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pollution

VIEWS: 12 PAGES: 13

									                                         Pollution
                      25 – 30% of the APES test questions relate to pollution

Toxicity and Health
   Toxin: any substance that is inhaled, ingested or absorbed at sufficient dosages that it
    damages a living organism
   Toxicity: the degree to which a toxin is biologically harmful (almost any substance if inhaled,
    absorbed, or ingested in a large enough quantity is toxic)
   Toxic Substance Considerations
       o Dosage amount over a period of time
       o Number of times of exposure
       o Size and/or age of the organism that is exposed
       o Ability of the body to detoxify that substance
       o Organism’s sensitivity to that substance (genetic predisposition or previous exposure)
       o Synergistic effect (more than one substance combines to cause a toxic effect greater
           than their individual effects)
   Dose Response Analysis: organisms are exposed to a toxin at different concentrations and
    the dosage that causes the death of the organism is recorded
   Dose Response Curve: the information from a dose response analysis is graphed for a set of
    organisms
   LD50: the dosage responsible for killing 50% of the test animals (lethal dosage for 50%)
   Poison: any substance that requires 50 mg or less per kg of bodyweight to achieve LD50
   ED50: the dosage responsible for causing a negative effect within 50% of the test animals
   Threshold dose: the dose at which negative effects begin to occur
   Acute effect: short term exposure to a high level of toxin (snake bite)
   Chronic effect: long term exposure to low levels of a toxin (lead paint in a house)
   Infection: the result of a pathogen invading our body
   Disease: when the infection causes a change in the state of health
                                 HIV is the infection; AIDS is the disease
   Five Categories of Pathogens
       o Viruses (including prions)
       o Bacteria
       o Fungi
       o Protozoa
       o Parasitic Worms
   Pathogens: bacteria, viruses, or other microorganisms that can cause disease
   Vector: a carrier organism of a pathogen (rocky mountain fever infects humans when they
    are bitten by a tick carrying the pathogen)
   Other environmental factors that can make people ill
       o Tobacco smoke
       o Asbestos
       o UV radiation
   Risk: the degree of likelihood that a person will become ill after exposure to a toxin or
    pathogen
   Risk Assessment: the practice of evaluating a decision for environmental, public, or medical
    benefit weighed against the decisions negative effect
   Risk Management: the use of strategies to reduce the amount of risk
    The US Department of Public Health decides the order in which flu shots are administered

Air Pollution
   Sources of air pollution
        o Natural-environmental releases
               Forest fire smoke
               Pollen
               Mold spores
               Dust
               Volcanic gases
        o Human generated releases
               Fossil fuel burning
               Wood burning
               Cleaning products
               Manufacturing
               Food production
   Air pollution effects on humans range from lethal to aggravating; as well as, acute to chronic
   Industrial Revolution has produced the greatest amount of human generated air pollutants
    through the burning of fossil fuels
   Primary pollutants: released directly into the lower atmosphere (troposphere) and are toxic
    (carbon monoxide emission from fossil fuel burning)
   Secondary pollutants: formed by the combination of primary pollutants in the atmosphere
    (acid rain from sulfur oxides and water vapor; both products of coal burning)
   Stationary sources: factories and power plants
   Moving sources: vehicles
   Point source pollution: a specific location from which pollution is released (power plant)
 Non-point source pollution: a combination of many sources (cows releasing methane in a
  field)

