Projects presented in this paper were funded by Severn Trent Water and Brunel University London. The authors would like to thank Alan Henshaw and John Churchley for providing field and laboratory assistance. T.J.C. thanks the Heinz Endowments for support. M.R.M. thanks the Steinbrenner Institute for a Steinbrenner Doctoral Fellowship and Carnegie Mellon University for a Presidential Fellowship.

<ol>
	<li>Bergman, &. #. 1. 9. 7. ;., Heindel, J., Jobling, S., Kidd, K., Zoeller, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=State-of-the-science+of+endocrine+disrupting+chemicals.">State-of-the-science of endocrine disrupting chemicals.</a> Toxicol. Lett. 211, (2012).</li><li>Rodgers-Gray, T. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exposure+of+juvenile+roach+(Rutilus+rutilus)+to+treated+sewage+effluent+induces+dose-dependent+and+persistent+disruption+in+gonadal+duct+development.">Exposure of juvenile roach (Rutilus rutilus) to treated sewage effluent induces dose-dependent and persistent disruption in gonadal duct development.</a> Environ. Sci. 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The authors have nothing to disclose.

Wastewater treatment plants are the major route of surface water contamination with EDC. An evaluation of the efficacy of removal of endocrine activity of conventional, advanced or emerging treatment processes requires the use of a variety of chemical and biological assays. Chemical analysis using non-targeted and targeted analysis provides qualitative or quantitative data on the efficacy of removal of individual components and therefore allows an assessment to be made against environmental quality standards or predicted no effect concentrations for the compounds or mixtures of compounds analyzed.
The generation of transformation products resulting from incomplete mineralization of substances following treatment and the presence of unknown biologically active components in wastewater limits the usefulness of chemical testing alone. A combination of in vivo and in vitro bioassays in combination with analytical chemistry screening provides a useful toolbox to determine the efficacy of EDC removal by emerging wastewater treatment processes. These tests, when conducted alongside traditional water quality parameters and other toxicological and microbiological end-points allow a critical evaluation of current and emerging wastewater treatment technologies.
It is important to note that Yeast based estrogen screens (e.g., YES) are not the only in vitro assays to determine estrogenic potency of chemicals and wastewaters. A number of stably transfected mammalian cell based assays have been developed too, for example, the ER-CALUX27 and hER&#945;-HeLa-990328 with human breast cancer cells or cervical tumor cells respectively. The YES has been compared to similar mammalian cell based assays and has been found to have a comparable high level of reproducibility, true positive and true negative estrogenic identification rates29, although it is sometimes considered to be slightly less sensitive27. One benefit of Yeast based reporter assays is that in labs without significant experience with mammalian cell culture the YES can be more easily adopted, as it requires less stringent bio-control measures and sterile techniques (YES can be performed on the bench top if necessary). The human cell based assays also require CO2 incubators and luminometers compared to the standard incubator and microplate readers used in the YES. Two yeast based estrogen reporter assays (YES, Saccharomyces cerevisiae and A-YES, Arxula adeninivorans) are currently undergoing inter-laboratory trails for the validation of ISO 19040 &#34;Water quality - Determination of the estrogenic potential of water and waste water&#34; highlighting the industries interest in these techniques.
There are a number of limitations of the methods described which include the potential contamination of samples during sampling, sample storage and analysis with estrogenic substances originating from the field or laboratory environment or by human contamination (e.g., plasticizers, surfactants, personal care products). This type of contamination in the YES assay (or other cell based reporter assays) will elevate the background and impact the use of the assay. Water samples or solvents stored in plastic bottles can easily cause false positives. False negatives are also of concern as both LCMS/MS and the YES assay require SPE to concentrate estrogens to detectable levels. The matrix, the choice of SPE sorbent and elution solvent can affect the extraction efficiency and the types of compounds eluted. Using C18 SPE cartridges for extraction using the conditions described in this protocol may generate a negative bias, as highly polar and basic compounds would be poorly retained by the sorbent. Furthermore, this protocol requires reconstitution of the eluted YES eluent from methanol to ethanol via evaporation to dryness funder nitrogen resulting in the loss of volatile compounds. As a result the protocol could provide underestimated estrogenic activity of tested samples. These limitations are especially important when considering the YES assay as unknown or unexpected compounds might be missed, because they have not been extracted or they are lost due to evaporation. Furthermore, the LCMS/MS technique makes use of labeled internal standards to correct for recovery; this approach cannot be used with the YES assay.
Significant limitations of in vivo testing of effluents include high cost and time required for assessment compared to in vitro methods. Currently the use of fish embryo tests to detect estrogenic activity is limited. However, there has been some success with producing estrogen responsive transgenic glowing fish embryos30, which could have future applications. Fathead minnows (used in this protocol) are a common laboratory species and VTG induction in male fish is a well-documented bio-marker of estrogenic exposure and a quantifiable measure of wastewater effluent estrogenicity22 or other estrogenic compounds or mixtures31. OECD test guidelines for endocrine disrupting chemicals have been validated using adult fathead minnow, Japanese medaka and zebrafish32,33, with VTG being a sensitive biomarker of estrogen exposure in all three species. However, VTG induction does not directly correlate to reproductive impairment and therefore the ecological consequences of wastewater exposure, as seen in severely intersex roach3. On the other hand, roach are not a classic &#39;laboratory species&#39; for ecotoxicology research due to their large size, long generation time (2-3 years to reach sexual maturity), reproductive style; group spawning (breeding) takes place once a year, and the difficulty to identify males from females (other than during the spawning season). However, this normally gonochoristic species has been very well studied in the UK, due to the discovery that downstream of estrogenic wastewater effluents, male fish exhibited perturbations to their endocrinology (e.g., presence of female-specific vitellogenin in their blood) and histopathology (ovotestes - developing eggs in the testis and/or female reproductive ducts)5,6. Therefore, as a future application of these protocols, roach (or similar species) could be a useful wild sentinel species to show if real improvements to wastewater quality (and reduced estrogenicity) are seen in rivers receiving advanced treated effluents. They can also be employed in end of pipe systems to monitor technologically improved effluents from pilot scale plants7. When considering which species to use in in vivo wastewater assessments there is a tradeoff between relatively quick and controlled testing using laboratory species compared to the longer field based, but more environmentally relevant, testing using native species. However, such in vivo assessments are high cost and should only be considered as the final set of tests following assessments using chemical analysis and in vitro assays.
Critical steps within the protocols described include the preparation and handling of samples and glassware (i.e., bottles and sampling equipment should be pre-treated with suitable surface active cleaning agent) to avoid contamination of samples from environmental contaminants including limiting contact of samples with plastics and other materials that can produce false positives. This is equally important when designing and building aquaria and fish exposure systems. Ideally aquaria (housing stocks and during exposures) should be built from materials with low adsorption32 with minimal contamination risk. Stainless steel can be used for effluent or water holding tanks. Whereas tanks of a glass construction are preferred for fish tanks (as this also provides easy observation of the fish). The use of low grade plastic pipes or tubing should be avoided32, PVC34 and ABS can be used if &#39;properly seasoned&#39;, i.e., left to leach out any contaminants in running dilution water for at least 12 hr prior to use. Medical grade silicon tubing has been employed successfully in our facility for peristaltic pump delivery of chemicals and wastewater/dilution water to tanks. As well as considering estrogenic contamination in construction and running of the aquatics system, it is also important to think about the diet of the fish; many propriety fish foods have been found to be estrogenic to fish. Therefore it is important to test any foods for activity (e.g., in the Yeast Estrogen Screen, See Beresford et al.14) prior to using them in these types of studies.
Troubleshooting of the chemical analysis or YES assay protocols described is simplified if quality assurance samples including multiple travel, laboratory and solvent blanks are analyzed alongside positive controls and real samples to eliminate false positive and false negative results. Positive (e.g., EE2) and negative (dilution water only) control should also always be used in the in vivo assays to confirm sensitivity of expected biological biomarker or endpoint (i.e., VTG or histopathology), and allow any unexpected contamination to be detected (e.g., from experimental set up, diet, or dilution waters). Any modifications in the protocol should be validated prior to conducting any study.
With stricter regulation of estrogenic compounds entering the environment via WWTP effluents it is envisage that more effective wastewater treatment technologies will need to be developed. The battery of tests described in this manuscript compliment the ecotoxicological and chemical evaluation tests normally applied to wastewater treatment plant effluent discharges. Therefore, future application of this type of holistic battery of test should enable wastewater technology developers, and plant operators, to implement the most ecologically safe designs considering the best methods to remove both specific regulated estrogenic chemicals and overall biological activity.

