Presence Of Endocrine Disrupting Chemicals Research Articles

Market analysis of the presence of endocrine disrupting chemicals in cosmetic products intended for oncological patients and other vulnerable groups.

There is growing concern about the presence of endocrine disrupting chemicals (EDCs) in cosmetics. We aimed to identify the main cosmetic ingredients with suspected endocrine-disrupting properties, and analyse their presence in current marketed products. Particular attention was given to products intended for susceptible (due to physiological status) and vulnerable (due to specific pathologies) groups with a view to informing cosmetologists and related health professionals of the scientific basis and current status of any concerns. Suspected EDCs used as cosmetic ingredients, included in lists published by regulatory agencies, were documented and investigated by weight of evidence analysis based on endocrine-related toxicity studies. In total, 49 suspected EDCs were identified from a sample of over a thousand cosmetic products marketed in the European Union. Suspected EDCs were found in approximately one third of products, with a similar frequency in products intended for susceptible and vulnerable groups. Avobenzone (CAS number:70356-09-1), octisalate (CAS number: 118-60-5), and butylated hydroxytoluene (CAS number: 128-37-0) were mostly commonly identified. The presence of EDCs was particularly high for sun care cosmetic products. Our results highlight potentially significant exposure through cosmetics to substances currently studied by regulatory institutions as suspected endocrine disrupters. EDCs are not yet universally regulated, and informing health professionals and educating the population as a precaution are options to reduce individual exposure levels, especially in vulnerable and susceptible groups. Special recommendations are needed for products intended for oncological patients.

Unveiling the presence of endocrine disrupting chemicals in northern French soils: Land cover variability and implications

Endocrine disrupting chemicals (EDCs) are chemicals that can be found in the environment and have adverse effects on human health by mimicking, perturbing and blocking the function of hormones. They are commonly studied in water surfaces, rarely in soils, although it can be an important source of their presence in the environment. Their detection in soils is analytically challenging to quantify, hence the lack of known background concentrations found in the literature. This scientific research aimed to detect EDCs in soils by analyzing 240 soil samples using an optimized protocol of double extraction and analysis using liquid chromatography coupled to mass spectrometry. The optimized protocol allowed for very sensitive detection of the targeted compounds. The results showed a high concentration of 29.391 ng/g of 17β-estradiol in soils and 47.16 ng/g for 17α-ethinylestradiol. Testosterone and Progesterone were detected at a highest of 1.02 and 6.58 ng/g, respectively. The ∑EDCs which included estrogens, progesterone, testosterone and Bisphenol A was found at an average of 22.72 ± 35.46 ng/g in the study area. The results of this campaign showed a heterogeneous geographic distribution of the EDCs compounds in the different zones of study. Additionally, the study conducted a comparison of the concentration of EDCs in different land covers including urban areas, agricultural lands, grasslands and forests. We observed a significant difference between forests and other land covers (p < 0.0001) for 17α-ethinylestradiol, estriol, and progesterone. This presence of EDCs in forest lands is not yet understood and requires further studies concerning its origins, its fate and its effect on human health. This study is the first large-scale sampling campaign targeting EDCs in soils in Europe and the second in the world. It is also the first to assess the concentrations of these compounds based on different land covers.

Occurrence, tissue distribution, and risk assessment of progestins, androgens, estrogens, and phenols in wild freshwater fish species.

