291 13 Hormo nesinWastefrom Concentrated Animal Feeding Operations Z. Zhao, K.F. Knowlton, and N.G. Love Contents 13.1 Introduction 292 13.2 Background 292 13.2.1 Concentrated Animal Feeding Operations (CAFOs) in the United States 292 13.2.2 Hormones and CAFO 293 13.3 Hormones i n CAFO s 295 13.3.1 Natural Estrogens 295 13.3.2 Biosynthesis of Estrogens 296 13.3.3 Metabolism of Estrogens 297 13.3.4 Excretion of Estrogens 298 13.3.5 Degradation of Estrogens 300 13.4 Natural Androgens 302 13.4.1 Biosynthesis of Androgens 302 13.4.2 Metabolism of Androgens 302 13.4.3 Excretion of Androgens 303 13.4.4 Degradation of Androgens 304 13.5 Natural Progestagens 304 13.5.1 Biosynthesis of Progesterone 304 13.5.2 Metabolism of Progesterone 305 13.5.3 Excretion of Progesterone 306 13.5.4 Degradation of Progesterone 306 13.6 Hormone Growth Promoter s 306 13.6.1 Naturally Occurring Hormonal Growth Promoters (HGPs) 307 13.6.2 Synthetic HGPs 307 13.7 Routes of Hormone Loss f rom CAFOs 310 13.7.1 Soil and Runoff 311 13.7.2 Streams and Rivers 312 13.7.3 Groundwater 312 13.8 Fate of Hormones during Manure Storage, Treatment, and Land Application 313 13.8.1 Conventional Manure Storage and Treatment Systems 313 13.8.1.1 Manure Handling on Dairy Farms 313 © 2008 by Taylor & Francis Group, LLC 292 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems 13.1 INTRODUCTION Concentratedanimalfeedingoperations(CAFOs)arethelargestofthe238,000live- stockfarmsoranimalfeedingoperations(AFOs)intheUnitedStates. 29 The U.S. Environmental Protection Agency (EPA) dened AFOs as livestock operations where animals are maintained or conned for more than 45 days in 1-year period, 19 and AFOsthatmeetcertainanimalsthresholdnumbersandon-farmsituationsarecatego- ri zedasCAFOs.Anestimated15,500AFOs(7%ofthetotal)constituteCAFOs. 29 Nitrogen (N) and phosphorus (P) pollution, pathogens, and odor of manure dischargingfromCAFOshavebeenagreatconcernforseveraldecades. 57,72,113 In recent years, hormones (estrogens, androgens, progesterone, and various synthetic hormones)containedinthemanurefromCAFOshavegeneratedwideinterest becauseoftheirendocrinedisruptingeffects. 48,79,90 When manure is land applied, part of these hormones may enter water systems through runoff or leaching 24,37,63,102 andmaycausedevelopmentalandreproductiveimpairmentinaquaticanimals.The effectivelevelsofthesehormonesmaybeaslowasnanogramsperliterofwater. 17 A highincidenceofintersexuality(feminization)wasobservedinawidepopulationof male roaches in the United Kingdom. 64 Afterexposuretocattlefeedlotefuent,both testosterone synthesis and testis size decreased in male fathead minnows. 105 This chapter focuses on the occurrence, persistence, treatment, and transforma- tion of n aturalandexogenoushormonesinwastefromCAFOs,includingdairy, beef, poultry, swine, and horse farms. The biochemistry, physiological functions, excretion,degradation,andenvironmentaleffectsofthesehormonesarediscussed. 13.2 BACKGROUND 13.2.1 C ONCENTRATED ANIMAL FEEDING OPERATIONS (CAFOS) IN THE UNITED STATES AFOsintheUnitedStateshavebeenidentiedasoneoftheleadingsourcesof impairmentforallkindsofwaterbodies,becausemorethan500milliontonsof 13.8.1.2 Poultry Farms 313 13 .8.1.3 Swine Farms 314 13.8.1.4 Beef Cattle Operations 314 13.8.2 Innovative Manure Treatment Systems 315 13.8.3 Composting 315 13.8.4 Anaerobic Digestion 315 13.8.5 Nitrication and Denitrication 315 13.8.6 Chemical and Biological Phosphorus Removal 316 13.8.7 Aeration of Dairy Manure 316 13.9 OtherBestManagementPracticestoReduceHormoneLossfrom CAFOs 317 13.9.1 Constructed Wetlands 318 13.9.2 Buffer Strips 319 13.9.3 Controlled Stream Access 319 13.10 Future Research Needs Regarding Manure Treatment 320 13.11 Conclusion 320 References 321 © 2008 by Taylor & Francis Group, LLC Hormones in Waste from Concentrated Animal Feeding Operations 293 animal manure need to be disposed from AFOs annually. 