Concerns regarding the adverse effects of endocrine disrupting compounds on wildlife reproductive health has led the European Union to place two estrogenic substances (estradiol and ethinylestradiol) on a &#34;watch list&#34; under the Water Framework Directive (WFD). EDC encompass a variety of chemical classes, including natural and synthetic steroid estrogens, drugs, pesticides, and industrial chemicals and constituents of consumer products with known adverse effects on wildlife. Some of these compounds may potentially impact human health1.
Research has shown that effluents from WWTP are estrogenic to fish2 and as a consequence many receiving waters are also estrogenic to fish3. This was first demonstrated through national surveys in the United Kingdom that showed increased vitellogenin concentrations (a female specific yolk protein precursor4) in the blood of wild male fish and a high prevalence of intersex (developing eggs and/or female reproductive ducts in the testis of male fish) in normally gonochoristic fish species5,6.
Conventional sewage treatment is typically a three stage process consisting of a preliminary screening followed by primary and secondary treatment which removes both dissolved and suspended organic matter. The efficacy of removal of individual EDC is dependent on the physicochemical properties of the substances and on the effectiveness of the treatment process applied. For many EDC removal via adsorption and biological degradation can be significant but incomplete. Tertiary treatment, such as sand filtration, can be effective at increasing EDC removal7 whereas advanced treatment using advanced oxidation (for example ozone) or activated carbon can be effective in achieving near complete removal7.
The assessment of any new technology for wastewater treatment needs to determine the efficacy of the proposed process in EDC removal. A battery of tests, including targeted chemical analysis alongside ecotoxicology testing, using in vivo and in vitro bioassays, provides comprehensive data for this purpose. Although very useful for regulatory purposes, targeted chemical analysis can only provide data on the compounds (and specific metabolites) monitored. Bioassays additionally allow the &#34;detection&#34; of adverse effects of metabolites and treatment-generated wastewater transformation by-products that would otherwise be undetected8,9. This paper describes the use of a battery of chemical and ecotoxicity laboratory assays to assess the efficacy of a number of advanced and emerging wastewater treatment processes in removing the estrogenic potency of crude and treated sewage and receiving waters.

