Pollution

1. Pollution

2. 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

3. 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.

4. 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.

5. 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)

6. 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

7. 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

8. Troposphere

9. Stratosphere

10. Mesosphere/Thermosphere

11. STRUCTURE AND SCIENCE OF THE ATMOSPHERE • The atmosphere consists of several layers with different temperatures, pressures, and compositions. Figure 19-2

13. Atmospheric Circulation (convection) • Heated air rises at equator • Cooler air descends at poles Maximum Sun warming

14. Solar Energy and Global Air Circulation: Distributing Heat • Global air circulation is affected by the uneven heating of the earth’s surface by solar energy, seasonal changes in temperature and precipitation. Figure 5-3

17. Coriolis Effect Coriolis effect deflects north-south winds into east-west winds

18. 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

19. Convection Currents Convection cells

20. Total Atmosphere Circulation

21. 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”

22. 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

23. 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 doesn’t 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

24. 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.

25. 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.

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

27. 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

28. Air Pollution • Primary Pollutants – methane, ozone, dust particles, microorganisms, and chlorofluorocarbons (CFC’s) • Causes of Primary Pollutants – factories, cars, wind and soil, volcanoes, forest fires, pollen, decaying plants, salt particles from the sea, and refrigerants.

29. 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

30. 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.

31. 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.

32. Major Air Pollutants • Sulfur dioxide (SO2)andsulfuric 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.

33. 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 < 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.

34. 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.

35. 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.

36. 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.

37. 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?

38. 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?