28 To ensure that the own- ers and managers of CAFOs take appropriate actions to manage manure effec- ti vely,CAFOsaresubjecttotheNationalPollutionDischargeEliminationSystem permitting requirements and the Efuent and Limitations Guidelines and Standards undertheCleanWaterAct. 29 CAFOsaredividedintolargeandmediumcategories(Table 13.1). Large CAFOs aredenedonlybyanimalnumbers,whilemediumCAFOsaredenedbybothani- ma lnumbersandon-farmconditions. 29 In addition to animal number requirement, medium CAFOs are also “discharging pollutants directly or indirectly via either a man-made ditch, ushing system, or other similar man-made devices into waters thatoriginateoutsideofandpassover,across,orthroughthefacilityortheanimals conned in the operations have direct contact with water.” 29 Swine CAFOs are fur- therdividedbyanimalsize,andpoultryoperationswithbothwetanddrymanure handling systems are included. The estimated numbers of CAFOs that need permits under the revised CAFO regulationsannouncedbyEPAin2003arelistedin Table 13.2. 29 Sixty percent of theCAFOsarehoganddairyfarms.CAFOsonlyaccountforasmallpercentage ofalllivestockfarms,buttheycontributeabout50%animalmanureproduction (Table 13.3). 68 13.2.2 HORMONES AND CAFO Hormones are synthesized from specialized glands in the endocrine system and are excreted at very low quantities in urine and feces. 86,95 The hormones in animal TABLE 13.1 Size Thresholds of CAFOs for Different Species of Livestock Animal Type Medium CAFOs Large CAFOs Mature dairy cows 200–699 (milked or dry) >700 (milked or dry) Veal calves 300–999 >1000 Other cattle 1 300–999 >1000 Swine (>55lbs) 750–2499 >2500 Swine (<55 lbs) 3000–9999 >10,000 Horses 150–499 >500 Sheep or lambs 3000–9999 >10,000 Turkeys 16,500–54,999 >55,000 Laying hens or broilers 2 9000–29,999 >30,000 Chickens (other than laying hens) 3 37,500–124,999 >125,000 Laying hens 4 25,000–81,999 >82,000 Ducks 5 10,000–29,999 >30,000 Ducks 6 1500–4999 >5000 1 Cattle includes heifers, steers, bulls, and cow/calf pairs 2,6 If the AFO uses a liquid manure handling system 3,4,5 If the AFO uses other than a liquid manure handling system Source: Adapted from U.S. EPA [Reference 29]. © 2008 by Taylor & Francis Group, LLC 294 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems manure that have important environmental effects include estrogens (estrone, estra- diol, and estriol), androgens (testosterone), and progestagens (progesterone). If these hormones enter the water system through runoff and leaching following manure land application, they may alter or disrupt the functions of the endocrine system and causeadverseeffectstoorganisms. 27 The adverse effects may include mimicking or blocking receptor binding, or altering the rate of hormone synthesis or metabolism throughinteractionswiththeendocrinesystem. 