home sweet home... or is it???? breathing! some basics
TRANSCRIPT
Home sweet home . . .Home sweet home . . .
Or is it????Or is it????
Breathing!Breathing!
Some basicsSome basics
What is in our atmosphere?What is in our atmosphere?
Normal chemical composition of our atmosphere:
(N2) 78%
(O2) 21%
Trace gases (water, argon, carbon dioxide, other pollutants) 1%
Pollution terminologyPollution terminology
• Pollutant
• Source
• Effect
Article: EPA Proposes New Article: EPA Proposes New Ozone StandardOzone Standard
• EPA = Environmental Protection Agency
Pollution unitsPollution units
Parts per thousand (ppt)
Parts per million (ppm)
Parts per billion (ppb)
Smog and ozone form togetherSmog and ozone form together
1. N2 + O2 2NO
2. 2NO + O2 2NO2
3. NO2 + UV radiation NO + O
4. O + O2 O3
Primary pollutants come directly Primary pollutants come directly from a sourcefrom a source
• Mobile sources
Mobile sourcesMobile sources
Stationary SourcesStationary Sources
• Power plants
RefineriesRefineries
Secondary pollutants form in Secondary pollutants form in atmosphere as gases reactatmosphere as gases react
• Smog, ground level ozone and acid rain
Secondary pollutants form in Secondary pollutants form in atmosphere as gases reactatmosphere as gases react
• Step two: 2NO + O2 2NO2
• NO2 is smog – a yellow brown gas
• Causes lung and eye irritation, makes asthma, bronchitis and emphysema worse
Ozone formationOzone formation
Step 3: NO2 + UV radiation NO + O
Step 4:O + O2 O3
Ozone slows photosynthesis, eye and lung irritant, makes asthma, emphysema, bronchitis worse
Check out ozone formationCheck out ozone formation
• Texas Commission on Environmental Quality– EPA: National/Federal Regulatory agency– TCEQ: state regulatory agency
• ozone animation
Houston Clean Air Network Map
AQI: set at 100 for each criterion AQI: set at 100 for each criterion pollutant level. pollutant level.
Ozone 100 AQI = 85ppbOzone 100 AQI = 85ppb
Smog and ozone form togetherSmog and ozone form together
1. N2 + O2 2NO2. 2NO + O2 2NO2
3. NO2 + UV radiation NO + O4. O + O2 O3
Ozone season: March- NovemberOzone daily formation: noon-early
evening
VOCs – a second route for OVOCs – a second route for O33
formationformation• Volatile Organic Compounds:
– Methane (CH4)
– Propane– Chlorofluorocarbons (CFC)
– VOCs can break O2 into free oxygen atoms (free radicals)
– VOC + O2 VOC + 2O
– O + O2 O3
We're #?We're #?
• . . . .for the number of days exceeding allowable ground level ozone levels.
• American Lung Association State of the Air
We're #?We're #?
• . . . .for the number of days exceeding allowable ground level ozone levels.
• American Lung Association State of the Air
Measuring pollutantsMeasuring pollutants
• parts per thousand = ppt
• parts per million = ppm
• Parts per billion = ppb
• Parts per trillion = ppt (must know from context)
Clean Air ActClean 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
National Ambient Air Quality National Ambient Air Quality StandardsStandards
• Six criterion pollutants: NOx, SOx, O3, Pb, CO, particulates
• Established minimum standards: 1hr and 8 hr
• EPA is working to have greenhouse gases added by Congress to the NAAQs
HoustonHouston’’s special issuess 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
Refineries create carcinogenic Refineries create carcinogenic air pollutantsair pollutants
Benzene, toluene, ethylbenzene, xylenes
So what is being done about So what is being done about this? - City monitoringthis? - City monitoring
45 mobile monitoring stations45 mobile monitoring stations
State monitoringState 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”
Check your understanding!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?