Pollution

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Pollution

• Chapter 13

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Water Pollution
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Types and Sources of Water Pollution

• 1 problem - Eroded soils

• Organic wastes, disease-causing agents

• Chemicals, nutrients

• Radioactive stuff, heat

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Point and Nonpoint Sources
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Major Problem Drinking Water

• 1/2 of worlds people drink polluted water

• Safe Drinking Water Act

• EPA Maximum contaminant levels (municipal, but
  not rural and private)

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Pollution of Surface Water Streams

• D.O., B.O.D., fecal coliform bacteria count

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Pollution of Surface Water Lakes

• Cultural eutrophication

• Slow turnover

• Accumulation of nutrients, excessive plant
  growth, algae blooms

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Case Study The Great Lakes
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Mississippi River Basin
Ohio River
Missouri River
Mississippi River
LOUISIANA
Mississippi River
Depleted
Oxygen
Dead Zone
Gulf of Mexico
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Suffocated fish
Altered food web
Low dissolved oxygen
Decreased fish population
Thermal Pollution
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Groundwater Pollution Sources

• Low flow rates

• Cold temperatures

• Few bacteria

Hazardous waste injection well
Pesticides
Coal strip mine runoff
De-icing road salt
Buried gasoline and solvent tank
Cesspool septic tank
Pumping well
Gasoline station
Waste lagoon
Water pumping well
Sewer
Landfill
Leakage from faulty casing
Accidental spills
Discharge
Unconfined freshwater aquifer
Confined aquifer
Confined freshwater aquifer
Groundwater flow
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Groundwater Pollution Prevention

• Monitoring aquifers - expensive

• Leak detection systems

• Strictly regulating hazardous waste disposal

• Protecting recharge areas
• - aquifer classifications

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Ocean Pollution dumping and oil
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Oil Spills

• Sources offshore wells, tankers, pipelines and
  storage tanks

• Effects death of organisms, loss of animal
  insulation and buoyancy, smothering

• Significant economic impacts

• Short-term cleanup problems - beaches, wildlife

• Long-term cleanup problem - persistence (decades)

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Case Study Chesapeake Bay

• Largest US estuary

• Relatively shallow

• Slow flushing action to Atlantic

• Major problems with dissolved O2

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Solutions Preventing and Reducing Surface Water
Pollution
Nonpoint Sources
Point Sources

• Reduce runoff

• Water Pollution
• Control Act (1972)

• Buffer zone vegetation

• Clean Water Act
• (1977)
• - set effluent standards
• - secondary treatment

• Reduce soil
• erosion

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Technological Approach Septic Systems

• Require suitable soils and maintenance

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Technological Approach Sewage Treatment

• Mechanical and biological treatment

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Technological Approach Advanced Sewage Treatment

• Removes specific pollutants

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Technological Approach Using Wetlands to Treat
Sewage
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Acid Deposition
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Automobiles as a Source
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Widespread Secondary Air Pollution Acid
Deposition

• Wet deposition

• Dry deposition

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Acid Deposition in the U.S.
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Acid Deposition, Plants, and Soil
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Acid Deposition, Plants, and Soil

• Direct damage to forest tree foliage
• Erodes protective waxes from leaves, needles
• Leaches nutrients from leaves

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Acid Deposition, Plants, and Soil

• Lowers soil pH
• Affects mineral solubility
• Leach out positively charged ions (K, Mg, Ca)
  from clay particles
• Easily flushed away

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Acid Deposition, Plants, and Soil

• Increases concentration of potentially toxic
  minerals
• E.g., aluminum
• Damages xylem - reduces ability to take in water,
  nutrients - die from lack of moisture, nutrients

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Acid Deposition, Plants, and Soil

• Has resulted in loss of large stands of trees in
  many different regions around world
• Canada, New England, Smoky Mountains

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Acid Deposition, Plants, and Soil
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Acid Deposition, Plants, and Soil

• Nearly 70 of forests in Czech Republic have been
  destroyed
• Trees in nearly half of Germanys Black Forest
  have been impacted

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Acid Deposition, Plants, and Soil

• Switzerland has lost 10 of its forests
• Increased chance of avalanches

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Acid Deposition, Plants, and Soil

• Large portions of forests in Norway have been
  lost, especially in southern regions

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Acid Deposition, Plants, and Soil

• Correlation between dying forests and thriving
  ground layer of mosses

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Acid Deposition, Plants, and Soil

• Mosses are acid-loving
• Thick layer holds do much moisture that surface
  soils become saturated
• Feeder roots, tree die from lack of oxygen (drown)

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Acid Deposition, Plants, and Soil

• Mosses also may kill mycorrhizal fungi
• Reduce uptake of nutrients

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Acid Deposition, Plants, and Soil

• Dense layer of mosses may further acidify water
  passing through them into soil
• Dissolve more toxic trace metals, leach more soil
  nutrients

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Acid Deposition, Plants, and Soil

• Even if trees somehow manage to survive all these
  problems, their growth is reduced substantially

