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IMPACTS OF ENDOCRINE DISRUPTER CHEMICALS ON AQUATIC ORGANISMS AND HUMAN HEALTH

IMPACTS OF ENDOCRINE DISRUPTER CHEMICALS ON AQUATIC ORGANISMS AND HUMAN HEALTH. Dr. Fran Solomon fsolomon@interchange.ubc.ca February 3, 2009. TOPICS TO BE COVERED. What are endocrine disrupter chemicals (EDCs) and how do they act? Properties and sources of EDCs Exposure pathways

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IMPACTS OF ENDOCRINE DISRUPTER CHEMICALS ON AQUATIC ORGANISMS AND HUMAN HEALTH

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  1. IMPACTS OF ENDOCRINE DISRUPTER CHEMICALS ON AQUATIC ORGANISMS AND HUMAN HEALTH Dr. Fran Solomon fsolomon@interchange.ubc.ca February 3, 2009

  2. TOPICS TO BE COVERED • What are endocrine disrupter chemicals (EDCs) and how do they act? • Properties and sources of EDCs • Exposure pathways • Impacts of specific groups and mixtures of EDCs • How to reduce exposure

  3. TOXIC CHEMICALS • Chemicals that have negative impacts on an organism’s survival, activity, growth, metabolism or reproduction • Include over 200,000 human-made organic chemicals (contain carbon) • EDCs are recent chemicals of concern.

  4. ENDOCRINE DISRUPTION • Endocrine disrupter chemical (EDC) is “any chemical with the potential to alter hormonally mediated signals in plants or animals.” • Hormone receptor – site on surface or interior of a cell that is activated or triggered by a hormone.

  5. EDC H H H EDC ENDOCRINE DISRUPTION • Hormones bind to cell receptors and induce a response • EDCs bind to receptors and • MIMIC a hormone • BLOCK hormone binding • INTERFERE with hormone synthesis, transport or degradation

  6. KNOWN OR SUSPECTED EDCS • Pesticides • Polychlorinated biphenyls (PCBs) • Polybrominated diphenyl ethers (PBDEs) • Bisphenol-A (BPA) • Phthalates

  7. PROPERTIES OF EDCs • Resistant to degradation • Can be transported long distances. • Lipophilic – fat soluble, therefore rapid absorption through cell membranes and accumulation in fatty tissues • Bioconcentration • Biomagnification

  8. BIOMAGNIFICATION

  9. SOURCES OF EDCs • Sewage • Urban stormwater runoff • Agricultural stormwater runoff • Industrial waste • Atmospheric deposition • Oil spills • Household products

  10. TOXIC CHEMICAL EXPOSURE PATHWAYS IN FISH • Gills – diffusion across membranes into bloodstream • Skin – diffusion into bloodstream • Drinking polluted water • Ingestion of sediments • Food chain

  11. FISH GILLS(www.sci.sdsu.edu; www.diatribune.com/marine-life-series)

  12. TOXIC CHEMICAL EXPOSURE PATHWAYS IN HUMANS • Lungs – inhaled particulates • Skin • Drinking contaminated water • Food chain

  13. TOXICITY ANDAGE/BODY SIZE Developmental and young life stages of all species are especially sensitive to EDCs. • Larger surface area/volume ratio → faster EDC uptake per unit weight • Higher breathing, metabolic, and growth rates → faster and more uptake of EDCs • Young animals and humans are not able to detoxify EDCs as well as adults.

  14. PESTICIDES Synthetic chemical compounds used to destroy or control pest organisms 5 billion tons applied annually worldwide 30-fold increase in pesticide use in U.S. since 1945 Found in surface waterbodies and groundwater, including drinking water wells.

  15. CHLORINATED HYDROCARBONS Examples – DDT, DDE, dieldrin, aldrin, methoxychlor, heptachlor Resistant to degradation Persistent in soil, sediments, and fatty tissues of organisms Strong biomagnification – DDT levels in birds are 50 times higher than in small fish and 625 times higher than in small insects.

  16. “SILENT SPRING” (1962) Bald eagles and brown pelicans almost completely disappeared from eastern U.S. in 1960s due to excess DDT use. Zoologist Rachel Carson warned that pesticides were contaminating natural environment and accumulating in our bodies. Book linked pesticides to thinning of bird egg shells and predicted “silent spring” (no birds) if trend continued.