<table><tbody><tr><td>Wellwash Versa plate washer</td><td>Thermo Scientific</td><td>5165010</td><td></td></tr><tr><td>Plate reader</td><td>Molecular Devices</td><td>SpectraMax 340PC</td><td></td></tr><tr><td>Incubator</td><td>Memmert</td><td>INB 400</td><td>37 &amp;#176;C incubation required for carp assay</td></tr><tr><td>Fisherbrand whirlimixer</td><td>Fisher Scientific</td><td>13214789</td><td></td></tr><tr><td>Icemaker</td><td>Scotsman</td><td>AF80</td><td></td></tr><tr><td>12-Channel F1 digital multichannel pipette</td><td>Thermo Scientific Finnpipette</td><td>4661070</td><td></td></tr><tr><td>ELISA kits</td><td>Biosense Laboratories</td><td>V01018401-096 (Fathead minnow)&lt;br/&gt; V01003402-096 (Carp)</td><td></td></tr><tr><td>Microfuge tubes, 0.5 ml</td><td>Alpha labs</td><td>LW2372</td><td></td></tr><tr><td>Microfuge tubes, 1.5 ml</td><td>Alpha labs</td><td>LW2375</td><td></td></tr><tr><td>Sulphuric acid, 95-98%</td><td>Sigma-Aldrich</td><td>258105</td><td></td></tr><tr><td>&lt;strong&gt;Histology&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Tissue processor</td><td>Leica Biosystems</td><td>TP1020</td><td></td></tr><tr><td>Wax dispenser</td><td>Thermo Scientific Raymond Lamb</td><td>E66HC</td><td></td></tr><tr><td>Metal embedding mold</td><td>Leica Biosystems</td><td>Various</td><td></td></tr><tr><td>Hot plate</td><td>Thermo Scientific Shandon</td><td>3120063</td><td></td></tr><tr><td>Cold plate (EG1150 C)</td><td>Leica Biosystems</td><td>14038838037</td><td></td></tr><tr><td>Heated forceps (EG F)</td><td>Leica Biosystems</td><td>14038835824</td><td></td></tr><tr><td>Microtome</td><td>Leica Biosystems</td><td>RM2235</td><td></td></tr><tr><td>Paraffin section floatation&amp;nbsp; bath</td><td>Electrothermal</td><td>MH8517</td><td></td></tr><tr><td>Slide drying bench</td><td>Electrothermal</td><td>MH6616</td><td></td></tr><tr><td>Stainmate automated stainer</td><td>Thermo Scientific Shandon</td><td>E103/S10L</td><td></td></tr><tr><td>Cassettes, Histosette II, biopsy</td><td>Simport</td><td>M493</td><td></td></tr><tr><td>Paraffin wax</td><td>Thermo Scientific Raymond Lamb</td><td>W1</td><td></td></tr><tr><td>Histo-Clear II</td><td>National Diagnostics</td><td>HS-202</td><td></td></tr><tr><td>IMS (ethanol mix), IDA99</td><td>Tennants</td><td>ID440</td><td></td></tr><tr><td>Polysine adhesion slides</td><td>Thermo Scientific Gerhard Menzel</td><td>J2800AMNZ</td><td></td></tr><tr><td>Cover slips, 22x50 mm</td><td>VWR</td><td>631-0137</td><td></td></tr><tr><td>Histomount</td><td>National Diagnostics</td><td>HS-103</td><td></td></tr><tr><td>Haematoxylin Harris GURR</td><td>VWR</td><td>351945S</td><td></td></tr><tr><td>Eosin, 1%, aqueous</td><td>Pyramid Inovation</td><td>S20007-E</td><td></td></tr><tr><td>Fisherbrand slide boxes</td><td>Fisher Scientific</td><td>11701486</td><td></td></tr><tr><td>Microtome blades, MB35</td><td>Thermo Scientific Shandon</td><td>3050835</td><td></td></tr><tr><td>Bouin&amp;rsquo;s solution</td><td>Sigma Aldrich</td><td>HT10132-1L</td><td></td></tr><tr><td>&lt;strong&gt;Yeast screen&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Flow cabinet</td><td>Labcaire Systems Ltd</td><td>SC12R</td><td></td></tr><tr><td>Cooled incubator</td><td>LMS Cooled Incubator</td><td>303</td><td></td></tr><tr><td>Incubator</td><td>Memmert</td><td>INB 400</td><td></td></tr><tr><td>Shaker</td><td>Grant</td><td>PSU-10i</td><td></td></tr><tr><td>Fisherbrand whirlimixer</td><td>Fisher Scientific</td><td>13214789</td><td></td></tr><tr><td>Plate shaker</td><td>Heidolph Titramax 100</td><td>544-11200-00</td><td></td></tr><tr><td>12-Channel F1 digital multichannel pipette</td><td>Thermo Scientific Finnpipette</td><td>4661070</td><td></td></tr><tr><td>12-channel pipette, electronic</td><td>Sartorius</td><td>735441</td><td></td></tr><tr><td>96-well flat-bottom microplates</td><td>MP Biomedicals&lt;br/&gt; Thermo Scientific Nunc&lt;br/&gt; Sarstedt</td><td>76-232-05&lt;br/&gt; 260860&lt;br/&gt; 82.1581.001</td><td>We have found that these multiwell plates all produce low backgrounds</td></tr><tr><td>HPLC grade water</td><td>Rathburn</td><td>RH1020</td><td></td></tr><tr><td>Absolute ethanol</td><td>Hayman Kimia</td><td>F200238</td><td></td></tr><tr><td>Potassium phosphate monobasic anhydrous</td><td>Sigma-Aldrich</td><td>P-5655</td><td></td></tr><tr><td>Ammonium sulphate</td><td>Sigma-Aldrich</td><td>A-2939</td><td></td></tr><tr><td>Potassium hydroxide, pellets</td><td>Sigma-Aldrich</td><td>P-1767</td><td></td></tr><tr><td>Magnesium sulfate, anhydrous</td><td>Sigma-Aldrich</td><td>M-2643</td><td></td></tr><tr><td>Iron(III) sulfate</td><td>Sigma-Aldrich</td><td>307718</td><td></td></tr><tr><td>L-Leucine</td><td>Sigma-Aldrich</td><td>L-8912</td><td></td></tr><tr><td>L-Histidine</td><td>Sigma-Aldrich</td><td>H-6034</td><td></td></tr><tr><td>Adenine</td><td>Sigma-Aldrich</td><td>A-2786</td><td></td></tr><tr><td>L-Argenine, hydrochloride</td><td>Sigma-Aldrich</td><td>A-6969</td><td></td></tr><tr><td>L-Methionine</td><td>Sigma-Aldrich</td><td>M-5308</td><td></td></tr><tr><td>L-Tyrosine</td><td>Sigma-Aldrich</td><td>T-8566</td><td></td></tr><tr><td>L-Isoleucine</td><td>Sigma-Aldrich</td><td>I-7403</td><td></td></tr><tr><td>L-Lysine, hydrochloride</td><td>Sigma-Aldrich</td><td>L-8662</td><td></td></tr><tr><td>L-Phenylalanine</td><td>Sigma-Aldrich</td><td>P-5482</td><td></td></tr><tr><td>L-Glutamic acid</td><td>Sigma-Aldrich</td><td>G-8415</td><td></td></tr><tr><td>L-Valine</td><td>Sigma-Aldrich</td><td>V-0513</td><td></td></tr><tr><td>L-Serine</td><td>Sigma-Aldrich</td><td>S-4311</td><td></td></tr><tr><td>Thiamine, hydrochloride</td><td>Sigma-Aldrich</td><td>T-1270</td><td></td></tr><tr><td>Pyridoxine</td><td>Sigma-Aldrich</td><td>P-5669</td><td></td></tr><tr><td>D-Pantothenic acid, hemicalcium salt</td><td>Sigma-Aldrich</td><td>P-5155</td><td></td></tr><tr><td>Inositol</td><td>Sigma-Aldrich</td><td>I-5125</td><td></td></tr><tr><td>D-Biotin</td><td>Sigma-Aldrich</td><td>B-4639</td><td></td></tr><tr><td>D-(+)-Glucose anhydrous; mixed anomers</td><td>Sigma-Aldrich</td><td>G-7021</td><td></td></tr><tr><td>L-Aspartic acid</td><td>Sigma-Aldrich</td><td>A-4534</td><td></td></tr><tr><td>L-Threonine</td><td>Sigma-Aldrich</td><td>T-8441</td><td></td></tr><tr><td>Copper(II) sulfate, anhydrous</td><td>Sigma-Aldrich</td><td>C-1297</td><td></td></tr><tr><td>Chlorophenolred-&amp;#946;-D galactopyranoside (CPRG)</td><td>Sigma-Aldrich</td><td>10884308001</td><td></td></tr><tr><td>Glycerol</td><td>Sigma-Aldrich</td><td>G-2025</td><td></td></tr><tr><td>17 &amp;beta;-Estradiol</td><td>Sigma-Aldrich</td><td>E-8875</td><td></td></tr><tr><td>&lt;strong&gt;Steroids&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Acetone</td><td>Rathburn</td><td></td><td></td></tr><tr><td>Acetonitrile</td><td>Rathburn</td><td></td><td></td></tr><tr><td>Ammonia solution</td><td>Rathburn</td><td></td><td></td></tr><tr><td>Ethylacetate</td><td>Rathburn</td><td></td><td></td></tr><tr><td>Copper(II) nitrate</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Acetone</td><td>Rathburn</td><td></td><td></td></tr><tr><td>Dichloromethane</td><td>Rathburn</td><td></td><td></td></tr><tr><td>2,4,16,16-d&lt;sub&gt;4&lt;/sub&gt;-17&amp;#946;-estradiol</td><td>CDN Isotopes</td><td></td><td></td></tr><tr><td>2,4,16,16-d&lt;sub&gt;4&lt;/sub&gt;-estrone</td><td>CDN Isotopes</td><td></td><td></td></tr><tr><td>2,4,16,16-d&lt;sub&gt;4&lt;/sub&gt;-17&amp;#945;-ethynyl oestradiol</td><td>CDN Isotopes</td><td></td><td></td></tr><tr><td>17&amp;#946;-estradiol</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Estrone</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>17&amp;#945;-ethynyl oestradiol</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Hexane</td><td>Rathburn</td><td></td><td></td></tr><tr><td>Hydrochloric acid</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Methanol</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Sodium hydrogen carbonate</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Sodium hydroxide</td><td>Sigma-Aldrich</td><td></td><td></td></tr><tr><td>Styrene divinyl benzene cartridge (Isolute ENV+) solid phase extraction cartridge (200 mg/6 ml)</td><td>Biotage</td><td></td><td></td></tr><tr><td>Isolute aminopropyl solid phase extraction cartridge (500 mg/6 ml)</td><td>Biotage</td><td></td><td></td></tr><tr><td>&lt;strong&gt;Fish study&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>orange-white silicon manifold tubing 0.63 bore pk 6</td><td>Watson Marlow</td><td>982.0063.000</td><td></td></tr><tr><td>straight connectors for 0.5/0.8 bore pk 20</td><td>Watson Marlow</td><td>999.2008.000</td><td></td></tr><tr><td>pumsil silicon tubing 0.8 bore 15 m</td><td>Watson Marlow</td><td>913.A008.016</td><td></td></tr><tr><td>200 series multi-channel persitaltic pump</td><td>Watson Marlow</td><td>205CA</td><td></td></tr><tr><td>Silicone tubing x 15 m (dosing tanks)</td><td>VWR</td><td>SFM1-3250</td><td></td></tr><tr><td>silicone tubing x 15 m (large for inflow/outflow)</td><td>VWR</td><td>SFM1-5450</td><td></td></tr><tr><td>2.5 L glass winchester pk 4</td><td>Fisher Scienctific</td><td>BTF-505-050B</td><td></td></tr><tr><td>magnetic stir bar 51 x 8 mm pk 10</td><td>Fisher Scienctific</td><td>FB55595&amp;nbsp;</td><td></td></tr><tr><td>Ethyl 3-aminobenzoate methanesulfonate (MS222)</td><td>Sigma Aldrich</td><td>E10521-10G</td><td></td></tr><tr><td>17&amp;alpha;-Ethynylestradiol</td><td>Sigma Aldrich</td><td>E4876-100MG</td><td></td></tr><tr><td>Absolute ethanol</td><td>Hayman Kimia</td><td>F200238</td><td></td></tr><tr><td>&lt;strong&gt;SPE&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>1/8 inch PTFE tubes &#039;straws&#039; colour coded pk 4</td><td>Sigma Aldrich</td><td>57276</td><td></td></tr><tr><td>disposable liners for manifold</td><td>Sigma Aldrich</td><td>57059</td><td></td></tr><tr><td>filtration tubes without frits 6 ml pk 30</td><td>Sigma Aldrich</td><td>57242</td><td></td></tr><tr><td>reservior adaptors pk 12</td><td>Sigma Aldrich</td><td>57020-U</td><td></td></tr><tr><td>stainless steel weight for manifold pk 4</td><td>Sigma Aldrich</td><td>57278</td><td></td></tr><tr><td>male Luer plug for manifold pk 12</td><td>Sigma Aldrich</td><td>504351</td><td></td></tr><tr><td>SPE Vacuum Manifold</td><td>Sigma Aldrich</td><td>57265</td><td></td></tr><tr><td>stop cocks for extraction mainfold (supelco) pk 12</td><td>Waters</td><td>WAT054806</td><td></td></tr><tr><td>Sep-Pak Plus C18 cartridge box 50&amp;nbsp;</td><td>Waters</td><td>WAT020515</td><td></td></tr><tr><td>Methanol HPLC grade 2.5 L</td><td>Fisher Scientific</td><td>M/4056/17</td><td></td></tr><tr><td>7 ml glass vials with lids (58 x 17 mm) pk 399</td><td>Fisher Scientific</td><td>TUL-520-031K</td><td></td></tr><tr><td>Absolute ethanol</td><td>Hayman Kimia</td><td>F200238</td><td></td></tr><tr><td>vacuum pump, &lt;em&gt;e.g.&lt;/em&gt;, VP Series Vacuum Pump</td><td>Camlab</td><td>1136915</td><td></td></tr></tbody></table>

