Measurement of estrogenic activity in sediments from Haihe and Dagu River, China

Sediments from two rivers in China, the Haihe and Dagu Rivers, were examined for estrogenic activity using an estrogen receptor (ER)-mediated in vitro bioassay system. ER-active compounds were isolated from sediments by Soxhlet extraction, and the crude extracts were fractionated using a florisil column into three fractions. The estrogenic activity of each extract was detected by measuring luciferase activity in the human breast cancer cell line MCF-7 transfected with a luciferase receptor gene. Significant estrogenic activity was observed in each total extract. The 17beta-estradiol equivalents (E2-EQs) ranged from 8.24 to 95.28 ng E2 g(-1) dw. As a result, the relative estrogenic potencies of three fractions in this study descended in the order of Fraction 3>Fraction 2>Fraction 1. The results of the bioassay analysis indicated the heavy pollution status of these sites with estrogenic contaminants. In this study, five selected chemicals, the natural estrogens 17beta-estradiol (E2) and estrone (E1), and the xeno-estrogens 4-octylphenol (OP), 4-nonylphenol (NP), and Bisphenol A (BPA) were also analyzed using the in vitro bioassay. The estrogenic activity of these chemicals were E2>E1>NP>OP>BPA.     

Analysis of phytoestrogens,progestogens and estrogens in environmental waters from Rio de Janeiro (Brazil)

The environment is currently exposed to a large variety of man-made chemicals (e.g. for industrial, medicinal use) which have potential adverse effects to its ecological status. In addition, the densely populated areas represent local high emissions of those chemicals leading to more aggravating consequences. Estrogenic compounds that end-up in environmental water directly affect living organisms by interfering with their endocrine metabolism. The assessment of their presence in the environment requires sensitive and selective analytical methods. Nineteen estrogenic compounds belonging to different classes (5 free estrogens, 6 conjugated estrogens, 3 progestogens and 5 phytoestrogens) have been studied. The analytical methodology developed is based on solid phase extraction followed by liquid chromatography tandem mass spectrometry and has been applied to study the occurrence of the above mentioned analytes in environmental waters from the state of Rio de Janeiro (Brazil). Due to insufficient infra-structure in this region, waste waters are released onto the environment without or with incomplete previous treatment. The results show that high levels of the phytoestrogens daidzein, coumestrol and genistein of up to 366 ng/L and progesterone of up to 47 ng/L could be found in river water. Estrogens and their conjugated derivatives were detected in the lower ng/L range up to 7 ng/L. The main estrogens estrone, estradiol and the synthetic ethinyl estradiol could not be detected. The developed method showed overall good performance with recoveries above 80% (with one exception), limits of detection ≤ 2 ng/L, good linearity and reproducibility.     

Occurrence,fate and ecological risk of five typical azole fungicides as therapeutic and personal care products in the environment: A review

Azole fungicides are widely used to treat fungal infection in human. After application, these chemicals may reach to the receiving environment via direct or indirect discharge of wastewaters, thus posing potential risks to non-target organisms. We aimed to review the occurrence, fate and toxicological effects of some representative household azole fungicides in the environment. Azole fungicides were widely detected in surface water and sediment of the aquatic environment due to their incomplete removal in wastewater treatment plants. These chemicals are found resistant to microbial degradation, but can undergo photolysis under UV irradiation. Due to different physiochemical properties, azole fungicides showed different environmental behaviors. The residues of azole fungicides could cause toxic effects on aquatic organisms such as algae and fish. The reported effects include regulation changes in expression of cytochrome P450-related genes and alteration in CYP450-regulated steroidogenesis causing endocrine disruption in fish. Further studies are essential to investigate the removal of azole fungicides by advanced treatment technologies, environmental fate such as natural photolysis, and toxic pathways in aquatic organisms.     