95 Itwaspredictedthatabout1500kgestroneandestradiolareexcretedeachyear byfarmanimalsintheUnitedKingdom(Table 13.4), 66 about four times more than thetotalestrogensfromhumans.Forty-ninetonsofestrogens,4.4tonsofandro- ge ns,and279tonsofgestagenswereexcretedbyfarmanimalsintheUnitedStates in 2002, 79 and cattle production contributes about 90% of estrogens and gestagens and 40% of androgens. These estimates are questionable as data available may not TABLE 13.3 Manure Available for Land Application Animals Total Manure (Billion lbs) By CAFOs (Billion lbs) Manure from CAFO (% of total) Dairy 45.5 10.5 23 Cattle 32.9 27.3 83 Swine 16.3 9.0 55 Poultry 33.5 16.4 49 Total 128.2 63.2 49.4 Source: Adapted from Kellogg et al. (Reference 68). TABLE 13.2 Numbers of CAFOs in the United States for Different Types of Operations Animals Medium CAFOs Large CAFOs Dairy 1949 1450 Veal 230 12 Fed cattle 174 1766 Hogs 1485 3924 Turkeys 37 388 Broilers 520 1632 Laying hens (dry manure) 26 729 Laying hens (wet manure) 24 383 Total 4452 10526 Source: Adapted from U.S. EPA (Reference 29). © 2008 by Taylor & Francis Group, LLC Hormones in Waste from Concentrated Animal Feeding Operations 295 be sufcient for accurate calculation of the total mass of estrogens excreted. 48 It is clear,however,thatlargeamountsofhormonesfromCAFOsarereleasedintothe environment each year. Synthetic hormones considered to be endocrine disruptors are commonly used in CAFOsfordifferentpurposes.AlthoughbannedintheEuropeanUnion,hormonal growth promoters (HGPs) are widely used by the largest cattle-producing countries in the world, including the United States, Australia, Argentina, and Canada. 139 Three synthetichormones,zearalanol,trenboloneacetate(TBA),andmelengestrolacetate (MGA),havebeenlicensedforanimalproduction.Alsousedarethenaturalhor- mo nes testosterone, 17C-estradiol, and progesterone. 81 TheseHGPsareprimarilyusedinthebeefcattleindustry,asexogenous androgensandestrogenshavelittleefcacyinpigs. 14 In the dairy industry, progesterone-releasing implant devices are approved in lactating cows for estrous synchronization. 114 The use of these hormones in CAFOs has raised concerns with the increased exposure of endocrine disruptors to the environment. 126,160 13.3 HORMONES IN CAFOS 13.3.1 N ATURAL ESTROGENS Estrogens are hormones that are mainly responsible for the development of female sex organs and the secondary sex characteristics (Figure 13.1). The naturally occur- ring estrogens in livestock include estrone or E1 (3C-Hydroxyestra-1,3,5(10)-trien- TABLE 13.4 Predicted Total Excretion of Estrogens from the Human and Farm Animal Populations in the United Kingdom (2004) Type Population (million) Estrone (kg/year) Estradiol (kg/year) Discharge Percentage (%) 1 Human 59 219 146 17 Dairy cattle 2.2 693 365 49 Pigs 5 367 19 18 Broiler chickens 112 15 34 2 Laying hens 2 29.2 NC 3 NC 12 Breeding ewes 7.6 19 6 1.9 Nonbreeding sheep 1.5 1.6 0.4 0.1 Total farm animals 157.5 1096 424 83 Total 216.5 1315 570 100 1 Based on the total amount of estrone and estradiol 2 The combined amount of estrone and estradiol is 260 kg/year 3 NC—not calculated for insufcient data Source: Adapted from Johnson et al. (Reference 66). © 2008 by Taylor & Francis Group, LLC 296 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems 17-one), 17C-estradiolorE2(estra-1,3,5(10)-triene-3,17C-diol), and estriol or E3 (estra-1,3,5(10)-triene-3,16C,17C-triol). 17B-estradiol is the optical isomer of 17C- estradiolwiththehydroxylgroupatC-17pointingdownwardfromthemolecule, and 17C-estradiol has the hydroxyl group pointing upward. 48 Natural estrogens are slightlysolubleinwater,moderatelyhydrophobic,andareweakacidswithlowvola- tility (Table 13.5). 17C-estradiol is the most potent natural estrogen, and the relative estrogenic potencies of estrone and estriol relative to 17C-estradiol(1.0)are0.38and 2.4×10 –3 ,respectively,basedontheyeastestrogenscreenassay. 