use of a battery of chemical and ecotoxicological methods for the assessment of the efficacy of wastewater treatment processes to remove estrogenic potency

Endocrine Disrupting Compounds pose a substantial risk to the aquatic environment. Ethinylestradiol (EE2) and estrone (E1) have recently been included in a watch list of environmental pollutants under the European Water Framework Directive. Municipal wastewater treatment plants are major contributors to the estrogenic potency of surface waters. Much of the estrogenic potency of wastewater treatment plant (WWTP) effluents can be attributed to the discharge of steroid estrogens including estradiol (E2), EE2 and E1 due to incomplete removal of these substances at the treatment plant. An evaluation of the efficacy of wastewater treatment processes requires the quantitative determination of individual substances most often undertaken using chemical analysis methods. Most frequently used methods include Gas Chromatography-Mass Spectrometry (GCMS/MS) or Liquid Chromatography-Mass Spectrometry (LCMS/MS) using multiple reaction monitoring (MRM). Although very useful for regulatory purposes, targeted chemical analysis can only provide data on the compounds (and specific metabolites) monitored. Ecotoxicology methods additionally ensure that any by-products produced or unknown estrogenic compounds present are also assessed via measurement of their biological activity. A number of in vitro bioassays including the Yeast Estrogen Screen (YES) are available to measure the estrogenic activity of wastewater samples. Chemical analysis in conjunction with in vivo and in vitro bioassays provides a useful toolbox for assessment of the efficacy and suitability of wastewater treatment processes with respect to estrogenic endocrine disrupting compounds. This paper utilizes a battery of chemical and ecotoxicology tests to assess conventional, advanced and emerging wastewater treatment processes in laboratory and field studies.