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Acid Deposition, Plants, and Soil
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Acid Deposition, Plants, and Soil

• Varying effects on crop productivity, but wide
  distribution of problem areas

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Acid Deposition, Plants, and Soil

• Some evidence for direct damage
• Potatoes in Canada - damage to foliage, potential
  uptake of toxins

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Acid Deposition, Plants, and Soil

• Coffee plants have shown damage to foliage in
  some areas

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Acid Deposition, Plants, and Soil

• Although much evidence points toward harmful
  effects from acid rain, some studies show the
  opposite

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Acid Deposition, Plants, and Soil

• Helpful to crops where soil nutrients may be very
  low - nitrogen-limited
• Acidification may release nutrients, allow for
  greater uptake

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Acid Deposition, Plants, and Soil

• Some evidence where crops show now effect of acid
  deposition, either negative or positive
• Balance each other out

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Acid Deposition and Aquatic Systems

• Fish,
• Invertebrates
• decline (lt5.0)

• Undesirable species

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Acid Deposition and Aquatic Systems

• Adirondacks - 25 of lakes too acidic for fish,
  20 threatened
• EPA 15,000 U.S. lakes acidified or threatened

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Acid Deposition and Aquatic Systems

• 1/3 of Florida lakes acidic enough to cause harm
  to aquatic life

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Acid Deposition and Aquatic Systems

• 20,000 lakes in Sweden are too acidic for fish

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Acid Deposition and Aquatic Systems

• Salmon runs in most Norway rivers have been
  eliminated
• No egg production

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Acid Deposition and Aquatic Systems

• 20 famous salmon-fishing rivers in Nova Scotia
  have lost or are near to losing the fish

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Acid Deposition and Aquatic Systems

• Half of Quebecs 48,000 lakes were acidified by
  year 2000, and more are becoming that way

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Acid Deposition and Aquatic Systems

• During most seasons, acids are not direct
  problem, but they mobilize toxic metals
  aluminum, lead, mercury
• Aluminum irritates gills of fish, causes mucus
  buildup, death from asphyxiation

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Acid Deposition and Aquatic Systems

• Major problem season snowmelt
• First 30 of meltwater contains virtually all the
  acid
• pH 3.0-3.5
• Toxic to eggs, fish fry, adult fish

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Global Carbon Cycle
Human effects fossil fuel combustion, cutting
and burning of trees
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Global Carbon Cycle
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Global Carbon Cycle

• Increasing atmospheric CO2 has brought about a
  rise in global temperature

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Greenhouse Effect

• CO2 acts like glass in a global greenhouse
• Slows escape of infrared radiation from earths
  surface

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Greenhouse Effect

• Many other gases are far more effective at
  trapping heat
• Methane, CFCs, nitrous oxide (N2O)
• 20-270 X as effective
• CO2 responsible for 2/3 of increase in greenhouse
  effect

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Greenhouse Effect

• CO2 concentrations increased 21.5 from 1870-1990
• Increasing consumption of fossil fuels,
  deforestation
• Doubling of CO2 concentrations may occur with
  continued fossil fuel use over 50-100 years

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Greenhouse Effect

• CO2 doubling may increase average global
  temperature by 2-5C
• Global temps have increased 0.8C over last
  century, 0.6 of that in last 30 years

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Major Climate Changes

• Worldwide change in patterns of precipitation,
  storms, winds, ocean currents
• Each 1C increase pushes climatic zones 90 mi N
  in N. hemisphere

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Major Climate Changes

• Variable effects worldwide, but greatest changes
  between 40 and 70N, in N. Amer. and Eurasia
• Caused by both warmer temps and increased CO2
  (greater forest productivity)

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Major Climate Changes

• Polar ice sheets and glaciers have been melting,
  and changes would escalate

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Major Climate Changes

• Sea levels would rise due to melting ice,
  expansion of warming water
• 4C increase would cause 0.5-1.5 m rise worldwide
• Flood coastal wetlands, low-lying cities,
  agricultural lands

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Major Climate Changes

• Frequency, intensity of weather extremes would
  increase
• Heat waves, drought, hurricanes

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Major Climate Changes

• Speed up decay of organic matter
• Further increase CO2 concentrations in atmosphere

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Major Climate Changes

• Warmer climates spreading northward would bring
  insect-borne diseases, more pests into areas
  currently protected by cold temperatures

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Major Climate Changes

• Growth rates of many tree species would be
  lowered
• Ranges would have to shift northward
• At rate up to 10 X greater than theyve ever done
  in the past
• Birch, sugar maple

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Major Climate Changes

• Stress from pests, disease microorganisms would
  increase
• Adapt faster than tress to changing environments

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Major Climate Changes

• More frequent fires
• Forest and grassland
• Increased disturbance decreased diversity?

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Major Climate Changes

• But are rising CO2 concentrations really a
  concern?
• 3-4 X higher 250 million years ago
• Regular cycling over past 400,000 years

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Major Climate Changes

• Rising global temperatures?
• 30 years ago there were signs that we were
  entering glacial cooling