122 13.3.2 BIOSYNTHESIS OF ESTROGENS Themajorsourceofestrogensinnonpregnantfemalesistheovary(granulosacells), and the placenta produces the majority of estrogens during pregnancy. 54 Other sources may include the adrenal cortex, adipose tissue, muscle, kidney, liver, and hypothalamus.ThemainpathwaysofbiosynthesisofestrogensareshowninFig- ure 13.2. 38 The synthesis starts with cholesterol, which is converted to pregnenolone, and subsequently 4-androstenedione and testosterone. The two androgens are then hydroxylated at C-19, and the resulted 19-hydroxyl groups are oxidized and further removed.Thenalproductswillbeestroneand17C-estradiolfromandrostenedi- one and testosterone, respectively. 17C-estradiol can then be converted to estriol OH O OH OH OH OH OH EstriolEstroneEstradiol FIGURE 13.1 Molecularstructuresofnaturalestrogens. TABLE 13.5 Physicochemical Properties of Natural Estrogens Property Estrone Estradiol Estriol Formula C 18 H 22 O 2 C 18 H 24 O 2 C 18 H 24 O 3 Molecular weight (g/mol) 270.4 272.4 288.4 Sw 1 (mg/L) 0.8–12.4 3.9–13.3 3.2–13.3 Vapor pressure (Pa) 3 × 10–8 3 × 10–8 9 × 10–13 Log K ow 2 3.1–3.4 3.1–4.0 2.6–2.8 pKa 3 10.3–10.8 10.5–10.7 10.4 1 S w —solubility in water 2 K ow —octanol-water partition coefcient 3 PK a —acid ionization constant Source: Adapted from Hanselman et al. (Reference 48). © 2008 by Taylor & Francis Group, LLC Hormones in Waste from Concentrated Animal Feeding Operations 297 by 16C-hydroxylase. The biosynthesis pathways of 17B-estradiol are not entirely known. 148 Generally it is synthesized from aromatization of epitestosterone by the cytochrome P450 aromatase. 36 13.3.3 METABOLISM OF ESTROGENS Aftersynthesisandsecretion,estrogensgothroughaseriesofmetabolicpathwaysin theliver,kidney,gastrointestinaltract,andtargettissues.Estroneand17C-estradiol a re interconvertible by 17C-hydroxysteroid dehydrogenase. 120 All estrogens may be converted to glucuronides or sulfates by UDP-glucuronosyltransferase and sulfo- tr ansferase, and glucuronidase and sulfatase will hydrolyze estrogen conjugates back to free forms, as shown in Figure 13.3. 115 Theseconjugatedestrogensarenotinvolvedinestrogenreceptor-mediated activity. 166 Estrogensulfateshaveamuchlongerhalf-lifeandhigherconcentrations in human circulation than the free forms, 108 so sulfation and desulfation may be                                                        FIGURE 13.2 Biosynthesis pathways of natural estrogens. (Adapted from Fotherby. 38 ) © 2008 by Taylor & Francis Group, LLC 298 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems important in the regulation of biologically active or free estrogens in the body. 52 Compared with estrogen sulfates, much less attention has been paid to estrogen glucuronides. 166 HepatichydroxylationofestrogensatC-2andC-4formscatecholestrogens(CEs) with less hydroxylation at C-4 than at C-2 in humans and most mammals. 103 The hydroxylated estrogens can form sulfates and glucuronides, or with the presence of catechol-O-methyltransferase,theCEsaremethylatedtoform2-or4-O-methylethers andthenexcretedasshownin Figure 13.4. 115 TheCEscanalsobeoxidizedfurther into quinones or semiquinones with subsequent glutathione conjugation. 9,124 In humans about half of the estrogen conjugates that enter or are formed in the liverwillbeexcretedintotheintestinethroughbileforenteroheptaticcirculation (intestinal reabsorption and reentering the liver for metabolism) or excretion in feces. 