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Published byAriel Bennett Modified over 8 years ago
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I thought I saw a blue jay this morning. But the smog was so bad that it turned out to be a cardinal holding its breath. Michael J. Cohen
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Air Pollution in Shanghai, China, in 2004
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China Smog Documentary
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Air Pollution Chapter 18
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Core Case Study: South Asia’s Massive Brown Cloud Asian Brown Cloud – Causes – Chemical composition – Areas impacted Air pollution connects the world Steps taken in China and India to reduce air pollution
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The Atmosphere Consists of Several Layers Atmosphere varies in – Density – Atmospheric pressure – Temperature
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Air Movements in the Troposphere Play a Key Role in Earth’s Weather and Climate Troposphere – 75–80% of the earth’s air mass – Closet to the earth's surface – Chemical composition of air – Rising and falling air currents: weather and climate – Involved in chemical cycling
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The Stratosphere Is Our Global Sunscreen Stratosphere – Similar composition to the troposphere, with 2 exceptions Much less water O 3, ozone layer, filters UV – Location
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Air Pollution Comes from Natural and Human Sources Air pollution (What is a pollutant?) Natural sources – Dust blown by wind – Pollutants from wildfires and volcanoes – Volatile organics released by plants – Withdrawing groundwater Human sources: mostly in industrialized and/or urban areas – Stationary sources – Mobile sources
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Some Pollutants in the Atmosphere Combine to Form Other Pollutants Primary pollutants Secondary pollutants
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Donora, PA at noon 11/29/1948
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What Are the Major Outdoor Air Pollutants? 1. Carbon oxides – Carbon monoxide (CO) – Carbon dioxide (CO 2 ) – Sources – Human health and environmental impact
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What Are the Major Outdoor Air Pollutants? 2. Nitrogen oxides (NO) and nitric acid (HNO 3 ) – Sources – Acid deposition – Photochemical smog – Human health and environmental impact 3. Sulfur dioxide (SO 2 ) and sulfuric acid (H 2 SO 4 ) Sources Industrial smog Human health and environmental impact
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What Are the Major Outdoor Air Pollutants? 4. Particulates – Suspended particulate matter (SPM) Fine Ultrafine – Sources – Human health and environmental impact
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What Are the Major Outdoor Air Pollutants? 5. Ozone (O 3 ) – see lab – Sources – Human and environmental impact 6. Volatile organic compounds (VOCs) – Hydrocarbons and terpenes – Sources – Human and environmental impact
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Science Focus: Detecting Air Pollutants Chemical instruments - Satellites Nanotechnology Biological indicators – Lichens EPA Habitable Planet
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Natural Capital: Lichen Species, Vulnerability to Air Pollutants
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Chemical Reactions That Form Major Outdoor Air Pollutants EPA
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A Model of How Pollutants That Make Up Photochemicals Are Formed
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Photochemical Smog – Chemical composition – Sources VOCs + NO 2 + Heat + Sunlight yields – Ground level O 3 and other photochemical oxidants – Aldehydes – Other secondary pollutants Human health and environmental impact
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Industrial Smog Chemical composition of industrial smog Reduction of this smog in urban cities of the United States China and smog – Human deaths
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How Pollutants Are Formed from Burning Coal and Oil, Leading to Industrial Smog
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Lead: A Highly Toxic Pollutant Does not break down in the environment Sources Human health and environmental impact – Most vulnerable Reduction of lead (Pb) – Unleaded gasoline – Unleaded paint Still problems – 2007: toys with Pb paint recalled – Global ban on lead in gasoline and paint
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Solutions: Lead Poisoning, Prevention and Control
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Several Factors Can Decrease or Increase Outdoor Air Pollution Outdoor air pollution may be decreased by – Settling of particles due to gravity – Rain and snow – Salty sea spray from the ocean – Winds – Chemical reactions
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Outdoor air pollution may be increased by – Urban buildings – Hills and mountains – High temperatures – Emissions of VOCs from certain trees and plants – Temperature inversions – Grasshopper effect
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Grasshopper effect...
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Acid Deposition Acid deposition, acid rain – Formation – Local versus regional problems – Effects of prevailing winds – Buffers – Where is the worst acid deposition?
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Natural Capital Degradation: Acid Deposition, Acid Rain
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Current and Possible Future Acid Rain Problem Areas
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Acid Deposition Has a Number of Harmful Effects Human respiratory disorders Aquatic ecosystems affected Release of toxic metals Leaching of soil nutrients Loss of crops and trees Damage to buildings, statues, and monuments know
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Natural Capital Degradation: Air Pollution Damage to Trees in North Carolina, U.S.
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Ocean Acidification
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We Know How to Reduce Acid Deposition Prevention approaches Clean up – Add lime to neutralize acidified lakes and soil – Add phosphate fertilizer to neutralize acidified lakes
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Indoor Air Pollution Developing countries – Indoor burning – Poor suffer the greatest risk Developed countries – Indoor air pollution is greater than outdoor air pollution Why? 11 of the common air pollutants higher inside than outside Greater in vehicles than outside Health risks magnified: people spend 70–98% of their time is indoors
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Cont’d Who are at greatest risk from indoor air pollution? – Children under 5 and the elderly – Sick – Pregnant women – People with respiratory disorders or heart problems – Smokers – Factory workers
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Cont’d Four most dangerous indoor air pollutants – Tobacco smoke – Formaldehyde – Radioactive radon-222 gas – Very small particles Sources of these pollutants Human health risks
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Other possible indoor air pollutants – Pesticide residue – Pb particles – Living organisms and their excrements E.g., Dust mites and cockroach droppings – Airborne spores of molds and mildews Sick-building syndrome
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Some Important Indoor Air Pollutants
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Your Body’s Natural Defenses against Air Pollution Can Be Overwhelmed Respiratory system protection from air pollutants – Role of cilia, mucus, sneezing, and coughing Effect of smoking and prolonged air pollution exposure – Chronic bronchitis – Emphysema
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Major Components of the Human Respiratory System
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Normal Human Lungs and the Lungs of a Person Who Died of Emphysema
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Air Pollution Is a Big Killer 3 Million deaths per year world-wide – Mostly in Asia – Main causes EPA: proposed stricter emission standards for diesel-powered vehicles Link between international trade and air pollution – Cargo ships and pollution
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Premature Deaths from Air Pollution in the U.S.
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Laws and Regulations Can Reduce Outdoor Air Pollution United States – Clean Air Acts: 1970, 1977, and 1990 Clean Air Acts: 1970, 1977, and 1990 EPA – National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants – National emission standards for 188 hazardous air pollutants (HAPs) Toxic Release Inventory (TRI)
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Cont’d Good news in U.S. – Decrease in emissions – Use of low-sulfur diesel fuel Cuts pollution Developing countries – More air pollution
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We Can Use the Marketplace to Reduce Outdoor Air Pollution Emission trading or cap-and-trade program – Mixed reactions to program – SO 2 emissions down significantly – NO 2 will be tried in the future
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There Are Many Ways to Reduce Outdoor Air Pollution 1980 –2006 – SO 2 emissions from U.S. electric power plants decreased by 66% – NO x emissions by 41% – Particulate emissions by 28% Older plants not governed by the same regulations New cars have better emissions
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Rather than... “what can we do about the air pollution we produce?” How about... “How can we avoid producing the pollutant in the first place?”
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Solutions: Stationary Source Air Pollution Solutions: Motor Vehicle Air Pollution, Prevention and Cleanup
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Reducing Indoor Air Pollution Should Be a Priority Greater threat to human health than outdoor pollution What can be done? – Prevention – Cleanup
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