Pollution

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Pollution
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Pollution

• Any substance (matter or energy) that is added to
  the biosphere by humans at a rate greater than
  what can be rendered harmless by the environment.
  
• Anything that can cause harm to the environment
  by human activity.
• Two main types of Pollutions
• Point Source Pollution where pollutants are
  released from a single identifying site.
• Ex a factory or sewage plant
• Non-Point Source Pollution where pollutants are
  released from many unidentifying areas.
• ex agricultural areas, urban traffic

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Point Source vs Non-Point Source

• Draw your own table in your notes.
• Using the information from your warm-up last
  class and textbook/companion bk
• Determine 3 specific areas of Denton where we can
  find these pollution sources. Name these areas.
• Determine which type of pollutants comes from
  each source.
• Where in Denton will these pollutants be affected.

Point Source Non-Point Source
1. 1.
2. 2.
3. 3.
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Atmosphere Air Pollution

• A little background
• The atmosphere is the envelope of gases that
  surround our planet
• It is a very thin layer compared to the radius of
  the Earth
• We refer to this layer informally as air
• The majority of the energy that drives the
  atmosphere is from the Sun.
• The atmosphere receives most of this energy from
  the surface.
• Imbalances of energy drive the winds.
  Eventually, all energy degrades down to friction.

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• We commonly express the state of the atmosphere
  by measuring it using the following variables
• Pressure
• Temperature
• Wind
• Humidity
• Cloud cover
• Precipitation type and amount
• Visibility (distance one can see horizontally)

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• Dry air (neglecting water vapor) is composed of
  the following gases
• Nitrogen (N2) 78
• Oxygen (O2) 21
• Argon (Ar) 1
• Trace Gases
• Dust, bacteria, and other particulates

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• Trace Gases
• Gases that are only found by examining a million
  or billion air molecules
• Examples include
• Carbon Dioxide (CO2) 340 ppmv
• Neon (Ne) 18 ppmv
• Helium (He) 5 ppmv
• Methane (CH4) 2 ppmv
• Hydrogen (H2) 0.5 ppmv

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Troposphere
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Stratosphere
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Mesosphere/Thermosphere
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STRUCTURE AND SCIENCE OF THE ATMOSPHERE

• The atmosphere consists of several layers with
  different temperatures, pressures, and
  compositions.

Figure 19-2
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Atmospheric Circulation (convection)

• Heated air rises at equator
• Cooler air descends at poles

Maximum Sun warming
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Solar Energy and Global Air Circulation
Distributing Heat

• Global air circulation is affected by the uneven
  heating of the earths surface by solar energy,
  seasonal changes in temperature and precipitation.

Figure 5-3
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Coriolis Effect
Coriolis effect deflects north-south winds into
east-west winds
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Coriolis Effect breaks upGlobal Circulation

• On Earth the large circulation cell breaks up
  into 3 smaller ones, moving diagonally
• Other worlds have more or fewer circulation cells
  depending on their rotation rate

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Convection Currents Convection cells
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Total Atmosphere Circulation
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Hadley Cell

• Air rises at the Equator due to high insolation
  at the surface (convection)
• The belt of rising air and clouds is called the
  Intertropical Convergence Zone (ITCZ)
• Large amounts of latent heat are released in the
  ITCZ
• Air blows in at the surface to replace the rising
  air these winds are the trade winds
• Wind speeds beneath the ITCZ are low, and this
  zone is also called the doldrums
• Air sinks in the subtropics as part of the Hadley
  Cell and forms the subtropical highs
• The winds in the subtropical highs are also very
  slow, and this zone is called the horse
  latitudes

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Polar Cell

• Thermally-direct cell at high latitudes
• Rising air occurs at a boundary between cold,
  polar air and warmer air in the mid-latitudes,
  called the polar front
• Extremely cold air at the poles lead to surface
  high pressure
• Winds blowing from the north to the south turn to
  blowing from the east due to the Coriolis force,
  so the surface winds are called the polar
  easterlies

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Ferrel Cell

• This cell is thermally-indirect (hot air sinks
  and cold air rises)
• The upper branch of the Ferrel Cell predicts
  easterly winds aloft, but they are observed to
  westerly
• Even though the complete cell doesnt exist, the
  rising air at the polar front, the sinking air at
  the subtropical high pressures, and the correct
  surface winds exist
• Surface flow from the south turns to the blowing
  from the west, resulting in our wind zone of the
  prevailing westerlies
• The mid-latitudes is a very complex region, with
  many secondary circulation features (storms)
  present

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Sea Breeze

• These are ocean-to-land breezes that occur during
  the day.
• Land Breeze
• These are land-to-ocean breezes that occur at
  night.