Attempts to understand the impact of improvements to wastewater treatment processes or to determine the most appropriate technology to retrofit equipment as tertiary treatment at existing WWTP with respect to the efficacy of removal of endocrine disrupting activity of discharged effluents, requires not only the measurement of key chemical components that enter the works but requires the analysis of the breakdown products which may also have endocrine disrupting activity. In domestic sewage effluents, the most estrogenic substances present are the steroid hormones, estrone (E1), 17&#946;-estradiol (E2) and 17&#945;-ethinylestradiol (EE2)5,8. Steroid estrogens are primarily excreted from the body as a mixture of inactive conjugates16,17. These conjugated estrogens are substantially deconjugated in the sewerage system by bacterial activity and further degradation occurs in the WWTP. The deconjugated steroids are removed from the wastewater stream by adsorption to sludge or biodegraded during secondary treatment resulting in the formation, firstly of transformation byproducts and ultimately complete mineralization can occur of the initial active component. The chemical analysis of all individual compounds in the effluent stream would be difficult, time consuming and costly and would not cover unknown active components present in a sample. Furthermore, a sum of the estrogenic contribution of each component will only provide an indication of the cumulative estrogenic potency of a sample of the compounds analyzed. This is a risk where transformation processes generate unknown estrogenic substances or where the influent is of industrial origin. Combining chemical analysis with in vivo and in vitro ecotoxicology bioassays provides a solution to the presence of unknown estrogenic components in mixtures such as treated sewage. In vitro assays such as the Yeast Estrogen Screen (YES) have been used extensively to determine the estrogenic activity of sewage effluents and to help identify the active components in treated samples8,18,19. However, comparisons between in vivo and in vitro testing can be significant11 and a comprehensive assessment of new processes with respect to treatment of endocrine disrupting potency requires a battery of chemical and ecotoxicology tests.
A determination of whether individual treatment plants or processes remove active compounds from the wastewater stream can be achieved using chemical analysis which follows sample extraction, concentration and clean-up of the extract prior to analysis, most often undertaken using LCMS(/MS) or GCMS(/MS) methods. The data obtained from chemical analysis can be used to determine compliance with individual predicted no effect concentrations (PNEC)20 or environmental quality standards (EQS)21 of specific individual compounds and therefore such methods are vital for regulatory compliance data. Furthermore, targeted or non-targeted chemical analysis methods allow the identification and quantitation of individual compounds or isomers compared with biological methods, which provide a total response. Chemical analysis methods therefore allow the assessment of discrete compounds to be made to meet and to address these wastewater treatment challenges on an individual treatment plant basis. Studies have shown that conventional wastewater treatment (e.g., activated sludge plants) can be highly effective in the removal of natural steroid hormones although removal of the synthetic hormone EE2 tends to be less effective. Field studies using advanced treatment utilizing techniques such as ozone, granulated activated carbon (GAC) and membranes have demonstrated, albeit at high cost, that they can be used as an end-of-pipe solution to remove EE2 to below predicted effect levels and to below the detection limits. Figure 3 shows the removal of EE2 using GAC at a pilot scale municipal wastewater treatment plant. Studies undertaken at pilot scale at municipal wastewater treatment plants using end of pipe GAC treatment also show the reduction in estrogenic potency following GAC measured using the Yeast Estrogen Screen (YES) as seen in Figure 4.
<img alt="Figure 3" src="/files/ftp_upload/54243/54243fig3.jpg" /> 
Figure 3. Example field data showing the removal of ethinylestradiol following advanced tertiary treatment. (A) Samples are collected from the WWTP following conventional (activated sludge plant) treatment following the procedures described for sample preservation. (B) Samples are extracted using solid phase extraction, cleaned-up to remove interfering substances using normal phase SPE and gel permeation chromatography. (C) The clean concentrated extract is concentrated to a low volume and analyzed using negative ion electrospray LCMS/MS in MRM mode. Results are calculated using internal standardization using isotopically labeled internal standards. In the example shown, EE2 is present in the final ASP effluent at a concentration above the predicted no effect level (PNEC) of 0.1 ng/L and is removed using GAC and ozone (O3) to an environmentally safe concentration. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54243/54243fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" src="/files/ftp_upload/54243/54243fig4.jpg" /> 
Figure 4. Photo of a Yeast Estrogen Screen (YES) assay plate (A) showing color change from yellow to red, relating to estrogenic activity of the samples. Plots created from the YES assay plate showing corrected absorbance (540 nm) of the estradiol standard (B), activated sludge process effluent (ASP) and Granular activated carbon (GAC) treated wastewater effluent samples (C). Each sample was tested in duplicate. ASP and GAC effluents were extracted and concentrated using the SPE methods outlined in section 1. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54243/54243fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Ozonation is also efficient in removing steroid estrogens and estrogenic activity from conventionally treated wastewater treatment plants. Ozone is able to oxidize a wide range of organic contaminants and dissolved organic matter in wastewater samples and provides disinfection properties. The effectiveness of ozonation depends on water characteristics such as pH, amount of organic matter and the applied dose of ozone. Estrogens that are poorly removed by conventional treatment can be removed from wastewater with doses between 0.8 and 2 mg O3/mg DOC. Ozone is a selective oxidizing agent, which reacts with electron rich sites (unsaturated carbon-carbon bonds, aromatic compounds including aromatic alcohols), which makes ozone applicable for the breakdown of a number of EDC. However, the elimination of individual compounds does not necessarily lead to the complete mineralization of the original compound. Organic substances following ozonation may be transformed generating intermediates or transformation oxidation by-products which include a number of low molecular weight, polar classes of compounds such as aldehydes, ketones, carboxylic acids, keto acids, and brominated compounds. Examples include, bromate, formaldehyde, acetaldehyde and carboxylic acids. Using in vivo and in vitro bioassays it has been shown that although ozone only partially oxidizes some chemical substances, the resulting major transformation products have a lower estrogenic potency and hence the application of ozone at an appropriate dose results in a high removal of estrogenic activity.
One of the major benefits of additional treatment of wastewaters is the reduction in the feminization of male fish in receiving waters; an adverse effect that can lead to reduced fertility3. In vivo studies using fish (e.g., roach or fathead minnow) exposed to wastewater show female germ cells or oocytes in the testis of male fish (e.g., as seen in Figure 5). Intersex or male VTG is absent or significantly reduced in fish following advanced treatment such as GAC7 or ozone22. These studies show that transformation products produced during ozonation are not estrogenic, however this does not address the toxicity of the effluent produced. This issue has been addressed in other studies, for example a study by Magdeburg et al.23 which shows that ozone oxidation by-products are toxic to rainbow trout but this toxicity can be removed by downstream sand filtration following ozonation.
<img alt="Figure 5" src="/files/ftp_upload/54243/54243fig5.jpg" /> 
Figure 5. Photomicrographs of a normal male (A) and intersex (B, C) gonads from adult roach (Rutilus rutilus) exposed to wastewaters in a field based assessment. Photomicrograph-A, depicts a histological section of normal male testis. Photomicrograph-B and -C, depicts histological sections of an intersex male fish, having been exposed to activated sludge process wastewater effluent for six months. Arrows indicate oocytes present in the testicular tissue. Scale bar represents 100 &#181;m in each photomicrograph. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54243/54243fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
The high cost of end of pipe treatment using ozone, GAC or membrane technology necessitates the development of alternative lower cost, sustainable methods for endocrine disrupting chemical (EDC) removal. Furthermore, adsorption and separation methods simply separate EDC from one phase to another rather than eliminating them via degradation. TAML activators have been developed to catalyze hydrogen peroxide oxidation of organic micropollutants in wastewater12,24-26. TAML activators with H2O2 effectively degrade EE2 and other steroid estrogens in pure laboratory water as well as in effluents from municipal wastewater treatment plants and in spiked urine samples12. Laboratory studies, shows TAML/H2O2 treatment provides high steroid estrogen removal including EE2 removal and substantially reduces estrogenic activity measured in vitro using the YES bioassay and substantially diminishes fish feminization in vivo measured using the VTG bioassay (Figure 1 and Figure 6).
<img alt="Figure 6" src="/files/ftp_upload/54243/54243fig6.jpg" /> 
Figure 6. Average EE2 concentration and estrogenic activity in treated and untreated tank waters (A) and plasma vitellogenin in baseline and exposed male fish (B). A) EE2 concentration (ng/L, dark blue bars) was measured by LCMS/MS, estrogenic activity (EE2 equivalent ng/L, dark green bars) was measured via in vitro Yeast Estrogen Screen (YES). B) Plasma vitellogenin (ng/ml, light blue bars) concentration in male fathead minnows were measured via a quantitative enzyme-linked immunosorbent assay (ELISA). EE2 chemical analysis results reported as &#60; 0.03 ng/L EE2 (i.e., lower than detection limit (LOD)) were treated as having half LOD (i.e., 0.015 ng/L EE2) for use in calculations of averages, standard error and statistical analysis. EE2 and estrogenic activity are average measured concentrations sampled over the 21 day exposure. Plasma VTG was measured prior to exposure (baseline) and after 21 days exposure. The treatment regime consisted of; negative control (dilution water only), EE2+H2O2+TAML, EE2+H2O2, and EE2-only. Error bars in graph-A represent standard error of the mean, error bars in graph-B represent standard deviation. Letters above bars in graph-B represent statistical similarity. This figure has been modified from Mills et al.12 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54243/54243fig6large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