  17. ATRAZINE Used for control of broad-leaved annual and perennial weeds in corn Very mobile and moderately persistent in soil Heavy rain can wash atrazine into nearby waterbodies. Found in drinking water wells in U.S. farming areas in spring and summer

  18. ATRAZINE AND FROGS– 1990s Exposure of leopard frog larvae and tadpoles to an environmentally realistic concentration of atrazine (0.1 part per billion - ppb) resulted in retarded gonad development and hermaphroditism. Male frogs had undeveloped testes and no or low numbers of sperm-producing cells. 29% had oocytes in testes or produced vitellogenin, an egg yolk protein that is normally produced only by female frogs.

  19. ATRAZINE AND FROGS – 1990s Same effects observed in frogs collected from atrazine-contaminated areas in U.S. Testicular oocytes were detected in male frogs from 7 of the 8 field sites. Atrazine contamination of waterbodies coincides with amphibian breeding season (early spring). Lab and field data suggest contribution of atrazine to declining amphibian populations.

  20. PCB USES AND PROPERTIES Used for heat transfer in electrical circuitry and electronic equipment due to their insulating properties and nonflammability Increased PCB production in 1960s Banned in U.S. in 1970s, but persist in soil, sediments, and fatty tissues Personal medical testing

  21. PCBs AND BRAIN DEVELOPMENT IN CHILDREN - 1980s Impaired intellectual development in children born to women who had eaten two or three Great Lakes fish meals monthly in the six years BEFORE pregnancy Children had losses in motor coordination, short-term memory, verbal skills and overall intelligence.

  22. PCBs AND BRAIN DEVELOPMENT IN CHILDREN - 1980s Correlation between severity of intellectual impairment in child and PCB levels in mother’s blood and milk at time of child’s birth PCBs impair normal thyroid function which has an important role in brain development. 。

  23. PBDEs ANNUAL WORLDWIDE USE: 150 million metric tons Furniture foams, carpet padding Plastic in electronics Computer and TV casings, kitchen appliances Upholstery / textiles Products can contain up to 30% PBDE by weight Used toreduce the ignition and spread of fire PBDEs SAVE LIVES

  24. PBDEs IN HUMAN BREAST MILK: Sweden 1972-1997 6 5 ppb lipid, Total PDBEs 4 3 2 1 0 (Norén and Meironyté 2000)

  25. PBDEs IN HUMAN BREAST MILK: Sweden vs. North America North America Sweden

  26. PBDE TOXICITY Closely related to PCB toxicity Animal studies: PBDEs disrupt thyroid hormones, therefore harming fetal brain development and impairing memory and learning. Developing fetuses, infants, and young children are most at risk.

  27. BPA USES ANDPROPERTIES Hard plastic in water bottles and baby bottles, lining of metal-based cans Migrates from containers to contents. Crosses placenta and is found in human breast milk. Chronic, low level exposure of almost all people in developed countries Binds to estrogen receptors and mimics estrogen.

  28. EDC EFFECTS OF BPA Reduced sperm counts, testicle size, and fertility in male mice exposed prenatally and as adults to low doses of BPA are believed to be applicable to humans. Evidence for BPA contribution to human breast cancer Correlation between BPA urinary levels in adults and incidence of diabetes

  29. PHTHALATES - PROPERTIES Used as fragrances and plasticizers, but not chemically bound to plastics Dispersed via food, air, water, soil Continuous exposure of aquatic organisms and humans, especially children Found in children’s toys, as high as 28% – 47% by weight

  30. PHTHALATES AND AQUATIC ORGANISMS Discharged in sewage and stormwater Exposure via water, sediments, food chain Impaired reproduction in mussels and sand fleas in Thea Foss Waterway in Tacoma, Washington Can have ripple effects on ecosystem.

  31. PHTHALATES AND HUMAN HEALTH Block testosterone production. Abnormal reproductive system development in male fetuses Correlation between exposure of baby boys to phthalates in breast milk and decreased testosterone production Correlation between reduced sperm quality and high urinary levels of phthalates in adult men

  32. VITELLOGENIN AND MALEFISH Male fish exposed to chemicals that act like estrogens produce vitellogenin (vtg). Puget Sound Assessment and Monitoring Program, spring of 1997-2001, surveyed adult English sole at 16 sites for exposure to EDCs, using blood plasma vtg as indicator.

