Endocrine disrupter nonylphenol and bisphenol A contamination in Okinawa and Ishigaki Islands, Japan--within coral reefs and adjacent river mouths

Certain chemicals possess the potential to modulate endocrine systems, and thereby interfere with reproduction and developmental processes in the wild. We analyzed endocrine disrupters nonylphenol (NP) and bisphenol A (BPA) levels at various sites in Okinawa and Ishigaki Islands, Japan. River-water samples showed undetectable to low concentrations of NP and BPA at most of the sites investigated. However, an appreciable amount of BPA was detected in sediments at one coral reef site. In addition, significant numbers of river sediment samples showed appreciable amounts of NP and BPA. Most of the sampling sites for this study are located within a distance of 1 km from the coral reefs, which are under influence of river-waters to a variable extent. Therefore, influence of endocrine disrupters may have already begun on adjacent coral reefs. Both endocrine disrupters were positively correlated with human population densities, but not with the contents of red soil generated by farm land reformation. Therefore, it is concluded that NP and BPA pollution is a consequence of human waste discharge, both domestic and industrial, and not by agricultural activities.     

Endocrine disrupters in the aquatic environment

Possible mechanisms to explain endocrine effects on reproduction and sex differentiation are presented for selected pharmaceuticals, agrochemicals, industrial chemicals and plant sterols which are known to be present in the aquatic environment. Disruptions of the hormonal coordination can be induced by xenobiotics on various levels of the hierachically organised endocrine system of vertebrates. Phthalate plasticisers, for example, may disrupt the pituitary control of gonadal functions; prenatal/larval exposure to synthetic estrogen impairs sex differentiation and neuroendocrine sexual determination of the central nervous system; phenylurea herbicides block the androgen receptor; the biotransformation of weakly estrogenic plant sterol components of paper mill wastewater (e.g. βsitosterol) may lead to androgenic compounds. The effect of hypolipidemic drugs on lipid homeostasis (peroxysom proliferation) is transmitted via a receptor protein that seems to be closely related to the endocrine system both functionally as well as phylogenetically; possible interferences with the neuroendocrine control of sex differentiation are also discussed. In invertebrates, tributyltin is known to effect the biosynthesis of steroidal sexual hormones. PCBs are suspected to be competitive inhibitors of the steroid catabolism. In order to identify potential risks caused by chemicals to the reproductive capacities of aquatic animals and to the quality of drinking water, methods should be established to detect endocrine disrupters at the various levels of the endocrine system.     

Toxic effects of endocrine disrupters on freshwater sponges: common developmental abnormalities

Endocrine disrupters are of substantial concern, in large part because effects of these compounds on the growth and development of many aquatic organisms are unknown. We examined toxic effects of three substances (ethylbenzene, nonylphenol, and bisphenol A), that are known to be hormonally active in many animals, on growth and development of two species of freshwater sponge. A common developmental abnormality was observed when sponges were treated with each of these compounds. The three compounds also caused significant reductions in growth rates. Lower concentrations resulted in malformed water vascular systems in several replicates. The utility of freshwater sponge bioassays is discussed as it relates to understanding possible mechanisms of action of endocrine disrupters on aquatic invertebrates.     

Selected endocrine disrupting compounds (Vinclozolin,Flutamide, Ketoconazole and Dicofol): Effects on survival,occurrence of males,growth, molting and reproduction of <Emphasis Type="Italic">Daphnia magna</Emphasis>