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Use of a Battery of Chemical and Ecotoxicological Methods for the Assessment of the Efficacy of Wastewater Treatment Processes to Remove Estrogenic Potency

Endocrine Disrupting Compounds (EDC) pose a substantial risk to the aquatic environment. Municipal wastewater treatment plants are major contributors to the estrogenic potency of surface waters. The methodology provided in this paper allows for an assessment of the efficacy and suitability of wastewater treatment processes with respect to EDC removal.

Endocrine Disrupting Compounds pose a substantial risk to the aquatic environment. Ethinylestradiol (EE2) and estrone (E1) have recently been included in ...

use-battery-chemical-ecotoxicological-methods-for-assessment-efficacy

Nanyang Technological University

Research

JoVE Journal

Environment

14.0K Views.  Brunel University London.  Hormoonverstorende stoffen (EDC) vormen een aanzienlijk risico voor het aquatisch milieu. Gemeentelijke afvalwaterzuiveringsinstallaties zijn belangrijke bijdragen aan de oestrogene potentie van oppervlaktewater. De methodologie in dit document maakt een evaluatie van de doeltreffendheid en de geschiktheid van afvalwaterzuiveringsprocessen opzichte van EDC verwijderd. 

Video: Use of a Battery of Chemical and Ecotoxicological Methods for the Assessment of the Efficacy of Wastewater Treatment Processes to Remove Estrogenic Potency

A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17&#946;-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 &#181;l of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

A protocol for the extraction and pre-concentration of estradiol from water samples by using an automated and miniaturized system is presented.

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and ...

Preparation and Testing of Impedance-based Fluidic Biochips with RTgill-W1 Cells for Rapid Evaluation of Drinking Water Samples for Toxicity

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity sensor. A monolayer of RTgill-W1 cells forms on the sensing electrodes enclosed within the biochips. The biochips are then used for testing in a field portable electric cell-substrate impedance sensing (ECIS) device designed for rapid toxicity testing of drinking water. The manuscript further describes how to run a toxicity test using the prepared biochips. A control water sample and the test water sample are mixed with pre-measured powdered media and injected into separate channels of the biochip. Impedance readings from the sensing electrodes in each of the biochip channels are measured and compared by an automated statistical software program. The screen on the ECIS instrument will indicate either "Contamination Detected" or "No Contamination Detected" within an hour of sample injection. Advantages are ease of use and rapid response to a broad spectrum of inorganic and organic chemicals at concentrations that are relevant to human health concerns, as well as the long-term stability of stored biochips in a ready state for testing. Limitations are the requirement for cold storage of the biochips and limited sensitivity to cholinesterase-inhibiting pesticides. Applications for this toxicity detector are for rapid field-portable testing of drinking water supplies by Army Preventative Medicine personnel or for use at municipal water treatment facilities.

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial cells for use in a field portable electric cell-substrate impedance sensor. The protocol for running a rapid drinking water toxicity test with the sensor is also described.

