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Published byEleanor Ryan Modified over 9 years ago
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Home sweet home...
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Or is it????
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Breathing! Some basics
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What is in our atmosphere? Normal chemical composition of our atmosphere: (N 2 ) 78% (O 2 ) 21% Trace gases (water, argon, carbon dioxide, other pollutants) 1%
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Pollution terminology Pollutant Source Effect
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Article: EPA Proposes New Ozone Standard EPA = Environmental Protection Agency
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Pollution units Parts per thousand (ppt) Parts per million (ppm) Parts per billion (ppb)
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Smog and ozone form together 1.N 2 + O 2 2NO 2.2NO + O 2 2NO 2 3.NO 2 + UV radiation NO + O 4.O + O 2 O 3
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Primary pollutants come directly from a source Mobile sources
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Stationary Sources Power plants
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Refineries
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Secondary pollutants form in atmosphere as gases react Smog, ground level ozone and acid rain
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Secondary pollutants form in atmosphere as gases react Step two: 2NO + O 2 2NO 2 NO 2 is smog – a yellow brown gas Causes lung and eye irritation, makes asthma, bronchitis and emphysema worse
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Ozone formation Step 3: NO 2 + UV radiation NO + O Step 4:O + O 2 O 3 Ozone slows photosynthesis, eye and lung irritant, makes asthma, emphysema, bronchitis worse
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Check out ozone formation Texas Commission on Environmental Quality –EPA: National/Federal Regulatory agency –TCEQ: state regulatory agency ozone animation Houston Clean Air Network Map
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AQI: set at 100 for each criterion pollutant level. Ozone 100 AQI = 85ppb
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Smog and ozone form together 1.N 2 + O 2 2NO 2.2NO + O 2 2NO 2 3.NO 2 + UV radiation NO + O 4.O + O 2 O 3 Ozone season: March- November Ozone daily formation: noon-early evening
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VOCs – a second route for O 3 formation Volatile Organic Compounds: –Methane (CH 4 ) –Propane –Chlorofluorocarbons (CFC)
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–VOCs can break O 2 into free oxygen atoms (free radicals) –VOC + O 2 VOC + 2O –O + O 2 O 3
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We're #? We're #?....for the number of days exceeding allowable ground level ozone levels. American Lung Association State of the AirAmerican Lung Association State of the Air
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We're #? We're #?....for the number of days exceeding allowable ground level ozone levels. American Lung Association State of the AirAmerican Lung Association State of the Air
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Measuring pollutants parts per thousand = ppt parts per million = ppm Parts per billion = ppb Parts per trillion = ppt (must know from context)
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Clean Air Act Passed by Congress in 1970, updated in 1990, ‘93, 97, 2008. Required EPA (Environmental Protection Agency) to identify criteria pollutants and to establish minimum standards: EPA came up with NAAQ’s
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National Ambient Air Quality Standards Six criterion pollutants: NO x, SO x, O 3, Pb, CO, particulates Established minimum standards: 1hr and 8 hr EPA is working to have greenhouse gases added by Congress to the NAAQs
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Houston’s special issues 1/3 of all US petrochemicals pass through our refineries Refineries separate crude oil into many different products from asphalt tar to gasoline to butane
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Refineries create carcinogenic air pollutants Benzene, toluene, ethylbenzene, xylenes
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So what is being done about this? - City monitoring
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45 mobile monitoring stations
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State monitoring Flexible permitting – each facility has total cap emissions limit, but flexibility in how they meet that limit. TCEQ issues permits for emitting certain amount of pollutants Facilities do “self reporting”
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Check your understanding! What is the difference between a primary and a secondary air pollutant? Give an example of a mobile source. Give an example of a stationary source. Which layer of the atmosphere are you in RIGHT NOW?!!!! What is the normal chemical composition of our atmosphere?
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