Items (plastic) removed from the gullet of a fledgling Laysan albatrosshttp://gadgets.boingboing.net/2007/08/31/plastic-litters-our.html

Today: Toxins in the Environment...

Tours this week

“Toxic Garbage Island” movieW 4/21 at 5pm in JES A121A(hmwk #8)

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 hatching2005- 3 of 9 fertile eggs2006- 5 of 82007- 7 of 9

http://www.iws.org/bald_eagles/Incubation%20Facility.html

http://www.nytimes.com/2008/11/25/science/25eagl.html

Bald eagles in New York have been found with elevated mercury levels.

We add thousands of chemicals to the environment each year...

BPA

estrogen

BPA is an estrogen mimic; it binds to estrogen receptors.

BPAU.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

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 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

Elevated BPA found in people with heart problems 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?

Items (plastic) removed from the gullet of a fledgling Laysan albatrosshttp://gadgets.boingboing.net/2007/08/31/plastic-litters-our.html

Next: Human Overpopulation

Tours this week

“Toxic Garbage Island” movieW 4/21 at 5pm in JES A121A(hmwk #8)