The presence of endocrine-disrupting chemicals (EDCs) in aquatic environments such as water, sediment, and sludge received more and more attention. However, the bioaccumulate properties of EDCs, particularly progestins and androgens, in various tissues of different wild freshwater fish species, as well as their effects on human health, have not been fully studied. The muscle, liver, and gills of three wild fish species obtained from the East Dongting Lake in southern China were examined for the presence of 19 EDCs (4 progestins, 5 androgens, 6 estrogens, and 4 phenols). Seventeen analytes were detected in all fish samples, and the concentrations of progestins, androgens, estrogens, and phenols ranged from ND-78.80 ng/g (wet weight, ww), ND-50.40 ng/g ww, ND-3573.82 ng/g ww, and ND-88.17 ng/g ww, respectively. The bioaccumulation of some EDCs in wild fish from East Dongting Lake was species-specific. Additionally, AND, EES, P4, and E2 were discovered in the liver at higher levels than in the muscle, suggesting that livers had a larger ability for enriching these EDCs than the muscle. Furthermore, the relationships between the fish sizes and the EDC concentrations indicated that total weight and length had a negligible impact on the bioaccumulation of EDCs in various fish species. Most importantly, the effects of EDCs on human health as a result of fish consumption were assessed. Although the estimated daily intakes (EDIs) of most EDCs were much lower compared with the corresponding acceptable daily intakes (ADIs) via consuming fish collected in this study, the EDI of EE2 in Silurus asotus was higher than the ADI of E2, indicating that Silurus asotus from East Dongting Lake should be eaten in moderation by local residents.

Synthesis of biochar-CoFe2O4 nanocomposite for adsorption of methylparaben from wastewater under full factorial experimental design.

The presence of endocrine-disrupting chemicals in municipal wastewater has emerged as a threat to human health and the environment. Therefore, this study aimed to develop biochar-cobalt ferrite (BCF) nanocomposite for the removal of methylparaben from water under the full factorial experimental design of 4 factors with 3 levels (34). The biochar-CoFe2O4 nanocomposite was developed by co-precipitation method from cobalt ferrite and biochar of Eucalyptus tree bark. Adsorbent surface morphology and functional and elemental composition were carried out by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDS) techniques which showed the presence of cracks with a rough surface, reasonable surface chemical composition, and many chemical functional groups, respectively. The experimental and predicted adsorption efficiencies ranged from 25.3 to 85.6% and 21.8 to 80.3%, respectively. The maximum adsorption performance (85.6%) reduced the methylparaben concentration from 27.5 to 4.0mg/L at the optimum condition of adsorbent dose of 55mg/100mL, pH 6, contact time 90min, and the initial methylparaben concentration of 27.5mg/L. However, the adsorbent dose was the most influential main factor whereas the least influential was the interaction between solution pH and contact time under the regression model. The model also showed that 69% methylparaben removal was described by the regression model. The experimental data best fitted with the Freundlich model indicate multilayer adsorption which is the implication of physisorption. The sorption mechanism is attributed to Vander Waals forces, H-bonding, and dipole interaction. This BCF nanocomposite adsorbent appears to be promising for the removal of methylparaben from wastewater, but a further optimization process is essential to boost the treatment performance.

Improved method for the determination of endocrine-disrupting chemicals in urine of school-age children using microliquid-liquid extraction and UHPLC-MS/MS.

The presence of endocrine-disrupting chemicals in our daily life is increasing every day and, by extension, human exposure and the consequences thereof. Among these substances are bisphenols and parabens. Urine is used to analyze the exposure. The determination of 12 bisphenol homologues and 6 parabens is proposed. A procedure based on a method previously developed by our research group in 2014 is improved. The extraction yield is higher, because the new protocol is 5 times more efficient. Also, a comparison between calibration with pure standards and matrix calibration, to calculate the matrix effect, was also made. A high grade of matrix effect for all analytes was observed. In terms of validation, the limits of detection (LOD) were between 0.03 and 0.3ngmL-1 and limits of quantification (LOQ) 0.1 to 1.0ngmL-1, respectively, and the recovery is higher than 86.4% and lower than 113.6%, with a RSD lower than 13.5% in all cases. A methodology for accurate and sensitive quantification of bisphenol homologues together with parabens in human urine using UHPLC-MS/MS was developed. The method was successfully applied to 30 urine samples from children.