41 Generallyestrogenconjugatesarehydrolyzedconsiderablyintheintestine, andestradiolisconvertedtoestronetoalargeextent. 1 Reconjugationcanoccurin the intestinal mucosal cells, and some of the conjugated and free estrogens are then reabsorbedtothebloodstreamandeitherreenterbileoraretransportedtothekidney for urinary excretion. 2 13.3.4 EXCRETION OF ESTROGENS Estrogens are mainly excreted through urine and feces. In feces, estrogens mainly existinfreeforms,whileurinaryestrogensaremostlyconjugated. 138 17C-estra- diol,17ß-estradiol,andestrone(freeandconjugated)accountformorethan90%of the excreted estrogens in cattle, 48 but 17C-estradiol is rarely excreted by swine and O HO HO OH OH O OO O O HO HO OH OH O O O OH OH OO O O EstradiolEstrone glucuronide Estrone glucuronide Estradiol sulfateEstrone sulfate Estrone S O OOS FIGURE 13.3 Conjugation and deconjugation pathways of estrogens. (Adapted from Rafto- gianis et al. 115 ) © 2008 by Taylor & Francis Group, LLC Hormones in Waste from Concentrated Animal Feeding Operations 299 poultry. In cattle 58% of the total estrogen excretion is via the feces, 59 while swine andpoultryexcrete96%and69%ofestrogensinurine,respectively. 3,106 Totalestrogenexcretionbycattleisclearlyquantitativelysignicant,butrela- tivelyfewdataareavailable.174μgperdayoftotalestrogenswasexcretedthrough cowurineindays6to25oflactation. 30 In cattle, 11.6 ng/g estrone, 60.0 ng/g 17C- estradiol,and33.6ng/g17ß-estradiol,respectively,werefoundinthefeces5days before parturition (giving birth), but no daily excretion rate data for estrogens were available. 53 Total estrogen content (estradiol plus estrone) was reported to be 28 ng/g of dry broiler litter. (“Litter” is the term used for the combination of manure and wood shaving bedding material. 137 )Similarly,30ng/gof17C-estradiol was found in broiler chicken manure. 10 Table 13.6 shows the calculated total daily excretion HO Estradiol OH OH OH OH OH O OH O O O HO HO 2-OH estradiol 4-OH estradiol Estradiol-3,4-Quinone Estradiol-2,3-Quinone HO Methylation and Conjugation Glutathione Conjugation FIGURE 13.4 Conjugation of catechol estrogens and estrogen quinines. (Adapted from Raftogianis et al. 115 ) TABLE 13.6 Estimation of Total Daily Estrogen Excretion by Farm Animals Species Category Fecal Excretion μg/day Urinary Excretion Total Excretion Cattle Cycling cows 200 99 299 Bulls 360 180 540 Pigs Cycling sows 14 100 114 Sheep Cycling ewes 20 3 23 Source: Adapted from Lange et al. (Reference 79). © 2008 by Taylor & Francis Group, LLC 300 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems ofestrogensforcattle,pigs,andsheep. 79 Several factors, such as age, diet, season, health status, and diurnal variation may contribute to variation in excretion rates. 130 13.3.5 DEGRADATION OF ESTROGENS Degradation of estrogens is a complicated process and may include deconjugation, dissipation, and mineralization. 61,83,145 A rapid biodegradation of 17C-estradiol and its related metabolites were reported by sewage bacteria under both aerobic and anaerobic conditions. 82 Thesamekindofresultoccurredduringaerobicbatchincu- bationwithactivatedsludgefromasewagetreatmentplant. 145 The hydrolysis or cleavage of sulfate or glucuronide of conjugated estrogens is called deconjugation. It was suggested that some natural fecal bacterial and enzymes maydegradeestrogenmetabolitesseveralhoursaftersamplingifnopreservative isaddedorsamplesarenotputintocoldstorage. 70 The fecal microorganism Esch- erichia coli (u biquitousinthedigestivetract)iscapableofproducinglargequanti- ties of C-glucuronidase. 