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Air Pollution Denise Tankle Abby Kushner
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Atmosphere Atmosphere- thin envelope of gasses surrounding the Earth * divided into 7 layers (spherical) by temperature Two important factors vary in atmosphere: - Density - Pressure
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Layers…. Troposphere- atmosphere layer closest to earth - air we breathe - dynamic system involved in chemical cycling of the earth’s nutrients - rising and falling air currents and winds are responsible for planet’s weather / climate
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Layers… Stratosphere- second layer -Less matter than troposphere -Similar composition with 2 exceptions -Volume of water is 1/1000 of troposphere volume -Concentration of ozone gases is higher -Ozone layer -Produced when oxygen molecules interact with UV radiation emitted by the sun “global sunscreen” -UV Filter: -Allows life to exist -Protects from sunburn -Cataracts -Damage to immune system -Prevent oxygen gas in troposphere from being converted to photochemical ozone.
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Air Pollution -Air pollution- presence of chemicals in the atmosphere in concentrations high enough to be harmful lethal -Natural sources: -Dust bowl -Pollutants from fire -Volcanic chemicals -Human sources: -Burning fossil fuels -Cars Natural pollutants are removed by chemical cycles, precipitation, and gravity
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Pollution Primary pollutants: 1.Harmful chemicals emitted directly into air from natural process 2.Human activities Secondary pollutants 1.Primary pollutants react with each other and components of the air
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Carbon Monoxide Characteristics: - colorless - highly toxic - gorms during incomplete combustion of carbon completing materials; exhaust, burning, smoke CO reacts with hemoglobin Chronic exposure can trigger heart attacks and lung disease
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Nitric Acid Colorless gas forms from N2 and O2 gas and react at high combustion temperatures f.e. auto engines, coal burning plants Lightening and certain bacteria in soil and H20 produce NO NO2 Photochemical smog Nitrous oxide- greenhouse gas
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Sulfur dioxide Colorless gas, SO2 comes from natural sources as part of sulfuric cycle. 2/3 SO2 is human sources (electricity) Aerosols = microscopic suspended droplets of sulfuric acid and sulfate
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Indoor Air Pollution Problems Developing countries – Indoor burning of: Wood Charcoal Coal – Expose people to high levels of air pollution Developed Countries – More air pollution inside than outside Chloroform Carbon monoxide
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Indoor Pollution vs. Outdoor Pollution Levels of the 11 common pollutants – 2 to 5 times higher inside Pollution levels inside cars are higher than outdoor pollution levels Health risks from chemical exposure – Force people indoors
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Radioactive Radon Gas Radon-222 – Colorless, odorless – Quickly decays – Damage lung tissue Outside – Radon gas disappears Inside – Comes through the cracks and foundation – Can build up to high levels
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Health Effects of Air Pollution Exposure to air pollutants can cause: – overload your natural defenses – Lung cancer, asthma attack, heart attack, stroke Years of smoking/breathing in smoke can cause: – Lung ailments – Chronic bronchitis – Emphysema
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Air Pollution is a Big Killer At least 3 million people worldwide die prematurely each year from air pollution – An average of 8,200 deaths per day – 2.2 million deaths result from indoor air pollution EPA – Estimates annual deaths related to indoor and outdoor pollution 150,000 – 350,000 Each year more than 125,000 Americans get cancer from breathing in diesel fumes (cars. buses) http://www.youtube.com/watch?v=UcWpkWB X04E
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Laws and Regulations Reduce Outdoor Air Pollution Laws and Regulations Clean Air Acts 1970, 1977, 1990 National ambient air quality standards (NAAQS) Primary standard Secondary standard Hazardous Air Pollutants (HAPs) Toxic Release Inventory (TRI) Overall Results Pollution emission decreased 49% – Between 1980-2006 Decreases in emissions were: – 97% lead (Pb) – 52% volatile organic compounds (VOCs) – 50% carbon monoxide (CO) – 47% sulfur dioxide (SO2) – 33% nitrogen oxides (NOx) – 21% ground level ozone
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U.S. Air Pollution Laws Can Be Improved Progress Air pollution reduction in the U.S. can be attributed to two factors: 1.U.S. citizens insisted that laws be passed and enforced 2.The country was affluent enough to afford such controls Improvement U.S. relies mostly on pollution clean up rather than prevention U.S. Congress – failed to improve fuel efficiency standards Little regulation on air pollution from ships Airports are exempt from many air pollution regulations
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We Can Use the Marketplace to Reduce Outdoor Air Pollution Clean Air Act of 1990 – Emission trading – Cap-and-trade Proponents – This approach is cheaper – More efficient Critics – Allows utilities to buy their way out of environmental responsibilities
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Reducing Outdoor Air Pollution Stationary Source – Burn low sulfur coal – Convert coal to a liquid or gaseous fuel Motor Vehicle – Use mass transit – Walk or bike – Improve fuel efficiency – Inspect car exhaust systems – 2 times a year – Set strict emission standards
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Reducing Indoor Air Pollution Prevention Clean ceiling tiles Ban smoking to well- ventilated areas Set stricter formaldehyde emissions standards Prevent radon infiltration Cleanup Increase intake of outside air Circulate a building’s air through rooftop greenhouses Use exhaust hoods for stoves http://www.youtube.com/watch?v=gciSp5X40t 0
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