The ABC's of EDCs: Endocrine Disrupting Chemicals in the Environment

Transcription

1 The ABC's of EDCs: Endocrine Disrupting Chemicals in the Environment David Quanrud Water Resources Research Center 2007 Water Conference Phoenix, Arizona June 5, 2007

2 What is an endocrine disrupting compound? An endocrine disruptor is an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny. From: Global Assessment of the State-of-the-Science of Endocrine Disruptors. International Programme on Chemical Safety, World Health Organization (2002).

3 Documented effects of EDCs in wildlife Adverse effects on fish development and reproduction Eggshell thinning in birds of prey Alligator population decline in a polluted lake (FL) Development of male sex organs in female marine animals such as whelks and snails

4 EDCs in the News Denver Post (September 6, 2006)

5 EDC effects at the population scale Field study at Canadian research lake, Ontario Fathead minnow population collapsed after two years of estrogen addition Kidd et al. 2007: Proceedings of the National Academy of Sciences

6 Speculated effects of EDCs in humans Reductions in male fertility and declines in the numbers of males born Abnormalities in male reproductive organs Female reproductive diseases including fertility problems, early puberty, and early reproductive senescence Increases in mammary, ovarian, and prostate cancers

7 How do endocrine disrupting compounds act? reduce hormone production in endocrine glands mimic or counteract hormones at target tissues

8 The USEPA has identified three important categories of EDCs Estrogenic Androgenic Thyroid active

9 Examples of known EDCs in wastewater Natural hormones (estrogens) Estradiol Estrone Estriol Synthetic compounds Ethinyl estradiol (birth control pill) Alkylphenols, e.g. nonylphenol (surfactant byproduct) Bisphenol A (polycarbonate plastic) PBDEs (flame retardant; partially phased out)

10 EDCs in the News AZ Daily Star (March 18, 2007) Bisphenol A Ingredient in polycarbonate plastic, epoxy resin Water bottles, CDs, epoxy lining in metal cans Controversial: some studies find low dose estrogenic effects, other studies do not

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12 Question: How can we measure estrogenic compounds in environmental samples? Individual chemical measurements Collective measurement using bioassays Total estrogenic activity

13 Yeast estrogen screen (YES) bioassay E R R E R E lacz CPRG yellow CPRG red Cytoplasm her β-gal Cytoplasm E =Estrogens 17-α Ethinylestradiol R = Receptor EC 50 =1.1 x M A570 nm - A630 nm E-13 1.E-12 1.E-11 1.E-10 1.E-09 1.E-08 1.E-07 1.E-06 Molar concentration in well

14 Estrogenic Activity: Comparison of six Arizona WWTPs Oxidation ditch Membrane bioreactor Nitrification/denitrification Activated (pure O 2 ) Influent Effluent Biotower #1 Biotower #2 (longer SRT)

15 Preliminary Comparison of six Arizona WWTPs Influent to effluent estrogenic activity removal (%) Overall estrogenic activity removal (%) Influent Effluent Raw Influent Oxidation Ditch 2 Clarifier Raw Influent Chlori- Final Effluent to nation Storage Pond Denitrifi- 1 Clarifier cation Aeration 2 Clarifier Bar Screen (RAS) Drying Beds 2 (WAS) Holding Tanks Bar Screen Grit Chamber 1 Clarifier RAS Final Filter/UV 2 (WAS) Final Effluent Final Oxidation ditch Membrane bioreactor Nitrification/denitrification Raw Influent 1 Clarifier Activated 2 Clarifier RAS Final Effluent Raw Influent Trickling Filters 2 Clarifier 1 Clarifier Final Effluent Raw Influent 1 Clarifier Biotowers 2 Clar 3 Filters Bar Screen Grit Chamber 1 Thickener Effluent 2 (WAS) Thickener #3 Thickener #2 Digester Supernatant Bar Screen 1 Thickener Effluent 2 (WAS) Thickener #3 Thickener #2 Digester Supernatant Bar Screen Grit Chamber WAS RAS 3 Filter Backwash 1 Clarifier Anaerobic Digester Chlor/ Dechlor Final Effluent Anaerobic Digested Activated sludge Anaerobic Digested Biotower # Digested to Storage Basins Biotower #

16 Summary 1.EDCs include estrogens, androgens, and thyroid active compounds 2.Removal of estrogenic activity during wastewater treatment is dependent on process selection/efficiency 3.There is a lot we don t know about a lot of trace organics in wastewater