Comprehensive study of endocrine disrupting compounds using grab and passive sampling at selected wastewater treatment plants in South East Queensland, Australia

Chemical (gas chromatography-mass spectrometry, GC-MS) and biological (E-Screen assay) analyses were used to determine the concentrations of 15 endocrine disrupting compounds (EDCs) and estrogen equivalent (EEq) in grab and passive samples from five municipal wastewater treatment plants (WWTPs) in South East Queensland, Australia. EEq concentrations derived by E-Screen assays for the grab samples were between 108-356 ng/L for the influents and < 1-14.8 ng/L for the effluents with the exception of one effluent sample which was at 67.8 ng/L EEq. The EDC concentrations and EEq values for the passive samples were several times lower than those of the grab samples: a decrease probably caused by, but not limited to biofouling, low flow rate, biodegradation and temperature which can progressively reduce the uptake of compounds into the sampler. At this stage, grab sampling is the most reliable method for field monitoring; nevertheless, passive sampler is a useful sampling tool but the method requires more research to ensure that the information obtained can be interpreted appropriately. Although alkylphenols and phthalates were detected at higher concentrations in the wastewater samples as compared to natural hormones, the environmental risk may be negligible as their estrogenic potencies are several orders of magnitude lower than that of the natural estrogens. In most wastewater samples, the natural estrogens contributed to 60% or more of the EEq value. Removal efficacy of most estrogenic and xenoestrogenic compounds from the conventional activated sludge or biological nutrient removal (BNR) WWTPs monitored in this study was in the range of 80-> 99%. The efficiency of the WWTPs in removing estrogenic activity was > 95%. The EEqs of the E-Screen and those calculated from the results of extensive chemical analyses using the estradiol equivalency factors were comparable for most of the WWTPs samples.     

Targeted analytical toxicology: Simultaneous determination of 17α-ethynylestradiol and the estrogen-induced vitellogenin biomarker

In most toxicological studies, chemical concentrations and its biological/molecular response (biomarker) levels are often quantified separately. We report a method, named as Targeted Analytical Toxicology (TAT), for the simultaneous determination of levels of chemicals and protein biomarkers in organisms by UPLC/ESI–MS/MS on the basis of targeted proteomics. The TAT method is successfully applied to detect the concentrations of 17α-ethynylestradiol (EE₂) and EE₂-induced vitellogenin (a biomarker for estrogens) in male zebrafish exposed to EE₂. It is expected for TAT to have broad application in toxicology, especially in environmental toxicology, due to its high sensitivity, accuracy, reproducibility, high throughput, and the savings of time, cost and labor.     

Occurrence,fate and effects of azoxystrobin in aquatic ecosystems: A review

The use of pesticides for crop protection may result in the presence of toxic residues in environmental matrices. In the aquatic environment, pesticides might freely dissolve in the water or bind to suspended matter and to the sediments, and might be transferred to the organisms' tissues during bioaccumulation processes, resulting in adverse consequences to non-target species. One such group of synthetic organic pesticides widely used worldwide to combat pathogenic fungi affecting plants is the strobilurin chemical group. Whereas they are designed to control fungal pathogens, their general modes of action are not specific to fungi. Consequently, they can be potentially toxic to a wide range of non-target organisms. The present work had the intent to conduct an extensive literature review to find relevant research on the occurrence, fate and effects of azoxystrobin, the first patent of the strobilurin compounds, in aquatic ecosystems in order to identify strengths and gaps in the scientific database. Analytical procedures and existing legislation and regulations were also assessed. Data gathered in the present review revealed that analytical reference standards for the most relevant environmental metabolites of azoxystrobin are needed. Validated confirmatory methods for complex matrices, like sediment and aquatic organisms' tissues, are very limited. Important knowledge of base-line values of azoxystrobin and its metabolites in natural tropical and estuarine/marine ecosystems is lacking. Moreover, some environmental concentrations of azoxystrobin found in the present review are above the Regulatory Acceptable Concentration (RAC) in what concerns risk to aquatic invertebrates and the No Observed Ecologically Adverse Effect Concentration (NOEAEC) reported for freshwater communities. The present review also showed that there are very few data on azoxystrobin toxicity to different aquatic organisms, especially in what concerns estuarine/marine organisms. Besides, toxicity studies mostly address azoxystrobin and usually neglect the more relevant environmental metabolites. Further work is also required in what concerns effects of exposure to multi-stressors, e.g. pesticide mixtures. Even though Log K_ow for azoxystrobin and R234886, the main metabolite of azoxystrobin in water, are below 3, the bio-concentration factor and the bioaccumulation potential for azoxystrobin are absent in the literature. Moreover, no single study on bioaccumulation and biomagnification processes was found in the present review.     

