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Bellwork 3/10 * Week 10 Please turn your lab notebooks into TBG 1. What are the two general major categories/sources of air pollution? 2. Please include examples in your answers. Hint: Read page 526. Air Pollution. Outdoor Air Pollution.
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Bellwork 3/10 * Week 10 Please turn your lab notebooks into TBG1. What are the two general major categories/sources of air pollution?2. Please include examples in your answers. Hint: Read page 526
Air Pollution Outdoor Air Pollution
Stationary and Mobile Sources of Air Pollution • Two Sources of Air Pollution 1. Stationary Sources: have a relatively fixed location • Point Sources: • Fugitive Sources: • Area Sources: 2. Mobile Sources: move from place to place while emitting pollutants • Ex) Airplanes
General Effects of Air Pollution • Visual quality of the environment • Vegetation, Animals, Soil • Water Quality • Natural and Artificial Structures • Human Heath
Primary and Secondary Pollutants, Natural and Human • Primary Pollutants • Those emitted directly into the air • Hydrocarbons, particulates, etc. • Secondary Pollutants • Produced through reactions between primary pollutants and normal atmospheric compounds • Ozone
Major Air Pollutants • Sulfur Dioxide (acid rain) • Nitrogen Dioxide / Nitrogen Oxide • Carbon Monoxide • Ozone and Other Photochemical Oxidants • Volatile Organic Compounds • Particulate Matter • Hydrogen Sulfide • Hydrogen Fluoride • Hazardous Gases • Lead
Outdoor Air Pollutants – Sulfur Dioxide (SO2) • Properties: colorless gas with irritating odor • Effects: produces acid rain (H2SO4), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators • Sources:burning high sulfur coal or oil, smelting or metals, paper manufacture • Class: sulfur oxides • EPA Standard: 0.3 ppm (annual mean) • Combines with water and NH4 to increase soil fertility
Outdoor Air Pollutants – Nitrogen Dioxide (NO2) • Properties: reddish brown gas, formed as fuel burnt in car, strong oxidizing agent, forms Nitric acid in air • Effects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth • Sources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soil • Class: Nitrogen oxides (NOx) • EPAStandard: 0.053 ppm
Outdoor Air Pollutants – Carbon Monoxide (CO) • Properties: colorless, odorless, heavier than air, 0.0036% of atmosphere • Effects: binds tighter to Hb than O2 • Sources:incomplete combustion of fossil fuels. 60 - 95% from auto exhaust • Class: carbon oxides (CO2, CO) • EPAStandard: 9 ppm • 5.5 billion tons enter atmosphere/year
Outdoor Air Pollutants – Ozone (O3) • Properties: colorless, unpleasant odor, major part of photochemical smog • Effects: lung irritant, damages plants, rubber, fabric, eyes, 0.1 ppm can lower PSN by 50% • Sources: Created by sunlight acting on NOx and VOC , cars, industry, gas vapors, chemical solvents, fuel combustion products • Class: photochemical oxidants
Outdoor Air Pollutants – Suspended Particulate Matter (PM10) • Properties: particles suspended in air (<10 um) • Effects: lung damage, mutagenic, carcinogenic, teratogenic • Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields • Class: SPM: dust, soot, asbestos, lead, PCBs, dioxins, pesticides • EPA Standard: 50 ug/m3 (annual mean)
Total Suspended Particulates (TSP)for several large countries
Outdoor Air Pollutants – VOCs (Volatile Organic Compounds) • Properties: organic compounds that evaporate easily, usually aromatic • Effects: eye and respiratory irritants; carcinogenic; decreased visibility due to brown haze; liver, CNS, or kidney damage; damages plants • Sources: evaporation of solvents or fuels, fossil fuels, plants (largest source), aerosols, paint thinners, dry cleaning • Class: HAPs (Hazardous Air Pollutants) • Concentrations indoors up to 1000x outdoors • 600 million tons of CFCs
Outdoor Air Pollutants – Lead (Pb) • Properties: grayish metal • Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high] • Sources: particulates, smelters, batteries • Class: toxic or heavy metals • EPAStandard: 1.5 ug/m3 • 2 million tons enter atmosphere/year
US Emissions of Six Major Air Pollutants Note that there have been significant reductions.
Urban Air Pollution • Potential for Air Pollution Determined by: • Rate of emission • Downwind distance • Average wind speed • Elevation • Atmospheric Inversion: • Occurs when warmer air is found above cooler air and it poses a particular problem when there is a stagnant air mass
Factors that influence Air Pollution formation and intensity • Local climate (inversions, air pressure, temperature, humidity) • Topography (hills and mountains) • Population density • Amount of industry • Fuels used by population and industry for heating, manufacturing, transportation, power • Weather: rain, snow,wind • Buildings (slow wind speed) • Mass transit used • Economics
Questions1. How would you define smog?2. What are the two types of smog and how do they form? Hint: Read pages 540-541
Smog • Smog • A mixture between smoke and fog that produces unhealthy urban air • Two Types • Sulfurous Smog / Industrial Smog / Fossil Fuels • Photochemical Smog / Sunlight & Pollutants
Pollution Control • Particulates • Automobiles • Sulfur Dioxide • Coal Gasification: converts coal to gas to remove sulfur • Scrubbing: gas desulfurization
Air Pollution: Legislation and Standards • Clean Air Act Amendments of 1990 • Comprehensive regulations enacted by U.S congress that address acid rain, toxic emissions, ozone depletion and automobile exhaust • Air Quality Standards • Attempt to control air pollution • Tougher Standards for PM 2.5 and Ozone • Air Quality Index
Specific Air Pollution Treatment Technology • Traditional • Move factory to remote location • Build taller smokestack so wind blows pollution elsewhere • New • Biofiltration : vapors pumped through soil where microbes degrade • High-energy destruction: high-voltage electricity • Membrane separation: diffusion of organic vapors through membrane • Oxidation: High temperature combustor
Specific Air Pollution Treatment Technology Continued… • New continued… • Vapor phase carbon absorption: gases pumped through series of carbon filled canisters which absorb contaminants • Electrostatic precipitators: Electrostatically charged surfaces attracts particles • Sulfur removal: mix crushed limestone with fuel • Nitrogen oxide control: staged burners or catalytic converters • Hydrocarbon control: closed system to prevent release before treatment with afterburners • Hybrid, electric and hydrogen powered vehicles
Air Pollution Indoor Air Pollution
Pathways, Processes and Driving Forces • Chimney Effect (Stack Effect) • Process whereby warmer air rises in buildings to upper levels and is replaced in the lower portion of the building by outdoor air drawn through a variety of openings, such as windows doors or cracks in the foundation or walls
Sick Building Syndrome • A condition associated with an indoor environment that appears to be unhealthy • The symptoms people report cannot be traced to any one particular cause
Environmental Tobacco Smoke • Secondhand smoke • 2 sources • Smoke exhaled by smokers • Smoke emitted from burning tobacco • The most hazardous indoor pollutant
QuestionsRead a closer look 25.1 (p 562-3) 1. Please explain why radon is a problem?2. Is radon a large hazard? If so why? If not, why? Hint: Read pages 540-541
Radon Gas • Radon • Naturally occurring radioactive gas • Colorless, odorless, tasteless • Only identified through proper testing • Health hazard when leaked into homes • Exposure is associated with lung cancer
How RadonEnters Houses Please read page 574 and explain how radon enters houses.
Major Indoor Pollutants Continued… http://www.metricmind.com/ac_honda/main.htm