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Hormones and Society: Endocrine disruptors What are they? Exogenous substances that act as hormones In the endocrine system Some studies have shown that endocrine disruptors disrupt normal hormonal cycles in humans. Concern emerges from increased sighting of weird defects in animals.
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Hormones and Society: Endocrine disruptors What are they?Exogenous substances that act as hormones In the endocrine system Some studies have shown that endocrine disruptors disrupt normal hormonal cycles in humans
Concern emerges from increased sighting of weird defects in animals What is causing them?
Ratios of estrogen/testosterone in male and female Alligators in Florida lakes
Sexual development in juvenile male alligators & Estrogen/testosterone ratio
Higher rate of allergies What is causing them?
Allergies more prevalent in industrialized nations New diet treatments include peanut butter
Term was coined in 1991 at a conference in Wisconsin Theo Colburn argued that environmental chemicals disrupt development of the endocrine system Effects of exposure during development are permanent. A variety of substances: -Hormones -Plant constituents -Pesticides -Compounds used in the plastics industry -Other industrial by-products
Health effects: Reproductive problems: -Reduced fertility -Male & female reproductive tract abnormalities -Skewed male/female sex ratios -Loss of fetus -Menstrual problems Changes in hormone levels -Early puberty -Brain and behavior problems -Impaired immune functions -Cancers
Some examples and controversies Bisphenol A An organic compound (CH3)2C(C6H4OH)2 A key monomer used in production of plastic and epoxy Also used as an antioxidant in plasticizers and in PVC pipes Estradiol-very similar
Some lab data Dose (µg/kg/day) Effects (lab animals) Study year 0.025 Changes to genital tract 2005 0.025 Changes in breast tissue 2005 2.00 30% increase in prostate 1997 2.40 Signs of early puberty 2002 2.40 Decline in testosterone 2004
Bisphenol A affects insulin levels - Diabetes A major health problem
Problem: Plastics are all around us…and we often wash them Example: Baby bottles A movement back towards glass??
In theory, water put back is clean (Don’t bother trying To recreate drawing)
Agricultural runoff a source of contamination
Contamination can occur from sewage systems
Streams and endocrine disruptors Upstream from wastewater plant: 18 females, 14 males, no intersex fish Downstream: 49 females, 5 males, 4 intersex fish Upstream from plant: 4 females, 2 males, no intersex fish Downstream: 16 females, no males, 4 intersex fish
Experiments in wastewater: 7 days exposure: Males began producing a sex hormone 14 days: Males began to lose their sex organs 28 days: Male testes diminished; lose sperm production
Hormones can affect sex in mature animals Ex. Dog had tumor that produced Estrogen – converted male dog into Part female
Problem not restricted to Colorado rivers Largemouth bass % male fish that are intersex Virginia South Fork Shenandoah river 80% North Fork Shenandoah river 100% Maryland Momocacy & Conocheague creeks 80-100%
More problems in Colorado: 2003: The city of Boulder and USGS found small concentrations of Tylenol and nicotine in creeks near Bolder Mostly downstream from wastewater plant Other studies: David Norris: integrative physiologist discovered that fish just below the plant were changing sex Potential culprits: birth-control and epilepsy medication
Trace amounts of pharmaceuticals may be seeping into water Side effects in animal populations: Fish -Lower sperm counts -Damaged sperm -Males becoming “feminized” -Females producing male genital organs Other animals: Kidney failure in vultures, impaired reproduction In mussels, inhibited growth in algae
What IS polluted? Looks pristine to me….