Know the types and proportions of the gases that make up the atmosphere.
78% nitrogen, 21% oxygen, 1% carbon dioxide, water, other gases
Distinguish between primary and secondary air pollutants.
primary: Materials that when released pose health risks in their unmodified formssecondary: Primary pollutants interact with one another, sunlight, or natural gases to produce new, harmful compounds
What is photochemical smog, and how do thermal inversions contribute to the problem?
Secondary pollutants formed by reaction of nitrogen oxides and HC with sunlight Includes ozone (O3)destroys chlorophyll, injures lung tissueground-level ozone is “bad ozone”Biggest problems in cities, mountains can make it even worseMountain ranges, wind directions lead to thermal inversionswhen cool air is trapped below layer of warm airpollutants accumulate, aren’t released to upper atmosphere
Why should we be concerned with indoor air pollution?
In U.S., 90% of time spent indoors; inside air often more polluted than outside airProblems with weatherized building: little air exchangeAsbestos, carbon monoxide, formaldehyde, lead, pollen, dust, smokingCauses diseases: emphysema, heart attacks, strokes, lung cancers
Distinguish between “bad” ozone and “good” ozone.
What is causing depletion of the “good” ozone?
“bad”= closest to earth, air pollutant that is harmful “good”=stratosphere, protects from suns UV rays Ozone Depletion, Ozone in the stratosphere is “good ozone”, Shields us from harmful ultraviolet light, Skin cancer and cataracts, depletion caused by chlorofluorocarbons from refrigerants, cleaning solvents, propellants
What does the Clean Air Act regulate, and how successful has it been?
Control requirements the federal government implements and states administerAll sources subject to ambient air quality regulation (NAAQS)New sources subject to more stringent controlsHazardous pollutants and visibility reducing emissions regulatedAugust 2003 changes reduce controlSince Clean Air Act passage, EPA reports air pollution cut by 1/3 and acid rain cut by 25%.EPA estimates human health, welfare, and environmental benefits have outweighed costs by 40 to 1. Old coal-fired power plants and SUVs, diesel trucks and buses are still major problems
In which zone of the atmosphere does weather take place? Which contains ozone?
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5 mm and 10 mm)Sulfur dioxideNitrogen oxides
Carbon monoxide, Where do they come from, and what problems do each cause?
Produced by burning of organic material (coal, gas, wood, trash, etc.), cigarette smoke, cars, Toxic because binds to hemoglobin, reduces oxygen in bloodNot a persistent pollutant, combines with oxygen to form CO2Most communities now meet EPA standards, but rush hour traffic can produce high CO levels
Organic compounds with hydrogen, carbon, From incomplete burning or evaporated from fuel supplies, Major source is automobiles, but some from industry
Small pieces of solid materials and liquid droplets (2.5 mm and 10 mm), Examples: ash from fires, asbestos from brakes and insulation, dust, Easily noticed: e.g. smokestacksCan accumulate in lungs and interfere with the ability of lungs to exchange gases.
Some particulates are known carcinogens, Those working in dusty conditions at highest risk (e.g., miners), pollution decreased 88% from 1970 – 2000
Produced by burning sulfur containing fossil fuels (coal, oil)When inhaled, can be very corrosive to lung tissueLondon1306 banned burning of sea coal1952 “killer fog”: 4,000 people died in 4 weekstied to sulfur compounds in smogCoal-burning power plants major sourceReacts in atmosphere to produce acidsOne of the major components of acid rain
Produced from burning of fossil fuelsContributes to acid rain, smogAutomobile engine main sourceNew engine technology has helped reduce, but many more cars