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity ...

Screening for Endocrine Activity in Water Using Commercially-available In Vitro Transactivation Bioassays

In vitro transactivation bioassays have shown promise as water quality monitoring tools, however their adoption and widespread application has been hindered partly due to a lack of standardized methods and availability of robust, user-friendly technology. In this study, commercially available, division-arrested cell lines were employed to quantitatively screen for endocrine activity of chemicals present in water samples of interest to environmental quality professionals. A single, standardized protocol that included comprehensive quality assurance/quality control (QA/QC) checks was developed for Estrogen and Glucocorticoid Receptor activity (ER and GR, respectively) using a cell-based Fluorescence Resonance Energy Transfer (FRET) assay. Samples of treated municipal wastewater effluent and surface water from freshwater systems in California (USA), were extracted using solid phase extraction and analyzed for endocrine activity using the standardized protocol. Background and dose-response for endpoint-specific reference chemicals met QA/QC guidelines deemed necessary for reliable measurement. The bioassay screening response for surface water samples was largely not detectable. In contrast, effluent samples from secondary treatment plants had the highest measurable activity, with estimated bioassay equivalent concentrations (BEQs) up to 392 ng dexamethasone/L for GR and 17 ng 17&#946;-estradiol/L for ER. The bioassay response for a tertiary effluent sample was lower than that measured for secondary effluents, indicating a lower residual of endocrine active chemicals after advanced treatment. This protocol showed that in vitro transactivation bioassays that utilize commercially available, division-arrested cell &#34;kits&#34;, can be adapted to screen for endocrine activity in water.

Screening for Endocrine Activity in Water Using Commercially-available In Vitro Transactivation Bioassays

A protocol to screen for endocrine activity in organic extracts of water samples, including treated wastewater effluent and surface (receiving) water, was adapted using commercially available division-arrested ("freeze and thaw") in vitro transactivation bioassays.

In vitro transactivation bioassays have shown promise as water quality monitoring tools, however their adoption and widespread application has been ...

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity.

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may ...

Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation

Monitoring pharmaceuticals throughout the water cycle is becoming increasingly important for the aquatic environment and eventually for human health. Targeted and non-targeted analysis are today's means of choice. Although targeted analysis usually conducted with the help of a triple quadrupole mass spectrometer may be more sensitive, only compounds previously selected can be identified. The most powerful non-targeted analysis is performed through time of flight mass spectrometers (TOF-MS) extended by a quadrupole mass analyzer (Q), as used in this study. Preceded by solid phase extraction and high-performance liquid chromatography (HPLC), the non-targeted approach allows to detect all ionizable substances with high sensitivity and selectivity. Taking full advantage of the Q-TOF-MS instrument, tandem mass spectrometry (MS/MS) experiments accelerate and facilitate the identification while a targeted MS method enhances the sensitivity but relies on reference standards for identification purposes. The identification of four pharmaceuticals from Rhine river water is demonstrated. The Rhine river originates in Tomasee, Graub&#252;nden, Switzerland and flows into the North Sea, near Southern Bight, The Netherlands. Its length amounts to 1232.7 km. Since it is of prime interest to effectively eliminate pharmaceuticals from the water cycle, the effect UV-C irradiation is demonstrated on a laboratory scale. This method allows fast degradation of pharmaceuticals, which is exemplarily shown for the macrolide antibiotic erythromycin. Using the above HPLC-Q-TOF-MS method, concentration-time diagrams are obtained for the parent drug and their photodegradation products. After establishing the equations for first-order sequential reactions, computational fitting allows the determination of kinetic parameters, which might help to predict irradiation times and conditions when potentially considered as fourth stage within wastewater treatment.

We present a protocol for non-targeted analysis using time of flight mass spectrometry as a perfect tool to identify pharmaceuticals in waters. We demonstrate the application of UV irradiation for their elimination. Analysis involving irradiation, compound isolation, identification and kinetic modelling of the degradation profiles is illustrated.

Monitoring pharmaceuticals throughout the water cycle is becoming increasingly important for the aquatic environment and eventually for human health. ...

Necropsy-based Wild Fish Health Assessment

Anthropogenic influences from increased nutrients and chemical contaminants, to habitat alterations and climate change, can have significant effects on fish populations. Adverse effects monitoring, utilizing biomarkers from the organismal to the molecular level, can be used to assess the cumulative effects on fishes and other organisms. Fish health has been used worldwide as an indicator of aquatic ecosystem health. The necropsy-based fish health assessment provides data on visible abnormalities and lesions, parasites, condition and organosomatic indices. These can be compared by site, season and sex, as well as temporally, to document change over time. Severity ratings can be assigned to various observations to calculate a fish health index for more quantitative assessment. A drawback of the necropsy-based assessment is that it is based on visual observations and condition factors, which are not as sensitive as tissue and subcellular biomarkers for sublethal effects. Additionally, it is rarely possible to identify causes or risk factors associated with observed abnormalities. So, for instance a raised lesion or "tumor" on the fins, lips or body surface may be a neoplasm. However, it could also be a response to a parasite, chronic inflammation or hyperplasia of normal cells in response to an irritant. Conversely, neoplasms, certain parasites, other infectious agents and many tissue changes are not visible and so may be underestimated. However, during the necropsy-based assessment, blood (plasma), tissues for histopathology (microscopic pathology), genomics and other molecular analyses, and otoliths for aging can be collected. These downstream analyses, together with geospatial analyses, habitat assessments, water quality and contaminant analyses can all be important in comprehensive ecosystem evaluations.

The health of wild fishes can be used as an indicator of aquatic ecosystem health. Necropsy-based fish health assessments provide documentation of visible lesions or abnormalities, data used to calculate condition indices as well as the opportunity to collect tissues for microscopic evaluation, gene expression and other more in-depth analyses.

Anthropogenic influences from increased nutrients and chemical contaminants, to habitat alterations and climate change, can have significant effects on ...

Using Tg(Vtg1:mcherry) Zebrafish Embryos to Test the Estrogenic Effects of Endocrine Disrupting Compounds

There are many endocrine disrupting compounds (EDC) in the environment, especially estrogenic substances. The detection of these substances is difficult due to their chemical diversity; therefore, increasingly more effect-detecting methods are used, such as estrogenic effect-sensitive biomonitor/bioindicator organisms. These biomonitoring organisms include several fish models. This protocol covers the use of zebrafish Tg(vtg1: mCherry) transgenic line as a biomonitoring organism, including the propagation of fish and the treatment of embryos, with an emphasis on the detection, documentation, and evaluation of fluorescent signals induced by EDC. The goal of the work is the demonstration of the use of the Tg(vtg1: mCherry) transgenic line embryos to detect estrogenic effects. This work documents the use of transgenic zebrafish embryos Tg(vtg1: mCherry) for the detection of estrogenic effects by testing two estrogenic substances, &#945;- and &#946;-zearalenol. The described protocol is only a basis for designing assays; the test method can be varied according to the test endpoints and the samples. Moreover, it can be combined with other assay methods, thereby facilitating the future use of the transgenic line.