Pollution biomarkers in two estuarine invertebrates,Nereis diversicolor and Scrobicularia plana,from a Marsh ecosystem in SW Spain

The polychaete worm Nereis diversicolor and the clam Scrobicularia plana were collected from several sites, affected by different types of contamination, in a littoral enclosure in the SW Spain (Caño Sancti-Petri and Rio San Pedro). N. diversicolor was present in 6 sampling sites whereas S. plana in 4 of them. The aim of our study was to relate several pollution biomarkers to chemical sources (metals and organic pollutants e.g. PCB, PAH) in these species, thereby confirming their adequacy as sentinels for this habitat. The biomarkers surveyed in the two invertebrates were the activities of the antioxidant enzyme catalase (CAT), the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE). Metallothionein (MT) levels were measured as a biomarker of exposure to metals. The results suggested a different response in the two sediment-dwelling organisms, the sediment-eating polychaete and the water-filtering clam, probably as a consequence of different contamination exposures. The results also suggested that samples from the “Caño Sancti-Petri” were exposed to biologically active compounds that altered some of their biochemical responses. Of all the biomarkers tested, AChE was the most sensitive one and N. diversicolor the potentially most robust sentinel in this ecosystem. In this low to moderately polluted environment, the biochemical approach better reflected temporal trends than site-related differences although it was also able to detect punctual chemical insults.     

Effects of natural and chemical stressors on Enchytraeus albidus: Can oxidative stress parameters be used as fast screening tools for the assessment of different stress impacts in soils?

Enchytraeids are important organisms of the soil biocenosis. They improve the soil pore structure and the degradation of organic matter. These organisms are used in standardized testing, using survival and reproduction (6 weeks) as endpoints. The use of biomarkers, linked to ecologically relevant alterations at higher levels of biological organization, is a promising tool for Environmental Risk Assessment. Here, enchytraeids were exposed for different time periods (two days and three weeks) to different soils (OECD artificial soil, different compositions in its organic matter, clay or pH value, and LUFA 2.2 natural soil) and different chemicals (Phenmedipham and copper). The main question addressed in the present study was if the effects of chemicals and different soil properties are preceded by alterations at the sub-cellular level, and if these endpoints may be used reliantly as faster screening tools for the assessment of different stress conditions in soils. The parameters measured in E. albidus whole body were: lipid peroxidation (LPO), total glutathione (TG), as well as the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST). The results showed that biomarker responses in E. albidus were significantly affected by the soil type (GST, CAT, GPx, GR and LPO) and the duration of exposure in OECD artificial soil (GST, GPx, GR, CAT and LPO) but not in LUFA 2.2 natural soil. For the abiotic factors studied, after 2 days, low pH decreased significantly the TG levels and the activities of CAT and GR,and low OM also significantly decreased CAT and GR activities. After 3 weeks, differences in soil properties caused a decrease in GR and GPx activities, whereas increased GST activity was observed due to low organic matter and pH. Copper significantly increased the activities of CAT, GPx and GR, and decreased the activity of GST after 2 days as well as inscreasing LPO levels after 3 weeks. Phenmedipham increased LPO levels, associated with increased levels of TG as well as increased activities of CAT and GPx and decreased GST activity after 3 weeks exposure. This study shows that both abiotic and chemical stresses could be followed through biomarker analysis and that some of these determinations are potential endpoints in a quick soil contamination assessment procedure.     