  33. VITELLOGENIN AND MALE FISH Vtg found in male fish at 12 sites Highest levels in Commencement and Elliott Bays: 1900 - 5900 ppb 11.8% - 47% of male fish affected at sites in these bays

  34. EDCs AND BREAST CANCER Incidence of breast cancer has tripled in industrialized countries since 1960. Currently 1 in 8 women in U.S. Genetic predisposition accounts for <10% of breast cancer cases. ~50% of breast cancer cases are in women with no known risk factors.

  35. EDCs AND BREAST CANCER Chronic exposure to EDCs that mimic estrogen may be a contributing factor. Significant body of experimental, epidemiologic, and ecologic studies support this hypothesis. Women who move from countries with low breast cancer rates to developed countries soon acquire the higher risk of their new country.

  36. SUPPORTING EVIDENCE Atrazine causes mammary cancer in other mammals. Exposing pregnant mice to extremely low levels of BPA altered the development of the mammary gland in their female offspring at puberty. Phthalates significantly increase cell proliferation in human breast cancer tumors.

  37. SUPPORTING EVIDENCE Increased breast cancer risk among Long Island, New York women residing within one mile of hazardous waste sites containing pesticides Correlation between PCB levels in fatty tissue and risk of breast cancer recurrence in Long Island women Exposure to three pesticides was associated with increased risk of breast cancer in Latina agricultural workers in California.

  38. SUPPORTING EVIDENCE Exposure to EDCs (prenatal and in everyday products) may be contributing to earlier puberty in girls. Earlier puberty is risk factor for breast cancer.

  39. EDCs AND MALE REPRODUCTIVE HEALTH Incidence of testicular cancer has doubled in past 50 years. Data from 15,000 men and 60 countries show 42% decrease in average sperm count and 18% decrease in average semen volume from 1940 to 1990. Especially true in urban areas

  40. SUMMARY OF EDC FINDINGS Many synthetic chemicals released into the environment can disrupt endocrine systems of fish, wildlife, and humans. EDCs have more severe effects on embryos or newborn organisms than on adults. One EDC or a mixture of EDCs may impair functioning of reproductive system, thyroid gland, and pancreas. EDCs are a major long-term threat to biodiversity and sustainability.

  41. BPA RESTRICTIONS Canada is first country to declare BPA is toxic (April 18, 2008) and to ban BPA in baby bottles (October 18, 2008). Most major retailers have also removed food-related BPA products from their stores. Proposed Washington State ban on BPA in food or drink containers for children age 3 or younger (Safe Baby Bottle Act of 2009) would begin on July 1, 2010.

  42. PHTHALATE RESTRICTIONS • Washington State Children’s Safe Products Act of 2008 prohibited sale of toys and other children’s products with phthalates >100 ppb. Took effect this year. • www.HealthyToys.org

  43. DECREASING EXPOSURE TO EDCs – INDIVIDUAL ACTIONS Heed government agency advisories about fish consumption. Avoid animal fat as much as possible. Avoid or decrease use of pesticides. Eat organically grown produce. Minimize contact between food and plastics. Do not give plastic toys to babies.

  44. DECREASING EXPOSURE TO EDCs – INDIVIDUAL ACTIONS • Ask your state legislators to vote for BPA ban. • Attend Toxic-Free Legacy Coalition lobbying day in Olympia – March 5 • Get involved in environmental nonprofit organizations that address EDC issues. • Sign petition to President Obama (see Breast Cancer Fund website).

  45. FOR FURTHER INFORMATION • Breast Cancer Fund (www.breastcancerfund.org) • Institute for Children’s Environmental Health (www.iceh.org) • Puget Soundkeeper Alliance (www.pugetsoundkeeper.org) • Silent Spring Institute (www.silentspring.org) • Toxic-Free Legacy Coalition (www.toxicfreelegacy.org) • Washington Toxics Coalition (www.watoxics.org)

  46. FOR FURTHER INFORMATION • Colburn, Theo, Dianne Dumanoski, and John Peterson Myers (1997), Our Stolen Future, Penguin Books, New York, N.Y. • two-credit course at Evergreen Olympia Extension during spring quarter: Wednesdays, April 1 – June 3, 6:30 – 8:30 PM

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