The Major Culprits
 Criteria Pollutants: pollutants described by the EPA as being the most harmful to humans
 The Dirty Half Dozen (criteria pollutants)
      o Carbon Monoxide (CO)
      o Lead (Pb)
      o Ozone (O3)
      o Nitrogen Dioxide (NO2)
      o Sulfur Dioxide (SO2)
      o Particulates
 Gases in the atmosphere are generally measured in parts per million (ppm) or parts per
  billion (ppb); 10 ppm = 10 parts per million
 Carbon monoxide
      o An odorless-colorless gas released from the incomplete combustion of fossil fuels
         (nearly impossible to have complete combustion)
      o Binds to hemoglobin in human blood preventing the transfer of oxygen and carbon
         dioxide (essentially you suffocate)
      o 60% of CO emission is from vehicles burning fossil fuels
 Lead
      o Been around since the Romans used it for smelting
      o Generally released as a particulate (small solid particle) that settles on land or water
         and becomes engrained into the food chain
      o In humans, causes nervous system damage
      o Lead burning fossil fuels were phased out during the 1970’s
 Ozone
      o EPA guideline refers to Ozone created by humans not naturally occurring stratospheric
         ozone
      o Secondary pollutant formed from the interaction of nitrogen oxides, heat, sunlight and
         volatile organic compounds (VOC’s)
      o Tropospheric ozone is a main component of smog
 Nitrogen Dioxide
      o Created from atmospheric nitrogen and oxygen reacting when exposed to high
         temperatures (combustion engines and power plants)
      o Secondary pollutant and a component of smog and acid precipitation (rain, sleet,
         snow, etc…)
   Sulfur Dioxide
       o Colorless gas with a penetrating-suffocating odor
       o Respiratory irritant commonly released during the combustion of coal
       o Scrubbers have reduced the amount of sulfur being released from power plants
       o Metal smelting, fossil fuel burning, and paper pulping release sulfur dioxide
       o Reacts with water in the atmosphere forming acid rain
   Particulates: solid material (dust from construction or other sources) that when inhaled is a
    respiratory irritant

  Smog
   Industrial smog (gray smog): smog generated from the burning of low quality coal
   Smog Incidents in London
       o 1911 smog killed 2000
       o 1952 smog killed 10000 and led to the Clean Air Act of 1952 in England
       o Deaths resulted from respiratory illnesses such as bronchitis, pneumonia, heart failure,
          tuberculosis, etc…
   Smog is the product of CO and CO2 combining with particulates in the atmosphere (industrial
    smog comes from the burning of fossil fuels
   Climate conditions contribute to smog formation (fog, temperature inversions, mountain
    ranges blocking air flow, valleys)
   Photochemical smog
       o Formed on hot sunny days in urban areas
       o Nitrogen oxides, VOC’s, and ozone combine to form a brownish hue
       o Los Angeles, CA and Athens, Greece suffer from many days per year of photochemical
          smog
       o Athens enacted driving limitations to reduce smog (even numbered license plates on
          even days and odd numbered license plates on odd days)

Ozone Depletion
   Ozone in the stratosphere blocks 95% of the suns UV rays
   Simplified ozone reaction

                                      O2 + UV (sunlight)  O + O

                                             O + O2  O3

   Chlorofluorocarbons (CFC’s)
       o a group of man-made chemicals found in fire extinguishers, hair spray, and propellants
         o stable compounds that migrate to the stratosphere through atmospheric mixing
         o intense UV radiation (sunlight) releases chlorine to react with ozone
                                              Cl + O3  ClO + O2
                                             ClO + O  Cl + O2
         o Ozone depletion is greatest in the spring
     Antarctica and the southern regions of the planet experience the greatest ozone loss
     Loss of ozone has implications on human health and ecosystems through killing
      phytoplankton (primary producers)
     Human issues include eye cataracts, skin cancers and immune system weakening
     1987 Montreal Protocol: designed to end worldwide CFC production
         o US stopped production in 1995
         o CFC production has been reduced by 95%

Acid Rain
   Acid precipitation: snow, hail, rain, etc… is primarily the result of sulfur and nitrogen oxides
    reacting with water vapor in the atmosphere
   Acid precipitation effects
       o Leaching of minerals from soil
       o Creating a buildup of nitrogen and sulfur in soil
       o Increasing aluminum to toxic levels for plants in soil
       o Leaching calcium from the needles of conifers (pine trees)
       o Lowering the pH of waterways and soil, killing fish and plants
       o Causing human respiratory irritation
       o Damaging all types of rocks (statues, monuments, and buildings)
   Dry acid particle deposition occurs within 3 days of emission
   Wet deposition occurs between 4 and 14 days of emission
   Most problems occur in urban areas with a lot of vehicle emissions and downwind from coal
    burning power plants

Motor Vehicles and Air Pollution
   Due to the Clean Air Act (CAA) cars produced in the US after 1999 emit 75% fewer emissions
    than cars made before 1970, mainly due to catalytic converters
   Catalytic converters: platinum coated plates that oxidize VOC’s and some CO converting
    them into CO2
   Corporate Average Fuel Economy (CAFÉ): Department of Transportation (DOT) sets limits on
    the fuel economy of a fleet of vehicles in an effort to reduce fuel consumption and emissions
       o Today’s CAFÉ is 27.5 mpg for cars, 22.7 mpg for SUV’s and minivans
      o Increases costs of vehicles and fuel to meet new standards
      o Sulfur released reduced from 300 ppm to 30 ppm
   Vehicles of the Future
      o Electric cars (pollution free) have a limited range, tend to be lighter (suffered greater
          crash damage), and lack amenities
      o Hybrid cars combine electric and gasoline engines to balance performance with
          efficiency
      o Hydrogen fuel cell vehicles are too expensive due to the fuel cell

