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Endocrine Disrupting Compounds: General Overview and Impact on Freshwater Biology SCAP Water Issues Committee Meeting May 5, 2011 Photo by Judy Gibson.

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Presentation on theme: "Endocrine Disrupting Compounds: General Overview and Impact on Freshwater Biology SCAP Water Issues Committee Meeting May 5, 2011 Photo by Judy Gibson."— Presentation transcript:

1 Endocrine Disrupting Compounds: General Overview and Impact on Freshwater Biology SCAP Water Issues Committee Meeting May 5, 2011 Photo by Judy Gibson From: Jenkins et al., 2009 P

2 The Endocrine System All vertebrates possess an endocrine system which consists of -Glands: Secrete hormones -Receptors: Detect and react to hormones

3 The Endocrine System All vertebrates possess an endocrine system which consists of -Glands: Secrete hormones -Receptors: Detect and react to hormones The endocrine system is responsible for biochemical signals that insure proper function of the body throughout the life cycle.

4 The Endocrine System All vertebrates possess an endocrine system which consists of -Glands: Secrete hormones -Receptors: Detect and react to hormones The 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 Nonylphenol Degradation product of nonionic surfactants (detergents) 17  -Estradiol Natural hormone

5 Endocrine Disrupting Compounds Exogenous Compounds-compounds (molecules) that originate outside of living organisms Encompass a variety of chemical classes including pesticides, pharmaceuticals, plastisizers, flame retardents, hormones, cleaning products, personal care products Many 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 estrogen Estrogen receptors are essentially the same among most vertebrates

6 EDCs Widespread in the Environment EDCCommon Use Alkylphenol ethoxylates (APEs) and their degradation products Industrial and household nonionic surfactants (detergents) Bisphenol-A (BPA)Most widely used plasticizer (softener) in the US 17  -ethynyl estradiol (EE2) Synthetic estrogen used in most birth control and hormone replacement drugs Organochloride pesticides (OCPs) Pesticides, herbicides and fungicides used by industry and household consumers (ex: DDT)-banned since PhthalatesUbiquitous component of leachable plastics Polyaromatic hydrocarbons (PAHs) Nonvolatile hydrocarbons present in oils and petroleum-based lubricants Polychlorinated biphenyls (PCBs) Oils used primarily in transformers (ex: Aroclor)-banned since 1976 Triclosan and degradation products Common ingredient of soaps and personal/household disinfectants

7 EDC Release to Freshwater Systems Discharge from wastewater treatment plants (WWTPs)  APEs, Hormones (e.g. EE2), Triclosan, BPA, Pharmaceuticals Agricultural wastewater discharges  Hormones Urban and agricultural runoff  PAHs, OCPs Industrial discharges  APEs, BPA, Phthalates Primary release mechanisms:

8 Impacts on Freshwater Biology Observations led to years of research to determine cause of abnormalities Abnormally high incidence of intersex fish observed downstream from WWTPs in late 1970s Field studies: Confirmed correlation between proximity to treated effluent and sexual disruption Measured concentrations of EDCs in rivers and treated wastewater effluent- detected at parts per billion (  g/L) to parts per trillion (ng/L) Laboratory studies: Examined estrogenic effects of individual EDCs on fish and other biota Determined potency (i.e. estrogenic activity) of individual EDCs (e.g. EE2 found to cause feminization at 1.2 ng/L)

9 Impacts on Freshwater Biology Rodgers-Gray et al −Possession of both male and female germ cells −Males in possession of “female-like” gonadal tissue and reproductive ducts −Increased levels of female-specific protein vitellogenin (VTG) −Reduced sperm density Evidence of sexual disruption includes:

10 Impacts on Freshwater Biology Rodgers-Gray et al Exposure of juvenile wild roach to sewage treatment water effluent (STWE) of various dilutions resulted in dose-dependent and sustained feminization of reproductive ducts in males −Possession of both male and female germ cells −Males in possession of “female-like” gonadal tissue and reproductive ducts −Increased levels of female-specific protein vitellogenin (VTG) −Reduced sperm density Evidence 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

11 Impacts on Freshwater Biota Aqueous concentration Partition (i.e. does it prefer to sorb into sediments or does it remain in the aqueous phase?) Degree of bioconcentration Estrogenic activity Degradation pathways The impact of individual EDCs is primarily a function of the compound’s chemical properties and the extent of its use in human activity Factors To Consider: Bisphenol-A DDT Possible treatment options will also depend on chemical properties

12 Factors Effecting EDCs’ Biological Impact Comparison of Common EDCs: EDCSorptionDegradationBio-concentration Estrogenic Activity Possible Treatment Options APEsModerateBio-aerobic & anaerobic ModerateHighSorption, oxidation, reduction BPAModerateBio-aerobic & Photo ModerateHighBiodeg. Photodeg. EE2StrongBio-aerobicStrongVery HighSorption, Oxidation OCPsModerateBio & Photo are minimal Very StrongLow to ModerateSorption, Photodeg. Oxidation PhthaltesWeakBio-aerobicWeakModerateBiodeg., Oxidation PAHsStrongBio-aerobic & Photo Highly VariableModerate to HighSorption, Oxidation PCBsStrongBio & Photo are minimal StrongModerate to HighSorption, Photodeg. Oxidation TriclosanModeratePhoto, Bio is disputed Dioxin biproducts strongly bioconcentrate Moderate (for Dioxins + Furans) Sorption, Oxidation, Possibly Reduction

13 EDCs in the Santa Ana River Issue: To what extent to EDCs in the SAR impact the reproductive ability of the Santa Ana Sucker Gross 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 (  g/L) in effluent upstream of Prado Dam EE2 not detected in river or effluent water at detection limit of 2 parts per trillion (ng/L) Significant downstream attenuation of compounds observed Recent studies from the SAR basin provide insight into this issue:

14 EDCs in the Santa Ana River Issue: To what extent to EDCs in the SAR impact the reproductive ability of the Santa Ana Sucker Jenkins 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 males Recent studies from the SAR basin provide insight into this issue:

15 Summary EDCs are exogenous compounds that encompass a variety of chemical classes and derive from numerous areas of human activity Mimic hormones, in particular estrogen, and bind to endocrine receptors thereby interfering with normal endocrine function Treated effluent is an important conduit of EDCs to the environment Fate, transport and biological impact is a function of chemical properties and extent of human use Large body of evidence that exposure to EDCs causes endocrine disruption in riverine fish, including mosquito fish in the Santa Ana River On-going research further investigates link between EDCs and reproductive impairment in aquatic biota


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