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Air Pollution Unit 12: Air Pollution FYI Nature of the Atmosphere Thin layer of gases surrounding earth Density (air mass/air volume) is greater at sea.

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Presentation on theme: "Air Pollution Unit 12: Air Pollution FYI Nature of the Atmosphere Thin layer of gases surrounding earth Density (air mass/air volume) is greater at sea."— Presentation transcript:

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2 Air Pollution Unit 12: Air Pollution

3 FYI Nature of the Atmosphere Thin layer of gases surrounding earth Density (air mass/air volume) is greater at sea level than in mountains Atmospheric pressure (force/area) decreases with altitude 78% nitrogen, 21% oxygen (water vapor, argon, CO₂)

4 FYI Layers of Atmosphere Troposphere: layer closest to earth (extends 11 miles above surface) -responsible for weather, climate, greenhouse effect Stratosphere: layer surrounding troposphere (extends 30 miles above troposphere) -ozone layer: protects earth from too much of sun’s UV radiation

5 Fig. 19-2, p. 440 Atmospheric pressure (millibars) Temperature Thermosphere Pressure Mesopause Heating via ozone Mesosphere Stratopause Altitude (kilometers) Stratosphere Altitude (miles) Tropopause Ozone “layer” Heating from the earth Troposphere Temperature (˚C) Pressure = 1,000 millibars at ground level (Sea level)

6 What Causes Air Pollution? Air pollution: the contamination of the atmosphere by wastes. -can be solid, liquid, or gas -natural: dust, pollen, spores, sulfur dioxide from volcanos -most is caused by human activities: industrial burning and automobile exhausts.

7 Primary and Secondary Pollutants Primary pollutant: a pollutant that is put directly into the atmosphere by human or natural activity. Ex: soot from smoke Secondary pollutant: forms in the atmosphere by chemical reactions with primary air pollutants, natural components in the air, or both. Ex: ground-level ozone Ground level ozone forms when the emission from exhaust reacts with the UV rays of the sun and then mix with the oxygen in the atmosphere.

8 FYI Remember Ozone in the stratosphere is good! Ozone in the troposphere is bad!

9 Primary Pollutants

10 Sources of Primary Air Pollutants

11 Primary pollutant sources: Household products Power plants Motor vehicles Primary pollutants: Carbon monoxide Nitrogen oxide Sulfur dioxide Volatile Organic Compounds (VOC’s)

12 Sources of Primary Air Pollutants Vehicles and coal-burning power plants: major sources of nitrogen oxide emissions. Power plants, refineries, and metal smelters contribute sulfur dioxide emissions. Vehicles and gas stations: make up most of the human-made emissions of VOCs.

13 Sources of Primary Air Pollutants Particulate matter: fine and coarse particles that pollute the air. -fine particles: enter air from fuel burned by vehicles and coal-burning power plants. Sources of course particles: cement plants mining operations incinerators wood-burning fireplaces fields and roads

14 The History of Air Pollution Air pollution is not a new phenomenon -1273: King Edward I ordered that burning a particularly dirty kind of coal called sea-coal was illegal. (world’s air quality problem is much worse today because modern industrial societies burn large amounts of fossil fuels) -most air pollution in urban areas comes from vehicles and industry.

15 Motor Vehicle Emissions Almost 1/3 of our air pollution comes from gasoline burned by vehicles. -according to the U.S. Department of Transportation, Americans drove their vehicles over 2.6 trillion miles in 1998. -over 90% of that mileage was driven by passenger vehicles. The rest was driven by trucks and buses.

16 Controlling Vehicle Emissions The Clean Air Act (1970) gives the Environmental Protection Agency (EPA) the authority to regulate vehicle emissions in the United States. -the EPA required the elimination of lead in gasoline, decreasing lead pollution by more than 90 percent in the United States. -catalytic converters, required in all automobiles, clean exhaust gases of pollutants before pollutants are able to exit the tail pipe.

17 Controlling Vehicle Emissions

18 California Zero-Emission Vehicle Program In 1990, the California Air Resources Board established the zero-emission vehicle (ZEV) program. Zero-emission vehicles are vehicles that have no: tailpipe emissions emissions from gasoline emission-control systems that deteriorate over time. -2016: 16% of all vehicles sold in California are required to be zero-emission vehicles, including SUVs and trucks.

19 Industrial Air Pollution Industries and power plants that generate our electricity must burn fuel, usually fossil fuel, to get the energy they need. -burning fossil fuels releases huge quantities of sulfur dioxide and nitrogen oxide into the air. -power plants that emit at least two-thirds of all sulfur dioxide and more than one-third of all nitrogen oxides pollutants.

20 Industrial Air Pollution Some industries produce VOCs: chemical compounds that form toxic fumes. Examples: -dry cleaning -oil refineries -chemical manufacturing plants -furniture refinishers -automobile repair shops

21 Regulating Air Pollution From Industry The Clean Air Act requires many industries to use scrubbers or other pollution-control devices. -scrubbers remove some harmful pollutants. -scrubbers move gases through a spray of water that dissolves many pollutants. -ammonia is an example of a pollutant gas that can be removed from the air by a scrubber.

22 Regulating Air Pollution From Industry Electrostatic precipitators: machines used in cement factories and coal-burning power plants to remove dust particles from smokestacks. -electrostatic precipitator blows dust particles through a chamber containing an electrical current. -electric charge is transferred to the dust particles, causing them to stick together and to the sides of the chamber.

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24 Electrostatic Precipitator (cont’d) -clean gas is released from the chamber; concentrated dust particles are collected and removed. -precipitators remove 20 million tons of ash generated by coal-burning power plants from the air each year in the United States.

