APES Exam Notes

Environmental Legislation

Air Quality

• Clean Air Act:
  • Sets emission standards for cars.
  • Establishes limits for the release of air pollutants.

Global Warming

• Kyoto Protocol:
  • Aims to control global warming.
  • Sets greenhouse gas emission targets for developed countries.

Ozone Depletion

• Montreal Protocol:
  • Focuses on the phaseout of ozone-depleting substances.

Waste Management

• Resource Conservation & Recovery Act (RCRA):
  • Controls hazardous waste from creation to disposal, using a "cradle to grave" system.
• Comprehensive Environmental Response, Compensation & Liability Act (CERCLA):
  • Also known as Superfund.
  • Designed to identify and clean up abandoned hazardous waste dump sites.
• Nuclear Waste Policy Act:
  • Mandates the US government to develop a high-level nuclear waste disposal site (e.g., Yucca Mountain).

Wildlife Protection

• Endangered Species Act:
  • Identifies threatened and endangered species in the US.
  • Prioritizes their protection over economic considerations.
• Convention on International Trade in Endangered Species (CITES):
  • Lists species that cannot be commercially traded as live specimens or wildlife products.
• Magnuson-Stevens Act:
  • Deals with the management of marine fisheries.

Food Safety

• Food Quality Protection Act:
  • Sets pesticide limits in food.
  • Requires screening of all active and inactive ingredients for estrogenic/endocrine effects.

General Environmental Policy

• National Environmental Policy Act (NEPA):
  • Mandates that Environmental Impact Statements (EIS) must be completed before any project affecting federal lands can commence.

Toxic Chemicals

• Stockholm Convention on Persistent Organic Pollutants (POPs):
  • Seeks to protect human health from the 12 most toxic chemicals.
  • Includes 8 chlorinated hydrocarbon pesticides.
  • Allows DDT use for malaria control.

APES Vocabulary Review

Radiation

• Ionizing radiation:
  • Has enough energy to remove electrons from atoms, creating ions.
  • Examples include gamma rays, X-rays, and UV radiation.
  • Capable of causing cancer.

Energy Quality

• High Quality Energy:
  • Organized and concentrated energy that can perform useful work.
  • Examples: fossil fuels and nuclear energy.
• Low Quality Energy:
  • Disorganized and dispersed energy.
  • Example: heat in the ocean or air, wind, solar.

Thermodynamics

• First Law of Thermodynamics:
  • Energy is neither created nor destroyed but can be converted from one form to another.
• Second Law of Thermodynamics:
  • When energy changes form, some useful energy is always degraded into lower quality energy, usually heat.

Radioactive Decay

• Natural radioactive decay:
  • Unstable radioisotopes decay, releasing gamma rays, alpha, and beta particles.
• Half-life:
  • The time it takes for half the mass of a radioisotope to decay.
• Safe Storage Time:
  • Radioactive isotopes should be stored for approximately 10 half-lives to decay to a safe level.

Nuclear Processes

• Nuclear Fission:
  • The nuclei of isotopes split apart when struck by neutrons.
• Nuclear Fusion:
  • Two isotopes of light elements (e.g., Hydrogen) are forced together at high temperatures to form a heavier nucleus.
  • Expensive and still hasn't reached the break-even point.

Mining and Soil

• Ore:
  • Rock containing a mineral concentration large enough to make mining profitable.
• Organic fertilizer:
  • Slow-acting and long-lasting because organic remains need time to decompose.
• Best solution to Energy shortage:
  • conservation and increase efficiency
• Surface mining:
  • Cheaper and can remove more minerals; less hazardous to workers.
• Humus:
  • Organic, dark material remaining after decomposition by microorganisms.
• Leaching:
  • Removal of dissolved materials from soil as water moves downwards.
• Illuviation:
  • Deposit of leached material in lower soil layers (B horizon).
• Loam:
  • Ideal agricultural soil with equal portions of sand, silt, and clay.
• Conservation:
  • Allows the use of resources in a responsible manner.
• Preservation:
  • Setting aside areas and protecting them from human activities.

Hydrologic Cycle

• Parts of the hydrologic cycle:
  • Evaporation, transpiration, runoff, condensation, precipitation, infiltration.
• Aquifer:
  • Any water-bearing layer in the ground.
• Cone of depression:
  • Lowering of the water table around a pumping well.
• Salt water intrusion:
  • Near the coast, overpumping of groundwater causes saltwater to move into the aquifer.

