decreased with increase in distance to the estuaries of those rivers which run through urban and industrial areas. The rivers seriously contaminated by phenolic EDCs were Xin River, Yunliang River, Chuanfang River, Cailian River, Jinjia River, Zhengda River, and Daqing River which run through the old area of Kunming City. Satisfying correlations were observed between the concentrations of the target compounds in water and in surface sediment. NP1EO, NP2EO, and BPA were identified as the three predominant phenolic EDCs. There were significant correlations between phenolic EDCs and many basic water quality parameters. Urban and industrial areas are the major contributors for phenolic EDCs, especially in Kunming City. Compositional profiles of phenolic EDCs in surface sediment were similar to those in river water. The concentrations of phenolic EDCs in the rivers located in the northwest part of the valley were very high, and posed a potential risk to aquatic organisms and even human. The concentrations of NP2EO, NP1EO, and BPA were at moderate levels of other areas. The basic water quality parameters (TOC, TN, DO, and pH) play important roles on the distribution, fate, and behavior of phenolic EDCs in the valley.     

Endocrine disrupting activities in sewage effluent and river water determined by chemical analysis and in vitro assay in the context of granular activated carbon upgrade

As part of endocrine disruption in catchments (EDCAT) programme, this work aims to assess the temporal and spatial variations of endocrine disrupting chemicals (EDCs) in River Ray, before and after the commissioning of a full-scale granular activated carbon (GAC) plant at a sewage treatment works (STW). Through spot and passive sampling from effluent and river sites, estrogenic and anti-androgenic activities were determined by chemical analysis and in vitro bio-assay. A correlation was found between chemical analyses of the most potent estrogens (estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2)) and yeast estrogen screen (YES) measurement, both showing clearly a reduction in estrogenic activity after the commissioning of the GAC plant at the STW. During the study period, the annual average concentrations of E1, E2 and EE2 had decreased from 3.5 ng L⁻¹, 3.1 ng L⁻¹ and 0.5 ng L⁻¹ to below their limit of detection (LOD), respectively, with a concentration reduction of at least 91%, 81% and 60%. Annual mean estrogenic activity measured by YES of spot samples varied from 1.9 ng L⁻¹ to 0.4 ng L⁻¹ E2 equivalent between 2006 and 2008 representing a 79% reduction. Similarly, anti-androgenic activity measured by yeast anti-androgen screen (anti-YAS) of spot samples was reduced from 148.8 to 22.4 μg flutamide L⁻¹, or by 85%. YES and anti-YAS values were related to each other, suggesting co-existence of both types of activities from chemical mixtures in environmental samples. The findings confirm the effectiveness of a full-scale GAC in removing both estrogenic and anti-androgenic activities from sewage effluent.     

Distribution of steroid- and dioxin-like activities between sediments, POCIS and SPMD in a French river subject to mixed pressures

The contamination of aquatic systems by endocrine disrupting chemicals (EDCs) is now a widely established fact. Nevertheless, there is still a scarcity of knowledge concerning the source, transport, fate and bioavailability of such active compounds. In the present study we assessed the distribution of estrogenic, (anti-)androgenic, pregnane X receptor-like (PXR) and dioxin-like activities between sediment and water compartments using a polar organic compound integrative sampler (POCIS) and a semi-permeable membrane device (SPMD) passive sampler in a river where sediment has been previously described as highly and multi-contaminated. We first confirmed the contamination pattern of this river sediment between 2004, 2009 and 2010 samples, suggesting that this river is subject to a constant high contamination level. However, we showed a different distribution pattern of these activities between compartments: estrogenic activity was mainly detected in POCIS extracts and to a lesser extent in sediment and SPMD extracts; anti-androgenic activities were mainly detected in SPMD and sediment extracts while no activity was detected in POCIS extracts; PXR-like activity was detected in all three investigated compartments, with POCIS > SPMD > sediment; dioxin-like activity was mainly found in the sediment and the SPMD extracts. Overall, partitioning of the biological activities was in accordance with physicochemical properties (e.g., log K _ow) of typical known active chemicals in each bioassay. Furthermore, in order to establish whether the chemicals involved in these activities were similar between the compartments, we fractionated sediment, POCIS and SPMD extracts using a multi-step fractionation procedure. This highlighted differences in the nature of active chemicals between compartments. Altogether, our results support the need to consider different compartments in order to enhance exposure assessment.     

Supercritical fluid extraction of polycyclic aromatic hydrocarbons from marine sediments and soil samples

Supercritical fluid extraction (SFE) was used to extract polycyclic aromatic hydrocarbons (PAH) from a certified sample of marine sediment. This sample contains a great number of organic pollutants that are present in low concentrations. The extractions were carried out at 50 and 80 degrees C, at a pressure varying from 230 to 600 bar and using CO2 in the supercritical phase and the effect of three organic modifiers (methanol, n-hexane and toluene), added at 5%/vol, at the same temperature and pressure conditions, were then considered. PAHs were characterized by GC-MS and the recover yield was estimated for 6 PAHs that were representative of those present in the sample, according to their molecular weight and to the number of condensed rings. The analytical conditions giving the best recovery efficiency were used on an unpolluted soil sample spiked with 11 PAHs of environmental importance at a concentration similar to that certified for the sediment sample. An increase in the yield of recovered PAHs, using methanol as co-solvent, was observed while higher temperatures caused a negative effect on the quantity of recovered pollutants. The recovery yield for PAHs from the spiked soil sample was measured and found to be greater than 90%. Better recoveries were obtained for those compounds with higher molecular weight.     

Removal of estrone, 17α-ethinylestradiol,and 17ß-estradiol in algae and duckweed-based wastewater treatment systems

Background, aim, and scope  

Many pollutants have received significant attention due to their potential estrogenic effect and are classified as endocrine disrupting compounds (EDCs). Because of possible ecological effects and increased attention for water reuse schemes, it is important to increase our understanding of the EDC removal capacities of various wastewater treatment systems. However, there has so far been little research on the fate and behavior of EDCs in stabilization pond systems for wastewater treatment, which represent an important class of wastewater treatment systems in developing countries because of their cost-effectiveness. The aim of this work is to study the fate and behavior of EDCs in algae and duckweed ponds. Because the synthetic hormone 17α-ethinylestradiol (EE2) and the natural hormones estrone (E1), as well as 17β-estradiol (E2), have been detected in effluents of sewage treatment plants and been suggested as the major compounds responsible for endocrine disruption in domestic sewage; E1, E2, and EE2 were therefore chosen as target chemicals in this current work.