Prospecting carbon-based nanomaterials for the treatment and degradation of endocrine-disrupting pollutants

The presence of endocrine-disrupting chemicals (EDCs) in water resources has significant negative implications for the environment. Traditional technologies implemented for water treatment are not completely efficient for removing EDCs from water. Therefore, research on sustainable remediation has been mainly directed to novel decontamination approaches including nano-remediation. This emerging technology employs engineered nanomaterials to clean up the environment quickly, efficiently, and sustainably. Thus, nanomaterials have contributed to a wide variety of remediation techniques like adsorption, filtration, coagulation/flocculation, and so on. Among the vast diversity of decontamination technologies catalytic advanced oxidation processes (AOPs) outstand as simple, clean, and efficient alternatives. A vast diversity of catalysts has been developed demonstrating high efficiencies; however, the search for novel catalysts with enhanced performances continues. In this regard, nanomaterials used as nanocatalysts are exhibiting enhanced performances on AOPs due to their special nanostructures and larger specific surface areas. Therefore, in this review we summarize, compare, and discuss the recent advances on nanocatalysts, catalysts doped with metal-based nanomaterials, and catalysts doped with carbon-based nanomaterials on the degradation of EDCs. Finally, further research opportunities are identified and discussed to achieve the real application of nanomaterials to efficiently degrade EDCs from water resources.

Endocrine disrupting chemicals (EDCs) in environmental matrices: Occurrence, fate, health impact, physio-chemical and bioremediation technology

Endocrine disrupting chemicals (EDCs) are an emerging category of toxicity that adversely impacts humans and the environment's well-being. Diseases like cancer, cardiovascular risk, behavioral disorders, autoimmune defects, and reproductive diseases are related to these endocrine disruptors. Because these chemicals exist in known sources such as pharmaceuticals and plasticizers, as well as non-point sources such as agricultural runoff and storm water infiltration, the interactive effects of EDCs are gaining attention. However, the efficiency of conventional treatment methods is not sufficient to fully remediate EDCs from aqueous environments as the occurrence of EDC bioremediation and biodegradation is detected in remediated drinking water. Incorporating modification into current remediation techniques has to overcome challenges such as high energy consumption and health risks resulting from conventional treatment. Hence, the use of advanced psychochemical and biological treatments such as carbon-based adsorption, membrane technology, nanostructured photocatalysts, microbial and enzyme technologies is crucial. Intensifying environmental and health concerns about these mixed contaminants are primarily due to the lack of laws about acute concentration limits of these EDCs in municipal wastewater, groundwater, surface water, and drinking water. This review article offers evidence of fragmentary available data for the source, fate, toxicity, ecological and human health impact, remediation techniques, and mechanisms during EDC removal, and supports the need for further data to address the risks associated with the presence of EDCs in the environment. The reviews also provide comprehensive data for biodegradation of EDCs by using microbes such as fungi, bacteria, yeast, filamentous fungi, and their extracellular enzymes.

Impact of Nonylphenols and Polyhalogenated Compounds in Follicular Fluid on the Outcome of Intracytoplasmic Sperm Injection.

Endocrine-disrupting chemicals (EDCs) interfere with the mammalian hormone system and alter its endo- and paracrine regulation. The goal of the present study was to examine the presence of 14 EDCs, including the technical mixture of nonylphenols and Mirex, in human follicular fluid (FF) and to find a potential correlation between endocrine active substances and a possible impact on female fertility. Furthermore, potential sources of EDC exposition regarding patients' lifestyle and socioeconomic factors were investigated. Human FF was collected from a total of 210 women undergoing intracytoplasmic sperm injection-treatment cycles because of male subfertility. The presence of EDCs was analyzed using gas chromatography coupled with mass spectrometry. Thirteen of the 14 investigated EDCs were present in every FF sample; compounds with the highest concentrations in FF were nonylphenol and Mirex. Nearly all kinds of EDCs led to significantly reduced maturation and fertilization rate. No significant influence of EDC concentration on the clinical pregnancy rate was observed for neither of the analyzed EDCs. Patients who obtained their clothes and textiles at fashion discounters displayed a higher amount of EDCs in their FF. In contrast, patients' residential area, source of food products, and nicotine or caffeine consumed were not associated with EDC accumulation. Clinicaltrials.gov NCT01385605 (11 July 2011).