Using TgVtg1:mcherry Zebrafish Embryos to Test the Estrogenic Effects of Endocrine Disrupting Compounds

Present here is a detailed protocol for the use of zebrafish embryos Tg(vtg1: mCherry) for the detection of estrogenic effects. The protocol covers the propagation of the fish and treatment of embryos, and emphasizes the detection, documentation, and the evaluation of fluorescent signals induced by endocrine disrupting compounds (EDC).

There are many endocrine disrupting compounds (EDC) in the environment, especially estrogenic substances. The detection of these substances is difficult ...

Long-term Behavioral and Reproductive Consequences of Embryonic Exposure to Low-dose Toxicants

Bisphenols, such as bisphenol A (BPA) and bisphenol S (BPS) are polymerizing agents widely used in the production of plastics and numerous everyday-use products. Based on their chemical structure and estradiol-like biological properties, they have been classified as endocrine disrupting compounds (EDC). Long-term exposure to EDCs, even at low doses, has been linked to various health defects including cancer, behavioral disorders and infertility, with greater vulnerability indicated during early developmental periods. Cellular and molecular studies with the genetically tractable nematode model Caenorhabditis elegans have demonstrated that exposure to BPA causes apoptosis, embryonic lethality and disruption in the DNA repair mechanisms. We have previously reported that exposure of C. elegans embryos to low doses of different bisphenols decreases fecundity. In addition, we have shown that the effects of exposure during the very early stages of development persist into adulthood as assayed by quantifying habituation behavior, a form of non-associative learning. Here, we provide detailed protocols for embryonic exposure to low-dose EDCs as well as the associated fecundity and anterior touch habituation assays, along with representative results.

Exposure to environmental toxicants can acutely impact development with long-term effects. Detailed protocols are provided to illustrate a strategy using an effective lab model to study the effect of early embryonic exposure to bisphenol A. We provide fecundity and behavioral assays to monitor the effectiveness of our toxicant exposure bio-assays.

Bisphenols, such as bisphenol A (BPA) and bisphenol S (BPS) are polymerizing agents widely used in the production of plastics and numerous everyday-use ...

Developmental Biology

In Silico Modeling Method for Computational Aquatic Toxicology of Endocrine Disruptors: A Software-Based Approach Using QSAR Toolbox

Computational analyses of toxicological processes enables high-throughput screening of chemical substances and prediction of their endpoints in biological systems. In particular, quantitative structure-activity relationship (QSAR) models have been increasingly applied to assess the environmental effects of a plethora of toxic materials. In recent years, some more highlighted types of toxicants are endocrine disruptors (EDs, which are chemicals that can interfere with any hormone-related metabolism). Because EDs may significantly affect animal development and reproduction, rapidly predicting the adverse effects of EDs using in silico techniques is required. This study presents an in silico method to generate prediction data on the effects of representative EDs in aquatic vertebrates, particularly fish species. The protocol describes an example utilizing the automated workflow of the QSAR Toolbox software developed by the Organization for Economic Co-operation and Development (OECD) to enable acute ecotoxicity predictions of EDs. As a result, the following are determined: (1) calculation of the numerical correlations between the concentration for 50% of lethality (LC50) and octanol-water partition coefficient (Kow), (2) output performances in which the LC50 values determined in experiments are compared to those generated by computations, and (3) the dependence of estrogen receptor binding affinity on the relationship between Kow and LC50.

Quantitative structure-activity relationship (QSAR) modeling is a representative bioinformatics-assisted method in toxicological screening. This protocol demonstrates how to computationally assess the risks of endocrine disruptors (EDs) in aquatic environments. Utilizing the OECD QSAR Toolbox, the protocol implements an in silico assay for analyzing toxicity of EDs in fish.

Computational analyses of toxicological processes enables high-throughput screening of chemical substances and prediction of their endpoints in biological ...

Bioengineering

Prospecting Microbial Strains for Bioremediation and Probiotics Development for Metaorganism Research and Preservation

Pollution affects all biomes. Marine environments have been particularly impacted, especially coral reefs, one of the most sensitive ecosystems on Earth. Globally, 4.5 billion people are economically dependent on the sea, where most of their livelihood is provided by coral reefs. Corals are of great importance and therefore their extinction leads to catastrophic consequences. There are several possible solutions to remediate marine pollutants and local contamination, including bioremediation. Bioremediation is the capacity of organisms to degrade contaminants. The approach presents several advantages, such as sustainability, relatively low cost, and the fact that it can be applied in different ecosystems, causing minimal impacts to the environment. As an extra advantage, the manipulation of endogenous microbiomes, including putative beneficial microorganisms for corals (pBMCs), may have probiotic effects for marine animals. In this context, the use of the two approaches, bioremediation and pBMC inoculation combined, could be promising. This strategy would promote the degradation of specific pollutants that can be harmful to corals and other metaorganisms while also increasing host resistance and resilience to deal with pollution and other threats. This method focuses on the selection of pBMCs to degrade two contaminants: the synthetic estrogen 17a-ethinylestradiol (EE2) and crude oil. Both have been reported to negatively impact marine animals, including corals, and humans. The protocol describes how to isolate and test bacteria capable of degrading the specific contaminants, followed by a description of how to detect some putative beneficial characteristics of these associated microbes to their coral host. The methodologies described here are relatively cheap, easy to perform, and highly adaptable. Almost any kind of soluble target compound can be used instead of EE2 and oil.

Pollution affects all biomes. Marine environments have been particularly impacted, especially coral reefs, one of the most sensitive ecosystems on Earth. Bioremediation is the capacity of organisms to degrade contaminants. Here, we describe methodologies to isolate and test microbes presenting bioremediation ability and potential probiotic characteristics for corals.

Pollution affects all biomes. Marine environments have been particularly impacted, especially coral reefs, one of the most sensitive ecosystems on Earth. ...

Use of a Battery of Chemical and Ecotoxicological Methods for the Assessment of the Efficacy of Wastewater Treatment Processes to Remove Estrogenic Potency

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