When we try to pick out anything by itself, we find it hitched to everything else in the universe. John Muir

Homework – Share out

1 – 2 minutes per team member 1. Identify the situation 2. Describe the graph 3. Explain your conclusion

Biomagnification

www.lab-initio.com

DDT and Bioaccumulation(absorbed or stored in organs) and Biomagnification (through a food chain)

Fig. 11-4p. 231

Biomagnification

Definition:Biomagnification, is the

increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain

The Problem:

Peregrine Falcons

Extirpatedfrom much of

U.S.

http://www.iowaccess.org/main/news/newsimages/peregrine.jpg

Osprey andBald Eagles were declining,as well.

http://www.state.tn.us/twra/graphics/OSPREY.jpg

http://www.state.tn.us/twra/graphics/BLDEAGLE.jpg

Meanwhile, in Borneo: Roofs began to fall Gecko-eating cats

began to die, and thriving rats

brought plague and typhus

The World Health Organization began to parachute cats into Borneo, but what was causing these problems?

http://www.herpafauna.com/pics/geckos/a-felinus.jpg

The problem magnifies:

MethylMercury concentrates just like DDT and damages human Nervous Systems

A person who eats one meal of lake trout from Lake Michigan will be exposed to more

PCBs in one meal than in a lifetime of drinking water from the lake!

Mercury Health Effects

Case Study: PCBs

PCBs, or polychlorinated biphenyls, are a group of man-made chemicals.

Introduced in 1929 and widely used in electrical transformers, cosmetics, varnishes, inks, carbonless copy paper, pesticides and for general weatherproofing and fire-resistant coatings to wood and plastic.

The federal government banned the production of PCBs in 1976

PCBs can effect the immune system, fertility, child development and possibly increase the risk of certain cancers

The Problem is ongoing:

PCBs (polychlorinated biphenyls) PAHs (polynuclear aromatic hydrocarbons) Heavy metals:

mercury copper cadmium chromium lead nickel zinc tin

TBT (tributyltin) mercury from gold mining cyanide selenium

The number of new molecules we introduce into our environment continues to increase.

The Ultimate Solution?

Models are being developed to predict toxicity of new chemicals

Pollution control must be intensified:Zero Tolerance in the Great Lakes?

Education: Increase awareness soeveryone will decrease use and dispose of chemicals properly.

Biomagnification Through the Food Chain

Horton, in Dr. Seuss’s Horton Hears a Who

“We’ve GOT to make noise in greater amounts! So, open your mouth, lad! For every voice counts!”