1. Pesticides, PCB’s, Organic Molecules
Moleculer Substances
Pesticides, PCB’s, Organic Molecules

2. Organic Molecules Carbon-based (chemical basis for life) Fats Sugars
Proteins
Nucleic Acids
*many things that we use every day are made of organic
molecules
clothes, soap, toothpaste, plastic, food, gasoline,
medicine, pesticides

3. Pesticides insects, weeds, birds, mammals, fish, and others
Organic compounds used to control pests including
insects, weeds, birds, mammals, fish, and others
Harmful to humans
Been used since 2500 BC to protect crops
Now must be controlled and regulated by the EPA
over 98% of sprayed insecticides and 95% of
herbicides don’t reach their targets,
contaminating the land and water

4. PCB’s (polychlorinated biphenyl)
Used as cooling and insulating fluids for industrial
transformers and capacitors (electrical), paints, cement,
adhesives
VERY TOXIC! – banned in 1973 for “open” use
can cause liver damage, skin rashes, cancer, and
death
can still be used in capacitors
and insulating fluids

5. Gases (like solids) can dissolve!
Dissolved Gases
Gases (like solids) can dissolve!

6. The solubility of solids increase with an increase in temperature

7. Solubility of Gases and Temperature
The solubility of gas decrease with an increase in temperature

8. Solubility of Gases and Pressure
The solubility of gases increase with an increase in pressure

9. Gases are FAR less soluble than solids!
Solubility of Gases
Gases are FAR less soluble than solids!
EX: 20oC = 30 g
20oC = g

10. Effect of Dissolved gases on Fish Life
Not enough………..
* Fish breathe and need O2*
- if the water is too warm
or other organic life
competing for O2, fish can suffocate 

11. Effect of Dissolved gases on Fish Life
Too much (Supersaturated levels of O2 or N2)………..
Caused by colder water and turbulence (rapids,
dams with a lot of release water)
Results in gas-bubble trauma where
the bubbles block the flow of blood