Organohalogenated contaminants in domestic cats' plasma in relation to spontaneous acromegaly and type 2 diabetes mellitus: A clue for endocrine disruption in humans?

It was recently hypothesized that pets may serve as sentinels to explore human exposure to organohalogenated chemicals (OHCs) via indoor environments and adverse health effects. The current study investigates OHCs contamination in domestic cats suffering from diabetes mellitus (DM), particularly DM induced by acromegaly and a form of DM akin to human type 2 DM (T2DM). Plasma from three groups of domestic cats was analyzed: acromegaly induced DM, T2DM and age matched control cats without DM. Analytes targeted included organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), together with their hydroxylated (HO-) metabolites. Similar PCB profiles were measured in cat plasma compared to humans, while the PBDE profile (dominated by BDE-99 (48%–55%) and BDE-47 (19%–25%)), the PCB and PBDE metabolite profiles were different in cat plasma than found in humans. Significantly higher OHC concentrations were recorded in plasma of acromegalic cats compared to the other two groups. Group differences in the PCBs/HO-PCBs ratios suggest that acromegalic cats have a lower capacity to metabolize persistent OHCs, like PCBs, than diabetic cats or cats without an endocrinopathy. As pituitary tumorigenesis in animals can be induced by estrogens, and PCBs may act as xenoestrogens, further investigation into whether there could be a causative link with the induction of feline acromegaly is warranted. Interestingly, BDE-47/BDE-99 ratios in cats were similar to the ratios in house dust. The results of this study suggest that domestic cats may represent a good model to assess human exposure to chemicals present in indoor dust.     

Phytoestrogens and mycoestrogens in surface waters — Their sources,occurrence, and potential contribution to estrogenic activity

This review discusses the potential contribution of phytoestrogens and mycoestrogens to in vitro estrogenic activities occurring in surface waters and in vivo estrogenic effects in fish. Main types, sources, and pathways of entry into aquatic environment of these detected compounds were summarized. Reviewed concentrations of phyto/mycoestrogens in surface waters were mostly undetectable or in low ng/L ranges, but exceeded tens of μg/L for the flavonoids biochanin A, daidzein and genistein at some sites. While a few phytosterols were reported to occur at relatively high concentrations in surface waters, information about their potencies in in vitro systems is very limited, and contradictory in some cases. The relative estrogenic activities of compounds (compared to standard estrogen 17β-estradiol) by various in vitro assays were included, and found to differ by orders of magnitude. These potencies were used to estimate total potential estrogenic activities based on chemical analyses of phyto/mycoestrogens. In vivo effective concentrations of waterborne phyto/mycoestrogens were available only for biochanin A, daidzein, formononetin, genistein, equol, sitosterol, and zearalenone. The lowest observable effect concentrations in vivo were reported for the mycoestrogen zearalenone. This compound and especially its metabolites also elicited the highest in vitro estrogenic potencies. Despite the limited information available, the review documents low contribution of phyto/mycoestrogens to estrogenic activity in vast majority of surface waters, but significant contribution to in vitro responses and potentially also to in vivo effects in areas with high concentrations.     