Indoor Air Pollution
   Air pollutants tend to be at higher concentrations indoors
   World Health Organization (WHO) estimates 1.6 million annual deaths to indoor air pollution
   Human health concerns arise due to amount of time spent indoors
        o Developed countries suffer from well sealed buildings preventing air mass transfer
               Volatile Organic Compounds (VOC’s) are commonly found in plastics, carpet,
                  cleaning products, furniture, pesticides, etc…
               Tobacco smoke effects smoker and others in the home
                      Second hand smoke kills 10’s of thousands annually
                      Children have increased respiratory illnesses and asthma
               Radon is released from Uranium decay and only occurs where Uranium is
                  present
        o Developing countries suffer from the burning of fuels(wood, coal, and crop waste) for
           heating purposes
   Living organisms (bacteria, mold, fungi, and insects) are often transferred through central air
    systems
   Sick Building Syndrome (SBS)
        o When a majority of a building’s occupants suffer from a set of symptoms based on
           time spent in the building and no other cause can be identified
        o Building Related Illness: an illness attributed to a specific pathogen discovered in a
           building
        o SBS symptoms
               Irritation of the eyes, nose, and throat
               Neurological symptoms (headaches and dizziness)
               Skin irritation
               Nausea or vomiting
               Odor or taste sensitivity or changes
Climate Change
   Global warming is not a myth; what’s causing it is debatable
   Greenhouse gases that absorb radiation (heat) and store it.
       o Carbon Dioxide preindustrial level 280 ppm to 380 ppm in 2003
       o Methane preindustrial level of 715 ppb to 1700 ppb in 2005
       o Nitrous Oxide preindustrial level of 270 ppb to 319 ppb in 2005
   Physical changes to the earth
       o Lessening of glaciers and ice sheets
       o Rising ocean sea levels
       o Changes in precipitation patterns (wet areas getting more and dry areas getting less)
       o Increased frequency and duration of storms
       o Increased crop yield
       o Cold tolerant species will have to migrate further
       o Heat tolerant species will spread (possibly mosquitoes and other vector species)
   Human health
       o Increased death to water and insect born diseases
       o Frequent heat spells will adversely affect the elderly and young
   Marine ecosystems will change due to rising ocean levels
   Reduction to global change focuses on carbon emissions and sequestration (Kyoto Accord
    1994)

  Thermal Pollution
   Urban environments tend to be 20 degrees Fahrenheit hotter than rural areas due to heat
    trapped by concrete, buildings, and asphalt
   Heat Island: urban areas
   Reducing heat islands
        o Change dark colored roofs to light colored reflective material
        o Plant trees and add to green spaces (parks)
   Trees reduce heat absorption in two ways
        o Transpiration (release of water through plant leaves) is a cooling process
        o Shade
   Water runoff due to poor absorbing materials causes pooling and reduces evaporation (a
    cooling process)
   Temperature Inversion: air pollutants become trapped over a city because they are not able
    to rise through the atmosphere due to warmer air above the city; normally warm air rises
    into cooler air
Water Pollution
   The Cuyahoga River near Cleveland, OH caught fire in 1969; poster child for the Clean Water
    Act (CWA) of 1972.
   CWA results
       o 94% of municipal water supplies meeting federal standards by 2002
       o 60% of stream lengths in 2002 have been deemed clean enough for fishing and
           swimming compared to 36% in 1972
       o Wetland loss has decreased 80%
   Water runoff can carry excess nutrients (fertilizer) and pollutants (vehicle emissions and
    pesticides) into natural water systems
   Dead Zone: areas where dissolved oxygen (DO) content is low enough to force aquatic
    species to move
   Gulf of Mexico Dead Zone
       o stretches 5000 square miles off of the coast of Louisiana
       o The Mississippi River collects runoff from farmlands and deposits it into the Gulf of
           Mexico
       o Warm, nutrient rich water does not mix with cold salty water
       o Eutrophication, excess nutrients spurs algae growth on the surface, ensues with a
           phytoplankton explosion
       o Zooplankton, which eat phytoplankton, populations explode
       o When the phytoplankton and zooplankton die and sink their decomposition consumes
           most of the dissolved oxygen (DO) creating a hypoxic zone (a zone where anything that
           depends on oxygen cannot grow).
       o Cooler wetter weather breaks up the zone during the fall and winter months