BACKGROUND, AIM AND SCOPE: Pollution-induced endocrine disruption in vertebrates and invertebrates is a worldwide environmental problem, but relatively little is known about effects of endocrine disrupting compounds (EDCs) in planktonic crustaceans (including Daphnia magna). Aims of the present study were to investigate acute 48 h toxicity and sub-chronic (4-6 days) and chronic (21 days) effects of selected EDCs in D. magna. We have investigated both traditional endpoints as well as other parameters such as sex determination, maturation, molting or embryogenesis in order to evaluate the sensitivity and possible use of these endpoints in ecological risk assessment. MATERIALS AND METHODS: We have studied effects of four model EDCs (vinclozolin, flutamide, ketoconazole and dicofol) on D. magna using (i) an acute 48 h immobilization assay, (ii) a sub-chronic, 4-6 day assay evaluating development and the sex ratio of neonates, and (iii) a chronic, 21 day assay studying number of neonates, sex of neonates, molting frequency, day of maturation and the growth of maternal organisms. RESULTS: Acute EC50 values in the 48 h immobilization test were as follows (mg/L): dicofol 0.2, ketoconazole 1.5, flutamide 2.7, vinclozolin >3. Short-term, 4-6 day assays with sublethal concentrations showed that the sex ratio in Daphnia was modulated by vinclozolin (decreased number of neonate males at 1 mg/L) and dicofol (increase in males at 0.1 mg/L). Flutamide (up to 1 mg/L) had no effect on the sex of neonates, but inhibited embryonic development at certain stages during chronic assay, resulting in abortions. Ketoconazole had no significant effects on the studied processes up to 1 mg/L. DISCUSSION: Sex ratio modulations by some chemicals (vinclozolin and dicofol) corresponded to the known action of these compounds in vertebrates (i.e. anti-androgenicity and anti-oestrogenicity, respectively). Our study revealed that some chemicals known to affect steroid-regulated processes in vertebrates can also affect sublethal endpoints (e.g. embryonic sex determination and/or reproduction) in invertebrates such as D. magna. CONCLUSIONS: A series of model vertebrate endocrine disrupters affected various sub-chronic and chronic parameters in D. magna including several endpoints that have not been previously studied in detail (such as sex determination in neonates, embryogenesis, molting and maturation). Evaluations of traditional reproduction parameters (obtained from the 21 day chronic assay). as well as the results from a rapid, 4-6 day, sub-chronic assay provide complementary information on non-lethal effects of suspected organic endocrine disrupters. RECOMMENDATIONS AND PERSPECTIVES: It seems that there are analogies between vertebrates and invertebrates in toxicity mechanisms and in vivo effects of endocrine disruptors. However, general physiological status of organisms may also indirectly affect endpoints that are traditionally considered 'hormone regulated' (especially at higher effective concentrations as observed in this study) and these factors should be carefully considered. Further research of D. magna physiology and comparative studies with various EDCs will help to understand mechanisms of action as well as ecological risks of EDCs in the environment.     

Determination of phthalates in particulate matter and gaseous phase emitted in indoor air of offices

Environmental Science and Pollution Research - Phthalate esters (PAEs) are endocrine disrupters and can disrupt the functioning of different hormones, causing adverse effects on human health. Due...     

4-n-Nonylphenol and 17-beta estradiol may induce common DNA effects in developing barnacle larvae

There is a growing concern over the potential effects of environmental endocrine disrupters on both human and wildlife populations. However, to date, minimal research has been conducted to determine the effect of estrogens and xenoestrogens at the DNA level. In this study, we used the random amplified polymorphic DNA (RAPD) assay to evaluate the effects on the genomic DNA of barnacle larvae that had been exposed to 17beta-estradiol (E2) and low concentrations of 4-n-nonylphenol (NP). DNA effects include DNA damage as well as mutations and possibly other effects at the DNA level that can be induced by chemical or physical agents that directly and/or indirectly interact with genomic DNA. Not only did exposure to NP and E2 induce changes in RAPD profiles in the exposed barnacle larvae when compared to control patterns, but also, and more importantly, there were similarities in the RAPD modifications in the exposed populations that had been treated to either chemical. We propose that NP and E2 induced some common DNA effects in barnacle larvae and that these specific modifications in RAPD patterns may arise as a consequence of hot spot DNA damage (e.g. DNA adducts) and/or mutations (point mutations or genomic rearrangements). This could help to explain how xenoestrogens mimic the effects produced by natural estrogens. In conclusion, in the field of endocrine disruption, the study of DNA effects induced by estrogens and/or xenoestrogens warrants further investigation. Indeed, changes at the DNA levcl may be the precursors of some of the numerous effects reported at higher levels of biological organisation such as the feminization of males, developmental abnormalities, and infertility.     