Estrogen-, androgen- and aryl hydrocarbon receptor mediated activities in passive and composite samples from municipal waste and surface waters

Passive and composite sampling in combination with in vitro bioassays and identification and quantification of individual chemicals were applied to characterize pollution by compounds with several specific modes of action in urban area in the basin of two rivers, with 400,000 inhabitants and a variety of industrial activities. Two types of passive samplers, semipermeable membrane devices (SPMD) for hydrophobic contaminants and polar organic chemical integrative samplers (POCIS) for polar compounds such as pesticides and pharmaceuticals, were used to sample wastewater treatment plant (WWTP) influent and effluent as well as rivers upstream and downstream of the urban complex and the WWTP. Compounds with endocrine disruptive potency were detected in river water and WWTP influent and effluent. Year-round, monthly assessment of waste waters by bioassays documented estrogenic, androgenic and dioxin-like potency as well as cytotoxicity in influent waters of the WWTP and allowed characterization of seasonal variability of these biological potentials in waste waters. The WWTP effectively removed cytotoxic compounds, xenoestrogens and xenoandrogens. There was significant variability in treatment efficiency of dioxin-like potency. The study indicates that the WWTP, despite its up-to-date technology, can contribute endocrine disrupting compounds to the river. Riverine samples exhibited dioxin-like, antiestrogenic and antiandrogenic potencies. The study design enabled characterization of effects of the urban complex and the WWTP on the river. Concentrations of PAHs and contaminants and specific biological potencies sampled by POCIS decreased as a function of distance from the city.     

Genotoxic effects of binary mixtures of xenoandrogens (tributyltin, triphenyltin) and a xenoestrogen (ethinylestradiol) in a partial life-cycle test with Zebrafish (Danio rerio)

A partial life-cycle test with the model fish Danio rerio was performed in order to evaluate the genotoxic potential of binary mixtures of xenoandrogenic (tributyltin--TBT; triphenyltin--TPT) and an estrogenic compound (ethinylestradiol--EE2). Five days post-fertilisation larvae were diet-exposed to environmental relevant concentrations of TBT and TPT (25 ng/g-100 ng/g), and water-exposed to ethinylestradiol (3.5 ng/L) for a four-month period; binary mixtures of TBT plus EE2 and TPT plus EE2 were run in parallel. The erythrocytic nuclear abnormalities (ENA) assay in circulating erythrocytes was used to evaluate genotoxicity in the end of the four-month exposure period. A significant increase (p<0.05, Kruskall-Wallis non-parametric ANOVA) in ENA frequency, in comparison with control animals, was observed in those animals exposed to TBT and TPT (the highest doses only), and to EE2 and the binary mixtures, although neither synergistic nor additive effects of the tested compounds were evident. Overall, the results clearly indicate that chronic exposure to low levels of TBT, TPT, EE2 and binary mixtures of TBT plus EE2 and TPT plus EE2 are genotoxic to zebrafish, which may suggest that wild fish populations may be under increased DNA damage in areas contaminated by these endocrine disrupting chemicals.     

Occurrence and fate of hormone steroids in the environment

Hormone steroids are a group of endocrine disruptors, which are excreted by humans and animals. In this paper, we briefly review the current knowledge on the fate of these steroids in the environment. Natural estrogenic steroids estrone (E1), 17beta-estradiol (E2) and estriol (E3) all have a solubility of approximately 13 mg/l, whereas synthetic steroids 17alpha-ethynylestradiol (EE2) and mestranol (MeEE2) have a solubility of 4.8 and 0.3 mg/l, respectively. These steroids have a moderate binding on sediments and are reported to degrade rapidly in soil and water. Estrogenic steroids have been detected in effluents of sewage treatment plants (STPs) in different countries at concentrations ranging up to 70 ng/l for E1, 64 ng/l for E2, 18 ng/l for E3 and 42 ng/l for EE2. E2 concentrations in river waters from Japan, Germany, Italy and the Netherlands ranged up to 27 ng/l. In addition, E2 concentrations ranging from 6 to 66 ng/l have also been measured in mantled karst aquifers in northwest Arkansas. This contamination of ground water has been associated with poultry litter and cattle manure waste applied on the land. Although hormone steroids have been detected at a number of sources worldwide, currently, there is limited data on the environmental behaviour and fate of these hormone steroids in different environmental media. Consequently, the exposure and risk associated with these chemicals are not adequately understood.     

