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Endocrine Disrupting Compounds:

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General Overview and Impact on Freshwater Biology. Endocrine Disrupting Compounds:. Photo by Judy Gibson From: Jenkins et al ., 2009 P. SCAP Water Issues Committee Meeting May 5, 2011. All vertebrates possess an endocrine system which consists of Glands : Secrete hormones - PowerPoint PPT Presentation
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  • Endocrine Disrupting Compounds:

    General Overview and Impact on Freshwater BiologySCAP Water Issues Committee MeetingMay 5, 2011Photo by Judy Gibson From: Jenkins et al., 2009 P

  • The Endocrine SystemAll vertebrates possess an endocrine system which consists ofGlands: Secrete hormonesReceptors: Detect and react to hormones

  • The Endocrine SystemAll vertebrates possess an endocrine system which consists ofGlands: Secrete hormonesReceptors: Detect and react to hormonesThe endocrine system is responsible for biochemical signals that insure proper function of the body throughout the life cycle.

  • The Endocrine SystemAll vertebrates possess an endocrine system which consists ofGlands: Secrete hormonesReceptors: Detect and react to hormonesThe endocrine system is responsible for biochemical signals that insure proper function of the body throughout the life cycle. Endocrine disrupting compounds (EDCs) mimic natural hormones and can bind with hormone receptors disrupting normal endocrine function

  • Endocrine Disrupting CompoundsExogenous Compounds-compounds (molecules) that originate outside of living organismsEncompass a variety of chemical classes including pesticides, pharmaceuticals, plastisizers, flame retardents, hormones, cleaning products, personal care productsMany are organic wastewater contaminants (OWCs) and some are contaminants of emerging concern (CECs)Primary focus has been on the EDCs estrogenic effects-where EDCs mimic the hormone estrogenEstrogen receptors are essentially the same among most vertebrates

  • EDCs Widespread in the Environment

    EDCCommon UseAlkylphenol ethoxylates (APEs) and their degradation productsIndustrial and household nonionic surfactants (detergents) Bisphenol-A (BPA)Most widely used plasticizer (softener) in the US17a-ethynyl estradiol (EE2)Synthetic estrogen used in most birth control and hormone replacement drugsOrganochloride pesticides (OCPs)Pesticides, herbicides and fungicides used by industry and household consumers (ex: DDT)-banned sincePhthalatesUbiquitous component of leachable plasticsPolyaromatic hydrocarbons (PAHs)Nonvolatile hydrocarbons present in oils and petroleum-based lubricantsPolychlorinated biphenyls (PCBs)Oils used primarily in transformers (ex: Aroclor)-banned since 1976Triclosan and degradation productsCommon ingredient of soaps and personal/household disinfectants

  • EDC Release to Freshwater SystemsDischarge from wastewater treatment plants (WWTPs)APEs, Hormones (e.g. EE2), Triclosan, BPA, PharmaceuticalsAgricultural wastewater dischargesHormonesUrban and agricultural runoffPAHs, OCPsIndustrial dischargesAPEs, BPA, PhthalatesPrimary release mechanisms:

  • Impacts on Freshwater BiologyObservations led to years of research to determine cause of abnormalitiesAbnormally high incidence of intersex fish observed downstream from WWTPs in late 1970s

  • Impacts on Freshwater BiologyRodgers-Gray et al. 2001Possession of both male and female germ cellsMales in possession of female-like gonadal tissue and reproductive ductsIncreased levels of female-specific protein vitellogenin (VTG)Reduced sperm densityEvidence of sexual disruption includes:

  • Impacts on Freshwater BiologyRodgers-Gray et al. 2001Exposure of juvenile wild roach to sewage treatment water effluent (STWE) of various dilutions resulted in dose-dependent and sustained feminization of reproductive ducts in malesPossession of both male and female germ cellsMales in possession of female-like gonadal tissue and reproductive ductsIncreased levels of female-specific protein vitellogenin (VTG)Reduced sperm densityEvidence of sexual disruption includes: Many EDCs bioconcentration in higher trophic level organisms such as fish, allowing for exposure even when aqueous concentrations are very low

  • Impacts on Freshwater BiotaAqueous concentration Partition (i.e. does it prefer to sorb into sediments or does it remain in the aqueous phase?)Degree of bioconcentrationEstrogenic activity Degradation pathwaysThe impact of individual EDCs is primarily a function of the compounds chemical properties and the extent of its use in human activityFactors To Consider:Possible treatment options will also depend on chemical properties

  • Factors Effecting EDCs Biological ImpactComparison of Common EDCs:

    EDCSorptionDegradationBio-concentrationEstrogenic ActivityPossible Treatment OptionsAPEsModerateBio-aerobic & anaerobicModerateHighSorption, oxidation, reductionBPAModerateBio-aerobic & Photo ModerateHighBiodeg. Photodeg.EE2StrongBio-aerobicStrongVery HighSorption, OxidationOCPsModerateBio & Photo are minimalVery StrongLow to ModerateSorption, Photodeg. OxidationPhthaltesWeakBio-aerobicWeakModerateBiodeg., OxidationPAHsStrongBio-aerobic & PhotoHighly VariableModerate to HighSorption, OxidationPCBsStrongBio & Photo are minimalStrongModerate to HighSorption, Photodeg. OxidationTriclosanModeratePhoto, Bio is disputedDioxin biproducts strongly bioconcentrateModerate (for Dioxins + Furans)Sorption, Oxidation, Possibly Reduction

  • EDCs in the Santa Ana RiverIssue: To what extent to EDCs in the SAR impact the reproductive ability of the Santa Ana SuckerGross et al., 2004:Measured concentrations of OWCs including APEs and EE2 in effluent of four WWTPs and in river water along the SAR.APE metabolites detected in all effluents/at all locations-max concentrations of 19.6 parts per billion (mg/L) in effluent upstream of Prado DamEE2 not detected in river or effluent water at detection limit of 2 parts per trillion (ng/L)Significant downstream attenuation of compounds observedRecent studies from the SAR basin provide insight into this issue:

  • EDCs in the Santa Ana RiverIssue: To what extent to EDCs in the SAR impact the reproductive ability of the Santa Ana SuckerJenkins et al., 2009:Detected OWCs, including EDCs, in aquatic biota and water in the SAR basin along a gradient of proximity to WWTP effluent (including one control site).Conducted in vitro assays of sexual parameters of western mosquitofish (proxy for santa ana sucker)Results indicate endocrine disruption in the form of altered hormone ratios in both sexes and secondary sex characteristics in malesRecent studies from the SAR basin provide insight into this issue:

  • SummaryEDCs are exogenous compounds that encompass a variety of chemical classes and derive from numerous areas of human activityMimic hormones, in particular estrogen, and bind to endocrine receptors thereby interfering with normal endocrine functionTreated effluent is an important conduit of EDCs to the environmentFate, transport and biological impact is a function of chemical properties and extent of human useLarge body of evidence that exposure to EDCs causes endocrine disruption in riverine fish, including mosquito fish in the Santa Ana RiverOn-going research further investigates link between EDCs and reproductive impairment in aquatic biota

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