El Nino Southern Oscillation (ENSO)

• ENSO:
  • See-sawing of air pressure over the South Pacific.
• During an El Nino year:
  • Trade winds weaken, and warm water sloshes back to South America.
• During a Non-El Nino year:
  • Easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient-rich water off the West coast of South America.
• Effects of El Nino:
  • Upwelling decreases, disrupting food chains.
  • The Northern US has mild winters.
  • The Southwestern US has increased rainfall.
  • Fewer Atlantic Hurricanes.

Nitrogen Cycle

• Nitrogen fixing:
  • Atmospheric $N$ cannot be used directly by plants; it must first be converted into ammonia by bacteria (Rhizobium).
• Ammonification:
  • Decomposers convert organic waste into ammonia.
• Nitrification:
  • Ammonia is converted to nitrate ions $(NO_3^-)$.
• Assimilation:
  • Inorganic $N$ is converted into organic molecules such as DNA/amino acids and proteins.
• Denitrification:
  • Bacteria convert ammonia back into $N$.

Phosphorus Cycle

• Phosphorus Limitations:
  • Phosphorus does not circulate as easily as $N$ because it does not exist as a gas, but is released by weathering of phosphate rocks.
• Excess phosphorus in aquatic ecosystems:
  • Comes from runoff of animal wastes, fertilizer, and sewage discharge.

Sustainability

• Sustainability:
  • The ability to meet humanity's current needs without compromising the ability of future generations to meet their needs.

Photosynthesis and Respiration

• Photosynthesis:
  • Plants convert atmospheric $C (CO<em>2)$ into complex carbohydrates (glucose $(C</em>6H<em>{12}O</em>6)$).
• Aerobic respiration:
  • Oxygen-consuming producers, consumers, and decomposers break down complex organic compounds and convert $C$ back into $CO_2$.

Carbon Cycle

• Largest reservoirs of $C$:
  • Carbonate rocks (first), oceans (second).

Ecosystem Components

• Biotic/abiotic:
  • Living & nonliving components of an ecosystem.
• Producer/Autotroph:
  • Photosynthetic life.

Water Quality Indicators

• Fecal coliform/Enterococcus:
  • Indicators of sewage contamination.

Energy Flow

• Energy flow in food webs:
  • Only 10% of the usable energy is transferred because usable energy is lost as heat (2nd law), not all biomass is digested & absorbed, and predators expend energy to catch prey.

Water Disinfection

• Chlorine:
  • Good: disinfection of water. Bad: can form trihalomethanes.

Ecological Succession

• Primary succession:
  • Development of communities in a lifeless area not previously inhabited by life (e.g., lava).
• Secondary succession:
  • Life progresses where soil remains (e.g., clear-cut forest, fire).

Energy Efficiency

• Cogeneration:
  • Using waste heat to make electricity.

Symbiotic Relationships

• Mutualism:
  • Symbiotic relationship where both partners benefit.
• Commensalism:
  • Symbiotic relationship where one partner benefits & the other is unaffected.
• Parasitism:
  • Relationship in which one partner obtains nutrients at the expense of the host.

Biomes

• Biome:
  • Large distinct terrestrial region having similar climate, soil, plants, & animals.

Population Ecology

• Carrying capacity:
  • The number of individuals that can be sustained in an area.
• R strategist:
  • Reproduce early, many small unprotected offspring.
• K strategist:
  • Reproduce late, few, cared for offspring.

Feedback Loops

• Positive feedback:
  • When a change in some condition triggers a response that intensifies the changing condition (e.g., warmer Earth - snow melts - less sunlight is reflected & more is absorbed, therefore warmer Earth).
• Negative feedback:
  • When a change in some condition triggers a response that counteracts the changed condition (e.g., warmer Earth - more ocean evaporation - more stratus clouds - less sunlight reaches the ground - therefore cooler Earth).

Natural Selection

• Natural selection:
  • Organisms that possess favorable adaptations pass them onto the next generation.

Population Theories

• Malthus:
  • Said human population cannot continue to increase; consequences will be war, famine, & disease.

Population Math

• Doubling time:
  • Rule of 70: 70 divided by the percent growth rate.
• Replacement level fertility:
  • The number of children a couple must have to replace themselves (2.1 developed, 2.7 developing).