Interpretation of fish biomarker data for identification,classification, risk assessment and testing of endocrine disrupting chemicals

Chemical induced changes in fish biomarkers vitellogenin (VTG), secondary sex characteristics (SSC), and sex ratio indicate modes/mechanisms of action (MOAs) of EAS (estrogen, androgen and steroidogenesis) pathways. These biomarkers could be used for defining MOAs and the causal link between MOAs and adverse effects in fish for the identification of endocrine disrupting chemicals (EDCs). This paper compiled data sets of 150 chemicals for VTG, 57 chemicals for SSC and 38 chemicals for sex ratio in fathead minnow, medaka and zebrafish. It showed 1) changes in fish biomarkers can indicate the MOAs as anticipated; 2) in addition to EAS pathways, chemicals with non-EAS pathways induced changes in fish biomarkers; 3) responses of fish biomarkers did not always follow the anticipated patterns of EAS pathways. These responses may result from the interaction of chemical-induced multiple MOAs and confounding factors like fish diet, infection, culture conditions, general toxicity and stress response. The complex response of fish biomarkers to a chemical of interest requires EDC testing at multiple biological levels. Interpretation of fish biomarker data should be combined with relevant information at different biological levels, which is critical for defining chemical specific MOAs. The utility of fish biomarker data for identification, classification, PBT assessment, risk assessment, and testing of EDCs in the regulatory context was discussed. This paper emphasizes the importance of fish biomarker data in the regulatory context, a weight of evidence approach for the interpretation of fish biomarker data and the need for defining levels of evidence for the identification of EDCs.     

武汉月湖和莲花湖表层沉积物中持久性有机物的污染状况

采用气－质联用技术分析了武汉汉阳月湖和莲花湖的4个表层沉积物样品中的有机污染物,探讨了两湖沉积物受持久性有机物污染的程度。月湖中共检测出124种有机物,其中属环境优先控制污染物和美国EPA筛选的内分泌干扰物19种;莲花湖中共检测出186种有机物,环境优先控制污染物和美国EPA筛选的内分泌干扰物34种。主要污染物包括：酞酸酯、酯类、酚类、杂环和苯及其衍生物等。污染物浓度顺序为L1＞L2＞Y2＞Y1,莲花湖中有机物浓度明显高于月湖。两湖邻苯二甲酸酯的含量最高,占了污染物总量的96%~98%,邻苯二甲酸乙基己基酯（平均值 17 59903 ng/g 干重）和邻苯二甲酸二丁酯（平均值 2 515.76 ng/g 干重）是两湖沉积物中的主要酞酸酯类污染物。     

Induction of EROD activity in European eel (Anguilla anguilla) experimentally exposed to benzo[a]pyrene and beta-naphthoflavone

The induction of liver ethoxyresorufin O-deethylase (EROD) activity was investigated in the European eel, Anguilla anguilla, collected from a Mediterranean brackish environment and experimentally exposed to benzo[a]pyrene (B[a]P) and beta-naphthoflavone (BNF). Eels were injected intraperitoneally at increasing doses (0.1, 1, 10, and 50 mg/kg wet body weight) using corn oil as a carrier and sacrificed after 7 days. The main objectives of the present study are: (1). to assess of the sensitivity of EROD induction as a biomarker to polycyclic aromatic hydrocarbon (PAH) exposure; (2). to determine an EROD dose-response relationship of the contaminants used; and (3). to compare the efficiency of B[a]P and BNF as inducers of EROD activity. Results showed that both chemicals resulted in a dose-dependent EROD induction, but increases were not linear. EROD activity seemed to reach a plateau at the exposure of 10 mg/kg in both treatment groups; B[a]P was a more potent inducer than BNF was at the higher doses (10 and 50 mg/kg), while the opposite result was observed at the lower ones (0.1 and 1 mg/kg). The greatest induction occurred in eels treated with 10 mg/kg B[a]P, in which a 261-fold increase in EROD activity was observed. Results showed that EROD activity in A. anguilla is significantly induced by B[a]P and BNF exposure, responding to a wide range of concentrations of these contaminants. We infer that this tool may be suited as a diagnostic biomarker for biomonitoring PAHs pollution in Mediterranean brackish environments and further field research is suggested.     