20,60 and has been considered to be responsible for estrogen glucuronides deconjugation to some extent. Escherichia coli has a w eak arysulfatase activity, 131 so it is possible that portions of estrogen sulfates are left intact. This may explain why several studies reported estrogen sulfates in sewers, 145 sewage treatment plants, 20 and river water. 121 No estrogen glucuronides were detected in sow feces, and afterincubationofestroneconjugatesat20°Cfor30mininfecalsuspension,90%of estroneglucuronidewasdeconjugated,butestronesulfatewasnothydrolyzed. 156 Thedissipationofestrogensreferstothedecreaseinextractableconcentrations, andthepossibledissipationpathwaysincludeconversionofestradioltoestroneand subsequent formation of nonextractable residues. 18 Mineralization is the nal deg- radationofestrogenstoCO 2 ,water,andothercompoundsthroughcleavageofthe phenolic ring. The degradation pathways for dissipation and mineralization have not beenclearlyunderstood,butbothbioticandabioticpathwaysarepossibleforestrogen degradation as shown in Figure 13.5. 71 Under aerobic conditions, the introduction of hydroxyl groups by mono- and dioxygenase ring cleavage, and nal decarboxylation, are the key steps for degradation of phenolic compounds. 128 Anaerobes may degrade phenolic compounds through hydroxylation and carboxylation followed by C-oxida- ti on to CO 2 . 11 With the assistance of TiO 2 ,estrogensaredegradedchemicallyatthe phenolringrstandthenDEO(10F-17C-dihydroxy-1,4-estradien-3-one)is p roduced as an intermediate for further degradation. 104 Because of the similarity in their basic structures,thedegradationofandrogensandprogesteroneisexpectedtogothrough thesamepathwaysintermsofthenalmineralization. Photodegradationhasalsobeensuggestedasanothermechanismofestrogendi s - si pation and mineralization. 35,97 Most reported work focuses on estrogens in manure- amended soil and biosolids from wastewater treatment systems; only a few studies have explored degradation of estrogens in stored manure. Estrogen concentrations decreasedsignicantlyinbroilerlitteratpH5and7after1weekincubation. 137 The totalestrogenswerereducedby80%incattlefecesfollowing12weeksofincuba- ti on at 20 to 23°C. 129 Substantial losses of 17C-estradiol(90%)andtotalestrogens (40%)occurredwithoutacidicationandcoldstorageinpress-cakesamplesofdairy manure. 116 © 2008 by Taylor & Francis Group, LLC [...]... LLC 302 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems 13. 4 NATURAL ANDROGENS Natural androgens are C-19 steroids that possess androgenic activities (stimulating and maintaining masculine characteristics), including testosterone, 5 -dihydrotestosterone, 5 -androstane-3 ,17 -diol, and three weakly androgenic steroids—4androstenedione, dehyroepiandrosterone (DHA), and androsterone—as... (Figure 13. 9) The anabolic effects are mediated directly by several organs and tissues (liver, bone, skin, and other tissues) and indirectly via the somatotropic axis involving growth hormone and insulin-like growth factor I 13. 