Recovery of subtropical coastal intertidal system prokaryotes from a destruction event and the role of extracellular polymeric substances in the presence of endocrine disrupting chemicals

Intertidal sediments constitute the micro-environment for the co-existence of endocrine disrupting chemicals (EDCs) and biofilms consisting of the microbial community and extracellular polymeric substances (EPS). However, the interactions and the resulting eco-function of this community are complex and poorly characterized, especially after a destruction event. This study evaluates the re-construction of biofilms in terms of the abundance of prokaryotic cells and related EPS characterization in two destroyed sedimentary matrices from subtropical environments simulated by sterilization in the presence of EDCs and investigates the role of EPS. The results show that benthic prokaryotes recover from the deposition of active prokaryotes in natural seawater and form biofilms after sterilization. Sterilization triggers the release of polysaccharides and protein from lysed native microbial cells and bound EPS in sedimentary organic matter, thus increasing their concentrations. The increased portion of EPS also acts as a persistent stress on re-colonizing prokaryotes and leads to the overproduction of sedimentary EPS. Due to the protective role mediated by EPS, the effect of EDCs on biofilm composition in sterilized sediment is not significant. The sedimentary matrix is the most important determinant of the composition of the biofilm and the occurrence of EDCs. At the end of an 84-day experiment, the abundance of prokaryotic cells and the concentrations of polysaccharides and protein in mangrove sediment are 1.6–1.8 times higher than those in sandflat sediment, regardless of EDCs. Sandflat sediment exhibits higher concentrations of nonylphenol and bisphenol A but a lower concentration of 17α-ethinylestradiol than mangrove sediment. This study enhances our understanding of the role of sedimentary biofilms and the fate of EDCs in intertidal systems and highlights the benefit of a destructive event in enhancing ecosystem function, particularly tolerance to EDC adversity due to EPS production.

Potential Health Risks Linked to Emerging Contaminants in Major Rivers and Treated Waters

The presence of endocrine-disrupting chemicals (EDCs) in our local waterways is becoming an increasing threat to the surrounding population. These compounds and their degradation products (found in pesticides, herbicides, and plastic waste) are known to interfere with a range of biological functions from reproduction to differentiation. To better understand these effects, we used an in silico ontological pathway analysis to identify the genes affected by the most commonly detected EDCs in large river water supplies, which we grouped together based on four common functions: Organismal injuries, cell death, cancer, and behavior. In addition to EDCs, we included the opioid buprenorphine in our study, as this similar ecological threat has become increasingly detected in river water supplies. Through the identification of the pleiotropic biological effects associated with both the acute and chronic exposure to EDCs and opioids in local water supplies, our results highlight a serious health threat worthy of additional investigations with a potential emphasis on the effects linked to increased DNA damage.

Detection of Steroids in Tap and Drinking Water Using an Optimized Analytical Method by Gas Chromatography–Mass Spectrometry

Endocrine-disrupting chemicals can produce effects on the human health or living beings. Hence, it is of high importance to determine their presence in water. This work presents a reliable method for determining 17β-Estradiol (E2) and 17α-Ethinylestradiol (EE2) in tap and drinking water. The analytic method proposed was optimized by spiking ultrapure water samples with a known amount of steroids in terms of solid phase extraction by varying elution solvent volume and analyte mass in the cartridge, the extract concentration by using either distinct temperatures in rotary evaporator or nitrogen gentle stream, and the solvent effect in chemical derivatization with N,O-bis (trimethylsilyl) trifluoroacetamide:trimethylchlorosilane (1%). The performance of the analytical method was assessed and applied to real samples; the efficiency of extraction and derivatization procedure ranged from 81 to 100% for E2 (CV 4–19%) and from 82 to 96% for EE2 (CV 4–18%). Limits of detection (quantification) were 1.0 (3.0) ng/L and 3.0 (10.0) ng/L for E2 and EE2, respectively. Analysis of the drinking water samples yielded concentrations ranging from 3.0 to 11.4 ng/L for E2 and from 10.0 to 246 ng/L for EE2. Analyses of steroids in tap water were found below the limit of detection. Consumption of drinking water in the presence of endocrine-disrupting chemicals could be a risk for the users in the long term and their consumption should be avoided under the principle of prevention.