25 Smog Smog: urban air pollution composed of mixture of smoke and fog produced from industrial pollutants and burning fuels. -results from chemical reactions that involve sunlight, air, automobile exhaust, and ozone. -vehicles and industries are the main causes of smog.

26 Smog

27 Temperature Inversions Circulation of air in the atmosphere usually keeps air pollution from reaching dangerous levels. -during the day, the sun heats the surface of the Earth and the air near the Earth. -warm air rises through the cooler air above it and carries pollutants away from the ground, and into the atmosphere. Sometimes pollution is trapped near the Earth’s surface by a temperature inversion.

28 Temperature Inversions (cont’d) Temperature inversion: the atmospheric condition in which warm air traps cooler air near Earth’s surface. -warmer air above keeps the cooler air at the surface from moving upward, pollutants are trapped below with the cooler air. -cities located in a valley have a greater chance of experiencing temperature inversions. Example: Los Angeles, surrounded on three sides by mountains, often has temperature inversions.

29 Temperature Inversions

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31 Understanding Check 1.What is air pollution? 2.What is the cause of most air pollution? 3.What is the difference between a primary and secondary pollutant? 4.List two examples of primary pollutants. 5.What are the two examples of particulate air matter? 6.What is smog?

32 Air Pollution Unit 9: Air Pollution Sect 2

33 Air Pollution Air pollution adds to the effects of existing diseases: -emphysema, heart disease, and lung cancer. - the American Lung Association has estimated that Americans pay tens of billions of dollars a year in health costs to treat respiratory diseases caused by air pollution.

34 Short-Term Effects of Air Pollution on Health Effects of air pollution are short-term and reversible if exposure to air pollution decreases. -short-term effects of air pollution include: -headache -nausea -irritation to the eyes, nose, and throat -coughing -upper respiratory infections, such as bronchitis and pneumonia.

35 Long-Term Health Effects of Air Pollution Long-term effects of air pollution include: -emphysema -lung cancer -heart disease. -long-term exposure may worsen medical conditions suffered by older people and may damage the lungs of children.

36 Indoor Air Pollution Air quality inside a building is sometimes worse than the quality of air outside. Major sources of pollution: -plastics -industrial chemicals Compounds can be found in: -carpets -building materials -paints -furniture

37 Indoor Air Pollution

38 Sick-building syndrome: set of symptoms affecting workers in airtight buildings: -headache -fatigue -eye irritation -dizziness Sick-building syndrome is most common in hot places where buildings are tightly sealed to keep out the heat.

39 Indoor Air Pollution Most effective way to maintain good indoor quality- identify and remove pollutant sources. -ventilation: mixing outdoor and indoor air for good air quality. -ventilation should be increased when sanding or painting is done.

40 Radon Gas Radon gas: colorless, tasteless, odorless, and radioactive. -produced by the decay of uranium, a radioactive element that occurs naturally in the Earth’s crust. -can seep through cracks and holes in foundations into homes, offices, and schools, where it adheres to dust particles.

41 Radon Gas (cont’d) -in the lungs, radon can destroy the genetic material in cells that line the air passages. -damage can lead to cancer, especially among people who smoke. Radon is the second-leading cause of lung cancer in the United States.

42 Asbestos Asbestos: silicate minerals that form bundles of fibers that are heat resistant, flexible, and durable. -primarily used as an insulator and as a fire retardant -used extensively in building materials. -government banned the use of most asbestos products in the early 1970s.

43 Asbestos (cont’d) Exposure to asbestos is very dangerous. -asbestos fibers can cut and scar the lungs, causing the disease asbestosis. -victims of disease have more and more difficulty breathing and may eventually die of heart failure.

44 Noise Pollution Noise: sound of any kind -some noises can cause noise pollution. Health problems caused by noise pollution include: -loss of hearing -high blood pressure -stress -loss of sleep, which may lead to decreased productivity at work and in the classroom.

45 Noise Pollution (cont’d) Decibel: common unit used to measure loudness, and is abbreviated dB. -quietest sound that a human ear can hear is 0 dB. -for each increase in decibel intensity, the decibel level is 10 times higher than the previous level. -120 dB is at the threshold of pain -permanent deafness may come as a result of continuous exposure to sounds over 120 dB.

46 Noise Pollution

47 Pitch Pitch: wave frequency Range of pitch for humans: 20hz – 20,000hz Infrasound: sound below human hearing Ultrasound: sound above human hearing

48 Ranges of Hearing for Mammals

49 Light Pollution Light pollution: does not present a direct hazard to human health, but it does negatively affect our environment. -inefficient lighting in urban areas is diminishing our view of the night sky. -urban sky is often much brighter than the natural sky.

50 Light Pollution (cont’d) Inefficient lighting is energy waste. -energy is wasted when a light is directed upward into the sky and lost to space. Examples: -lighting on billboards -poor-quality street lights -the lighting of building exteriors

51 Light Pollution (cont’d) Solutions to light pollution: -shielding light so it is directed downward -using time controls so light is used only when needed -using low-pressure sodium sources, which are the most energy-efficient sources of light

52 Human Pollution Video

53 Noise Pollution YouTube Video

54 Asbestos

55 Pollution Posters Choose group of 4 Choose topic and create educational poster for: -indoor pollutants (pollutant, source) -long term and short term health effects of indoor pollutants -outdoor pollutants (pollutant, source) -long term and short term health and environmental effects of outdoor pollution -noise pollution (include health effects) -light pollution (include environmental effects)

56 Pollution Posters Rubric Poster title Easily read: large, neat print/information in bulleted points Accuracy of information Colored illustrations Non-distracting boarder

57 Understanding Check 1.List three short-term effects of air pollution on a person’s health. 2.List three long-term effects of air pollution on a person’s health. 3.What are major sources of indoor air pollution? 4.What is sick building syndrome caused by? 5.How is radon produced?


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