4-n-Nonylphenol and 17-β estradiol may induce common DNA effects in developing barnacle larvae

There is a growing concern over the potential effects of environmental endocrine disrupters on both human and wildlife populations. However, to date, minimal research has been conducted to determine the effect of estrogens and xenoestrogens at the DNA level. In this study, we used the random amplified polymorphic DNA (RAPD) assay to evaluate the effects on the genomic DNA of barnacle larvae that had been exposed to 17β-estradiol (E₂) and low concentrations of 4-n-nonylphenol (NP). DNA effects include DNA damage as well as mutations and possibly other effects at the DNA level that can be induced by chemical or physical agents that directly and/or indirectly interact with genomic DNA. Not only did exposure to NP and E₂ induce changes in RAPD profiles in the exposed barnacle larvae when compared to control patterns, but also, and more importantly, there were similarities in the RAPD modifications in the exposed populations that had been treated to either chemical. We propose that NP and E₂ induced some common DNA effects in barnacle larvae and that these specific modifications in RAPD patterns may arise as a consequence of hot spot DNA damage (e.g. DNA adducts) and/or mutations (point mutations or genomic rearrangements). This could help to explain how xenoestrogens mimic the effects produced by natural estrogens. In conclusion, in the field of endocrine disruption, the study of DNA effects induced by estrogens and/or xenoestrogens warrants further investigation. Indeed, changes at the DNA level may be the precursors of some of the numerous effects reported at higher levels of biological organisation such as the feminization of males, developmental abnormalities, and infertility.     

Agonistic and antagonistic toxic effects observed with miniaturized growth and luminescence inhibition assays

Kinetic data recordings with miniaturized growth and luminescence inhibition assays with prokaryotes (Pseudomonas putida and Vibrio fischeri) reveal typical sample and species specific growth and light emission patterns respectively. Growth inhibiting influences, based on toxicokinetic and toxicodynamic sample specificities appeared in each growth phase. Agonistic and antagonistic effects of combinations of heavy metals like Cd2+, Hg2+ and Pb2+ and other compounds were easily recognized after accurate curve discussions. Some of the influences that made it more difficult to evaluate toxicological results only by restriction on EC values (effective concentrations) were investigated. The findings may lead to a more comprehensive interpretation of toxicological data and a presumption on the composition of complex samples in terms of screening investigations. Therefore, the conclusions demonstrate the possibilities and limits of kinetic data recordings in chronic and acute toxicity testing.     

环境中内分泌干扰物质的研究概述

在总结最新文献的基础上，就环境中的内分泌干扰物质的概念，研究背景，研究方法，在环境中的分布情况作了简单综述和介绍，并对有待开展的研究提出了建议，为国内在环境内分泌干扰物方面的研究提供参考。     

Vitellogenin content in European eel (Anguilla anguilla) in Flanders, Belgium

As part of a large-scale monitoring program of bioaccumulating contaminants in the European eel (Anguilla anguilla) in Flanders (Belgium), we investigated potential effects of xenoestrogens in these fish. The present paper describes the results of the plasma vitellogenin (VTG) content, measured in 142 eels sampled at 20 different locations, in relation to the internal pollution levels. To validate the blood VTG assays, a small number of eels (n=8) was exposed to 10 microg ethinylestradiol/l (EE2) for 9 days. In this experiment, VTG was detected as a protein with a molecular weight of 214 kDa and confirmed by Western blotting. Compared with the solvent controls, significantly higher concentrations of VTG were measured in EE2 exposed eel. However, the VTG content was relatively low compared with other fish species exposed to high concentrations of estrogens. The plasma VTG content of eels from the field study was very low, despite a very high internal load of endocrine disrupters. These results, together with previously published studies, suggest that immature yellow European eel might not be the best sentinel species to study the effects of estrogenic compounds on VTG levels of wild fish populations.     