Water Pollution Sources

   Point source: specific polluting sources, such as a paper mill
   Nonpoint source: no definitive source, results from the contribution of many sources
   Water Pollution Sources
       o Agricultural runoff
       o Industry activities
       o Mining of minerals or fossil fuels
   Standing bodies of water
       o Ponds, lakes, reservoirs and ground water
       o Do not recover quickly from pollution
       o Lack of water flow does not allow for dilution
       o Biomagnification of the pollutant occurs in the food chain
   Flowing water (rivers and streams) can recover from moderate pollution if it’s biodegradable
   Oceans have an unknown ability to recover from pollution due to their size
   Major Water Pollutants
       o Excess nutrients (nitrogen, phosphate, etc…)
       o Organic Waste
       o Toxic Waste (pesticides, petroleum, acids, heavy metals)
       o Sediments (soil from runoff)
       o Hot or Cold water (hot from industry; cold from the bottom of reservoirs)
       o Coliform bacteria in animal intestines indicating fecal matter in water
   Factors for judging water quality
       o pH: measure of acidity or alkalinity
       o Hardness: measure of the concentration of magnesium and/or calcium
       o Dissolved Oxygen (DO): low levels = less life
       o Turbidity: the density of suspended particles in water

Wastewater

   Wastewater is any water that has been used by humans
       o Sewage
       o Drainage from sinks, tubs, etc…
       o Industrial water runoff
       o Storm water runoff
   Fecal waste contains symbiotic bacteria that aids in digestion and disease causing bacteria
   Wastewater diseases include cholera and typhoid fever
   Clean water has improved health conditions more than medical improvements
   US wastewater travels through pipes to a water treatment facility (CWA requirement)
   Developing countries to tend to dump wastewater directly into rivers
   Wastewater processing
       o Physical treatment: water enters the plant and is filtered by a screen to remove large
          solids
       o Settling tanks allow precipitates to settle at the bottom
       o Primary treatment: addition of chemical polymers to precipitate organic waste that
          requires oxygen to decompose
       o Secondary treatment: biological treatment used to remove biodegradable waste by
          passing it over bacteria covered rock beds that digest the waste
       o Sludge processor: a tank filled with aerobic bacteria; all solids, including bacteria, are
          left to settle out
       o Sludge is treated with anaerobic bacteria to further breakdown pollutants
         o In the end… have been removed
                 97% of the solids
                 95-97% of the organic material
                 70% of the toxic metals, organic chemicals, and phosphates
                 50% of the nitrogen
                 5% of the dissolved salts
         o However, almost no… have been removed
                 Persistent organic chemicals
                 Pesticides
                 Radioactive isotopes
         o Chlorine is added to kill any remaining living organisms and the water is dumped into a
            river or used to water lawns (gray water), chlorination can cause carcinogenic
            substances to form
         o Alternatives to chlorination include ozonation or UV radiation, but they are not as
            effective or as long lasting
    If water is deposited into ground water tertiary treatment must be performed
         o Tertiary treatment: passing water through sand and carbon filters with additional
            chlorination
         o Tertiary treatment is done in arid climates to conserve water table levels