Differential Activation of a Mouse Estrogen Receptor β Isoform (mERβ2) with Endocrine-Disrupting Chemicals (EDCs).

Background:Endocrine-disrupting chemicals (EDCs) are suspected of altering estrogenic signaling through estrogen receptor (ER) α or β (mERβ1 in mice). Several EDC effects have been reported in animal studies and extrapolated to human studies. Unlike humans, rodents express a novel isoform of ERβ (mERβ2) with a modified ligand-binding domain sequence. EDC activity through this isoform remains uncharacterized.Objectives:We identified the expression pattern of mERβ2 in mouse tissues and assessed the estrogenic activity of EDCs through mERβ2.Methods:mERβ2 mRNA expression was measured in mouse tissues. HepG2 cells were used to assess the transactivation activity of mERβ isoforms with EDCs and ER co-activators. 293A cells transiently transfected with mER isoforms were used to detect EDC-mediated changes in endogenous ER target gene expression.Results:Expression of mERβ2 mRNA was detected in mouse reproductive tissues (ovary, testis, and prostate) and lung and colon tissues from both female and male mice. Five (E2, DES, DPN, BPAF, Coum, 1-BP) of 16 compounds tested by reporter assay had estrogenic activity through mERβ2. mERβ2 had a compound-specific negative effect on ERβ/ligand-mediated activity and ER target genes when co-expressed with mERβ1. mERβ2 recruited coactivators SRC2 or SRC3 in the presence of EDCs, but showed less recruitment than mERβ1.Conclusion:mERβ2 showed weaker estrogenic activity than mERβ1 in our in vitro system, and can dampen mERβ1 activity. In vivo models of EDC activity and ER-mediated toxicity should consider the role of mERβ2, as rodent tissue responses involving mERβ2 may not be reproduced in human biology.Citation:Donoghue LJ, Neufeld TI, Li Y, Arao Y, Coons LA, Korach KS. 2017. Differential activation of a mouse estrogen receptor β isoform (mERβ2) with endocrine-disrupting chemicals (EDCs). Environ Health Perspect 125:634–642; http://dx.doi.org/10.1289/EHP396

Endocrine disrupting chemicals (EDCs) and female cancer: Informing the patients.

Breast and uterine cancer are the most frequent female gender related neoplasms whose growth is mostly estrogen dependent. Therefore, any EDC exhibiting estrogenic effects may increase the risk of these two malignancies. This review focuses on the potential role of EDCs with estrogenic potential on the risk of breast and uterine neoplasms but also points to the possible role of the exposure to EDCs in the pathogenesis of ovarian and cervical cancer. It also underlines the necessity of informing the public about the presence of EDCs in common consumer products, their detrimental health effects and methods of reducing the exposure risk.

The trenbolone acetate affects the immune system in rainbow trout, Oncorhynchus mykiss

In aquatic systems, the presence of endocrine-disrupting chemicals (EDC) can disrupt the reproductive function but also the immune system of wildlife. Some studies have investigated the effects of androgens on the fish immune parameters but the mechanisms by which the xenoandrogens alter the immunity are not well characterized. In order to test the effects of trenbolone acetate (TbA) on fish immune system, we exposed rainbow trout male juveniles during three weeks to TbA levels at 0.1 and 1μg/L. The present results suggest that TbA impacts, in a tissue-dependent manner, the rainbow trout immunity by affecting primarily the humoral immunity. Indeed, TbA inhibited lysozyme activity in plasma and liver and enhanced the alternative complement pathway activity (ACH50) in kidney. In plasma, the modulation of the complement system was time-dependent. The mRNA expression of genes encoding some cytokines such as renal TGF-β1, TNF-α in skin and hepatic IL-1β was also altered in fish exposed to TbA. Regarding the cellular immunity, no effect was observed on the leucocyte population. However, the expression of genes involved in the development and maturation of lymphoid cells (RAG-1 and RAG-2) was decreased in TbA-treated fish. Among those effects, we suggest that the modulation of RAG-1 and mucus apolipoprotein-A1 gene expression as well as plasma and hepatic lysozyme activities are mediated through the action of the androgen receptor. All combined, we conclude that trenbolone affects the rainbow trout immunity.