Removal of trace organic contaminants from domestic wastewater: A meta-analysis comparison of sewage treatment technologies

Trace organic contaminants (TrOCs), such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs), represent global threats to aquatic animals and ecosystems. A major source of TrOCs in the aquatic environment is via the discharge of treated sewage, so there is an urgent need to evaluate the comparative efficiencies of the most widely used sewage treatment technologies as regards elimination of these compounds from wastewater. To address this need, 976 published articles were compiled focusing on estimates of removal (%) for 20 common environmental TrOCs, from five major sewage treatment technologies: conventional activated sludge (CAS), oxidation ditch (OD), membrane bioreactor (MBR), ponds and constructed wetlands (PCW), and trickling biological filters (TBF). A quantitative meta-analysis was performed to compare standardized relative removal efficiencies (SREs) of the compounds amongst these technologies, and where possible potential sources of heterogeneity were considered (e.g., flow rates and chemical sorption potential). The results indicate that the most widely used CAS treatment and the less common TBF provide comparatively poor overall removal of common organic micropollutants. Membrane bioreactors appear to be capable of achieving the greatest overall removal efficiencies, but the sustainability and economic viability of this option has been questioned. Treatment with OD systems may be more economical while still achieving comparatively high removal efficiencies, and the analysis revealed OD to be the best option for targeting highly potent estrogenic EDCs. This study offers a unique global assessment of TrOC removal via leading sewage treatment technologies, and is an important step in the identification of effective options for treating municipal sewage.     

Estrogenic activity of pharmaceuticals in the aquatic environment

In the last years pharmaceuticals have aroused great interest as environmental pollutants for their toxic effects towards non target organisms. This study wants to draw attention to a further adverse effect of drugs, the endocrine interference. The most representative drugs of the widespread classes in environment were investigated. The YES-test and the E-screen assay were performed to detect the capability of these substances to bind the human estrogenic receptor α (hERα) in comparison with 17β-estradiol. Out of 14 tested pharmaceuticals, 9 were positive to YES-assay and 11 were positive to E-screen assay; in particular, Furosemide and the fibrates (Bezafibrate, Fenofibrate and Gemfibrozil) gave the maximal estrogenic response. Tamoxifen showed its dual activity as agonist and antagonist of hERα.     

Trace metal bioaccumulation: models, metabolic availability and toxicity

Aquatic invertebrates take up and accumulate trace metals whether essential or non-essential, all of which have the potential to cause toxic effects. Subsequent tissue and body concentrations of accumulated trace metals show enormous variability across metals and invertebrate taxa. Accumulated metal concentrations are interpreted in terms of different trace metal accumulation patterns, dividing accumulated metals into two components - metabolically available metal and stored detoxified metal. Examples of different accumulation patterns are described from crustaceans but have a general applicability to all aquatic invertebrates. Toxicity does not depend on total accumulated metal concentration but is related to a threshold concentration of internal metabolically available metal. Toxicity ensues when the rate of metal uptake from all sources exceeds the combined rates of detoxification and excretion (if present) of the metal concerned. The biodynamic model of trace metal bioaccumulation allows the prediction and explanation of widely differing accumulated trace metal concentrations in organisms, combining geochemical analyses of environmental metal concentrations with the measurement of key physiological parameters for a species from the site under consideration. The combination of the biodynamic model as a unified explanation of metal bioaccumulation with an understanding of the relationship between accumulation and toxicity sets the stage for a realistic understanding of the significance of trace metal concentrations in aquatic invertebrates.