Population Statistics

• World Population:
  • 6.5 billion
• US Population:
  • 300 million

Demographic Transition Model

• Preindustrial stage:
  • Birth & death rates high, population grows slowly, infant mortality high.
• Transitional stage:
  • Death rate lower, better health care, population grows fast.
• Industrial stage:
  • Decline in birth rate, population growth slows.
• Postindustrial stage:
  • Low birth & death rates.

Population Structure

• Age structure diagrams:
  • (Broad base, rapid growth) (Narrow base, negative growth) (Uniform shape, zero growth).

Most Populated Countries

• 1st & 2nd most populated countries:
  • China & India.

Factors Affecting Population Growth

• Most important thing affecting population growth:
  • Low status of women.

Decreasing Birth Rate

• Ways to decrease birth rate:
  • Family planning, contraception, economic rewards & penalties.

Water Distribution

• Percent water on earth by type:
  • 97.5% seawater, 2.5% freshwater.

Soil Issues

• Salinization of soil:
  • In arid regions, water evaporates leaving salts behind.

Water Conservation

• Ways to conserve water:
  • (Agriculture, drip/trickle irrigation) (Industry, recycling) (Home, use gray water, repair leaks, low flow fixtures).

Pollution Sources

• Point vs. non-point sources:
  • Point: from a specific location such as a pipe. Non-point: from over an area such as runoff.

Water Quality

• BOD (biological oxygen demand):
  • Amount of dissolved oxygen needed by aerobic decomposers to break down organic materials.
• Eutrophication:
  • Rapid algal growth caused by an excess of $N$ & $P$.
• Hypoxia:
  • When aquatic plants die, the BOD rises as aerobic decomposers break down the plants, the DO drops & the water cannot support life.
• Minamata Disease:
  • Mental impairments caused by mercury.

Air Pollutants

• Primary air pollutants:
  • Produced by humans & nature (CO, CO2, SO2, NO, hydrocarbons, particulates).
• Particulate matter: (Source: burning fossil fuels & diesel exhaust) (reduces visibility & respiratory irritation) (filtering, electrostatic precipitators, alternative energy).
• Nitrogen Oxides: (Source: auto exhaust) (Effects: acidification of lakes, respiratory irritation, leads to smog & ozone) (Equation for acid formation: $NO+ O<em>2 = NO</em>2 + H<em>2O = HNO</em>3$) (Reduction: catalytic converter).
• Sulfur oxides: (Source: coal burning) (Effects: acid deposition, respiratory irritation, damages plants) (Equation for acid formation: $SO<em>2 + O</em>2 = SO<em>3 + H</em>2O = H<em>2SO</em>4$) (Reduction: scrubbers, burn low sulfur fuel).
• Carbon oxides: (Source: auto exhaust, incomplete combustion) (Effects: CO binds to hemoglobin reducing bloods ability to carry $O<em>2$, $CO</em>2$ contributes to global warming) (Reduction: catalytic converter, emission testing, oxygenated fuel, mass transit).
• Ozone: (Formation: secondary pollutant, $NO<em>2+UV=NO+0 ; 0+0</em>2=0_3$, with VOC's) (Effects: respiratory irritant, plant damage) (Reduction: reduce NO emissions & VOCs).
• Radon: radioactive gas, formed from the decay of Uranium, causes lung cancer and is a problem in the Reading Prong
• Photochemical smog: formed by chemical reactions involving sunlight (NO, VOC,O)
• Acid deposition: caused by sulfuric and nitric acids resulting in lowered pH of surface waters

Greenhouse Effect

• Greenhouse gases:
  • Examples: $(H<em>2O, CO</em>2, O<em>3, methane (CH</em>4), CFC's)$
  • Effect: they trap outgoing infrared (heat) energy causing earth to warm

Global Warming Effects

• Effects of global warming:
  • Rising sea level (thermal expansion), extreme weather, droughts (famine), extinctions

Ozone Depletion

• Ozone depletion caused by:
  • CFC's, methyl chloroform, carbon tetrachloride, halon, methyl bromide all of which attack stratospheric ozone
• Effects of ozone depletion:
  • increased UV, skin cancer, cataracts, decreased plant growth

