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Today: Toxins in the Environment... Tours this week “Toxic Garbage Island” movie W 4/21 at 5pm in JES A121A (hmwk #8) Items (plastic) removed from the gullet of a fledgling Laysan albatross http://gadgets.boingboing.net/2007/08/3 1/plastic-litters-our.html http://www.youtube.com/watch?v=Se12y9hSOM0 Published in 1962 Resources move from producer to consumers, and so do toxins. Bald eagle populations decreased because of DDT and other toxins. The accumulation of toxins in the eagle causes “fragile egg syndrome” In the late 1700's there were an estimated 100,000 bald eagles in the continental U.S. By 1963 there were 417 nesting pairs. 1967-73 bald eagle listed as endangered 1972 DDT use banned in the U.S. 2007 bald eagle delisted http://www.fws.gov/midwest/eagle/population/chtofprs.html Even though the bald eagle is no longer listed as endangered, there are still problems... On Catalina Island, CA only about 18% of bald eagle eggs have hatched over the past 15 years, largely because of DDT contamination in the eggs. http://www.iws.org/bald_eagles/Incubation%20Facility.html Catalina Island egg hatching 2005- 3 of 9 fertile eggs 2006- 5 of 8 2007- 7 of 9 http://www.iws.org/bald_eagles/Incubation%20Facility.html Bald eagles in New York have been found with elevated mercury levels. http://www.nytimes.com/ 2008/11/25/science/25e agl.html We add thousands of chemicals to the environment each year... BPA estrogen BPA is an estrogen mimic; it binds to estrogen receptors. BPA U.S. produces more than 2.3 billion pounds per year Linked to health problems in animals and humans There is significant debate about whether it is safe, and at what concentration it can have detrimental affects BPA is released from some plastics (polycarbonate), but not from others (HDPE) X Bisphenol A is released from polycarbonate drinking bottles and mimics the neurotoxic actions of estrogen in developing cerebellar neurons. Toxicology Letters. Volume 176, Issue 2, 30 January 2008, Pages 149-156 Bisphenol A is released from polycarbonate drinking bottles and mimics the neurotoxic actions of estrogen in developing cerebellar neurons. Toxicology Letters. Volume 176, Issue 2, 30 January 2008, Pages 149-156 BPA mimics the effects of estrogen Bisphenol A is released from polycarbonate drinking bottles and mimics the neurotoxic actions of estrogen in developing cerebellar neurons. Toxicology Letters. Volume 176, Issue 2, 30 January 2008, Pages 149-156 Elevated BPA found in people with heart problem s and diabetes Association of Urinary Bisphenol A Concentration With Medical Disorders and Laboratory Abnormalities in Adults. Iain A. Lang, PhD; Tamara S. Galloway, PhD; Alan Scarlett, PhD; William E. Henley, PhD; Michael Depledge, PhD, DSc; Robert B. Wallace, MD; David Melzer, MB, PhD. JAMA. 2008;300(11):1303-1310. BPA has been found in over 90% of urine samples in people around the world. What criteria should be used to determine the safety of a chemical? What should the balance be between convenience, economy, and safety? How should conflicting or controversial data be interpreted? Who should make these decisions? Next: Human Overpopulation Tours this week “Toxic Garbage Island” movie W 4/21 at 5pm in JES A121A (hmwk #8) Items (plastic) removed from the gullet of a fledgling Laysan albatross http://gadgets.boingboing.net/2007/08/3 1/plastic-litters-our.html