Ecotoxic Effect of Photocatalytic Active Nanoparticles (TiO2) on Algae and Daphnids (8 pp)

Background, Aim and Scope Due to their large potential for manifold applications, the use of nanoparticles is of increasing importance. As large amounts of nanoparticles may reach the environment voluntarily or by accident, attention should be paid on the potential impacts on the environment. First studies on potential environmental effects of photocatalytic TiO2 nanoparticles have been performed on the basis of widely accepted, standardized test systems which originally had been developed for the characterization of chemicals. The methods were adapted to the special requirements of testing photocatalytic nanoparticles. Materials and Methods: Suspensions of two different nanoparticles were illuminated to induce their photocatalytic activity. For testing, the growth inhibition test with the green alga Desmodesmus subspicatus and the immobilization test with the daphnid Daphnia magna were selected and performed following the relevant guidelines (algae: ISO 8692, OECD 201, DIN 38412-33; daphnids: ISO 6341, OECD 202, DIN 38412-30). The guidelines were adapted to meet the special requirements for testing photocatalytic nanoparticles. Results: The results indicate that it is principally possible to determine the ecotoxicity of nanoparticles. It was shown that nanoparticles may have ecotoxicological effects which depend on the nature of the particles. Both products tested differ in their toxicity. Product 1 shows a clear concentration-effect curve in the test with algae (EC50: 44 mg/L). It could be proven that the observed toxicity was not caused by accompanying contaminants, since the toxic effect was comparable for the cleaned and the commercially available product. For product 2, no toxic effects were determined (maximum concentration: 50 mg/L). In the tests with daphnids, toxicity was observed for both products, although the concentration effect-curves were less pronounced. The two products differed in their toxicity; moreover, there was a difference in the toxicity of illuminated and non-illuminated products. Discussion: Both products differ in size and crystalline form, so that these parameters are assumed to contribute to the different toxicities. The concentration-effect curves for daphnids, which are less-pronounced than the curves obtained for algae, may be due to the different test organisms and/or the differing test designs. The increased toxicity of pre-illuminated particles in the tests with daphnids demonstrates that the photocatalytic activity of nanoparticles lasts for a period of time. Conclusions: The following conclusions can be drawn from the test results: (I) It is principally possible to determine the ecotoxicity of (photocatalytic) nanoparticles. Therefore, they can be assessed using methods comparable to the procedures applied for assessing soluble chemicals. - (II) Nanoparticles may exert ecotoxicological effects, which depend on the specific nanoparticle. - (III) Comparable to traditional chemicals, the ecotoxicity depends on the test organisms and their physiology. - (IV) The photocatalytic activity of nanoparticles lasts for a relevant period of time. Therefore, pre-illumination may be sufficient to detect a photocatalytic activity even by using test organisms which are not suitable for application in the pre-illumination-phase. Recommendations and Perspectives: First results are presented which indicate that the topic 'ecotoxicity and environmental effects of nanoparticles' should not be neglected. In testing photocatalytic nanoparticles, there are still many topics that need clarification or improvement, such as the cause for an observed toxicity, the improvement of the test design, the elaboration of a test battery and an assessment strategy. On the basis of optimized test systems, it will be possible to test nanoparticles systematically. If a potential risk by specific photocatalytic particles is known, a risk-benefit analysis can be performed and, if required, risk reducing measures can be taken.     

EU-wide survey of polar organic persistent pollutants in European river waters

This study provides the first EU-wide reconnaissance of the occurrence of polar organic persistent pollutants in European river waters. More than 100 individual water samples from over 100 European rivers from 27 European Countries were analysed for 35 selected compounds, comprising pharmaceuticals, pesticides, PFOS, PFOA, benzotriazoles, hormones, and endocrine disrupters. Around 40 laboratories participated in this sampling exercise. The most frequently and at the highest concentration levels detected compounds were benzotriazole, caffeine, carbamazepine, tolyltriazole, and nonylphenoxy acetic acid (NPE₁C). Only about 10% of the river water samples analysed could be classified as “very clean” in terms of chemical pollution. The rivers responsible for the major aqueous emissions of PFOS and PFOA from the European Continent could be identified. For the target compounds chosen, we are proposing “indicative warning levels” in surface waters, which are (for most compounds) close to the 90th percentile of all water samples analysed.     

