Pollution – Air

• Particulates

• Acid-forming compounds

• Photochemical smog

• CO2

• CFCs

Pollution – Water and Land

• Nutrient oversupply

• Solid wastes

• Toxic chemicals

• Pesticides/herbicides

• Nuclear waste

Water Pollution Source

Pathogens Carried by Sewage

• Disease-causing agents• Safety measures

– Purification of public water supply– Sanitary collection/treatment of sewage– Sanitary practices when processing food

Testing Water for SewageFecal Coliform Test

Chemical Pollutants

• Inorganic chemicals

– Heavy metals, acids, road salts

• Organic chemicals

– Petroleum, pesticides, detergents

Upper Hudson River

• Over 200 miles of river polluted– Polychlorinated biphenyls (PCB’s)– Mercury– Chlordane– Dioxins– DDT– Cesium– Lead

• Longest Superfund Site

PCB’s in Hudson River

• General Electric Factories– 1944-1977

• 1.3 million pounds of PCB’s dumped into Hudson River

• EPA steps in…– Evidence– Dumping of PCB stopped– Hudson river declared a Superfund Site– 2002 – GE must dredge river and remove

PCB’s

Problem…

• To dredge or not to dredge… that is the question!– GE – leave it alone

• Low level of PCB’s not harmful

• Disrupting sediment will release large quantities of PCB’s

– EPA – dredge and remove• Low levels over time will cause health problems

• With proper care discharge will be minimal

More Problems…

• How much PCB exposure is safe?– 100 ppm increases cancer rates in rats– Guesstimate of 1 ppb considered safe

• When do you stop dredging?

• 90% of material can be removed easily

• Last 10% very difficult

Effect of Sediments on Stream Ecology

• Loss of hiding/resting places for small fish

• Attached aquatic organisms scoured from the rocks and sand

• Poor light penetration

Organic Wastes

• Dissolved oxygen (DO) in the water is depleted during decomposition of organic wastes.

• Water quality test– Biochemical oxygen demand (BOD):

measure of the amount of organic material.

Aquatic Plants

• Benthic plants– Emergent vegetation– Submerged aquatic vegetation (SAV)

• Floating Plants– Duck weed

• Phytoplankton– Green filamentous and single cell– Blue-green single cell– Diatoms single cell

Eutrophication

• As nutrients are added from pollution, an oligotrophic condition rapidly becomes eutrophic.

Natural and Cultural Eutrophication

• Natural eutrophication– aquatic succession– occurs over several hundreds of years

• Cultural eutrophication– driven by human activities– occurs rapidly

Controlling Point Sources

• Ban phosphate detergents– Suffolk county banned phosphate detergents in

1970 – we survived!!!

• Sewage-treatment improvements

Controlling Non-point Sources

• Runoff pollutants– Agricultural fields

– Deforested woodlands

– Overgrazed pastures

• Those damn ducks and geese!!!

Sometimes Solutions are Simple

Development of Sewage Collection and Treatment Systems

• Through the 1970s sewage was discharged directly into waterways

• Clean Water Act of 1972

Sewage Treatment – Methane Gas Production

• Biogas

• Fermentation byproduct

• Can be used as fuel to generate electricity

Atmospheric Structure

Formation of the Ozone Shield

UV light + O2 O + O

Free O + O2 O3

Free O + O3 O2 + O2

UV light + O3O + O2

Chlorofluorocarbons (CFCs)

• Organic molecules in which both chlorine and fluorine atoms replace some of the hydrogen atoms

• Sources:– refrigerators and air conditioners– production of plastic foam– cleaner for electronic parts– pressurizing agent in aerosol cans

Breakdown of Ozone Shield

CFCl3 + UV Cl + CFCl2

Cl + O3 ClO + O2

ClO + ClO 2 Cl + O2

Chlorine is a catalyst that destroys the production of ozone.

Montreal Protocol

• 1987 – scale back CFC production by 50% by 2000

• 1990 – amendment to completely phase out ozone-destroying chemicals by 2000

• 1992 – amendment to completely phase out ozone-destroying chemicals by 1996

pH Scale

• pH 1 2 3 4 5 6 7 8 9 10 11 12 13 14

• pH < 7 acidic

• pH 7 neutral

• pH < basic

pH

• Negative log of H+ concentration

• pH 1 = 10-1 grams/Liter = 0.1 grams/Liter

• As pH increases OH- (hydroxide ions) decreases

• pH 7 neutral = equal amount of H+ and OH- ions

Acidity of Precipitation

• Normal pH 5.6

• Anything less is acid rain

Acid Rain

Causes of Acid Rain

• Sulfur dioxide (SO2) + OH sulfuric acid (H2SO4)

• Nitrogen oxides (NOx)+ OH nitric acid (HNO3)

Hydroxide Radicals

• O3 + UV light O2 + O

• O + H2O 2OH

Sources

• Natural– Sulfur dioxide

• 50-70

– Nitrogen oxides• 30-40

• Anthropogenic– Sulfur dioxide

• 100-130

– Nitrogen oxides• 60-70

Anthropomorphic Sources of Acid Rain Pollution

Effects of Acid Rain

• Fresh Water– Decreased pH

• Die off of higher organisms

• Low reproductive rate in higher organism

• Example: Adirondacks– ~200 lakes are without complex life– Granite based watershed– Acid shock during spring thaw

Why are some lakes not effected?

• Buffering capacity– Limestone (CaCO3) reacts with H+ to form CO2

and water– Limestone is lost

Effects of Acid Rain

• Forests– Some trees are sensitive to acid– Example: Red Spruce in northeast– Replaced by acid tolerant Balsam Fir

Effects of Acid Rain

• Heavy metal leaching– Acidic pH causes normally insoluble heavy

metals to become soluble– Example: Mercury content of fish in Great

Lakes

Solutions

• Low sulfur coal

• Scrubber in smokestacks– Injects buffered or basic water into the exhaust

stream

• Use less fossil fuels