Water Quality Legislation

  Date         Name of Legislation                                Description
1972      Clean Water Act                 Protects all surface water in the US
                                               Reduced direct pollutant discharges into
                                                  waterways
                                               Financed water treatment facility construction
                                               Restored chemical, physical, and biological
                                                  integrity of waterways
                                               Supported protection and propagation of fish,
                                                  shellfish, and wildlife in and on the water
1974      Safe Drinking Water Act         Monitors and increases the safety of the drinking
1996                                      water supply; does not apply to water for less than
                                          25
1972      Ocean Dumping Act               Illegal to dump or transport for dumping sewage,
                                          sludge or industrial waste into the ocean
1990      Oil Spill Prevention and        EPA fund for preventing and cleaning up oil spills
          Liability Act                   (paid for by a tax on oil)
Solid Waste (Garbage)
    Solid waste: hazardous, industrial solid, or municipal waste
    Reduce, Reuse, Recycle
        o Reduce: minimize waste disposal
        o Reuse: refill tanks, bottles, secondhand materials
        o Recycle: reuse of materials in similar or different products
    Recycling
        o Primary: plastic or aluminum is reused to make the same product
        o Secondary: materials are used to make new products; usually of lower quality
        o Composting: allows organic matter to decompose and be returned to the soil
                                         RECYCLING Percentages
                    Material                Percent of all Material that
                                                was recycled in 2003
     Newspaper                                           82
     Corrugated cardboard boxes                          71
     Steel cans                                          60
     Yard trimmings                                      56
     Aluminum cans                                       44
     Scrap tires                                         36
     Magazines                                           33
     Plastic milk and water bottles                      32
     Plastic soft drink bottles                          25
     Glass containers                                    22
    PAYT: to encourage recycling Pay As You Throw programs are being considered (tax on
     trash)

Landfills

    After landfills in NY were found to be contaminating groundwater, the garbage barge Mabro
     symbolized NIMBY (Not In My BackYard) syndrome by being denied portage in southern
     states and 3 countries before returning to NY
    Sanitary Landfills: liners and clay are used to prevent seepage into groundwater, locations
     need to be away from faults, wetlands, or floodplains and must be 6 feet above the water
     table
    Periodically, waste is covered by soil or compost to prevent rodent/insect buildup
    Leachates (perchlorates), are piped to the top and monitored in pools
    Gases that buildup, methane, can be used for power generation
    Waste-to-Energy (WTE): garbage is incinerated and used for power generation
Hazardous Waste
    Hazardous waste: any waste that poses a threat to human health
    Hazardous waste items
        o Corrosive: corrodes metal
        o Ignitable: alcohol or gasoline that can catch on fire
        o Reactive: chemically reactive and may form explosives
        o Toxic: creates health risks when inhaled, ingested, or absorbed
    Hazardous waste disposal methods
        o Injection well: wells are drilled below the water table and the waste is left there
        o Surface impoundments: lined pools with liquid waste is allowed to evaporate
        o Landfills: greater restraints and controls than sanitary landfills
    Nuclear Waste
        o Yucca Mountain Nevada (underground storage facility)
        o Waste Isolation Plant (New Mexico) for burial
        o Transuranic waste: waste from nuclear weapons production
    Low-level radioactive waste: low levels of ionizing radiation
    High-level radioactive waste: high levels or ionizing radiation
    EPA waste classifications and level
        o Nuclear reactor: high
        o Reprocessed spent nuclear fuel: high
        o Nuclear weapons production: high
        o Mining and processing of uranium ore: high
        o Industrial and research (clothing, animal carcasses, needles, etc…): low
        o Natural materials: not a waste

Contaminated Waste Sites

   Superfund Program: EPA administered program to clean up contaminated waste sites that
    were in use prior to the 1970’s environmental legislation movement
       o Rocky Flats, Colorado: nuclear weapons, plutonium, uranium, beryllium, and stainless
          steel manufacturing and processing facility
       o Love Canal, New York: a landfill that was filled and covered; eventually homes were
          built on top (barrels of waste, dead trees, smelly pools of liquid in basements, and
          numerous skin irritations were soon noticed)
Laws for Solid and Hazardous Waste

    Date                       Law                                     Description
1976          The Resource Conservation and                 Landfill requirements
              Recovery Act                                  Hazardous waste requirements
                                                            Underground storage tank
                                                              program
1980          The Comprehensive Environmental               Tax on chemical and petroleum
              Response, Compensation, and Liability           industry for funding
              Act (Superfund)                               Rules for closed/abandoned
                                                              hazardous waste sites
                                                            Liability of person(s) polluting
                                                            Trust fund for clean-up if no party
                                                              found responsible
1976          Toxic Substances Control Act (TOSCA)      EPA controls and tracks 75000 industrial
                                                        chemicals and requires testing
1982          Nuclear Waste Policy Act                  Federal government is responsible for
                                                        disposal of nuclear waste


Noise Pollution
   U.S. Noise Control Act (1972): sets noise emission standards for transportation, machinery,
    and construction
   Noise Pollution: any noise that caused stress or has the potential to damage human health

								
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