Inventory of marine biotest methods for the evaluation of dredged material and sediments

An inventory of marine biotest methods for the evaluation of dredged material and sediments was compiled on behalf of the Federal Environmental Agency of Germany. Relevant assays were identified from the literature and experts from several countries contributed to a questionnaire survey on established and developing procedures. The biotest methods are applicable to whole sediment, sediment suspension, sediment elutriate, porewater and/or sediment extract. The endpoints cover acute and long-term toxicity, bioaccumulation, endocrine effects, toxic effects on reproduction, carcinogenicity and mutagenicity. Comparative analyses and evaluation of the biotest methods were conducted with regard to their sensitivity, specificity, applicability (regional specificity, availability and suitability of the test organisms), variability (physicochemical factors, natural factors and factors related to sampling and testing), cost-effectiveness, aspects of animal ethics, standardization (guidelines, intercalibration) and application for monitoring purposes in the areas of the OSPAR and Helsinki Conventions. The available information was integrated to rate the validity of the methods, their relevance for assessing impacts on ecosystems and the suitability of the methods for the evaluation of marine sediments and dredged material. Based on the rating of the individual bioassays, a tiered testing is suggested in a hierarchical approach representing a variety in taxa, biological processes and exposure routes, thereby covering the cellular, species, population and community level with a wide discriminatory and sensitivity range. The toxicological significance and complexity increases with the tiers: (1) screening and detection of impacts, (2) characterization of toxic effects, (3) verification of in situ alterations.     

Effect-Directed Analysis of Key Toxicants in European River Basins. A Review (9 pp)

Background, Aim and Scope Extensive monitoring programs on chemical contamination are run in many European river basins. With respect to the implementation of the European Union (EU) Water Framework Directive (WFD), these programs are increasingly accompanied by monitoring the ecological status of the river basins. Assuming an impact of chemical contamination on the ecological status, the assignment of effects in aquatic ecosystems to those stressors that cause the effects is a prerequisite for taking political or technical measures to achieve the goals of the WFD. Thus, one focus of present European research is on toxicant identification in European river basins in order to allow for a reduction of toxic pressure on aquatic ecosystems according to the WFD. Main Features: An overview is presented on studies that were performed to link chemical pollution in European river basins to measurable ecotoxic effects. This includes correlation-based approaches as well as investigations that apply effect-directed analysis (EDA) integrating toxicity testing, fractionation and non-target chemical analysis. Effect-based key toxicants that were identified in European surface waters are compiled and compared to EU priority pollutants. Further needs for research are identified. Results: Studies on the identification of effect-based key toxicants focused on mutagenicity, aryl hydrocarbon receptor-mediated effects, endocrine disruption, green algae, and invertebrates. The identified pollutants include priority pollutants and other well-known environmental pollutants such as polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins, furans, and biphenyls, nonylphenol, some pesticides and tributyltin, but also other compounds that were neither considered as environmental pollutants before nor regulated such as substituted phenols, natural or synthetic estrogens and androgens, dinaphthofurans, 2-(2-naphthalenyl)benzothiophene, and N-phenyl-2-naphthylamine. Discussion: Individual studies at specific sites in a European river basin demonstrated the power of combined biological and chemical analytical approaches and, particularly, of effect-directed analysis. However, the available information on effect-based key toxicants is very limited with respect to the entirety of rivers possibly at risk due to chemical contamination and with respect to toxicological endpoints considered at a specific site. A relatively broad basis of information exists only for estrogenicity and aryl hydrocarbon, receptor-mediated effects. Conclusions: The development of tools and strategies for an identification of key toxicants on a broader scale are a challenging task for the next years. Since investigations dealing with toxicant identification are too labor and cost-intensive for monitoring purposes, they have to be focused on the key sites in a river basin. These should include hot spots of contamination, particularly if there is evidence that they might pose a risk for downstream areas, but may also involve accumulation zones in the lower reach of a river in order to get an integrated picture on the contamination of the basin. Perspectives: While EDA is almost exclusively based on measurable effects in in vitro and in vivo biotests to date, an increasing focus in the future should be on the integration of EDA into Ecological Risk Assessment and on the development of tools to confirm EDA-determined key toxicants as stressors in populations, communities and ecosystems. Considering these requirements and applied in a focused way, toxicant identification may significantly help to implement the Water Framework Directive by providing evidence on the main stressors and possible mitigation measures in order to improve the ecological status of a river ecosystem.     