Endocrine-disrupting compounds in reclaimed water and residential ponds and exposure potential for dislodgeable residues in turf irrigated with reclaimed water.

Endocrine-disrupting chemicals (EDCs) occur in reclaimed water (RW), which may serve as an exposure source for humans. The presence of EDCs in RW used to irrigate turf and in nearby water-retention ponds was determined. In addition, the total dislodgeable mass of each EDC was determined after irrigation (using RW) to simulate exposure of a 3-year-child playing in turf grass recently irrigated with RW. Five EDCs (estrone, 17β-estradiol, 17α-ethynylestradiol, bisphenol A, and 4-n-nonylphenol) were quantified in 28 samples of RWs (wastewater-treatment plant effluents) and 88 samples from residential surface water-retention ponds. St. Augustine variety of turf grass was irrigated with spiked RW to study dislodgement of the five EDCs overtime using a drag-sled method. Grass clippings were analyzed to relate masses of EDC on grass with masses dislodged. EDCs were detected in both RW and ponds at ng/L concentrations. Maximum EDC masses were dislodged immediately after irrigation. Dislodged masses of estrone and 17β-estradiol are two separate EDCs, 17β-estradiol and 17α-ethynylestradiol decreased rapidly and were lower than detection limits 4h after application. Dislodged bisphenol-A and nonylphenol decreased more slowly but were not detected 6h after application. Avoiding contact with recently irrigated turf grass should decrease the risks of exposure to these EDCs.

In utero exposure to the oestrogen mimic diethylstilbestrol disrupts gonadal development in a viviparous reptile

The ubiquitous presence of endocrine-disrupting chemicals (EDCs) in the environment is of major concern. Studies on oviparous reptiles have significantly advanced knowledge in this field; however, 30% of reptilian species are viviparous (live-bearing), a parity mode in which both yolk and a placenta support embryonic development, thus exposure to EDCs may occur via multiple routes. In this first study of endocrine disruption in a viviparous lizard (Niveoscincus metallicus), we aimed to identify effects of the oestrogen mimic diethylstilbestrol (DES) on gonadal development. At the initiation of sexual differentiation, pregnant N. metallicus were treated with a single dose of DES at 100 or 10µgkg(--1), a vehicle solvent or received no treatment. There was no dose-response effect, but the testes of male neonates born to DES-exposed mothers showed reduced organisation of seminiferous tubules and a lack of germ cells compared with those from control groups. The ovaries of female neonates born to DES-exposed mothers exhibited phenotypic abnormalities of ovarian structure, oocytes and follicles compared with controls. The results indicate that, in viviparous lizards, maternal exposure to oestrogenic EDCs during gestation may have profound consequences for offspring reproductive fitness.

Well Water in Karst Regions of Northeastern Wisconsin Contains Estrogenic Factors, Nitrate, and Bacteria

Well water in karst regions is particularly susceptible to contamination by various nonpoint source pollutants such as nitrate, fecal bacteria, and endocrine disrupting chemicals (EDCs). This study analyzed 40 wells in heavily farmed karst areas of northeastern Wisconsin to determine whether these and other pollutants are present, and if so, whether their presence is (1) correlated with other contaminants and (2) exhibits seasonal variation. Nitrate, bacteria, and estrogenicity (indicating the presence of EDCs) were present in at least some of well water samples collected over the course of four time periods between the summers of 2008 and 2009. Although estrogenicity was greatest during the summer months, bacterial contamination was most prevalent during snowmelt. Levels of estrogenicity present in some well water samples approached a threshold concentration that is known to exert endocrine disruption in wildlife. Strong correlations between estrogenicity and other water quality parameters were not found.