Environmental Disasters

• Love Canal, NY:
  • chemicals buried in old canal and school & homes built over it causing birth defects & cancer

Waste Management

• Municipal solid waste is mostly:
  • paper and most is landfilled

Economic Considerations

• True cost/External costs:
  • harmful environmental side effects that are not reflected in a products price
• Sanitary landfill problems and solutions:
  • (leachate, liner with collection system) (methane gas, collect gas and burn) (volume of garbage, compact & reduce)
• Incineration advantages:
  • volume of waste reduced by 90% & waste heat can be used
• Incineration disadvantages:
  • toxic emissions (polyvinyl chloride-dioxin), scrubbers & electrostatic precipitators needed, ash disposal (contains heavy metals)
• Best way to solve waste problem:
  • reduce the amounts of waste at the source

Species Ecology

• Keystone species:
  • species whose role in an ecosystem are more important than others, ex sea otter
• Indicator species:
  • species that serve as early warnings that an ecosystem is being damaged ex trout
• Most endangered species:
  • have a small range, require large territory or live on an island
• In natural ecosystems, 50-90% of pest species are kept under control by:
  • predators, diseases, parasites

Pest Control

• Major insecticide groups and examples:
  • (chlorinated hydrocarbons, DDT) (organophosphates, malathion) (carbamates, aldicarb)
• Pesticide pros:
  • saves lives from insect transmitted disease, increases food supply, increases profits fo farmers
• Pesticide cons:
  • genetic resistance, ecosystem imbalance, pesticide treadmill, persistence, bioaccumulation, biological magnification
• Bio Natural pest control:
  • better agricultural practices, genetically resistant plants, natural enemies, biopesticides, sex-attractants-

Electricity Generation

• Electricity is generated by:
  • using steam (from water boiled by fossils fuels or nuclear) or falling water to turn a generator

Petroleum

• Petroleum forms from:
  • microscopic aquatic organisms in sediments converted by heat & pressure into a mixture of hydrocarbons
• Pros of petroleum:
  • cheap, easily transported, high quality energy
• Cons of petroleum:
  • reserves depleted soon, pollution during drilling, transport and refining, burning makes $CO_2$

Coal

• Steps in coal formation:
  • peat, lignite, bituminous, anthracite

Nuclear Power

• Major parts of a nuclear reactor:
  • core, control rods, steam generator, turbine, containment building
• Two most serious nuclear accidents:
  • (Chernobyl,Ukraine) (Three Mile Island, PA)

Alternative Energy Sources

• Alternate energy sources:
  • wind, solar, waves, biomass, geothermal, fuel cells

Toxicology

• $LD_{50}$:
  • the amount of a chemical that kills 50% of the animals in a test population
• Mutagen, Teratogen, Carcinogen:
  • causes hereditary changes, Fetus deformities, cancer

Endangered Species Examples

• Endangered species:
  • North spotted Owl (loss of old growth forest), Bald Eagle (thinning of eggs caused by DDT), Piping Plover (nesting areas threatened by development)
• LI Exotic species:
  • gypsy moth, Asian Long Horned Beetle

Tragedy of the Commons

• Garret Hardin & The Tragedy of the Commons:
  • Freedom to breed is bringing ruin to all. Global commons such as atmosphere & oceans are used by all and owned by none

Earth Science

• Volcanoes and Earthquakes occur:
  • at plate boundaries (divergent, spreading, mid-ocean ridges) (convergent, trenches) (transform, sliding, San Andreas)

Pollution Sources Specifics

• Sources of mercury:
  • burning coal, Compact Fluorescent bulbs
• Major source of sulfur:
  • burning coal

Toxicology - Dose Response

• Threshold dose:
  • the maximum dose that has no measurable effect

Laws, Laws & More Laws

Mining Laws

• Surface Mining Control & Reclamation Act:
  • requires coal strip mines to reclaim the land
• Madrid Protocol:
  • Moratorium on mineral exploration for 50 years in Antarctica

Water Protection Laws

• Safe Drinking Water Act:
  • set maximum contaminant levels for pollutants in drinking water that may have adverse effects on human health
• Clean Water Act:
  • set maximum permissible amounts of water pollutants that can be discharged into waterways..aim to make surface waters swimmable and fishable
• Ocean Dumping Ban Act:
  • bans ocean dumping of sewage sludge & industrial waste in the ocean