6.2 SYNTHETIC HGPS The structures of TBA (17 -acetoxyestra-4,9,11-triene-3-one), MGA (17 -acetoxy6-methyl-16-methylene-pregna-4,6-diene-3,20-dione), and zeranol are shown in Figure... circulation and fecal excretion In cattle urine, the main metabolites of testosterone are three isomers of androstane-3,17© 2008 by Taylor & Francis Group, LLC 304 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems diol, 5 -androstan-3 -ol-17-one, and epietiocholanolone.123 In the intestine, androgen metabolites are subjected to hydrolase, dehydroxylase, reductase, and epimerase... hydroxylation at C-17 and subsequent removal of the side-chain.42 Then the resulted DHA is metabolized into testosterone through either 5 -androstane-3 ,17 -diol, or 4-androstenedione Another pathway starts with progesterone converted from pregnenolone, and then hydroxylation at C-17 and removal of the side-chain gives 4-androstenedione Finally, testosterone is formed from 4-androstenedione by 17 -hydroxysteroid... progesterone into a mixture of 11 -hydroxy-4-androstene-3,17-dione and 11 -hydroxy-1,4-androstadiene-3,17-dione.111 The side-chain progesterone was degraded by some species of Aspergillus flavus; 4-androstene-3,17-dione, testosterone, and testololactone were the main degraded metabolites.100 Progesterone was also detected up to 6 ng/g in river sediments in some Spanish rivers.88 13. 6 HORMONE GROWTH PROMOTERS In. .. of manure in farmland, hormones from CAFOs may enter surface and groundwater through runoff or leaching The half-lives of the hormones vary with environmental matrix, such as in stored manure, soil, rivers, and sediments (Table 13. 11), and half-lives of hormones in manure and soil are longer than in the aquatic environment TABLE 13. 11 The Half-Lives of Hormones in the Environment Hormone 17 -estradiol... Pharmaceuticals in the Environment and in Water Treatment Systems also determined, and more than 55% of the conjugated metabolites was 5 -pregnane3 ,20 -diol glucuronide 3 -hydroxy-5 -pregnan-20-one 3 sulfate was reported to be the major metabolite in pregnant sheep plasma after injection of 14C-progesterone.150 Progesterone also serves as a precursor for estrogen and testosterone synthesis, as shown in Figure 13. 2... clarified.142 Androgens are important for the development of male sex organs and the maintenance of the secondary sex characteristics.8 13. 4.1 BIOSYNTHESIS OF ANDROGENS Androgens are largely synthesized in the testes, secondly in the adrenal cortex, and to a limited extent in the ovaries and placenta As shown in Figure 13. 2, pregnenolone is also the precursor for androgen biosynthesis, and it goes through... Animal Feeding Operations 309 17 -TBOH has only 2% of the androgenic potency, 5% of the anabolic effect,112 and 4% the affinity to the recombinant human androgen receptor compared to that of TBA.7 As with the natural steroidal hormones, little data are available on the excretion or fate of synthetic HGPs in manure storage 17 -TBOH and 17 -TBOH ranged from 10 to 120 ng/L and 10 to 20 ng/L in the liquid... eliminate of the possible interactions of these hormones and other contaminants in the environment. 73 In a river adjacent to a feedlot in eastern Nebraska, the concentrations of estrone, 17 -estradiol, and 17 -estradiol were 900 pg/L, 35 pg/L, and 84 pg/L, respectively, 80 km downstream from the feedlot.141 13. 7.3 GROUNDWATER Sources of groundwater contamination with reproductive hormones may include . LLC 296 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems 17-one), 17C-estradiolorE2(estra-1,3,5(10)-triene-3,17C-diol), and estriol or E3 (estra-1,3,5(10)-triene-3,16C,17C-triol) LLC 302 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems 13. 4 NATURAL ANDROGENS NaturalandrogensareC-19steroidsthatpossessandrogenicactivities(stimulating and maintaining. with the presence of catechol-O-methyltransferase,theCEsaremethylatedtoform2-or4-O-methylethers andthenexcretedasshownin Figure 13. 4. 115 TheCEscanalsobeoxidizedfurther into quinones or semiquinones