Removal of Endocrine Disrupting Chemicals in Wastewater Treatment by Fenton-Like Oxidation

The presence of endocrine-disrupting chemicals (EDCs) in wastewater effluent is a major concern to the scientific community. This research effort was aimed at investigating Fenton-like degradation of two EDCs 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). The results of the study showed that E2 and EE2 were effectively removed by the Fenton-like oxidation process. Removal efficiencies of 95% and 98% at ferric concentration of 1 × 10−3 M (58.6 mg l−1) were achieved for E2 and EE2, respectively. The kinetics of Fenton-like degradation of E2 and EE2 were adequately described by the pseudo second order kinetic model. Values of 27.8 and 22.5 kJ mol−1 were obtained for the activation energy for E2 and EE2, respectively, from the Arrhenius-type plot, showing that the process does not just involve radical reactions but also intermediate reaction steps involving radical–molecule or ion–molecule reactions. The presence of high dissolved organics in wastewater significantly reduced the removal efficiencies. The reaction by-products for E2 and EE2 were more stable to the oxidation process and more readily biodegradable. Fenton-like oxidations therefore offers a promising alternative for the removal of these EDCs in wastewater treatment applications at the tertiary treatment stage.

Transport and Modeling of Estrogenic Hormones in a Dairy Farm Effluent through Undisturbed Soil Lysimeters

The presence of endocrine-disrupting chemicals, including estrone (E1) and 17beta-estradiol (E2), in surface waters has been associated with physiological dysfunction in a number of aquatic organisms. One source of surface and groundwater contamination with E1 and E2 is the land application of animal wastes. The processes involved in the transport of these hormones in the soil, when applied with animal wastes, are still unclear. Therefore, a field-transport experiment was carried out, where a dairy farm effluent spiked with E1 and E2 was applied on large (50 cm diameter and 70 cm depth) undisturbed soil lysimeters. The concentrations of E1 and E2 in the leachate were monitored over a 3-month period, during which irrigation was applied. The experimental data suggest that E1 and E2 were transported through preferential/macropore flow pathways. The data from the experiment also show that E1 and E2 are leached earlier than the inert tracer (bromide). This observation can be explained either by the presence of antecedent concentrations in the soil or by an enhanced transport of E1 and E2 through the soil. A state-space mixing-cell model was further developed in order to describe the transport of E1 and E2 by three transport processes in parallel. The inverse modeling of the leaching data did not support the hypothesis that antecedent concentrations of estrogens could be responsible for the observed breakthrough curves but confirmed that estrogens were transported mainly via preferential/macropore flow and also via an enhanced transport. The parameter values that characterized this enhanced transport strongly suggest that this enhanced transport is mediated by colloids. For the first time, the simultaneous transport of E1 and E2 was modeled under transient conditions, taking into account the advection-dispersion, preferential/macropore flow, and colloidal-enhanced transport processes as well as E1 and E2 dissipation in the soil. These findings have major implications in terms of management practices to decrease E1 and E2 transport and water contamination.

Interferentes endócrinos no ambiente

Although the hypothesis that environmental chemicals may exhibit endocrine disrupting effects is not new, the issue has been a growing level of concern due to reports of increased incidences of endocrine-related disease in humans, including declining male fertility, and more significantly, to adverse physiological effects observed in wildlife where cause and effect relationships are more evident. The list of endocrine disrupting chemicals (EDCs) includes a range of anthropogenic compounds, phytoestrogens, naturally occurring sex steroids and synthetic estrogens. Within the aquatic environment, the presence of EDCs has concerned many scientists and water quality regulators. Discharge of effluents from treatment facilities is likely to be a significant source of input of contaminants to many systems, and the potential for concentration of hydrophilic compounds and transformation products within sludges has implications for their disposal. Then, understanding the processes and the fate of EDCs on the environment, as well as the mechanisms of endocrine disruption, may facilitate controlling or limiting exposure of both humans and the environment to these compounds.