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

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

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

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

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

The solubility of solids increase with an increase in temperature

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

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

Gases are FAR less soluble than solids! Solubility of Gases Gases are FAR less soluble than solids! EX: KNO3 @ 20oC = 30 g O2 @ 20oC = 0.009 g

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 

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