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Valley Breeze

• As the wind blows from the plains into a valley
  between two mountains, the wind must divert into
  a smaller area. This causes high winds to form
  through the valleys.

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Mountain Breeze

• Cool air coming from the top of the mountain
  sinks down on the eastern slope, causing
  increased winds on the mountain.

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Air Pollution

• Pollution any contaminate to the Earth or
  Atmosphere so that the environment systems are
  negatively affected.
• Regularly monitored air pollutants
• Sulfur Dioxide, Oxides of Nitrogen, ozone (O3),
  volatile organic compounds and particles.
• EPA Regulations Denton

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Air Pollution

• Primary Pollutants methane, ozone, dust
  particles, microorganisms, and chlorofluorocarbons
  (CFCs)
• Causes of Primary Pollutants factories, cars,
  wind and soil, volcanoes, forest fires, pollen,
  decaying plants, salt particles from the sea, and
  refrigerants.

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AIR POLLUTION

• Some primary air pollutants may react with one
  another or with other chemicals in the air to
  form secondary air pollutants.

Figure 19-3
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Major Air Pollutants

• Carbon oxides
• Carbon monoxide (CO) is a highly toxic gas that
  forms during the incomplete combustion of
  carbon-containing materials.
• 93 of carbon dioxide (CO2) in the troposphere
  occurs as a result of the carbon cycle.
• 7 of CO2 in the troposphere occurs as a result
  of human activities (mostly burning fossil
  fuels).
• It is not regulated as a pollutant under the U.S.
  Clean Air Act.

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Major Air Pollutants

• Nitrogen oxides and nitric acid
• Nitrogen oxide (NO) forms when nitrogen and
  oxygen gas in air react at the high-combustion
  temperatures in automobile engines and
  coal-burning plants. NO can also form from
  lightening and certain soil bacteria.
• NO reacts with air to form NO2.
• NO2 reacts with water vapor in the air to form
  nitric acid (HNO3) and nitrate salts (NO3-) which
  are components of acid deposition.

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Major Air Pollutants

• Sulfur dioxide (SO2) and sulfuric acid
• About one-third of SO2 in the troposphere occurs
  naturally through the sulfur cycle.
• Two-thirds come from human sources, mostly
  combustion (S O2 ? SO2) of sulfur-containing
  coal and from oil refining and smelting of
  sulfide ores.
• SO2 in the atmosphere can be converted to
  sulfuric acid (H2SO4) and sulfate salts (SO42-)
  that return to earth as a component of acid
  deposition.

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Major Air Pollutants

• Suspended particulate matter (SPM)
• Consists of a variety of solid particles and
  liquid droplets small and light enough to remain
  suspended in the air.
• The most harmful forms of SPM are fine particles
  (PM-10, with an average diameter lt 10
  micrometers) and ultrafine particles (PM-2.5).
• According to the EPA, SPM is responsible for
  about 60,000 premature deaths a year in the U.S.

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Major Air Pollutants

• Ozone (O3)
• Is a highly reactive gas that is a major
  component of photochemical smog.
• It can
• Cause and aggravate respiratory illness.
• Can aggravate heart disease.
• Damage plants, rubber in tires, fabrics, and
  paints.

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Major Air Pollutants

• Volatile organic compounds (VOCs)
• Most are hydorcarbons emitted by the leaves of
  many plants and methane.
• About two thirds of global methane emissions
  comes from human sources.
• Other VOCs include industrial solvents such as
  trichlorethylene (TCE), benzene, and vinyl
  chloride.
• Long-term exposure to benzene can cause cancer,
  blood disorders, and immune system damage.

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Major Air Pollutants

• Radon (Rn)
• Is a naturally occurring radioactive gas found in
  some types of soil and rock.
• It can seep into homes and buildings sitting
  above such deposits.

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Water Pollution

• Poisoned Waters Frontline PBS
• Take notes answer the questions (set 1)
• Where does waste from our toilets and sink wind
  up?
• What about chemicals that we use to clean our
  homes, wash our cars, fertilize our lawns?
• What happens to our makeup, deodorant, shampoos
  and other personal care items when we take a
  shower?
• What about pharmaceuticals tossed in the toilet?

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Question set 2

• Where does your drinking water come from? Can you
  think of anything that might pollute that source
  of water?
• What problems have scientists detected in nature
  that they believe are caused by emerging
  contaminants?
• Are humans potentially vulnerable to some of
  these same chemicals?
• What should the government and/or industry do
  about these emerging contaminants?
• What can you do to make water safer for
  yourself, your community and the fish?