New insights into the endocrine disrupting effects of brominated flame retardants

The objective of this review is to provide an overview of recent studies demonstrating the endocrine disrupting (ED) effects of brominated flame retardants (BFRs), while highlighting interesting data presented at the recent international BFR workshop in Amsterdam in April, 2007. A review written in 2002 was used as a starting point and about 60 publications published since 2003 were reviewed. New insights into the in vivo effects of BFRs on thyroid hormone, estrogen and androgen pathways in both mammalian and non-mammalian models are provided, and novel (in vitro) findings on the mechanisms underlying ED effects are highlighted. Special attention is also given to reports on neurotoxicological effects at relatively low doses of BFRs, although an endocrine-related mechanism is disputable. Convincing evidence has been published showing that BFRs and importantly, BFR metabolites, have the potential to disrupt endocrine systems at multiple target sites. While some studies suggest a wide margin of safety between effect concentrations in rodent models and levels encountered in humans and the environment, other studies demonstrate that exposure to low doses relevant for humans and wildlife at critical time points in development can result in profound effects on both endocrine pathways and (neuro)development.     

Endocrine disrupting nonyl- and octylphenol in infant food in Germany: considerable daily intake of nonylphenol for babies

Nonylphenol and octylphenol are persistent endocrine disrupters that are priority substances of the European Union Water Framework Directive. Their presence in the environment has caused increasing concern about their impact to human health. Infants are more sensitive to hormonal impacts of environmental chemicals than adults. The results of the present study indicate that nonylphenol is ubiquitous in foodstuffs for babies and toddlers commercially available in Germany, while octylphenol could only be determined in 80% of all food samples. The daily intakes based on consumption studies in μg nonylphenol kg⁻¹ body weight per day for high consumers in the baby category (0.23-0.65 μg kg⁻¹ bw d⁻¹) were relatively high. This could lead to a higher risk especially for babies.     

The influence of deoxynivalenol and zearalenone on steroid hormone production by porcine ovarian granulosa cells in vitro

Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) are frequently occurring in feed of pigs together. The aim of this study was to evaluate the possible in vitro effects of DON and ZEA, alone or their combination on steroid secretion of porcine ovarian granulosa cells (GCs). A species-specific model with porcine ovarian GCs was used to study the potential endocrine disrupting effects of DON and ZEA alone and in co-exposure. Progesterone (P4) and estradiol (E2) were determined by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA). The results of this study demonstrate that DON alone at the higher concentrations may act to stimulate P4 (at 1,000, 2,000, 3,000 and 5,000 ng mL^?1 but not 10 and 100 ng mL^?1) and E2 (at 2,000, 3,000 and 5,000 ng mL^?1 but not 10, 100 and 1000 ng mL^?1) secretion. The effects of ZEA on P4 and E2 secretion were not confirmed. DON in combination with the other fusariotoxin ZEA may impair steroidogenesis. Results aslo demonstrate different toxicological effects of fusariotoxins on follicle stimulating hormone-induced secretion of P4 and E2. All these results taken together suggest that fusariotoxin and their interactions can impact ovarian steroidogenesis, thereby demonstrating their potential reproductive effects in pigs.     

Implications of research on endocrine disruption for the environmental risk assessment, regulation and monitoring of chemicals in the European Union

We assess the implications which research on endocrine disrupting chemicals (EDCs) has for the regulation of synthetic substances and for the protection of the environment, particularly under the forthcoming European Union (EU) REACH legislation. EDCs present regulatory problems inter alia because they can act additively at concentrations which are individually harmless, and they may have non-classical dose (concentration)-response relationships at low exposure levels. Furthermore, current in vivo testing routines were not specifically designed to assess the endocrine disrupting properties of chemicals, whilst in silico and in vitro methods have only limited applicability and availability for this purpose. We need to ensure that the assessment approaches specified in the draft REACH legislation and Technical Guidance are able to evaluate EDCs efficiently. However, it must also be recognised that environmental monitoring procedures in Europe will need to be improved to detect EDCs that have evaded identification, and where appropriate, control, under REACH.